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1.
Acta Neurochir Suppl ; 108: 127-35, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21107949

RESUMO

Research in spine surgery has proposed new soft and less invasive techniques. These are the results of our experience with oxygen-ozone therapy, which we could experiment within the Italian National Health System over 3 years. A total of 1,920 patients were admitted on the basis of unselected enrolment because of lumbosciatic pain. Patients were divided into three groups: (A) Patients with degenerative disc disease and arthropathy: 509 (26.5%), (B) Patients with failed back surgery syndrome (FBSS): 1,027 (53.489%), and (C) Patients with pure herniated lumbar disc: 384 (20%). The rationale of the treatment for all these different pathologies we have taken into consideration is the biochemical mechanism by which they can engender pain and dysfunction. Treatment for group A: paravertebral injection and phleboclysis (two cycles of 6 sessions, one each 3 days) +endoscopic neurolysis. Treatment for group B: paravertebral injection and phleboclysis (two cycles of 6 sessions, one each 3 days) + endoscopic neurolysis with intradiscal procedure (named percutaneous peridurodiscolysis). Treatment for group C: paravertebral injection (two cycles of 6 sessions, one each 3 days) + percutaneous discolysis.The perceived quality of result for this minimally invasive procedure makes oxygen-ozone therapy an interesting weapon in the hands of doctors. Furthermore, if the technique loses its clinical effectiveness, it can be repeated without harm for the patient, and costs for the health organization are notably very low, above all if compared to surgical procedures.We underline the need that this treatment should be performed in protected structures, in operative rooms, under anesthesiologic control, and in the hands of specialists.


Assuntos
Quimiólise do Disco Intervertebral/métodos , Degeneração do Disco Intervertebral/tratamento farmacológico , Dor Lombar/tratamento farmacológico , Vértebras Lombares , Oxigênio/uso terapêutico , Ozônio/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Combinada , Endoscópios , Síndrome Pós-Laminectomia/tratamento farmacológico , Feminino , Humanos , Degeneração do Disco Intervertebral/complicações , Deslocamento do Disco Intervertebral/tratamento farmacológico , Dor Lombar/etiologia , Vértebras Lombares/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Estudos Retrospectivos , Adulto Jovem
2.
J Chemother ; 17(1): 82-5, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15828449

RESUMO

The distribution of amphotericin B in lung tissue was studied in 18 patients with primary or secondary lung cancer who underwent thoracotomy and pulmonary resection. At different times before surgery the patients were treated with liposomal amphotericin B 1.5 mg/kg by i.v. infusion over 1h. Blood and lung tissue samples were collected during surgery (one subject for each collecting time) and assayed for amphotericin B levels by HPLC. Due to surgical requirements, it was possible to obtain data from the 10th to the 25th h after the end of infusion. Plasma amphotericin B concentrations progressively decreased from 3.4 microg/ml at the 10th h to 1 microg/ml at the 25th h after the end of intravenous infusion. In lung tissue samples the lowest amphotericin B concentration (about 1 microg/g) was observed at the 10th h, then a progressive increase was observed with the highest value (2.5 microg/g) determined at the 25th h.


Assuntos
Anfotericina B/farmacocinética , Antifúngicos/farmacocinética , Neoplasias Pulmonares/metabolismo , Pulmão/metabolismo , Sarcoma/metabolismo , Adulto , Idoso , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Infusões Intravenosas , Lipossomos , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Sarcoma/cirurgia , Toracotomia
3.
J Chemother ; 16(1): 82-5, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15078004

RESUMO

Inflammation is crucial for the pathogenesis of both infectious and chronic obstructive pulmonary diseases. It is therefore important to modulate pulmonary inflammation in patients with these lung disorders. Macrolide antibiotics modulate inflammation in vitro and in in vivo by inhibiting the production of proinflammatory cytokines and prostaglandin E2, neutrophil chemotactic activity and elastase activity. This study evaluates the effect of clarithromycin (500 mg b.i.d. x 7 days) in comparison to amoxicillin (1 g t.i.d. x 7 days) in patients with community acquired pneumonia by testing plasma levels of IL-6, IFNgamma and IL-10 before starting therapy and at the 3rd and 7th days of therapy. Clarithromycin significantly decreased plasma levels of IL-6 and significantly increased those of IFNgamma and IL-10 at the 3rd and 7th day in comparison to basal levels. In patients treated with amoxicillin a significant decrease in IL-6 plasma levels was observed at the 7th day of therapy, probably in relation to the resolution of inflammatory symptoms. In the same patients IFNgamma plasma levels decreased during treatment while IL-10 plasma levels were unaffected.


