Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Spectrochim Acta A Mol Biomol Spectrosc ; 58(13): 2849-59, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12477029

RESUMO

The modification of kaolinite surfaces through mechanochemical treatment has been studied using a combination of mid-IR and near-IR spectroscopy. Kaolinite hydroxyls were lost after 10 h of grinding as evidenced by the decrease in intensity of the OH stretching vibrations at 3695 and 3619 cm(-1) and the deformation modes at 937 and 915 cm(-1). Concomitantly an increase in the hydroxyl-stretching vibrations of water is observed. The mechanochemical activation (dry grinding) causes destruction in the crystal structure of kaolinite by the rupture of the O-H, Al-OH, Al-O-Si and Si-O bonds. Evidence of this destruction may be followed using near-IR spectroscopy. Two intense bands are observed in the spectral region of the first overtone of the hydroxyl-stretching vibration at 7065 and 7163 cm(-1). These two bands decrease in intensity with mechanochemical treatment and two new bands are observed at 6842 and 6978 cm(-1) assigned to the first overtone of the hydroxyl-stretching band of water. Concomitantly the water combination bands observed at 5238 and 5161 cm(-1) increase in intensity with mechanochemical treatment. The destruction of the kaolinite surface may be also followed by the loss of intensity of the two hydroxyl combination bands at 4526 and 4623 cm(-1). Infrared spectroscopy shows that the kaolinite surface has been modified by the removal of the kaolinite hydroxyls and their replacement with water adsorbed on the kaolinite surface. NIR spectroscopy enables the determination of the optimum time for grinding of the kaolinite. Further NIR allows the possibility of continual on-line analysis of the mechanochemical treatment of kaolinite.


Assuntos
Caulim/química , Espectrofotometria Infravermelho , Hidróxidos/química , Estresse Mecânico
2.
J Colloid Interface Sci ; 239(2): 458-466, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11427011

RESUMO

Kaolinite surfaces were modified by mechanochemical treatment for periods of time up to 10 h. X-ray diffraction shows a steady decrease in intensity of the d(001) spacing with mechanochemical treatment, resulting in the delamination of the kaolinite and a subsequent decrease in crystallite size with grinding time. Thermogravimetric analyses show the dehydroxylation patterns of kaolinite are significantly modified. Changes in the molecular structure of the kaolinite surface hydroxyls were followed by infrared spectroscopy. Hydroxyls were lost after 10 h of grinding as evidenced by a decrease in intensity of the OH stretching vibrations at 3695 and 3619 cm(-1) and the deformation modes at 937 and 915 cm(-1). Concomitantly an increase in the hydroxyl stretching vibrations of water is found. The water-bending mode was observed at 1650 cm(-1), indicating that water is coordinating to the modified kaolinite surface. Changes in the surface structure of the OSiO units were reflected in the SiO stretching and OSiO bending vibrations. The decrease in intensity of the 1056 and 1034 cm(-1) bands attributed to kaolinite SiO stretching vibrations were concomitantly matched by the increase in intensity of additional bands at 1113 and 520 cm(-1) ascribed to the new mechanically synthesized kaolinite surface. Mechanochemical treatment of the kaolinite results in a new surface structure. Copyright 2001 Academic Press.

3.
Med Sci Monit ; 7(3): 350-6, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11386008

RESUMO

BACKGROUND: The kappa and delta opioid receptors were characterized in longitudinal muscle strip of guinea-pig ileum (GPI, mu, kappa), mouse (MVD, delta, mu, kappa) and rabbit (LVD, kappa) vas deferens and rabbit ear artery (ART, delta, kappa) with particular attention to the presence of receptor subtypes. MATERIAL AND METHODS: For this purpose, type/subtype selective agonist and antagonist were used such as [D-Ala2, D-Leu5]-enkephalin (delta agonist) [D-Pen2,5]-enkephalin (delta 1 agonist), deltorphin II (delta 2 agonist) naltriben (NTB, delta 2 antagonist), BOC-YPGFLT(OtBu) (delta antagonist) on the one hand and ethylketocyclazocine (EKC, kappa/(agonist), PD-117 302 (kappa 1 agonist), [Met5]-enkephalin-Arg6, Phe7 (ME-RF, delta/kappa 2/(agonist) and its amide ME-RF-NH2, kappa 2/(agonist), naltrexone (NTX, mu > delta = kappa antagonist) and norbinaltorphimine (nBNI, kappa antagonist) on the other hand. RESULTS AND CONCLUSION: In MVD the Ke of NTB against different (agonists revealed no receptor type heterogeneity. In LVD the Ke of nBNI but not of NTX against EKC versus the ones against ME-RF and ME-RF-NH2 indicated inhomogenous (receptor population. The (receptor antagonist BOC-YPGFLT(OtBu) antagonized the action of ME-RF-NH2 in ART but not in MVD or LVD indicating a special receptor subtype in ART (kappa, possibly delta).


