RESUMEN
BACKGROUND: Chronic rhinosinusitis (CRS) can be classified into CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). CRSwNP displays more intense eosinophilic infiltration and the presence of Th2 cytokines. Mucosal eosinophilia is associated with more severe symptoms and often requires multiple surgeries because of recurrence; however, even in eosinophilic CRS (ECRS), clinical course is variable. In this study, we wanted to set objective clinical criteria for the diagnosis of refractory CRS. METHODS: This was a retrospective study conducted by 15 institutions participating in the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC). We evaluated patients with CRS treated with endoscopic sinus surgery (ESS), and risk of recurrence was estimated using Cox proportional hazard models. Multiple logistic regression models and receiver operating characteristics curves were constructed to create the diagnostic criterion for ECRS. RESULTS: We analyzed 1716 patients treated with ESS. To diagnose ECRS, the JESREC scoring system assessed unilateral or bilateral disease, the presence of nasal polyps, blood eosinophilia, and dominant shadow of ethmoid sinuses in computed tomography (CT) scans. The cutoff value of the score was 11 points (sensitivity: 83%, specificity: 66%). Blood eosinophilia (>5%), ethmoid sinus disease detected by CT scan, bronchial asthma, aspirin, and nonsteroidal anti-inflammatory drugs intolerance were associated significantly with recurrence. CONCLUSION: We subdivided CRSwNP in non-ECRS, mild, moderate, and severe ECRS according to our algorithm. This classification was significantly correlated with prognosis. It is notable that this algorithm may give useful information to clinicians in the refractoriness of CRS before ESS or biopsy.
Asunto(s)
Rinitis/clasificación , Rinitis/epidemiología , Sinusitis/clasificación , Sinusitis/epidemiología , Adulto , Distribución por Edad , Edad de Inicio , Anciano , Algoritmos , Enfermedad Crónica , Estudios de Cohortes , Eosinofilia/inmunología , Femenino , Humanos , Incidencia , Japón/epidemiología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Rinitis/inmunología , Medición de Riesgo , Índice de Severidad de la Enfermedad , Distribución por Sexo , Sinusitis/inmunología , Adulto JovenRESUMEN
This study aimed to evaluate the efficacy and toxicity of concurrent chemoradiotherapy as a primary treatment modality for larynx preservation in patients with stage two squamous cell carcinoma (SCC) of the glottic larynx. Between February 2000 and August 2003, a total of 20 patients received concurrent chemoradiotherapy. Carboplatin was given intravenously once a week during the period of radiotherapy. The weekly carboplatin dose was based on the area under the curve 1 to 1.25. Uracil-ftegafur (UFT) was given in a daily oral dose of 300 mg as tegafur. Radiotherapy was delivered five days a week using a once-daily fractionation of 2.0 Gray (Gy), to a total dose of 66-72 Gy. The three-year overall survival rate with larynx preservation was 100 per cent. Concurrent chemoradiotherapy with carboplatin and UFT for stage two SCC of the glottic larynx was safe and effective in improving local control with larynx preservation.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Escamosas/terapia , Glotis , Neoplasias Laríngeas/terapia , Adulto , Anciano , Anciano de 80 o más Años , Carboplatino/administración & dosificación , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/radioterapia , Quimioterapia Adyuvante , Terapia Combinada , Supervivencia sin Enfermedad , Esquema de Medicación , Femenino , Humanos , Neoplasias Laríngeas/tratamiento farmacológico , Neoplasias Laríngeas/radioterapia , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Dosificación Radioterapéutica , Tegafur/administración & dosificación , Uracilo/administración & dosificaciónRESUMEN
The aim of this study was to evaluate the efficacy and toxicity of a concurrent chemoradiotherapy using docetaxel, cisplatin and 5-fluorouracil (5-FU) (TPF) in patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN). In total, 19 patients with previously untreated stage III-IV SCCHN were entered onto this trial. Patients received two cycles of chemotherapy. Cycles were repeated every 4 weeks. The starting doses (dose level 1) were docetaxel 60 mg m(-2), cisplatin 70 mg m(-2), and 5-day continuous infusion of 5-FU 600 mg m(-2) day(-1). Radiation was targeted to begin on the first day of chemotherapy, day 1. The total radiation dose to the primary tumour site and neck lymph nodes was between 63.0 and 74.0 Gy. At least three patients were examined at each dose level before advancing to the next level. The maximum-tolerated dose (MTD) of this regimen was docetaxel 60 mg m(-2), cisplatin 60 mg m(-2) and 5-FU 600 mg m(-2) day(-1). The main toxicities were mucositis (grade 3 and 4, 79%), leukocytopenia (grade 3 and 4, 53%), neutropenia (grade 3 and 4, 42%), anaemia (grade 3, 16%), liver dysfunction (grade 3, 11%) and renal dysfunction (grade 2, 11%). The overall response rate was 100%, including 84% complete responses (CRs). This concurrent chemoradiotherapy with TPF was safe and well tolerated. The high CR rate justifies further evaluation of this chemoradiotherapy modality in advanced SCCHN patients.