RESUMO
BACKGROUND AND PURPOSE: Progressive changes in the substantia nigra pars compacta and locus ceruleus of patients with Parkinson disease and Alzheimer disease visualized by neuromelanin MRI and cardiac postganglionic sympathetic nerve function on (123)I-metaiodobenzylguanidine scintigraphy have not been fully evaluated. We compared the diagnostic value of these modalities among patients with early Parkinson disease, late Parkinson disease, and Alzheimer disease. MATERIALS AND METHODS: We compared contrast ratios of signal intensity in medial and lateral regions of the substantia nigra pars compacta and locus ceruleus with those of the tegmentum of the midbrain and the pons, respectively, by use of neuromelanin MRI in patients with early Parkinson disease (n = 13), late Parkinson disease (n = 31), Alzheimer disease (n = 6), and age-matched healthy control subjects (n = 20). We calculated heart-to-mediastinum ratios on (123)I-metaiodobenzylguanidine scintigrams after setting regions of interest on the left cardiac ventricle and upper mediastinum. RESULTS: The signal intensity of the lateral substantia nigra pars compacta on neuromelanin MRI was significantly reduced in early and late Parkinson disease, and that of the medial substantia nigra pars compacta was gradually and stage-dependently reduced in Parkinson disease. The signal intensity of the locus ceruleus was obviously reduced in late Parkinson disease. Signal reduction was not significant in the substantia nigra pars compacta and locus ceruleus of patients with Alzheimer disease. The heart-to-mediastinum ratio on (123)I-metaiodobenzylguanidine scintigrams was stage-dependently reduced in Parkinson disease and normal in Alzheimer disease. The signal intensity ratios in substantia nigra pars compacta and locus ceruleus on neuromelanin MRI positively correlated with the heart-to-mediastinum ratio on (123)I-metaiodobenzylguanidine scintigrams. CONCLUSIONS: Both neuromelanin MRI and (123)I-metaiodobenzylguanidine scintigraphy can help to evaluate disease progression in Parkinson disease and are useful for differentiating Parkinson disease from Alzheimer disease.
Assuntos
3-Iodobenzilguanidina/farmacocinética , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Melaninas/metabolismo , Doença de Parkinson/diagnóstico , Doença de Parkinson/metabolismo , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Imagem Molecular/métodos , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Distribuição TecidualRESUMO
BACKGROUND AND PURPOSE: The risk of hemorrhage in the context of developmental venous anomaly is considered to be very low, but it has never been evaluated by susceptibility-weighted MR imaging at 3T. The goal of the present study was to evaluate the prevalence of hypointense foci (ie, microhemorrhage or cavernous malformation) associated with DVA on phase-sensitive MR imaging, on the basis of principles similar to those of susceptibility-weighted MR imaging, and to evaluate the relationship between the hypointense foci and several factors, such as white matter hyperintense lesions adjacent to DVA on T2-weighted imaging, DVA morphology, and clinical symptoms. MATERIALS AND METHODS: This study retrospectively evaluated 61 lesions in 59 consecutive patients with DVA who underwent MR imaging including phase-sensitive MR imaging. Two neuroradiologists independently assessed for the presence of hypointense foci and other factors such as DVA location, depth, size, direction of draining vein on phase-sensitive MR imaging, and white matter hyperintense lesion on T2-weighted imaging. Clinical symptoms were also assessed. RESULTS: Hypointense foci were observed in 62.3% (38/61) of lesions. White matter hyperintense lesion was more frequently observed in patients with hypointense foci (26/38) than in patients without hypointense foci (7/23) (P < .01). There was no significant association between hypointense foci and other factors. CONCLUSIONS: Our results support the hypothesis that microhemorrhage or cavernous malformation can be related to venous congestion caused by abnormal venous drainage. We conclude that phase-sensitive MR imagingis useful for the detection of microhemorrhage or cavernous malformation in patients with DVA, especially when associated with white matter hyperintense lesion.