Assuntos
Encefalina Metionina/análogos & derivados , Naltrexona/análogos & derivados , Antagonistas de Entorpecentes/farmacologia , Receptores Opioides delta/biossíntese , Receptores Opioides kappa/biossíntese , Analgésicos Opioides/farmacologia , Animais , Orelha/patologia , Ala(2)-MePhe(4)-Gly(5)-Encefalina/farmacologia , Leucina Encefalina-2-Alanina/farmacologia , Encefalina Metionina/farmacologia , Cobaias , Íleo/metabolismo , Masculino , Camundongos , Músculos/metabolismo , Naltrexona/farmacologia , Peptídeos/farmacologia , Coelhos , Receptores Opioides delta/agonistas , Receptores Opioides delta/antagonistas & inibidores , Receptores Opioides kappa/agonistas , Receptores Opioides kappa/antagonistas & inibidores , Fatores de Tempo , Ducto Deferente/metabolismo
4.
Magy Onkol ; 45(1): 81-88, 2001.
Artigo em Húngaro | MEDLINE | ID: mdl-12050733

RESUMO

The morphin-analogue, Durogesic, has robust analgetic effect without repeated side-effects and is suitable for special applications providing it as the first choice for therapy of cancer pain and as an acceptable alternative for CR morphin. Clinical studies not only provided evidences for the pharmacological effectivity of Durogesic but suggested that the quality of life of cancer patients improved significantly as well.

5.
Eur J Radiol ; 35(3): 154-67, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11000558

RESUMO

The etiology of inflammatory bowel disease (IBD) is still unknown. However, a satisfactory solution cannot be far away. IBD actually encompasses two diseases, i.e. Crohn's disease (CD) and ulcerous colitis (UC). These diseases resemble each other so closely that they cannot be distinguished even pathologically, but differ from each other sufficiently to regard them as independent entities. Epidemiological observations may be helpful in identifying the true causative factors of this evasive disease. Geographically, the prevalence of the disease has a slope from North to South and, to a lesser degree, from West to East. The Western-Eastern discrepancy can be attributed to a difference in Western life styles. The incidence of the disease has been increasing world-wide of late, but its spread has been slowing down in highly affected countries. Racial and ethnic relations in different populations and immigration studies offer interesting data which can reflect genetic, inherited, environmental and behavioural factors. The disease seems to have a characteristic racial-ethnic distribution: the Jewish population is highly susceptible everywhere, but its prevalence in that population nears that of the domestic society in which they live. In Hungary, the Roma (Gypsies) have a considerably lower prevalence than the average population. This can be attributed to a genetic or environmental influence. According to age, the onset of the disease occurs more often in the second or the third decade of life, but there also is another peak in the 60s. Regarding sexual distribution, there is a slight preponderance of colitis ulcerosa in men and of Crohn's disease in women. It may correspond to the stronger auto-immune affection in the process of Crohn's disease. Environmental factors and behavioural influences also are investigated. Diet, the role of the early ages, smoking habits and the influence of hormonal status and drugs are viewed as useful contributing factors in the manifestation of the disease. Genetic studies show that one-fourth of IBD patients have an affected family member. HLAB27 histocombatibility also plays an important, but not determining role in the development of the disease. Genetic factors seem to have a stronger influence in Crohn's disease than ulcerative colitis. The existence of multiple sclerosis-IBD families may reflect the common genetic background or the similar microbial effect as well. A great number of bacterial and viral factors has been suspected of being infectious factors in IBD, mostly in CD. Mycobacteria, Yersinia, Campylobacter, Clostridium, Clamidias, etc. as well as bacteria and some viruses such as herpes and rotavirus and the primary measles virus. None of them has been proven as a real and exclusively pathogenic factor. Immunological background has an important function in the manifestation of the disease. If an individual has a genetic susceptibility to infections, the down regulation of an inflammation in the bowel wall does not occur in a proper way. This initiates the auto-immune process which is a self-increasing cycle. Extra-intestinal manifestations of IBD are of high importance because they can not only follow intestinal symptoms, but precede them by years. Hepatic and biliary disturbances (primary sclerosing cholangitis), are the most serious complications. Mucocutaneous manifestations can be the first appearance of the main disease (in the mouth). Auto-immune consequences (erythema nodosum) or complications caused even by the therapy can occur. Ocular and musculoskeletal manifestations supposedly have the same genetic background and often precede the intestinal symptoms. Considering the epidemiological, genetic and immunological data, we can conclude that ulcerative colitis and Crohn's disease are heterogeneous disorders of mutifactorial etiology in which hereditary (genetic) and environmental (microbial, behaviour) factors interact to produce the disease.