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/radioterapia , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/radioterapia , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Carcinoma de Células Escamosas/patología , Cisplatino/administración & dosificación , Terapia Combinada , Femenino , Fluorouracilo/administración & dosificación , Neoplasias de Cabeza y Cuello/patología , Humanos , Infusiones Intravenosas , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Taxoides/administración & dosificación , Resultado del TratamientoRESUMEN
Kaposi's sarcoma (KS) is frequently seen in the head and neck regions of HIV-infected patients. We report two cases of patients with AIDS who consulted the ENT clinic. One patient came to our clinic complaining of abnormal sensations in the pharynx, and dysphasia due to a gross KS in the oropharynx. The excision of the tumor improved the difficulty of swallowing. The other patient complained of masticatory problems and tongue pain due to a bulky KS on the dorsal side of the tongue. We treated the tongue lesion with intralesional chemotherapy. The administration of intralesional vinblastine resulted in a partial response. Unless systemic chemotherapy is effective enough to improve a functional disorder, it is thought that local therapy employing excision or intralesional chemotherapy is one of the common therapeutic option of the otolaryngologist, because this treatment avoids severe side effects caused by systemic chemotherapy or radiotherapy.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/complicaciones , Neoplasias Orofaríngeas/terapia , Sarcoma de Kaposi/etiología , Sarcoma de Kaposi/terapia , Neoplasias de la Lengua/terapia , Adulto , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Humanos , Inyecciones Intralesiones , Masculino , Neoplasias Orofaríngeas/diagnóstico , Neoplasias Orofaríngeas/etiología , Neoplasias Orofaríngeas/cirugía , Sarcoma de Kaposi/diagnóstico , Sarcoma de Kaposi/cirugía , Tomografía Computarizada por Rayos X , Neoplasias de la Lengua/diagnóstico por imagen , Neoplasias de la Lengua/etiología , Neoplasias de la Lengua/patología , Vinblastina/administración & dosificación , Vinblastina/uso terapéuticoRESUMEN
We report an unusual case of Kimura's disease. An 81-year-old Japanese woman was shown to have bilateral auricular masses that had begun to enlarge 6 years before. On CT scans, slightly high-density masses with faint contrast enhancement were seen. The masses were heterogeneous and hypointense on T1-weighted MR images, were slightly hyperintense on T2-weighted MR images, and showed heterogeneous enhancement after the administration of contrast material. Kimura's disease should be included in the differential diagnosis of bilateral auricular tumors.
Asunto(s)
Hiperplasia Angiolinfoide con Eosinofilia/diagnóstico , Enfermedades del Oído/diagnóstico , Imagen por Resonancia Magnética , Tomografía Computarizada por Rayos X , Anciano , Anciano de 80 o más Años , Diagnóstico Diferencial , Oído Externo/patología , Femenino , Humanos , Aumento de la ImagenRESUMEN
Aspergillosis of the paranasal sinus usually affects the maxillary sinus and isolated aspergillosis of the sphenoid sinus is less frequent. Aspergillosis of the paranasal sinus has been generally classified into the non-invasive type and the invasive type. There is controversy whether such difference of invasion depends on impairment of the host's immunological function or aspergillus offense factors. We report three cases of aspergillosis of the sphenoid sinus affecting individuals whose immunological states were different from each other. The prognosis among these cases was also different. These three cases suggest that the difference in the degree of aspergillus invasion may depend on the immunological state of each patient. Therefore, immediate diagnosis and therapy are very important for paranasal aspergillosis in the immunocompromised patient.