Assuntos
Hemorragia Cerebral/patologia , Hemangioma Cavernoso do Sistema Nervoso Central/patologia , Imageamento Tridimensional/métodos , Malformações Arteriovenosas Intracranianas/patologia , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Hemorragia Cerebral/epidemiologia , Criança , Pré-Escolar , Bases de Dados Factuais , Feminino , Hemangioma Cavernoso do Sistema Nervoso Central/epidemiologia , Humanos , Incidência , Malformações Arteriovenosas Intracranianas/epidemiologia , Leucoencefalopatias/epidemiologia , Leucoencefalopatias/patologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores de Risco , Adulto JovemRESUMO
During hemodiafiltration (HDF) treatment for chronic renal failure patients, replacing large volumes using high-flux membranes with relatively large pores is preferred from the standpoint of enhancing the elimination of large molecules (10 to 50 kd). Aggressive protein-permeable treatment often results in massive leakage of essential albumin, however, which may cause fatigue, hypotension, and a decrease in the plasma albumin concentration in some patients. During 5-hour conventional HDF treatment with the filtration rate or pressure set at constant values, fractional albumin loss in the dialysate was assayed, which revealed that the albumin concentration in the dialysate showed a maximum value in the beginning with a steep decline within 1 hour. Approximately 40% to 50% of the total amount of albumin leakage occurred during the first 30 minutes. Concomitantly the large molecules transferred into the pores by aggressive filtration during the beginning partially plugged the pores, resulting in a decrease in the permeability for beta(2)-microglobulin. From the standpoint of achieving the highest clearance for large molecules, while suppressing albumin leakage below the acceptable range, the optimal profiles for filtration conditions in HDF have been proposed, in which either the transmembrane pressure is regulated according to the sigmoid curve in the pressure control manner or the flow rate is set along the concave in the flow control manner. The profiles of pressure or flow as a function of time have been programmed and installed in a HDF machine to perform an optimal HDF treatment automatically. The new filtration methods gave significantly higher beta(2)-microglobulin removal and lower albumin leakage than conventional HDF methods with constant filtration.
Assuntos
Albuminas/análise , Hemodiafiltração/métodos , Feminino , Humanos , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Microglobulina beta-2/análiseRESUMO
Mulberry leaves treated with UV-C were found to accumulate three different phytoalexins, moracin C, moracin N, and chalcomoracin. The increased level of malondialdehyde in UV-treated leaves along with moracins suggested their role as a free-radical scavenger in stressed plants. All the three moracins induced under UV stress were capable of scavenging the superoxide anion generated by the xanthine-xanthine oxidase system. Also, moracins were capable of inhibiting lipid peroxidation, which strongly indicates their role as a scavenger.
Assuntos
Sequestradores de Radicais Livres/química , Moraceae/química , Extratos Vegetais/química , Sequestradores de Radicais Livres/isolamento & purificação , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Moraceae/metabolismo , Extratos Vegetais/isolamento & purificação , Folhas de Planta/metabolismo , Sesquiterpenos , Superóxidos/metabolismo , Terpenos , Raios Ultravioleta , Xantina Oxidase/metabolismo , Ácido alfa-Linolênico/química , FitoalexinasRESUMO
Stereochemical studies of a cruciferous oxindole phytoalexin, (S)-(-)-spirobrassinin [(-)-4], and its oxazoline analogue, spirooxazoline (11), were carried out. Racemic spirobrassinin [(+/-)-4] was synthesized by SOCl(2)- or MsCl-mediated cyclization of dioxibrassinin [(+/-)-8]. Treatment of (3-hydroxyoxindol-3-yl)methylammonium chloride [(+/-)-9] with CSCl(2) and subsequent methylation of the obtained spirooxazolidinethione (+/-)-10 afforded spirooxazoline [(+/-)-11]. Enantioresolution of (+/-)-4 and (+/-)-11 was achieved by derivatization with (S)-(-)-1-phenylethyl isocyanate (12), chromatographic separation of diastereomeric amides 13, 14 or 15, 16, and their cleavage with CH(3)ONa. Absolute configuration of the stereogenic center in natural (S)-(-)-4 was derived from the exciton, calculated via CD methods, and unequivocally confirmed by X-ray crystallographic analyses of 1-[1'S,4'R-(-)-camphanoyl] derivatives [(-)-19 and (-)-20] of (+)- and (-)-4. Novel enantiomeric enrichment phenomena of 4 and 11 were discovered during their chromatographic separations under achiral HPLC conditions. Screening of antifungal activity against the fungus Bipolaris leersiae revealed no significant dependence of this activity on absolute configuration.