Assuntos
Colite Ulcerativa/epidemiologia , Colite Ulcerativa/etiologia , Doença de Crohn/epidemiologia , Doença de Crohn/etiologia , Adolescente , Adulto , Colite Ulcerativa/genética , Colite Ulcerativa/imunologia , Doença de Crohn/genética , Doença de Crohn/imunologia , Dieta , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Fumar/efeitos adversos
6.
Eur J Radiol ; 35(3): 168-75, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11000559

RESUMO

INTRODUCTION: During the last few decades introducing many of new radiologic methods, diagnostic conditions and facilities of Crohn's disease has became markedly improved. Appropriate using of these technics definitely modifies the management of patients with known or suspected Crohn's disease serving reliable information about extent, severity and possible complications of disease. Enteroclysis and Computed tomography are the two major and basic methods to disclose or confirme diagnosis of Crohn's disease, obtain appropriate inforination about disease either with mucosal, transmural or extraintestinal manifestation. METHODS AND PATIENTS: We evaluated 281 patients who were referred in our institution under suspition of Crohn's disease. Enteroclysis and abdominal spiral CT in all cases were carried out usually within 1 week. The 172 patients underwent abdominal spiral CT as the primary examination to evaluate diagnostic value of spiral CT in this entity, while 109 patiens had enteroclysis followed by abdominal CT. In 11 cases we also perforined CT enteroclysis with administration of 0.5% methylcellulose solution thorough nasojejunal tube controlled by electric motor driven contrast pump. Results were compared with final clinical, pathological or surgical data were available. RESULTS: From the 281 patients eventually 74 proved Crohn's disease; sensitivity and specificity of enteroclysis proved to be 96 and 98%, while spiral CT sensitivity and specificity was 94 and 95%, respectively. Enteroclysis was superior to the spiral CT in demonstration of early lesions and functional disorders, while spiral CT proved to be essential in evaluation of transmural and extraintestinal complications. CONCLUSIONS: Regarding enteroclysis and spiral CT as complementary methods, they provide excellent results in diagnosis of Crohn's disease.


Assuntos
Doença de Crohn/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Sulfato de Bário , Meios de Contraste , Feminino , Humanos , Intestino Delgado/diagnóstico por imagem , Masculino , Metilcelulose , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos
7.
Eur J Radiol ; 35(3): 176-82, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11000560