Asunto(s)
Aspergilosis/diagnóstico , Enfermedades de los Senos Paranasales/diagnóstico , Seno Esfenoidal , Anciano , Anciano de 80 o más Años , Aspergilosis/patología , Aspergilosis/terapia , Femenino , Humanos , Huésped Inmunocomprometido , Persona de Mediana Edad , Enfermedades de los Senos Paranasales/patología , Enfermedades de los Senos Paranasales/terapia , Resultado del TratamientoRESUMEN
Myotonic dystrophy (MD) is an autosomal dominant systemic disorder with an unstable expansion of the CTG triplet repeat in the 3'-untranslated region of the gene encoding myotonine protein kinase (DMPK) which maps to chromosome 19q13.3. Somatic mosaicism of CTG repeats in MD has been reported; and it has been observed that CTG repeats in tumor tissues associated with MD are more expanded than the other tissues. It is not rare that parotid tumors are found in patients with MD. We performed Southern blot analysis for tissues from the parotid tumor, the normal parotid gland, the skeletal muscles, and the leukocyte from a 60-year-old patient with MD. CTG repeat was most expanded in the parotid tumor, and the normal parotid gland had longer expansion of CTG repeat than the skeletal muscles. The leukocyte had the shortest expansion of CTG repeat. The expansion of CTG repeat in the parotid tumor may be related to active cell division and may underlie the occurrence of tumors in MD.
Asunto(s)
Adenoma Pleomórfico/genética , Mosaicismo , Distrofia Miotónica/genética , Neoplasias de la Parótida/genética , Proteínas Serina-Treonina Quinasas , Expansión de Repetición de Trinucleótido , Adenoma Pleomórfico/etiología , Cromosomas Humanos Par 19/genética , Genes Dominantes , Humanos , Masculino , Persona de Mediana Edad , Distrofia Miotónica/complicaciones , Proteína Quinasa de Distrofia Miotónica , Neoplasias de la Parótida/etiología , Proteínas Quinasas/genéticaRESUMEN
We determined the clinical characteristics of chronic sinusitis in patients with different lower respiratory tract diseases. Sinusitis was divided into three groups. The first group was sinusitis with bronchial asthma. The second group was sinusitis with chronic bronchitis, bronchiectasis or diffuse panbronchiolitis. This type of sinusitis is generally called sinobronchial syndrome (SBS). The third group was sinusitis without lower respiratory tract disease. Because the pathogenesis of these lower respiratory tract diseases differs with the diseases, the pathogenesis of sinusitis accompanied by these lower respiratory tract diseases also may be different. Clinical and laboratory examinations used in this study were rhinoscopy, X-ray examination of the paranasal sinuses, cytological study of nasal secretion and the saccharin test for the muco-ciliary function of the nasal mucosa. By rhinoscopic examination, no difference was found in the size of the nasal polyp among three groups. The results of other examinations were as follows. X-ray examination: Involvement of the ethmoid sinuses was greater than that of the maxillary sinuses in the patients with sinusitis with bronchial asthma. In contrast, involvement of the maxillary sinuses in SBS patients was greater than that of the ethmoid sinuses. Cytology of nasal secretion: Dominant inflammatory cells in the patients with sinusitis with bronchial asthma were eosinophils, while neutrophil were more frequently found in the SBS patients. Saccharin test: Most of the patients with bronchial asthma showed normal responses. In the SBS patients, however, only a few patients showed a normal response and the others showed prolonged responses. Clinical characteristics of the patients with sinusitis without lower respiratory diseases were more similar to those of the SBS patients. In conclusion, there were distinct differences in these clinical characteristics between sinusitis with bronchial asthma and SBS. These results suggest that the pathogenesis or the inflammatory process of sinusitis is heterogeneous and whether the inflammation is allergic or not may be important.