Assuntos
Antifúngicos/síntese química , Brassicaceae/química , Compostos de Espiro/síntese química , Tiazóis/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Ascomicetos/efeitos dos fármacos , Dicroísmo Circular , Cristalografia por Raios X , Testes de Sensibilidade Microbiana , Conformação Molecular , Oxazóis/síntese química , Oxazóis/química , Espectrofotometria Ultravioleta , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Estereoisomerismo , Tiazóis/química , Tiazóis/farmacologiaRESUMO
BACKGROUND: Plasma concentrations of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and cyclic guanosine monophosphate (cGMP) are suitable markers of 'dry body weight' (DW) in hemodialysis (HD) patients. However, it is still unknown whether these markers can be applied to patients with renal failure and coronary artery disease (CAD). We examined the reliability of these peptides as volume markers in HD patients with CAD. We also assessed the relationship between natriuretic peptides and indices of left ventricular (LV) function. METHODS: Plasma concentrations of ANP, BNP and cGMP were determined before and after HD in patients with CAD (group 1, n = 19, mean age 63 +/- 12 years) and were compared with those of patients without cardiac disease (group 2, n = 20, age 61 +/- 15 years). Using data obtained by cardiac catheterization, we examined the relationship between natriuretic peptides and indices of LV function in HD patients with CAD. RESULTS: Baseline ANP (244 +/- 205 pg/ml), BNP (713 +/- 928 pg/ml) and cGMP (29.6 +/- 21.6 pmol/ml) were significantly higher in group 1 than in 11 healthy volunteers (18.6 +/- 9.9 pg/ml, 7.7 +/- 7.6 pg/ml, cGMP 8.9 +/- 4.9 pmol/ml, respectively). HD significantly reduced plasma ANP (87 +/- 75 pg/ml) and BNP (477 +/- 702 pg/ml) although they were still above normal control. HD reduced plasma cGMP (7.2 +/- 4.5 pmol/ml) to normal values, suggesting the elimination of cGMP across the dialyzers. Baseline levels of ANP, BNP and cGMP in group 2 were less than those of group 1 but higher than the control. HD reduced natriuretic peptides in group 2 to levels lower than those in post-HD group 1. After HD, there was no significant correlation between reductions in body weight and changes in ANP or BNP. Baseline ANP and BNP levels closely correlated with pulmonary artery pressure, pulmonary artery wedge pressure, left ventricular end-diastolic pressure and left ventricular ejection fraction. A significant correlation was observed between BNP levels and the severity of CAD. CONCLUSION: ANP, BNP and cGMP seem to be a useful markers for fluid overload but not for DW in HD patients with CAD. Plasma ANP and BNP might be useful markers for left ventricular function.
Assuntos
Fator Natriurético Atrial/sangue , Biomarcadores/sangue , Doença das Coronárias/sangue , GMP Cíclico/sangue , Peptídeo Natriurético Encefálico/sangue , Diálise Renal , Doença das Coronárias/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência Renal/sangue , Insuficiência Renal/complicações , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologiaRESUMO
We tried to establish an assay system for screening and assessment of immunoregulatory factors using whole cell cultures of mouse splenocytes and found that splenic adhesive cells markedly increased immunogobulin (Ig) production of splenocytes. In the absence of adhesive cells, lipopolysaccharides, pokeweed mitogen, and phytohemagglutinin stimulated the production of IgA, IgG, and IgM in a class-dependent manner. Adhesive cells increased more markedly Ig production of splenocytes stimulated with these mitogens. When mouse splenocytes were cultured with milk proteins in the absence of adhesive cells, lactoferrin, beta-lactoglobulin, alpha-casein, and beta-casein stimulated IgA and IgG production. Adhesive cells increased IgA production of splenocytes stimulated with milk proteins, especially. These results suggest that the assay system is useful for assessment of Ig production-regulating factors.
Assuntos
Bioensaio/métodos , Imunoglobulinas/biossíntese , Lipopolissacarídeos/farmacologia , Proteínas do Leite/farmacologia , Mitógenos/farmacologia , Baço/citologia , Animais , Adesão Celular , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Baço/efeitos dos fármacosRESUMO
Enantiomeric purity of a cruciferous phytoalexin, spirobrassinin (1), was determined by chiral HPLC analysis. The enantiomeric excesses of two natural spirobrassinin fractions separated by nonchiral chromatography were considerably different. A significant enantiomeric enrichment was observed during the nonchiral chromatographic separation of an artificial enantiomeric mixture of 1.