Assuntos
Amoxicilina/farmacologia , Antibacterianos/farmacologia , Claritromicina/farmacologia , Interferon gama/sangue , Interleucina-10/sangue , Interleucina-6/sangue , Penicilinas/farmacologia , Pneumonia/tratamento farmacológico , Administração Oral , Adulto , Amoxicilina/administração & dosagem , Antibacterianos/administração & dosagem , Claritromicina/administração & dosagem , Infecções Comunitárias Adquiridas , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Penicilinas/administração & dosagem
4.
Int J Clin Pharmacol Res ; 23(1): 23-30, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14621070

RESUMO

The aim of the present study was to investigate the possible normalizing effect of antioxidants on certain parameters indicative of oxidative stress in Down's syndrome (DS). The study was performed in pediatric patients with DS with proven redox imbalance, who were advised to take a dietary supplementation composed of alpha-lipoic acid and L-cysteine for several treatment cycles (one treatment cycle = 30 days dietary supplementation plus 30 days wash-out). Serum thiol groups, serum total and septic reactive oxygen species (ROS) and total antioxidant status of serum were determined before and after dietary supplementation, using commercially available kits. In all the evaluable patients (n = 20), after 3.8 +/- 1.1 treatment cycles, thiol group serum concentrations and total antioxidant status of serum significantly increased (p < 0.0001 for both parameters) in comparison with basal values, while serum total and septic ROS significantly decreased (p < 0.0001 for both parameters). On the basis of these results it is impossible to demonstrate the clinical effects of the biochemical normalization obtained in patients with DS after supplying alpha-lipoic acid and L-cysteine. These data suggest that delaying the clinical expression of redox imbalance in patients with DS might be feasible by normalizing their redox balance.


Assuntos
Cisteína/uso terapêutico , Suplementos Nutricionais , Síndrome de Down/sangue , Síndrome de Down/dietoterapia , Ácido Tióctico/uso terapêutico , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/sangue
5.
J Pineal Res ; 25(3): 147-58, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9745983

RESUMO

Thirteen patients with tumors in the pineal region were submitted to pre- and post-operative blood sampling (08:00, 14:00, 20:00, and 02:00 hr) for three or four consecutive days. A single cerebrospinal fluid (CSF) sample was collected at surgery, and melatonin levels determined. In all patients, serum and CSF beta subunit of human chorionic gonadotrophin (betaHCG), carcino embryonic antigen (CEA), and alpha-fetoprotein (AFP) levels were measured. Histology revealed four pineocytomas, one pineoblastoma, four germinomas, one immature teratoma, one pilocytic astrocytoma, one lymphoma, and one meningioma. Serum and CSF levels of serological biomarkers were normal, except for one of the germinoma cases. In most patients, alteration either in the circadian rhythm or in the melatonin concentration was observed before surgery. In benign neoplasms the circadian rhythm was conserved. In pineoblastoma, lymphoma, and three out of four germinomas, melatonin concentrations were undetectable. In one case of germinoma, melatonin levels were high, with the circadian rhythm being abolished. According to conventional histology, all germinomas were similar. Therefore, in a rare case of pineal germinoma with high melatonin levels, the tissue was subjected to an in depth investigation (immunohistochemical and ultrastructural) in order to determine the pathology and the possible differences from the other typical germinomas. Results were compared to those provided from other pineal neoplasms. Electron microscopy examination detected the presence of clusters of intermediate filaments and numerous electrondense granules only in the case of a germinoma producing melatonin.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias Encefálicas/sangue , Neoplasias Encefálicas/ultraestrutura , Melatonina/sangue , Glândula Pineal/metabolismo , Glândula Pineal/ultraestrutura , Adulto , Biomarcadores Tumorais/líquido cefalorraquidiano , Neoplasias Encefálicas/líquido cefalorraquidiano , Antígeno Carcinoembrionário/sangue , Antígeno Carcinoembrionário/líquido cefalorraquidiano , Criança , Gonadotropina Coriônica Humana Subunidade beta/sangue , Gonadotropina Coriônica Humana Subunidade beta/líquido cefalorraquidiano , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , Melatonina/líquido cefalorraquidiano , Pessoa de Meia-Idade , Radioimunoensaio , alfa-Fetoproteínas/líquido cefalorraquidiano , alfa-Fetoproteínas/metabolismo
6.
Biol Signals Recept ; 7(1): 61-72, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9641799