RESUMO

OBJECTIVE: The purpose of this work is to prospectively evaluate high resolution ultrasonography with graded compression in the ability to detect Crohn's disease of the small bowel (CDSB) together with its complications and activity signs, compared with enteroclysis, CT and immunoscintigraphy in the mirror of the final diagnosis. METHODS AND MATERIAL: In a series of 73 consecutive patients, who were referred for enteroclysis with suspected Crohn's disease of the small bowel computed tomography (CT), ultrasound (US), immunoscintigraphy with 99mTc labeled monoclonal antigranulocyte antibody (AGAb) examinations were performed within 10 days from each other. For the final evaluation the diagnosis of CDSB was based on combination of clinical and enteroclysis findings (73 cases) and in 17 cases additional surgical and pathological data were available. The results of other modalities were blinded to the radiologists performing and reading out the exams. The diagnostic values of each modality was assessed also in those 18 patients, who had early Crohn's disease. In the group of 43 patients with proven CDSB who had all the four imaging modalities, the modalities were compared in their ability to demonstrate various pathological conditions related to CD. Increased (>500 ml/min) flow measured by Doppler US in the superior mesenteric artery and increased color signs in the gut wall seen by power Doppler sonography were compared to CDAI. RESULTS: Of the 73 patients the combination of enteroclysis and clinical tests demonstrated CDSB in 47. The sensitivity, specificity and accuracy of ultrasound were 88.4, 93.3 and 90.4%, respectively. Enteroclysis was the most accurate method. CT was more sensitive than US, but less specific. The accuracy of US, CT and scintigraphy were similar. In the group of 18 patients, who had early CDSB, the sensitivity of US decreased to only 67%, CT and scintigraphy had higher values. Intra- and perimural abscesses, and sinus tracts were also more frequently visualized by US, especially if they were small. US was superior than CT in detecting stenoses and skip lesions, but inferior to enteroclysis. US and CT detected more fistulas, than enteroclysis. Compared to CT, US detected more cases with mesenteric lymphadenopathy, equal cases with abscesses and free peritoneal fluids. In detecting mesenteric inflammatory proliferation CT, and in detecting colonic involvement CT and immunoscintigraphy were slightly superior than graded compression US. Patterns of mural stratification detected by ultrasound correlated well with the enteroclysis severity stages. There was only 59% agreement between increased superior mesenteric artery flow detected by Doppler sonography and CDAI, and 60.5% agreement between increased number of Color pixels in the gut wall measured by power Doppler and increased CDAI. CONCLUSION: High resolution graded compression sonography is a valuable tool for detecting small intestinal Crohn's disease. It has similar diagnostic values as CT. However in early disease the sensitivity substantially decreases. In known Crohn's disease for following disease course, evaluating relapses and extramural manifestations US is an excellent tool. Doppler and Power Doppler activity measurements do not correlate well with the more widespread clinical activity index.


Assuntos
Doença de Crohn/diagnóstico por imagem , Adulto , Sulfato de Bário , Meios de Contraste , Doença de Crohn/diagnóstico , Feminino , Humanos , Intestino Delgado/diagnóstico por imagem , Intestino Delgado/patologia , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Radioimunodetecção , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X , Ultrassonografia Doppler
8.
Eur J Radiol ; 35(3): 183-92, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11000561

RESUMO

UNLABELLED: The diagnosis of inflammatory bowel disease (IBD) needs a complex diagnostic work-up. Beside verifying the disease itself, it is fundamental to assess disease extent and activity and to detect associated complications, to find the most effective treatment and for follow up. Scintigraphy with radiolabelled leukocytes is able to provide a complete survey of the whole intestinal tract, both the small and large bowel, and detects septic complications successfully with negligible risk. Radionuclide procedures are useful in establishing or ruling out IBD in patients with intestinal complaints, in assessing disease severity, and in the evaluation of extraintestinal septic complications. Widely available radionuclide procedures are discussed, i.e. scintigraphy by 111Indium oxime or 99mTechnetium HMPAO labelled white blood cells and immunoscintigraphy with 99mTc anti-granulocyte antibodies. Advantages and disadvantages of all three methods are stressed out. PATIENTS AND METHODS: The immunoscintigraphies with 99mTc anti-granulocyte antibodies (ANTI-GRANULOCYTE(R) BW 250/183) of 27 patients with suspicion of IBD were retrospectively analysed. Planar anterior and posterior images were obtained 4 and 24 h postinjection, respectively. The bowel was divided into six segments and the activity was visually graded with reference to bone marrow in each segments. The scans were compared with the results of radiological and endoscopical investigations. The diagnosis of IBD was proved or ruled out by means of enteroclysis, large bowel enema or endoscopy. RESULTS: In the 27 patients, 74 bowel segments with increased activity were detected. In the case of 30 segments in 16 patients, bowel inflammation was revealed by the other methods (true positives). In the case of 44 bowel segments, no underlying bowel inflammation could be verified, and these activities were regarded as aspecific activity. We could not differentiate between true positive and aspecific activity based on scan pattern or intensity. DISCUSSION: These findings of aspecific bowel activity using imuunoscintigraphy are in contrast with the results of former studies, while the existence of non-specific activity decreases the reliability of the method. Based on the literature and our experiences, we conclude that 99mTc HMPAO labelling should be the method of choice for the investigation of IBD patients.