Assuntos
Extratos Vegetais/química , Compostos de Espiro/química , Tiazóis/química , Brassica/química , Cromatografia Líquida de Alta Pressão , Sesquiterpenos , Análise Espectral , Estereoisomerismo , Terpenos , FitoalexinasRESUMO
To characterize the clinical features and etiology of recently encountered cases of community-acquired pneumonia (CAP), we carried out a hospital-based retrospective study of 120 episodes of CAP (115 patients) at Tagami Hospital, Nagasaki City between 1994 and 1997. We identified the causative pathogens in 55 episodes (50 patients) by sputum Gram stain and quantitative culture, for a determination rate of 45.8%. Streptococcus pneumoniae (17 episodes) and Haemophilus influenzae (15 episodes) were the primary causative organisms. It is noteworthy that two major nosocomial pathogens, Pseudomonas aeruginosa (P. aeruginosa; 5 episodes) and Methicillin-resistant Staphylococcus aureus (MRSA; 2 episodes), were also identified as causative agents of CAP. These two pathogens were isolated from patients with severe underlying diseases and patients who had been repeatedly hospitalized. The incidence of CAP due to P. aeruginosa and MRSA is increasing because patients with respiratory colonization by these nosocomial pathogens are often followed up on an outpatient basis.
Assuntos
Pneumonia Bacteriana/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Feminino , Haemophilus influenzae/isolamento & purificação , Haemophilus influenzae/patogenicidade , Humanos , Japão/epidemiologia , Masculino , Resistência a Meticilina , Pessoa de Meia-Idade , Pneumonia Bacteriana/epidemiologia , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/patogenicidade , Estudos Retrospectivos , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/patogenicidade , Streptococcus pneumoniae/isolamento & purificação , Streptococcus pneumoniae/patogenicidadeRESUMO
Oligonucleotides can be used as sequence-specific DNA ligands by forming a local triple helix. In order to form more stable triple-helical structures or prevent their degradation in cells, oligonucleotide analogues that are modified at either the backbone or base level are routinely used. Morpholino oligonucleotides appeared recently as a promising modification for antisense applications. We report here a study that indicates the possibility of a triple helix formation with a morpholino pyrimidine TFO and its comparison with a phosphodiester and a phosphoramidate oligonucleotide. At a neutral pH and in the presence of a high magnesium ion concentration (10 mM), the phosphoramidate oligomer forms the most stable triple helix, whereas in the absence of magnesium ion but at a physiological monovalent cation concentration (0.14 M) only morpholino oligonucleotides form a stable triplex. To our knowledge, this is the first report of a stable triple helix in the pyrimidine motif formed by a noncharged oligonucleotide third strand (the morpholino oligonucleotide) and a DNA duplex. We show here that the structure formed with the morpholino oligomer is a bona fide triple helix and it is destabilized by high concentrations of potassium ions or divalent cations (Mg(2+)).
Assuntos
DNA/química , Magnésio/metabolismo , Morfolinas/química , Nucleotídeos de Pirimidina/química , Sequência de Bases , Primers do DNA , Eletroforese/métodos , Cinética , Espectrofotometria Ultravioleta , Termodinâmica , Tionucleotídeos/químicaAssuntos
Infecção Hospitalar/microbiologia , DNA Bacteriano/isolamento & purificação , Surtos de Doenças , Moraxella catarrhalis/isolamento & purificação , Infecções por Neisseriaceae/microbiologia , Mapeamento por Restrição , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Moraxella catarrhalis/genéticaRESUMO
Seven chlorine-containing orcinol derivatives (2-8) and orcinol (9) have been isolated from diseased bulbs of the edible lily Lilium maximowiczii, and their structures have been elucidated. Six of the chlorinated orcinol derivatives (2, 4-8) showed antifungal activity. Because organochlorine compounds are rare in terrestrial higher plants, their biosynthetic origin was examined. These compounds were shown to be induced in intact bulb scales by UV irradiation or by inoculation with the pathogenic fungus Fusarium oxysporum f. sp. lilii. Biosynthetic studies suggested that these "natural organochlorine pesticides" are produced by enzymatic chlorination of orcinol (9) with chloroperoxidase and hydrogen peroxide, which are both induced in the plant tissue under stress conditions.