RESUMO

The most studied endocrine product of the pineal gland, melatonin, has been reported to be involved in the feedback between neuroendocrine and immune functions and to exert oncostatic action, at least in certain experimental conditions. Melatonin seems to be an integral part of the immune system, by exerting direct and/or indirect stimulatory effects on both cellular and humoral immunity. Likewise, an antitumor activity of melatonin has been shown in several experimental models in vivo and in vitro. The means by which melatonin exerts its effects on immunity and neoplastic growth have not been elucidated. The different putative mechanisms of action of melatonin investigated so far are here briefly discussed.


Assuntos
Imunidade/fisiologia , Melatonina/fisiologia , Neoplasias/fisiopatologia , Adjuvantes Imunológicos/fisiologia , Animais , Humanos , Melatonina/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos
7.
Biol Signals ; 7(1): 61-72, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9588327

RESUMO

The most studied endocrine product of the pineal gland, melatonin, has been reported to be involved in the feedback between neuroendocrine and immune functions and to exert oncostatic action, at least in certain experimental conditions. Melatonin seems to be an integral part of the immune system, by exerting direct and/or indirect stimulatory effects on both cellular and humoral immunity. Likewise, an antitumor activity of melatonin has been shown in several experimental models in vivo and in vitro. The means by which melatonin exerts its effects on immunity and neoplastic growth have not been elucidated. The different putative mechanisms of action of melatonin investigated so far are here briefly discussed.

8.
J Clin Oncol ; 15(6): 2467-73, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9196163

RESUMO

PURPOSE: To compare, in a double-blind, placebo-controlled, randomized trial, the efficacy of two different doses of the depot formulation of adrenocorticotropic hormone (ACTH) in controlling delayed emesis after cisplatin. PATIENTS AND METHODS: One hundred fifty-two patients were enrolled onto the study. On day 1, all patients received cisplatin (60 to 120 mg/m2) and a combination of dexamethasone 20 mg plus ondansetron or metoclopramide to prevent acute emesis. On day 2 (24 hours after cisplatin administration), patients were randomized to receive placebo, or ACTH 1 mg intramuscularly (I.M.), or ACTH 2 mg I.M. plus one additional dose of 1 mg on day 4. Details of vomiting, nausea, and adverse effects were recorded daily for every 24-hour period from day 2 to day 6. In a subset of patients, serum cortisol levels were measured between 20 and 72 hours after cisplatin administration. RESULTS: One hundred fifty patients were assessable. Over the 5 days of the study, delayed vomiting occurred less frequently in the patients treated with ACTH 2 mg plus 1 mg than in those treated with ACTH 1 mg or placebo (28%, 38%, and 65%, respectively; P = .001). The greatest observed differences were seen on days 2 (24 to 48 hours; P = .01) and 3 (48 to 72 hours; P = .01). On days 4, 5, and 6 (96 to 144 hours), no significant differences were observed among the three arms. The severity of delayed emesis expressed as the mean number of emetic episodes per day was 0.48, 0.70, and 0.80, respectively (P = .002). Patients treated with the higher dose of ACTH had the least nausea on day 3 (P = .02) and day 4 (P = .03). Adrenal cortisol secretion rapidly increased after ACTH injection, but was suppressed for approximately 44 hours in the placebo group. Toxicity was mild and transient in all groups. CONCLUSION: ACTH reduces the incidence and severity of delayed vomiting and nausea after cisplatin. A dose of 2 mg 24 hours after cisplatin is better than one of 1 mg. Whether the activity of ACTH is mediated only by adrenal corticosteroids needs to be verified.