Asunto(s)
Enfermedades Respiratorias/complicaciones , Sinusitis/complicaciones , Adulto , Anciano , Asma/complicaciones , Enfermedades Bronquiales/complicaciones , Enfermedad Crónica , Humanos , Persona de Mediana EdadRESUMEN
The gene for epidermal growth factor receptor (EGFR) is associated with development of certain human cancers. In this study, we employed the improved fluorescence in situ hybridization technique to detect EGFR gene amplification in cell lines and tissue sections from human squamous cell carcinomas. We detected multiple distinct signals as arrayed amplicons on metaphase chromosomes and interphase nuclei of tumor cells. Our results provide a basis for rapid and quantitative DNA diagnosis of the EGFR gene amplification in individual cells of tumor specimens.
Asunto(s)
Carcinoma de Células Escamosas/genética , Receptores ErbB/genética , Amplificación de Genes , Mapeo Cromosómico , Humanos , Hibridación Fluorescente in Situ , Células Tumorales CultivadasRESUMEN
Extracts of Homalanthus nutans, a plant used in Samoan herbal medicine, exhibited potent activity in an in vitro, tetrazolium-based assay which detects the inhibition of the cytopathic effects of human immunodeficiency virus (HIV-1). The active constituent was identified as prostratin, a relatively polar 12-deoxyphorbol ester. Noncytotoxic concentrations of prostratin from greater than or equal to 0.1 to greater than 25 microM protected T-lymphoblastoid CEM-SS and C-8166 cells from the killing effects of HIV-1. Cytoprotective concentrations of prostratin greater than or equal to 1 microM essentially stopped virus reproduction in these cell lines, as well as in the human monocytic cell line U937 and in freshly isolated human monocyte/macrophage cultures. Prostratin bound to and activated protein kinase C in vitro in CEM-SS cells and elicited other biochemical effects typical of phorbol esters in C3H10T1/2 cells; however, the compound does not appear to be a tumor promoter. In skin of CD-1 mice, high doses of prostratin induced ornithine decarboxylase only to 25-30% of the levels induced by typical phorbol esters at doses 1/30 or less than that used for prostratin, produced kinetics of edema formation characteristic of the nonpromoting 12-deoxyphorbol 13-phenylacetate, and failed to induce the acute or chronic hyperplasias typically caused by tumor-promoting phorbols at doses of 1/100 or less than that used for prostratin.
Asunto(s)
VIH-1/efectos de los fármacos , Ésteres del Forbol/aislamiento & purificación , Plantas Medicinales/química , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Efecto Citopatogénico Viral/efectos de los fármacos , Edema/inducido químicamente , Humanos , Hiperplasia , Estado Independiente de Samoa , Espectroscopía de Resonancia Magnética , Ratones , Monocitos/efectos de los fármacos , Monocitos/microbiología , Ornitina Descarboxilasa/biosíntesis , Ésteres del Forbol/química , Ésteres del Forbol/farmacología , Proteína Quinasa C/metabolismo , Piel/efectos de los fármacos , Piel/enzimología , Piel/patología , Linfocitos T/efectos de los fármacos , Linfocitos T/microbiología , Replicación Viral/efectos de los fármacosRESUMEN
The resolution of middle ear effusions (MEE) of children with otitis media with effusion (OME) who underwent myringotomy for the bacteriological examination was analyzed in terms of the culture results and the clinical features. The present study consisted of 193 children (258 ears), and the MEE from 77 ears (30%) were culture positive and the respiratory pathogens were detected from 44 ears (17%). Each child was then assigned to receive either a more than two-week course of antibiotics, cefaclor (CCL) or not. At one month following entry, 53 (55%) out of 97 ears in CCL-treated group were effusion-free compared with 31 (40%) out of 78 ears in the control group (P less than 0.05). In the control group, the resolution of MEE was significantly poor in the recurrent cases and the cases with pathogen positive-MEE. The presence of accompanying diseases such as adenoid vegetation, chronic sinusitis and allergy, however, was not related to the resolution of MEE. On the other hand, the cure rate of the cases with pathogen positive-MEE and recurrent cases in the CCL-treated group showed significant improvement. Furthermore, the cases accompanying adenoid vegetation and chronic sinusitis tended to become effusion-free after the antibiotic treatment. Therefore, the persistent bacterial infection in the middle ear and/or surrounding organs such as adenoid plays possibly an important role in the delayed recovery of OME. Antibiotics treatment could increase, to some extent, the resolution of MEE in cases with OME.