Assuntos
Antifúngicos/isolamento & purificação , Fusarium/química , Hidrocarbonetos Clorados/isolamento & purificação , Doenças das Plantas , Raízes de Plantas/química , Plantas Medicinais/química , Resorcinóis/isolamento & purificação , Antifúngicos/farmacologia , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Hidrocarbonetos Clorados/farmacologia , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Fungos Mitospóricos/metabolismo , Peroxidases/antagonistas & inibidores , Resorcinóis/farmacologia , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
Pyrimidine oligonucleotides bind to the major groove of an oligopyrimidine-oligopurine DNA sequence by triple helix formation. A 14-mer oligopyrimidine 3'-psoralen-conjugate (P) and a doubly modified 5'-acridine/3'-psoralen-oligonucleotide (PA) were photo-crosslinked to their target site. The crosslinked complexes were tested regarding their sensitivity to Uvr(A)BC excinuclease/DNA complex formation and excision, and compared to free psoralen crosslinked to the same site (M). An electrophoretic mobility-shift assay showed that the crosslinked triple-helix did not hamper formation of the (A)2B complex under conditions where the third strand was bound to its target. In vitro excision experiments performed on damaged DNA fragments containing crosslinked 5-methoxypsoralen (M-target) confirmed that the psoralen photoadduct was recognized by Uvr(A)BC and that excision occurred at the crosslinked site. The major cleavage reaction took place on the 5'-side of oligopurine strand. The excision was less efficient on the 5'-side of the pyrimidine strand. The 3'-side incision either on the purine or pyrimidine strand was even weaker. With optimal Uvr(A) concentrations, it was observed that the incision reaction on (P)- and (PA)-modified targets was clearly inhibited compared to the (M)-modified target, reflecting an effect of the oligonucleotide on the recognition/excision process. These results demonstrate that a triple helix is efficient in promoting inhibition of Uvr(A)BC excision nuclease activity. These results could account for divergent findings concerning the effects of triple helix-forming oligonucleotides on repair systems and open new perspectives to study DNA repair processes through the use of bi-substituted triple helix-forming oligonucleotides.
Assuntos
Adutos de DNA/metabolismo , DNA/metabolismo , Endodesoxirribonucleases/metabolismo , Proteínas de Escherichia coli , Furocumarinas/metabolismo , Conformação de Ácido Nucleico , Sequência de Bases , Reagentes de Ligações Cruzadas , Dano ao DNA , Reparo do DNA , Escherichia coli/enzimologia , Furocumarinas/química , Dados de Sequência Molecular , Especificidade por Substrato , beta-Lactamases/genéticaRESUMO
The expression of arginine vasopressin (AVP) gene in the paraventricular (PVN) and supraoptic nuclei (SON) was investigated in rats with lithium (Li)-induced polyuria, using in situ hybridization histochemistry and radioimmunoassay. The male Wistar rats consuming a diet that contained LiCl (60 mmol/kg) for 4 weeks developed marked polyuria. The Li-treated rats produced a large volume of hypotonic urine with low ionic concentrations. Plasma sodium concentrations were found to be slightly increased in the Li-treated rats compared with those in controls. Plasma concentration of AVP and transcripts of AVP gene in the PVN and SON were significantly increased in the Li-treated rats compared with controls. These results suggest that dehydration and/or the activation of visceral afferent inputs may contribute to the elevation of plasma AVP and the upregulation of AVP gene expression in the PVN and the SON of the Li-induced diabetes insipidus rat.