Assuntos
Anticorpos Monoclonais , Doenças Inflamatórias Intestinais/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Exametazima , Tecnécio , Adulto , Feminino , Humanos , Radioisótopos de Índio , Leucócitos , Masculino , Radioimunodetecção , Estudos Retrospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada de Emissão de Fóton Único
9.
Eur J Radiol ; 35(3): 193-8, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11000562

RESUMO

OBJECTIVE: Most of the studies on virtual colonoscopy are dealing with the role of detecting colorectal polyps or neoplasms. We have undertaken this study to evaluate the value of CT colonography in patients with colonic Crohn's disease. METHODS AND MATERIAL: Five patients (three males, two females, 23-51 years, mean age 42 years) with known (4) or suspected (1) Crohn's disease of the colon underwent fiberoptic colonoscopy and CT colonography in the same day or during a 1-week period. The images were evaluated with the so called zoomed axial slice movie technique and in some regions intra- and extraluminal surface shaded and volume rendered images were generated on a separate workstation. The results were compared to those of a colonoscopy. RESULTS: The final diagnosis was Crohn's disease in four patients and colitis ulcerosa in one. Total examination was possible by colonoscopy in two cases, and with CT colonography in all five cases. The wall of those segments severely affected by the disease were depicted by the axial CT scans to be thickened. The thick walled, segments with narrow lumen seen on CT colonography corresponded to the regions where colonoscopy was failed to pass. Air filled sinus tracts, thickening of the wall of the terminal ileum, loss of haustration pseudopolyps and deep ulcers were seen in CT colonography. Three dimensional (3D) endoluminal views demonstrated pseudopolyps similar to endoscopic images None of the colonoscopically reported shallow ulcerations or aphtoid ulcerations or granular mucosal surface were observed on 2- or 3D CT colonographic images. CONCLUSION: CT colonography by depicting colonic wall thickening seems to be a useful tool in the diagnosis of Crohn's colitis, which could be a single examination depicting the intraluminal, and transmural extent of the disease.


Assuntos
Doenças do Colo/diagnóstico por imagem , Doença de Crohn/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Colo/diagnóstico por imagem , Colonoscopia , Feminino , Humanos , Masculino , Interface Usuário-Computador
10.
Eur J Radiol ; 35(3): 199-208, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11000563

RESUMO

OBJECTIVES: A new high resolution computed tomography (HRCT) scoring system of sacroiliac joint (SIJ) involvement in enteropathic arthritis is introduced. PATIENTS AND METHODS: SIJ's of 100 patients were studied. A total of 25 patients presented with pain syndrome, 25 with suspicious seronegative spondylarthritis, 25 with inflammatory bowel diseases and 25 without joint or bowel diseases, as a control group. HRCT was carried out in all 100 patients. For comparison, a plain film radiography (PFR), conventional CT (slices of 10 mm) and bone scan were used. RESULTS: Quantitative differences: In the pain syndrome group, there were no erosions identified neither intraarticular calcifications. Disc degeneration was seen in 12/25 cases. In 4/25 patients, vacuum phenomena appeared in the SIJ. In 3/25 patients, ventral capsular calcification occurred in the ventral sacroiliac ligament (anterior capsule complex). In the seronegative spondylarthritis group, 16/25 patients had positive findings, while PFR documented erosions only in 3/25 cases. In the bowel diseases group, erosions were detected in 17/25 cases with HRCT, while the plain film was positive only in three cases and in seven cases the findings were questionable. Intraarticular calcification with erosion was documented in three cases and in seven cases without erosion. The bone scan was positive in 7/25 of this cases, but in 5/7 there was mismatching with HRCT. Important new finding was the HRCT detected erosion which was not detected on BS but was obvious on Anti-Granulocyte-Antibody scintigraphy. In the control group, only degenerative changes were seen in 4/25 cases and no erosions. CONCLUSION: HRCT is: (1) the reliable imaging of definitive (often 'cold stage') sacroileitis; (2) gives optimal detection of erosion; and (3) appears to be the only method in the documentation of calcifications in the posterior ligamental portion of the SIJ.