Asunto(s)
Otitis Media con Derrame/microbiología , Adolescente , Bacterias/aislamiento & purificación , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/microbiología , Cefaclor/uso terapéutico , Niño , Preescolar , Femenino , Humanos , Lactante , Japón , Masculino , Estudios Multicéntricos como Asunto , Otitis Media con Derrame/tratamiento farmacológicoRESUMEN
Tumours of the head and neck were examined for gene amplification and expression of the epidermal growth factor (EGF) receptor by Southern blot and Western blot analyses. The EGF receptor gene was found to be amplified in four (19%) of 21 squamous cell carcinomas. The EGF receptor was overexpressed in eight (53%) of 15 squamous cell carcinomas examined, including all four tumours showing gene amplification. No amplification or overexpression of the EGF receptor gene was detected in any of nine malignant or eight benign tumours of other types of the head and neck. The tumours showing amplification and/or overexpression of the EGF receptor gene (8/15) were all identified histologically as well differentiated squamous cell carcinomas, whereas none of the histologically less differentiated squamous cell carcinomas (0/9) showed amplification and/or overexpression of the EGF receptor gene. Within our sample set, no correlation was evident between amplification and/or overexpression and the clinical stage or tumour site. Our results support the possible involvement of gene amplification and overexpression of the EGF receptor in a subclass of squamous cell carcinomas of the head and neck.
Asunto(s)
Carcinoma de Células Escamosas/genética , Receptores ErbB/genética , Amplificación de Genes , Neoplasias de Cabeza y Cuello/genética , Adulto , Anciano , Anciano de 80 o más Años , Southern Blotting , Western Blotting , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
When neutrophils were stimulated by the chemotactic peptide, fMLP, a rapid, transient increase in the activity of diacylglycerol(DG) kinase in the membrane fraction was detected. DG kinase in cytosol, on the contrary, showed a transient decrease. The total activity in homogenates was not affected. Tetradecanoylphorbol acetate(TPA) and 1-oleoyl-2-acetylglycerol(OAG) also caused an increase in DG kinase activity in the membrane fraction. Km value of DG kinase in membranes was not changed by the treatment of fMLP or TPA, though Vmax was increased. Considering these results, DG kinase may translocate from cytosol to membranes on stimulation by fMLP, TPA or OAG in neutrophils. The translocation may play important roles in regulation of protein kinase C activity, since DG kinase competes with protein kinase C for DG, which is formed by receptor-activation.
Asunto(s)
Diglicéridos/farmacología , Glicéridos/farmacología , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/enzimología , Fosfotransferasas/sangre , Acetato de Tetradecanoilforbol/farmacología , Membrana Celular/enzimología , Quimiotaxis de Leucocito , Citosol/enzimología , Diacilglicerol Quinasa , Humanos , Cinética , Neutrófilos/efectos de los fármacosRESUMEN