Assuntos
Arginina Vasopressina/fisiologia , Diabetes Insípido/metabolismo , Lítio/toxicidade , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Núcleo Supraóptico/efeitos dos fármacos , Animais , Arginina Vasopressina/genética , Arginina Vasopressina/metabolismo , Diabetes Insípido/induzido quimicamente , Expressão Gênica/efeitos dos fármacos , Histocitoquímica/métodos , Hibridização In Situ , Masculino , Núcleo Hipotalâmico Paraventricular/metabolismo , Radioimunoensaio , Ratos , Ratos Wistar , Núcleo Supraóptico/metabolismo , Regulação para CimaRESUMO
We have experienced a case of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-related glomerulonephritis induced by propylthiouracil (PTU). A 45-year-old female had been treated with PTU for 4 years after the diagnosis of hyperthyroidism. She was referred to out hospital because of abrupt macroscopic hematuria and moderate proteinuria after several days of upper respiratory tract infection. On admission, her laboratory findings showed deterioration of renal function. Renal biopsy revealed crescentic glomerulonephritis without deposition of immune complexes. Her serology was found to be MPO-ANCA-positive and cytoplasmic-ANCA-negative. Based of these findings, we diagnosed idiopathic crescentic glomerulonephritis. Following the initiation of steroid pulse therapy, her urinary protein excretion and renal function gradually improved in parallel with a decrease in the MPO-ANCA titer. Although steroid therapy effectively responded to their renal function without the withdrawal of PTU, it seems that PTU may be closely associated with the development of (MPO-ANCA)-related glomerulonephritis in this case. Therefore, hyperthyroidism patients treated with PTU should be paced under vigilant observation by monitoring their urinalysis and serum creatinine level.
Assuntos
Anticorpos Anticitoplasma de Neutrófilos/análise , Antitireóideos/efeitos adversos , Glomerulonefrite/induzido quimicamente , Peroxidase/análise , Propiltiouracila/efeitos adversos , Biomarcadores/análise , Feminino , Glomerulonefrite/patologia , Humanos , Hipertireoidismo/tratamento farmacológico , Pessoa de Meia-IdadeRESUMO
The effect of serotonin (5-hydroxytryptamine, 5-HT) on Ca2+ mobilization in bovine adrenal chromaffin cells in culture was examined. 5-HT (10(-5) M) did not increase secretion of catecholamine, uptake of 45Ca2+ and levels of intracellular free Ca2+ ([Ca/+]i). However, 5-HT (10(-8)-10(-5) M) stimulated the efflux of 45Ca2+ from cultured bovine adrenal chromaffin cells in a concentration-dependent manner. Its stimulatory effect on 45Ca2+ efflux was inhibited by cyproheptadine (a 5-HT1A and 5-HT2 receptor antagonist) or mianserin (a 5-HT2 receptor antagonist). The increase in 5-HT-stimulated 45Ca2+ efflux was dependent on extracellular Na+ concentration, but not extracellular Ca2+ concentration. These results indicate that stimulation of the 5-HT receptors induces extracellular Na(+)-dependent Ca2+ efflux from bovine adrenal chromaffin cells in culture, probably by acceleration of Na+/Ca2+ exchange.
Assuntos
Glândulas Suprarrenais/metabolismo , Cálcio/metabolismo , Células Cromafins/metabolismo , Serotonina/farmacologia , Sódio/fisiologia , Glândulas Suprarrenais/citologia , Animais , Bovinos , Células Cultivadas , Ciproeptadina/farmacologia , Relação Dose-Resposta a Droga , Membranas Intracelulares/metabolismo , Mianserina/farmacologia , Concentração Osmolar , Antagonistas da Serotonina/farmacologiaRESUMO
The effect of pituitary adenylate cyclase-activating polypeptide (PACAP) on catecholamine secretion with ouabain, an inhibitor of Na(+)-K+ ATPase, in cultured bovine adrenal chromaffin cells was examined, to determine whether movement of Na+, as well as Ca2+, is involved in the secretory process. PACAP (10(-10)-10(-6)M)-induced catecholamine secretion was markedly potentiated by addition of ouabain (10(-5)M). When cultured cells were preincubated with PACAP for 30 min in Ca(2+)-free medium in the presence of ouabain and then stimulated for 15 min with Ca(2+)-containing medium without PACAP or ouabain, their catecholamine secretion was dependent on the external Ca2+ concentration, and 45Ca2+ influx into the cells was increased. When the cells had been preincubated with PACAP and ouabain in Na(+)-free sucrose medium, their Ca(2+)-induced catecholamine secretion was greatly reduced. PACAP increased 22Na+ influx into cells treated with ouabain. These results suggest that stimulation by PACAP and inhibition of the Na(+)-pump both increase the intracellular Na+ level, resulting in increase in Ca2+ influx and catecholamine secretion.