Assuntos
Artrite/diagnóstico por imagem , Articulação Sacroilíaca , Tomografia Computadorizada por Raios X/métodos , Artrite/etiologia , Estudos de Casos e Controles , Diagnóstico Diferencial , Humanos , Doenças Inflamatórias Intestinais/complicações , Articulação Sacroilíaca/diagnóstico por imagem
11.
J Physiol Paris ; 94(2): 135-8, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10791695

RESUMO

The GABA-ergic and opioid modulation of neurally induced muscle responses was studied in isolated guinea-pig taenia coli and human colonic circular muscle, using identical field stimulation parameters (rectangular pulses of 0.5 ms duration, 9 V x cm(-1) intensity, trains of 3 pulses at 0.5 Hz, repeated every 1/3/5 min). The stimulation-induced contractions were inhibited in both preparations by GABA and baclofen; the IC50 values in human colonic circular muscle were approximately 100 and 31.0 microM, respectively. In guinea-pig taenia coli, the inhibition by 10(-4) M GABA was dose-dependently reversed by 10(-4)-10(-3) M of GABA(B) receptor antagonist CGP 35348; antagonism by phaclofen was less effective in the same concentration range. In human colonic circular muscle, inhibition by 3 x 10(-5) M baclofen was fully reversed by 10(-3) M CGP 35348. With the exception of caecum, the delta 2 opioid receptor agonist deltorphin II was a potent inhibitor in human colonic circular muscle. 10(-8) M Deltorphin caused a 74.4 +/- 9.6% (n = 4) inhibition which was reversed by 10(-6) M of delta receptor selective peptide antagonist BOC-Tyr-Pro-Gly-Phe-Leu-Thr(OtBu). Deltorphin II was ineffective in guinea-pig taenia coli even at 10(-6) M; the same concentration caused an 84.3 +/- 7.9 (n = 4) inhibition in human preparations. It is concluded that: 1) GABA-ergic modulatory mechanisms are present both in human colonic circular muscle and guinea-pig taenia coli; 2) the GABA receptors involved are of type B; and 3) delta opioid receptor-mediated modulation functions only in human colonic circular muscle in regions other than the caecum.


Assuntos
Colo/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Receptores de GABA-B/efeitos dos fármacos , Receptores Opioides delta/efeitos dos fármacos , Adulto , Idoso , Animais , Baclofeno/análogos & derivados , Baclofeno/farmacologia , Colo/inervação , Estimulação Elétrica , Feminino , Agonistas GABAérgicos/farmacologia , Antagonistas GABAérgicos/farmacologia , Agonistas dos Receptores de GABA-B , Antagonistas de Receptores de GABA-B , Cobaias , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Músculo Liso/inervação , Oligopeptídeos/farmacologia , Compostos Organofosforados/farmacologia , Receptores Opioides delta/agonistas , Receptores Opioides delta/antagonistas & inibidores
12.
J Med Chem ; 43(7): 1359-66, 2000 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-10753473

RESUMO

Two approaches to the design of very active and highly selective delta opioid peptides were used to obtain new deltorphin analogues with altered hydrophobic and stereoelectronic properties. Deltorphin II analogues were synthesized with the substitution of Ile instead of Val at positions 5 and 6 in the address domain and 6-hydroxy-2-aminotetralin-2-carboxylic acid (Hat) instead of Tyr(1) in the message domain. In the radioreceptor-binding studies, in which type-specific tritiated opioid ligands were used, (R)- and (S)-Hat-deltorphins exhibited similar K(i) values, revealing high delta selectivity. The peptides displayed agonist properties in the in vitro bioassay, with IC(50) values in the subnanomolar range in the mouse vas deferens assay and in the micromolar or higher range in the guinea pig ileum assay, again demonstrating a high selectivity toward delta receptors. The agonist property of the new ligands was confirmed by means of [(35)S]GTPgammaS-binding experiments in membranes of the rat frontal cortex.