Assuntos
Hormônio Adrenocorticotrópico/administração & dosagem , Antineoplásicos/efeitos adversos , Cisplatino/efeitos adversos , Neoplasias/tratamento farmacológico , Vômito/prevenção & controle , Adulto , Idoso , Antieméticos/uso terapêutico , Preparações de Ação Retardada , Dexametasona/uso terapêutico , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vômito/induzido quimicamente
9.
J Med Chem ; 40(13): 1990-2002, 1997 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-9207940

RESUMO

The design, synthesis, and biological profile of several indole melatonin analogues with a conformationally restricted C3 amidoethane side chain are presented. Examination of the accessible conformations of the melatonin side chain led us to explore some of its fully or partially restricted analogues, 2-12, the binding affinity values of which were utilized to gain further insight on the melatonin binding site. Two pharmacophoric models have been devised for melatonin and the active compounds by conformational analysis and superimposition performed using the DISCO program. In these models, the melatonin side chain can adopt a gauche/anti conformation out of the indole plane. Another contribution of this study regards the observation of a possible binding point interaction around the C2 position of the indole, as suggested by the remarkably increased binding affinity observed in the C2-substituted analogues 6 and 9 and especially in the more rigid analogue 5. The biological activity and the efficacy of the new compounds were tested by measuring the inhibition of the forskolin-stimulated cAMP accumulation and the GTP gamma S index. Both analyses demonstrated that all of the compounds were full agonists with the exception of 4 and 9, which showed a slight reduction in efficacy and would seem to be partial agonists.


Assuntos
Melatonina/análogos & derivados , Receptores de Superfície Celular/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Ligação Competitiva , Galinhas , Colforsina/farmacologia , AMP Cíclico/metabolismo , Desenho de Fármacos , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Melatonina/síntese química , Melatonina/metabolismo , Melatonina/farmacologia , Modelos Moleculares , Codorniz , Receptores de Melatonina , Colículos Superiores/efeitos dos fármacos , Colículos Superiores/metabolismo
10.
J Med Chem ; 40(13): 2003-10, 1997 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-9207941

RESUMO

A new series of indole melatonin analogues, bearing the amido ethyl side chain attached at the N-1 position of the indole nucleus, were synthesized and tested for their affinity for the melatonin receptor isolated from quail optic tecta in a series of in vitro ligand-binding experiments using 2-[125I]iodomelatonin as the labeled ligand. The biological activity was evaluated using two models: effects on the forskolin-stimulated cAMP accumulation in explants from quail optic tecta and evaluation of the GTP gamma S index derived from competition experiments performed in the absence or presence of GTP gamma S. Compounds 2a and 2k-n, obtained by shifting the methoxy group and the ethylamido side chain from the C-5 and C-3 positions of melatonin to the C-6 and N-1 positions of the indole nucleus, exhibited an affinity similar to that of melatonin itself, as well as full agonist activity. Optimization of the C-2 substituent by introducing Br, phenyl, or COOCH3 (2b-d) resulted in a significantly enhanced affinity (in the picomolar range) and improved agonist biological activity. Compounds lacking the methoxy group and bearing an N-alicyclic group (2h-j) behaved as partial agonists or antagonists.


Assuntos
Indóis/síntese química , Melatonina/análogos & derivados , Animais , Sítios de Ligação , Ligação Competitiva , Galinhas , Colforsina/farmacologia , AMP Cíclico/metabolismo , Desenho de Fármacos , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Indóis/farmacologia , Melatonina/síntese química , Melatonina/farmacologia , Modelos Químicos , Codorniz , Colículos Superiores/efeitos dos fármacos , Colículos Superiores/metabolismo
11.
Nephrol Dial Transplant ; 11 Suppl 9: 31-3, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9050032

RESUMO

Ageing brings about an impairment of all body functions. Any antimicrobial and oncological treatment must take into account the senescent condition of the patient. Aged people are considered an immunodepressed population and oncotherapy has envisaged the use of components of the immune system. Our hope is to dispose shortly such neuroimmunomodulators as to be able to activate the impaired immune system which is present in the elderly.