The interaction between prostaglandin E1 (PGE1) and chemotactic peptide formylmethionyl-leucyl-phenylalanine (fMLP) in cAMP production in guinea pig neutrophils was investigated. Both PGE1 and fMLP increased the cAMP content in neutrophils. At low concentrations of PGE1 (less than 10 nM), the effects of fMLP and PGE1 in stimulating cAMP accumulation were additive, but at high concentrations of PGE1, their effects were synergistic. The effects of PGE1 and Ca2+ ionophore A23187 instead of fMLP on cAMP accumulation were also synergistic. The synergy did not appear to be related to change in cyclic nucleotide phosphodiesterase activity, because it was still marked in the presence of isobutyl-3-methyl-1-xanthine, a phosphodiesterase inhibitor. Studies on the time course of PGE1-induced cAMP accumulation showed that cAMP production ceased within 5 min after the addition of high concentrations of PGE1. The period of cAMP production could not be prolonged by combined treatment with PGE1 and fMLP or Ca2+ ionophore A23187. The synergy was found to be caused through Ca2+-dependent processes, because depletion of the medium of Ca2+ and addition of the Ca2+ antagonist TMB-8 inhibited the synergistic increase in cAMP. Moreover, the calmodulin antagonist W-7 also effectively inhibited the synergistic increase in cAMP. These results suggest that the potentiation of PGE1-induced cAMP production by fMLP or Ca2+ ionophore A23187 is catalyzed by calmodulin-dependent processes. However, the synergistic increase in cAMP production was not inhibited by arachidonic acid cascade inhibitors such as indomethacin, BW755C, or nordihydroguiaretic acid, and a combination of PGE1 and a protein kinase C activator, tetradecanoyl phorbol acetate (TPA), did not cause synergistic increase in cAMP. Marked increase in cAMP was also induced by a combination of cholera toxin and fMLP or Ca2+ ionophore A23187, but not by a combination of forskolin and fMLP or Ca2+ ionophore A23187. The synergistic increase in cAMP was not sustained in isolated membranes. On the contrary, PGE1-induced cAMP production in isolated membranes was suppressed by their pretreatment with fMLP or Ca2+ ionophore A23187. These data suggest that the synergistic effects of PGE1 and fMLP or Ca2+ ionophore in increasing the cAMP level are due to potentiation of PGE1-induced cAMP production by Ca2+ and calmodulin-dependent processes.
Asunto(s)
Alprostadil/farmacología , Calcimicina/farmacología , Calmodulina/fisiología , AMP Cíclico/biosíntesis , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/metabolismo , 1-Metil-3-Isobutilxantina/farmacología , Adenilil Ciclasas/metabolismo , Animales , Colforsina/farmacología , Sinergismo Farmacológico , Femenino , Guanosina Trifosfato/farmacología , Cobayas , Proteínas de la Membrana/metabolismo , Neutrófilos/efectos de los fármacos , Antagonistas de Prostaglandina/farmacología , Sulfonamidas/farmacología , Acetato de Tetradecanoilforbol/farmacologíaRESUMEN
Cyclic AMP-increasing agents such as PGE2 and dibutyryl cAMP inhibited the fMLP-induced inositol phospholipids metabolism mainly through the suppression of the conversion of phosphatidylinositol(PI) to phosphatidylinositol 4,5-bisphosphate(PIP2). A part of this inhibition was found to be caused by the inhibitory effect of cAMP on PI kinase using isolated plasma membranes. On the other hand, 12-O-tetradecanoyl phorbol acetate(TPA) mainly inhibited the conversion of phosphatidylinositol 4-phosphate(PIP) to PIP2 without a significant effect on the fMLP-induced breakdown of PIP2, though direct effect of TPA on PI and PIP kinases was not demonstrated in isolated plasma membranes. Concerning Ca2+ mobilization, both cAMP-increasing agents and TPA inhibited the fMLP-induced second phase of Ca2+ elevation, while they did not affect the first phase of Ca2+ rapid increase. However, Ca2+ ionophore ionomycin-induced Ca2+ elevation was only inhibitable by TPA but not PGE2. These results suggest that cAMP inhibits the fMLP-induced Ca2+ influx, while TPA stimulates Ca2+ removal from cytosol.
