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1.
Osteoporos Int ; 28(4): 1385-1392, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28012019

RESUMO

Bone status impairment represents a complication of generalized forms of epidermolysis bullosa (EB); however, the prevalence and the main determinants of this event in localized forms remain poorly defined. Birmingham epidermolysis bullosa severity (BEBS) score and 25-hydroxyvitamin D levels are strongly associated with low bone mass, suggesting that vitamin D may play a potential beneficial role in bone health. Further longitudinal studies are needed in order to confirm this hypothesis. INTRODUCTION: Bone status impairment represents a complication of generalized forms of EB; thus, we aimed to estimate the prevalence of low bone mass, to examine mineralization differences in various EB subtypes and to identify the most important determinants of bone impairment in children with either generalized or localized EB. METHODS: An observational study of 20 children (11 males; mean age ± standard deviation, 11.7 ± 3.9 years) with EB was performed. Clinical history, physical examination, laboratory studies, X-ray of the left hand and wrist for bone age, and dual energy X-ray absorptiometry scans of the lumbar spine were obtained. Areal bone mineral density (aBMD Z-scores) and bone mineral apparent density were related to the BEBS score. RESULTS: Areal BMD Z-score (mean -1.82 ± 2.33, range, -7.6-1.7) was reduced (<-2 SD) in 8 patients (40%), whereas aBMD Z-score adjusted for bone age was low in 7 patients (35%). BEBS score and 25-hydroxyvitamin D serum levels were the most important elements associated with aBMD (P = 0.0001 and P = 0.016, respectively). A significant correlation between the aBMD Z-score and area of skin damage, insulin-like growth factor-1, C-reactive protein, and sodium serum levels was also found. CONCLUSIONS: Low aBMD can be considered a systemic complication of EB, primarily associated with BEBS score and 25-hydroxyvitamin D levels. Therefore, longitudinal evaluation of bone status is ongoing in these patients to define whether vitamin D supplementation would prevent, or at least reduce, bone status impairment.


Assuntos
Epidermólise Bolhosa/complicações , Osteoporose/etiologia , Vitamina D/análogos & derivados , Absorciometria de Fóton , Adolescente , Densidade Óssea/fisiologia , Criança , Epidermólise Bolhosa/sangue , Epidermólise Bolhosa/patologia , Epidermólise Bolhosa/fisiopatologia , Feminino , Humanos , Imobilização , Vértebras Lombares/fisiopatologia , Masculino , Osteoporose/sangue , Osteoporose/fisiopatologia , Índice de Gravidade de Doença , Pele/patologia , Vitamina D/sangue
2.
J Endocrinol Invest ; 38(4): 413-20, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25330765

RESUMO

PURPOSE: Adult patients operated for craniopharyngioma develop more frequently GH deficiency (GHD) than patients operated for non-functioning pituitary adenoma (NFPA). The aim of the study was to compare both short- (1 year) and long-term (5 years) effects of rhGH in 38 GHD adult patients (19 operated for Craniopharyngioma (CP) and 19 for NFPA). METHODS: IGF-I levels, body composition (BF%), BMI, lipid profile and glucose homeostasis were evaluated in all patients. Pituitary MRI was performed at baseline and during follow-up, as needed. RESULTS: At baseline no difference between the two groups was observed, apart from a higher prevalence of diabetes insipidus in CP patients (79 vs 21%). After 12 months, IGF-I SDS normalized and BF% significantly decreased only in the NFPA group. During long-term treatment, decrease in BF% and improvement in lipid profile shown by reduction in total- and LDL-cholesterol were present in NFPA group only, while increase in insulin levels and HbA1c and decrease of QUICKI were observed in CP patients only. Accordingly, after long-term therapy, the prevalence of metabolic syndrome (MS) was significantly higher in CP than in NFPA group (37% in CP and in 5% in NFPA group; p < 0.05). CONCLUSION: The present data suggest that CP patients are less sensitive to the positive rhGH effects on lipid profile and BF% and more prone to insulin sensitivity worsening than NFPA patients, resulting in increased prevalence of MS in CP only.