Assuntos
Adjuvantes Imunológicos/farmacologia , Envelhecimento/imunologia , Humanos , Interferons/farmacologia , Interleucina-2/farmacologia , Melatonina/farmacologia
12.
Ann Oncol ; 7(1): 99-102, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9081401

RESUMO

PURPOSE: To evaluate the endocrine effects as well as the pharmacokinetic parameters, efficacy and safety of letrozole, a new fourth-generation non-steroidal aromatase inhibitor. PATIENTS AND METHODS: Fourteen postmenopausal women with progressive metastatic breast cancer, previously treated with endocrine therapy and/or chemotherapy for advanced disease, were treated with 0.5 mg daily doses of letrozole, orally. Endocrine and pharmacokinetic measurements were made before treatment and on days 14, 28, 56, and 84 of therapy. RESULTS: Letrozole induced a >86% decrease in plasma estrone and a approximately 67% reduction in circulating estradiol from day 14 on. There was a statistically significant decrease in plasma cortisol, which appeared clinically irrelevant since all values remained within the normal range. No significant changes in aldosterone concentration were noted. One patient achieved a complete response (CR) and 4 patients a partial response (PR), with an objective response rate of 36% (95% CI 13% to 65%). Median duration of response was 24 months, ranging from 4 to 44 months. No toxic effects attributable to letrozole were noted in any patient. CONCLUSION: Letrozole appears to be a very promising new antiaromatase drug. The characteristics of the patients more likely to respond, taking into account prior systemic treatment, should be defined by future studies. Further phase II and phase III studies comparing letrozole to other available second or even first-line endocrine-therapy agents, are warranted.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Nitrilas/uso terapêutico , Triazóis/uso terapêutico , Adulto , Idoso , Aldosterona/sangue , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Inibidores da Aromatase , Neoplasias da Mama/sangue , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/farmacocinética , Estradiol/sangue , Estrona/sangue , Feminino , Humanos , Hidrocortisona/sangue , Letrozol , Pessoa de Meia-Idade , Nitrilas/efeitos adversos , Nitrilas/farmacocinética , Projetos Piloto , Triazóis/efeitos adversos , Triazóis/farmacocinética
13.
Eur J Endocrinol ; 131(2): 191-200, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8075790

RESUMO

Dogs kept under controlled photoperiodic conditions of 12 h light and 12 h dark expressed a clear diurnal melatonin rhythm in the peripheral blood, with a swift peak restricted to the late part of the scotophase. The highest density of high-affinity, G-protein-linked 2-[125I]iodomelatonin binding sites was found in the pars tuberalis of the pituitary gland. Binding sites were found also in the pars distalis, and light microscopy/high-resolution autoradiography showed that binding was located exclusively over the chromophobe and basophilic cells forming the adenopituitary zona tuberalis, well developed in this species, and extending into the gland as a continuation of pars tuberalis. Cords of basophilic cells located in the pars distalis proper also expressed high receptor density. The eosinophils in the adenohypophysis and the neural lobe were devoid of binding. Heavily labeled were the external laminar and the mitral cell layers of the olfactory bulbs, but no binding was detected in the filae nervi olfactorii or tractus olfactorius. The hypothalamic suprachiasmatic nuclei were discernible clearly. Quantitative autoradiography inhibition experiments revealed that the apparent melatonin inhibitory constant (IC50) in all those areas was around 0.1 nmol/l, which is a physiologically appropriate value considering the peripheral blood melatonin levels. Co-incubation with guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) led to a consequential decrease in the binding density. The specific binding observed in other areas (hippocampus, frontal, parietal, occipital cortex and cerebellum) was rather weak, diffuse and could not be attributed to a particular layer; the apparent IC50 for melatonin was about 1 mumol/l, and co-incubation with GTP gamma S did not modify the binding density. Collectively, these data show that the dog possess all the prerequisites for an efficient network adapted to photoperiodic time measurements. A circadian melatonin signal in the peripheral blood and an apparently functional readout receptor system located in key positions within the brain are both present in this species.