Assuntos
2-Naftilamina/síntese química , Aminoácidos/síntese química , Oligopeptídeos/síntese química , 2-Naftilamina/análogos & derivados , 2-Naftilamina/química , 2-Naftilamina/farmacologia , Aminoácidos/química , Aminoácidos/farmacologia , Animais , Estimulação Elétrica , Lobo Frontal/metabolismo , Cobaias , Íleo/efeitos dos fármacos , Íleo/fisiologia , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Modelos Moleculares , Conformação Molecular , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Ensaio Radioligante , Ratos , Ratos Wistar , Receptores Opioides delta/agonistas , Receptores Opioides delta/metabolismo , Estereoisomerismo , Relação Estrutura-Atividade , Ducto Deferente/efeitos dos fármacos , Ducto Deferente/fisiologia
14.
Life Sci ; 65(17): 1795-805, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10576559

RESUMO

Opioid receptor binding properties and pharmacological profiles of novel peptides containing maleoyl function were determined in order to develop new affinity labels. Based on the enkephalin structure peptide ligands were synthesized and tested. Both in in vitro receptor binding experiments and pharmacological studies, all ligands showed agonist character with relatively high affinity (Ki values in the nanomolar range) and good to moderate selectivity. Replacement of Gly2 in the enkephalin frame with D-Ala led to higher affinities with a small decrease in selectivity. The longer peptide chains resulted in compounds with high percentage (up to 86%) of irreversible binding. The selectivity pattern of the ligands is in good agreement with the data obtained from the pharmacological assays (guinea pig ileum and mouse vas deferens bioassays). The newly synthesized peptides could be used in further studies in order to determine more detailed characteristics of the ligand-receptor interaction.


Assuntos
Maleatos/farmacologia , Peptídeos Opioides/farmacologia , Receptores Opioides/efeitos dos fármacos , Marcadores de Afinidade , Substituição de Aminoácidos , Animais , Encéfalo/metabolismo , Encefalinas/síntese química , Encefalinas/química , Encefalinas/farmacologia , Cobaias , Técnicas In Vitro , Ligantes , Masculino , Maleatos/síntese química , Maleatos/química , Membranas/metabolismo , Camundongos , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Peptídeos Opioides/síntese química , Peptídeos Opioides/química , Ensaio Radioligante , Ratos , Ratos Wistar , Receptores Opioides/metabolismo
15.
Life Sci ; 64(2): 145-52, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10069492

RESUMO

The dipeptidyl aminopeptidase IV (DP IV) inhibitor Diprotin A produces a full, dose-dependent, short-lasting and naloxone-reversible analgesia in the rat tail-flick test when given intracerebroventricularly, with an ED50 of 295 nmol/rat but it has no direct opioid agonist activity in the longitudinal muscle strip of guinea-pig ileum bioassay. Two of the potential DP IV substrates, morphiceptin and endomorphin 1, identified recently in bovine brain were also analgesic given by similar route. The action of endomorphin 1 was more potent (ED50 = 7.9 nmol/rat) and slightly but significantly more sustained than that of Diprotin A. Diprotin A neither potentiated nor prolonged the effect of a marginally analgesic dose of endomorphin 1. The distinct time course and the lack of potentiation indicate that in the analgesic effect of Diprotin A in rats the protection of a brain Tyr-Pro-peptide other than endomorphin 1 is involved.


Assuntos
Analgesia , Dipeptidil Peptidases e Tripeptidil Peptidases/antagonistas & inibidores , Naloxona/farmacologia , Oligopeptídeos/farmacologia , Analgésicos Opioides/farmacologia , Animais , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Endorfinas/administração & dosagem , Endorfinas/farmacologia , Cobaias , Técnicas In Vitro , Masculino , Camundongos , Músculo Liso/efeitos dos fármacos , Antagonistas de Entorpecentes/farmacologia , Oligopeptídeos/administração & dosagem , Medição da Dor , Ratos , Ratos Wistar
16.
Scand J Gastroenterol Suppl ; 228: 47-50, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9867112

RESUMO

Interleukin-6 is one of the most well-characterized cytokines with pleiotropic properties. Besides its B-lymphocyte activation role in hematopoiesis, interleukin-6 plays a central role in regulation of systemic inflammation. Interleukin-6 binds to receptors on target cells (such as hepatocytes and lymphocytes), consisting of an 80 kDa binding chain and gp130, a polypeptide responsible for signal transduction. In addition to the detection of elevated amounts of interleukin-6 in the blood, gene expression (mRNA) of subunits of the interleukin-6 receptor complex have also been studied by examining the reverse transcriptase polymerase chain reaction on peripheral lymphocytes from patients with characteristic radiological symptoms suffering from Crohn's disease. Our data show significantly elevated gene expression both of the 80 kDa interleukin-6 binding chain and gp130. These results suggest that enhancement of the expression of the constituents of interleukin-6 and the interleukin-6 receptor system plays a relevant role in systemic inflammation in inflammatory bowel disease.