Assuntos
Células Cromafins/efeitos dos fármacos , Neuropeptídeos/administração & dosagem , Ouabaína/administração & dosagem , Adenilil Ciclases/metabolismo , Animais , Cálcio/metabolismo , Catecolaminas/metabolismo , Bovinos , Células Cultivadas , Células Cromafins/fisiologia , Sinergismo Farmacológico , Transporte de Íons , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Sódio/metabolismoRESUMO
By using cultured rat mesangial cells, we compared the effects on cyclic nucleotide levels of adrenomedullin with those of the structurally related peptides, calcitonin gene-related peptide (CGRP) and amylin. Adrenomedullin potently increased cAMP levels 7-fold in a time- and concentration-dependent manner. Its EC50 was 3 x 10(-9) M. CGRP was less potent (2-fold) with an EC50 of 10(-7) M, and amylin had no effect on cAMP levels. All three peptides failed to increase cGMP levels. Treatment of cells with near maximal concentrations of adrenomedullin (10(-7) M) and CGRP (10(-6) M) had no additive effect on cAMP levels. Human adrenomedullin-(22-52)-NH2, a putative adrenomedullin receptor antagonist, inhibited the production of cAMP elicited by adrenomedullin (IC50: 7 x 10(-8) M) and CGRP (IC50: 5 x 10(-8) M). Human CGRP-(8-37), a CGRP receptor antagonist, conversely, reduced the cAMP elevation caused by these peptides with a lower potency (IC50: 10(-6) M for both peptides). This demonstrated that human adrenomedullin-(22-52)-NH2 was a more effective antagonist for adrenomedullin- and CGRP-specific receptors than human CGRP-(8-37). Results suggest that receptors sensitive to adrenomedullin are preferentially expressed in cultured rat mesangial cells. Immunohistochemical study showed almost no immunoreactive adrenomedullin and CGRP, if any, in the cells. Adrenomedullin may regulate mesangial function as either a paracrine or circulating hormone via a cAMP- but not a cGMP-dependent mechanism.
Assuntos
Mesângio Glomerular/efeitos dos fármacos , Peptídeos/farmacologia , Vasodilatadores/farmacologia , Adrenomedulina , Animais , Células Cultivadas/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Imuno-Histoquímica , Ratos , Ratos WistarRESUMO
We established an avidin-biotin method for the sensitive determination of rat IgE and found that a non-specific signal was generated depending on the reaction temperature. When the sera of rats immunized or not with ovalbumin (OVA) were fractionated in a hydroxyapatite column and OVA-specific IgE was determined by the avidin-biotin method at 4 degrees C or 37 degrees C, OVA-specific IgE peaks were detected at 37 degrees C, even with nonimmunized rats, but not at 4 degrees C.
Assuntos
Imunoglobulina E/análise , Animais , Avidina/química , Biotina/química , Ensaio de Imunoadsorção Enzimática , Hidroxiapatitas , Imunoglobulina E/isolamento & purificação , Indicadores e Reagentes , Masculino , Ovalbumina/imunologia , Ratos , Ratos Endogâmicos BN , TemperaturaRESUMO
Systemic lupus erythematosus (SLE) patients, especially those with antiphospholipid antibodies, have a high incidence of arterial and venous thrombotic manifestations. However, renovascular hypertension (RVH) has been rarely reported in these patients. We describe here a 49-year-old female with antiphospholipid antibodies, complicated with RVH and presenting with sudden onset of severe hypertension, headache and nausea. She had experienced phlebitis and arterial thrombosis of the right leg. At the age of 38 years, she was diagnosed as SLE and steroid therapy was started, but she had poor drug compliance and irregularly visited our clinic. On admission, hypertension was recognized and abdominal bruit was audible on physical examination. Serological findings were compatible with SLE. She was also found to have IgG anti-cardiolipin antibody and lupus anticoagulant. Peripheral plasma renin activity (PRA) was elevated, and captopril test showed hyper-response of PRA with lowering of blood pressure. Renal echography and scintigram showed a small and poorly perfused right kidney. Selective angiography demonstrated a severe stenosis of the right renal artery at origin. A stenosis at the origin of both the superior mesenteric artery (SMA) and celiac trunk was also detected. Percutaneous transluminal angioplasty was performed, achieving successful dilatation of the right renal artery and SMA, whereas the attempt to insert the catheter into the celiac trunk was unsuccessful. After this procedure, abdominal bruit has not been audible. Following the initiation of steroid pulse therapy combined with heparin and dipyridamole, her blood pressure was gradually depressed and the test for lupus anticoagulant became negative. Therefore, RVH of this patient is thought to be associated with antiphospholipid antibodies.