Assuntos
Encéfalo/metabolismo , Carnívoros/metabolismo , Ritmo Circadiano , Melatonina/sangue , Receptores de Superfície Celular/metabolismo , Animais , Autorradiografia , Cães , Feminino , Masculino , Receptores de Melatonina
14.
Chemotherapy ; 40(3): 215-20, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7515782

RESUMO

Microbial adherence to epithelial cell surfaces has been implicated as the first step in the initiation of several infectious diseases. The ability of antibiotics to affect the properties of bacterial adherence to cell surfaces may be a criterion in selecting antibiotics for therapy. This study was performed in order to investigate the activity of amoxicillin, chloramphenicol, and clarithromycin in modifying the adhering activity of Bordetella pertussis to human epithelial cells. The actions of antibiotics, alone or combined with aprotinin, were compared with that of trypsin, aprotinin and trypsin+aprotinin, to investigate the chemical nature of the ligand where antibiotics could act. The adhering activity was evaluated on human epithelial cells, collected from the oral mucosa, challenged with B. pertussis A2963 previously incubated in the presence of the tested substances for 1 h at 37 degrees C in a shaker incubator. After staining, the percentage of mucosal cells with more than 50 adhering bacteria was evaluated. Under the described experimental conditions, trypsin significantly reduced the adherence of B. pertussis. Aprotinin had no effect but was able to counteract the inhibitory action of trypsin. Both clarithromycin and chloramphenicol markedly reduced adhering activity and their actions were not counteracted by aprotinin. Amoxicillin was without effect. It was hypothesized that chloramphenicol and clarithromycin, exerting their antimicrobial action by inhibiting bacterial protein synthesis, affected bacterial adhesion through an unknown mechanism without proteolytic effect.


Assuntos
Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Bordetella pertussis/efeitos dos fármacos , Mucosa Bucal/microbiologia , Amoxicilina/farmacologia , Aprotinina/farmacologia , Bordetella pertussis/fisiologia , Cloranfenicol/farmacologia , Claritromicina/farmacologia , Células Epiteliais , Epitélio/microbiologia , Humanos , Mucosa Bucal/citologia
15.
Chronobiologia ; 21(1-2): 89-92, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7924644

RESUMO

Currently, the melatonin receptor is depicted as a membrane-associated protein, linked to a guanine nucleotide-binding protein (G-protein), and thus the melatonin receptor represents a member of a receptor superfamily, acting through G-proteins in the first step of their signal-transduction pathways. Although on a number of occasions specific binding of radioactive melatonin has been demonstrated in a wide variety of tissues and organs, to date, high affinity G-protein-regulated melatonin binding sites, suggestive for a functional melatonin receptor, have been convincingly confirmed in the brain only. There is a significant species variation in the distribution of the melatonin receptor in the vertebrate brain. The limited number of studies prevents any definitive conclusion in terms of phylogeny, though generally speaking, the lower vertebrates' brains tend to express melatonin receptors with wider distribution. Two sites have been consistently found to express high density of melatonin receptors: the pars tuberalis of the adenohypophysis and the hypothalamic suprachiasmatic nuclei (SCN). It must be pointed out, however, that there are some exceptions. Binding in the human pars tuberalis has not been reported, and apparently, the sheep and the mustelids' suprachiasmatic nuclei do not express detectable binding. The function of melatonin in pars tuberalis is unclear, and the control of the synthesis (and release) of paracrine factors that act at site(s) distant from the melatonin target cells, have been suggested.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Relógios Biológicos/fisiologia , Receptores de Superfície Celular/metabolismo , Animais , Encéfalo/metabolismo , Humanos , Lobo Parietal/metabolismo , Coelhos , Receptores de Melatonina
16.
Chemotherapy ; 39(6): 416-23, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8222870

RESUMO

An in vitro infection model was created using a suspension of macrophages, polymorphonuclear leukocytes, lymphocytes, fibroblasts, and human serum to which pathogen and antibiotic were added. Separate intracellular and extracellular antibiotic concentrations and activity against Staphylococcus aureus and Legionella pneumophila were assessed for three antimicrobial agents: amoxicillin, azithromycin and clarithromycin. Amoxicillin was found almost exclusively in extracellular fluid, where it was active; intracellularly, it was ineffective. Azithromycin, in contrast, was primarily concentrated and active intracellularly, with little activity in extracellular fluid. Clarithromycin was present in both compartments and possessed significant activity both intracellularly and extracellularly.