Assuntos
Antígenos CD/biossíntese , Doença de Crohn/metabolismo , Interleucina-6/metabolismo , Glicoproteínas de Membrana/biossíntese , Receptores de Interleucina-6/biossíntese , Receptor gp130 de Citocina , Expressão Gênica , Humanos , Interleucina-6/biossíntese , Linfócitos/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais
17.
Orv Hetil ; 139(52): 3107-12, 1998 Dec 27.
Artigo em Húngaro | MEDLINE | ID: mdl-9914730

RESUMO

During a period of 17 months, a total of 101 patients were examined by high resolution computed tomography (HRCT) whose minor focal changes revealed by chest X-ray raised the suspicion of diffuse infiltrative pulmonary disease. The disease of the interstitium was primarily caused by idiopathic pulmonary fibrosis (19%), autoimmune disease (18%), Boeck sarcoidosis (18%) as well as by specific (16%) and aspecific inflammation (12%). HRCT disclosed reticular (61%), nodular (55%), ground-glass opacity-like (48%), emphysematous (33%) and ring-like changes (17%). Also transbronchial excision was performed in 51 patients the results of which were compared to the changes observed during HRCT. Concerning fibrosis and inflammation, HRCT and histological analysis showed identical results in 70%. According to the authors observations, this technique is suitable for detection of fairly fine fibrotic, empysematous and inflammatory signs and for defining the activity of the individual disease as also for the selection of the optimal site of transbronchial excision. HRCT is a useful investigative method both for diagnosing diffuse infiltrative pulmonary disease as well as in following up the effectiveness of treatment.


Assuntos
Pneumopatias/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Diagnóstico Diferencial , Humanos , Pneumopatias/classificação
18.
Eur Radiol ; 7(5): 625-42, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9166558

RESUMO

Preoperative diagnosis of primary small intestinal neoplasms can be a challenge for both clinicians and radiologists. As a result of their infrequent occurrence, they invariably present difficult problems in diagnosis and management. These problems are reflected mainly in the delayed treatment and a very poor prognosis for such malignant tumours. Their morphological changes, however, shown in enteroclysis and CT, correlate almost perfectly with the lesions identified in the gross pathological specimens. This ability to accurately image a small intestinal neoplasm, independently of its size, anatomical localization and growing tendency, represents a major improvement in the diagnosis and management of these neoplasms. This paper, based on a large series of patients with primary small intestinal neoplasms, focuses on the recognition of their detailed radiological appearances when evaluated by enteroclysis and CT.


Assuntos
Sulfato de Bário , Meios de Contraste , Neoplasias Intestinais/diagnóstico por imagem , Intestino Delgado/patologia , Tomografia Computadorizada por Raios X , Humanos , Neoplasias Intestinais/patologia , Intestino Delgado/diagnóstico por imagem
19.
Orv Hetil ; 137(38): 2093-6, 1996 Sep 22.
Artigo em Húngaro | MEDLINE | ID: mdl-8966027

RESUMO

Leiomyomas are uncommon benign tumors of smooth muscle which may occur wherever smooth muscle is present. The small bowel is the most frequent site. Bleeding is the most common presenting symptom. Other symptoms, nausea, vomiting, abdominal pain are rare. In this article a 44 year-old male, presented, who was admitted with intermittent gastrointestinal bleeding in requence of jejunal leiomyoma with exulceration.


Assuntos
Hemorragia Gastrointestinal/etiologia , Neoplasias do Jejuno/complicações , Leiomioma/complicações , Adulto , Colonoscopia , Humanos , Neoplasias do Jejuno/diagnóstico , Neoplasias do Jejuno/patologia , Neoplasias do Jejuno/cirurgia , Leiomioma/diagnóstico , Leiomioma/patologia , Leiomioma/cirurgia , Masculino , Melena/etiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...