Asunto(s)
Calcio/sangre , AMP Cíclico/sangre , Neutrófilos/metabolismo , Ésteres del Forbol/farmacología , Fosfatidilinositoles/sangre , Animales , Bucladesina/farmacología , Dinoprostona , Éteres/farmacología , Femenino , Cobayas , Ionomicina , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/efectos de los fármacos , Fosfatidilinositoles/metabolismo , Prostaglandinas E/farmacología , Proteínas Quinasas/metabolismoRESUMEN
The effect of prostaglandin E2 (PGE2), forskolin, and dibutyryl cAMP on arachidonic acid release, inositol phospholipid metabolism, and Ca2+ mobilization was investigated. The chemotactic tripeptide (formylmethionyl-leucyl-phenylalanine (fMLP))-induced arachidonic acid release in neutrophils was significantly inhibited by PGE2, forskolin, and dibutyryl cAMP. Among them, PGE2 was found to be the most potent inhibitor. However, when neutrophils were stimulated by Ca2+ ionophore A23187, such inhibitory effect by these agents was less marked. PGE2 also suppressed the enhanced incorporation of [32P]Pi into phosphatidic acid (PA) and phosphatidylinositol in a dose-dependent manner in fMLP-stimulated neutrophils. Also in this case, Ca2+ ionophore-induced alterations were hardly inhibited by PGE2. As well, PGE2 inhibited the fMLP-induced decrease of [3H]arachidonic acid in phosphatidylcholine and phosphatidylinositol and the increase in PA very significantly. But the inhibitory effect by PGE2 was found to be weak in Ca2+ ionophore-stimulated neutrophils. These results suggest that a certain step from receptor activation to Ca2+ influx is mainly inhibited by PGE2. Concerning polyphosphoinositide breakdown, PGE2 did not affect the fMLP-induced decrease of [32P]phosphatidylinositol 4,5-bisphosphate which occurred within 10 s but inhibited the subsequent loss of [32P]phosphatidylinositol 4-phosphate and [32P]phosphatidylinositol, suggesting that the compensatory resynthesis of phosphatidylinositol 4,5-bisphosphate was inhibited. On the other hand, fMLP-induced diacylglycerol formation was suppressed for the early period until 1 min, but with further incubation, diacylglycerol formation was rather accelerated by PGE2. Moreover, the inhibition of PA formation by PGE2 became evident after a 30-s time lag, suggesting that the conversion of diacylglycerol to PA is inhibited by PGE2. The formation of water-soluble products of inositol phospholipid degradation by phospholipase C, such as inositol phosphate, inositol 1,4-bisphosphate, and inositol 1,4,5-trisphosphate, was also suppressed by PGE2 treatment. However, the inhibition was not so marked as that of arachidonic acid release and PA formation. Thus, PGE2 appeared to inhibit not only initial events such as polyphosphoinositide breakdown but also turnover of inositol phospholipids. PGE2, forskolin, and dibutyryl cAMP did not block the rapid elevation of intracellular Ca2+ which was observed within 10 s in fMLP-stimulated neutrophils. However, subsequent increase in intracellular Ca2+ which was caused from 10 s to 3 min after stimulation was inhibited by PGE2, forskolin, and dibutyryl cAMP.(ABSTRACT TRUNCATED AT 400 WORDS)
Asunto(s)
Ácidos Araquidónicos/metabolismo , Bucladesina/farmacología , Colforsina/farmacología , Neutrófilos/efectos de los fármacos , Fosfatidilinositoles/metabolismo , Prostaglandinas E/farmacología , 4,5-dihidro-1-(3-(trifluorometil)fenil)-1H-pirazol-3-amina , Animales , Ácido Araquidónico , Calcimicina/farmacología , Catecoles/farmacología , Dinoprostona , Ácidos Grasos no Esterificados/metabolismo , Cobayas , Lisosomas/enzimología , Masoprocol , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/metabolismo , Pirazoles/farmacología , Superóxidos/metabolismoRESUMEN
When guinea pig neutrophils were stimulated with chemotactic peptide [formylmethionyl-leucyl-phenylalanine (fMLP)], a marked release of lysosomal enzyme and production of superoxide anion were detected. The breakdown of phosphatidylinositol 4,5-bisphosphate (TPI) and the subsequent formation of diacylglycerol, phosphatidic acid and free arachidonic acid also occurred during the processes. Ca2+ ionophore A23187 caused an evident secretion of lysosomal enzyme but no superoxide anion production. Ca2+ ionophore also caused TPI breakdown to diacylglycerol although this breakdown was not as significant as that detected by fMLP. The tumor promotor tetradecanoylphorbol acetate (TPA), which is a strong activator of superoxide anion production but not a good stimulator of lysosomal enzyme secretion, did not cause a significant decrease of TPI or arachidonic acid release. Since TPA is known not to increase the intracellular Ca2+ level, these results suggest that lysosomal enzyme secretion is correlated closely with enhanced inositol phospholipid metabolism and Ca2+-dependent processes. On the other hand, superoxide anion production seemed to be caused mainly by Ca2+-independent processes, perhaps by protein kinase-C activation through newly formed diacylglycerol, when neutrophils were activated by chemotactic peptide.