Assuntos
Amoxicilina/farmacologia , Azitromicina/farmacologia , Infecções Bacterianas , Claritromicina/farmacologia , Espaço Extracelular/química , Líquido Intracelular/química , Modelos Biológicos , Fibroblastos/microbiologia , Humanos , Legionella pneumophila/efeitos dos fármacos , Leucócitos/microbiologia , Linfócitos/microbiologia , Macrófagos/microbiologia , Testes de Sensibilidade Microbiana , Neutrófilos/microbiologia , Staphylococcus aureus/efeitos dos fármacos
17.
Arzneimittelforschung ; 43(9): 986-8, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8240464

RESUMO

The kinetics and bioavailability of a new formulation of metoclopramide (CAS 364-62-5) nasal spray (MTC NS) were assessed in two separate studies versus the same drug administered intravenously (MTC IV) according to a balanced-block design where each study subject served as his own control. The first study involved 10 healthy subjects, each receiving metoclopramide NS 20 mg (one 10-mg puff per nostril) and metoclopramide IV 20 mg on two trial days separated by a 7-day washout period. On both occasions, blood samples were obtained at time 0 and at 20, 40, 60, 120, 150, 210, 280 and 360 min of dosing. Metoclopramide concentrations were assayed in plasma by HPLC. The second study involved 10 patients of oncologic domain, scheduled to receive mildly emetic chemotherapy regimes. The experimental design was similar to the one above except that blood was sampled at 0, 20, 40 and 60 min and again at 2, 3, 4, 6, and 8 h of dosing. All healthy subjects completed the trial without experiencing any adverse or untoward events; in the group of cancer patients, one subject dropped out after the nose spray treatment when he was removed to another department. This patient was replaced by another, and included in final data analysis only for the segment of treatment actually received. Metoclopramide kinetics after intravenous dosing were in good agreement with known data for the active substance, with no meaningful differences between healthy subjects and cancer patients. With MTC NS administration there was only a slight but significant difference of Cmax, being lower in the cancer patient group (p < 005).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Metoclopramida/farmacocinética , Neoplasias/metabolismo , Administração Intranasal , Adolescente , Adulto , Aerossóis , Idoso , Disponibilidade Biológica , Humanos , Injeções Intravenosas , Metoclopramida/administração & dosagem , Pessoa de Meia-Idade , Neoplasias/complicações
18.
Neurosci Lett ; 156(1-2): 131-4, 1993 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-8414175

RESUMO

The existence and subunit identification of the nicotinic cholinergic receptors in the rat pineal gland were examined by autoradiography, using [3H]cytisine and [125I]alpha-bungarotoxin as labelled ligands. The experiments performed with radioactive cytisine did not reveal specific binding, while iodinated alpha-bungarotoxin disclosed moderate specific binding density, suggesting that the nicotinic cholinergic receptor in the rat pineal is structurally organized with the alpha 7 or alpha 8 subunits present, the only ones that bind alpha-bungarotoxin with high affinity. In vitro functional experiments using pineal explants demonstrated that the binding site may represent a readily accessible nicotinic cholinergic receptor. Nicotine, though having no effect per se on the synthesis and release of melatonin, significantly diminished, in a dose-dependent manner, the norepinephrine-stimulated melatonin accumulation. This effect could be blocked by coincubation with the cholinergic antagonist d-tubocurarine, suggesting that the nicotinic cholinergic receptor in the rat pineal could be involved in the functional regulation of the gland.


Assuntos
Melatonina/metabolismo , Nicotina/farmacologia , Norepinefrina/farmacologia , Glândula Pineal/metabolismo , Receptores Nicotínicos/fisiologia , Tubocurarina/farmacologia , Alcaloides/metabolismo , Animais , Azocinas , Bungarotoxinas/metabolismo , Radioisótopos do Iodo , Masculino , Técnicas de Cultura de Órgãos , Quinolizinas , Ratos , Ratos Sprague-Dawley , Receptores Nicotínicos/análise , Receptores Nicotínicos/metabolismo , Valores de Referência , Maturidade Sexual
19.
Endocrinology ; 130(4): 2152-9, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1312448

RESUMO

The cortex of the rabbit (Oryctolagus cuniculus) is rich in melatonin binding sites, and particularly abundant is the parietal cortex. Consequently, we characterized the putative melatonin receptor in the parietal cortex by a series of in vitro ligand-receptor binding experiments and biochemical and electrophysiological studies. The in vitro saturation and competition experiments demonstrated that the binding in the crude cortical membrane preparations was of high affinity and specificity. Guanine nucleotides (GDP, GTP, and GTP gamma S) inhibited the specific 2-[125I]iodomelatonin binding in a dose-dependent manner. Coincubation with a nonhydrolyzable GTP analog provoked a shift in the binding affinity; the numerical values of the Kd increased from 20-30 to 200-600 pM. Melatonin, in nanomolar concentrations, was able to inhibit the forskolin-stimulated accumulation of cAMP in parietal cortex explants, and preincubation with pertussis toxin counteracted this effect of melatonin. Apparently, the melatonin binding site in the rabbit parietal cortex is linked to its second messenger via a pertussis toxin-sensitive G-protein, probably of the inhibitory Gi class, similar to what has been described for different parts of the brain of other vertebrates. The experiments on the spontaneous firing activity of single neurons in the third to fourth layer of the parietal cortex in anesthetized animals showed that melatonin and its potent agonist 2-iodomelatonin exhibited gamma-aminobutyric acid (GABA)-like effects and were able alone, in nanomolar concentrations, to significantly slow the neuronal firing activity. Moreover, both melatonin and 2-iodomelatonin potentiated the effect of GABA on the neuronal activity, leading to powerful inhibition of the tested neurons. Undoubtedly, the binding site in the rabbit parietal cortex possesses all of the characteristics of a functional receptor. We suggest that melatonin is involved in the control of fundamental cortical functions and that it acts in concert with GABA, one of the two major inhibitory neurotransmitters in the central nervous system.


Assuntos
Melatonina/metabolismo , Lobo Parietal/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Sítios de Ligação , AMP Cíclico/metabolismo , Técnicas In Vitro , Masculino , Melatonina/análogos & derivados , Melatonina/farmacologia , Lobo Parietal/efeitos dos fármacos , Toxina Pertussis , Coelhos , Receptores de GABA-A/efeitos dos fármacos , Receptores de Melatonina , Receptores de Neurotransmissores/análise , Fatores de Virulência de Bordetella/farmacologia , Ácido gama-Aminobutírico/farmacologia
20.
Minerva Endocrinol ; 16(3): 127-39, 1991.
Artigo em Italiano | MEDLINE | ID: mdl-1806810

RESUMO

In 51 patients with gastric adenocarcinoma the fasting blood concentrations of hCG, beta hCG, alpha subunits, ADH, calcitonin, enteroglucagon, gastrin, GH, melatonin, somatostatin, estradiol, CEA and pepsinogen I in the peripheral vein were estimated by radioimmunoassay at the time of diagnosis and, in those who underwent surgery, 7 days after the operation, to determine the incidence of the modifications of the above mentioned substances' blood levels and the existence of possible markers. In presence of increases of the examined parameters greater than 50%, considering M +/- 2 SD of 10 control subjects as normal range, the tumours were examined immunohistochemically. In patients with gastric adenocarcinoma, in comparison with normal subjects, we found significant higher blood levels of hCG alpha subunits, gastrin and CEA and lower of melatonin, pepsinogen I and GH. The immunohistological results demonstrated CEA in both examined cases, alpha subunits in 2 of 6 (respectively in dysplasic areas and in surrounding non neoplastic mucosa) and enteroglucagon in 1 of 3 (dysplasic areas). Our results indicate that none of the parameters we examined, because of their non-specificity or of the low incidence of their modifications, can be considered a marker of gastric adenocarcinoma.


Assuntos
Adenocarcinoma/sangue , Biomarcadores Tumorais/análise , Hormônios/análise , Proteínas de Neoplasias/análise , Neoplasias Gástricas/sangue , Adenocarcinoma/química , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígeno Carcinoembrionário/análise , Gonadotropina Coriônica/análise , Feminino , Mucosa Gástrica/química , Mucosa Gástrica/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Neoplasias Gástricas/química , Neoplasias Gástricas/patologia
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