Assuntos
Adenoma/sangue , Adenoma/metabolismo , Craniofaringioma/sangue , Terapia de Reposição Hormonal , Hormônio do Crescimento Humano/farmacologia , Síndrome Metabólica/sangue , Neoplasias Hipofisárias/sangue , Adenoma/tratamento farmacológico , Adenoma/cirurgia , Adulto , Craniofaringioma/tratamento farmacológico , Craniofaringioma/cirurgia , Feminino , Hormônio do Crescimento Humano/administração & dosagem , Hormônio do Crescimento Humano/deficiência , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/tratamento farmacológico , Neoplasias Hipofisárias/cirurgia , Adulto Jovem
3.
Nutr Metab Cardiovasc Dis ; 23(5): 459-65, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22118958

RESUMO

BACKGROUND AND AIM: Growth Hormone Deficiency (GHD) is characterized by increased visceral fat accumulation. Echocardiographic epicardial fat thickness is a new marker of visceral adiposity. Aim of the present study was to evaluate whether epicardial fat thickness can significantly change and therefore serve as a marker of visceral fat reduction after short-term rhGH replacement therapy in patients with adult-onset GHD. METHODS AND RESULTS: Echocardiographic epicardial fat thickness was measured in 18 patients (10 M, 8 F, age 48 ± 11.8 yrs, BMI 29 ± 5.9 kg/m(2)) with adult-onset GHD, at baseline and after 6 and 12 months of rhGH therapy and in 18 healthy matched controls, at baseline. Echocardiographic epicardial fat thickness, conventional anthropometric and metabolic parameters, body fat percentage and quality of life were also evaluated. Epicardial fat thickness in adult GHD patients was higher than in controls (9.8 ± 2.8 vs 8 ± 3 mm, p < 0.05). Epicardial fat thickness significantly decreased after 6-months of rhGH replacement therapy (from 9.8 ± 2.8 to 7.0 ± 2.3 mm, P < 0.01, i.e. -29% from baseline). After 12 months of rhGH replacement therapy, epicardial fat thickness showed a further significant decrease (from 7.0 ± 2.3 to 5.9 ± 3.1 mm, P < 0.01, i.e. -40% from baseline). No significant changes in BMI or waist circumference after 6 or 12 months of rhGH therapy were observed. CONCLUSIONS: Echocardiographic epicardial fat thickness may represent a valuable and easy marker of visceral fat and visceral fat changes during rhGH replacement treatment in patients with adult-onset growth hormone deficiency.


Assuntos
Nanismo Hipofisário/tratamento farmacológico , Terapia de Reposição Hormonal , Hormônio do Crescimento Humano/deficiência , Hormônio do Crescimento Humano/uso terapêutico , Pericárdio/metabolismo , Adiposidade , Adulto , Índice de Massa Corporal , Nanismo Hipofisário/complicações , Ecocardiografia , Feminino , Humanos , Fator de Crescimento Insulin-Like I/uso terapêutico , Gordura Intra-Abdominal/diagnóstico por imagem , Gordura Intra-Abdominal/metabolismo , Masculino , Pessoa de Meia-Idade , Obesidade/diagnóstico por imagem , Obesidade/tratamento farmacológico , Obesidade/etiologia , Qualidade de Vida
4.
Horm Metab Res ; 42(1): 45-9, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19813164

RESUMO

The aim of this study was to evaluate GH/IGF-I axis and other pituitary functions in adult patients with coeliac disease. For this purpose, twenty-eight adult coeliac patients [20M, 8F:19-74 years; body mass index (BMI): 18.5-28 kg/m (2)] were recruited. Basal thyroid, adrenal and gonadal function, serum IGF-I and PRL, and routine parameters were evaluated. Dynamic GH secretion was carried out by GHRH plus arginine test. In 20 patients, antipituitary antibodies (APA) were also evaluated. Seven out of 28 patients, independently from disease onset and the gluten-free diet (GFD), showed an impaired GH secretion (25%). All were males, 2 with severe growth hormone deficiency (GHD) and 5 with partial GHD. In patients with GHD, as compared to coeliac patients with normal GH secretion, HOMA (2.1+/-1.2 vs. 0.9+/-0.4) and QUICKI (0.35+/-0.03 vs. 0.39+/-0.02) levels were significantly higher and lower, respectively, while IGF-I levels were slightly lower (17.7+/-3.7 vs. 24.7+/-6.3, p=NS). APA were negative in all 20 patients studied. In conclusion, a significant number of adult coeliac patients show an impaired GH secretion, this alteration being predominant in males and independent from disease onset and diet regimen. Given the absence of APAs, the cause of this pituitary dysfunction remains unclear even if a previous autoimmune involvement in some cases cannot be excluded.


Assuntos
Doença Celíaca/metabolismo , Hormônio do Crescimento Humano/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Adulto , Idoso , Doença Celíaca/sangue , Hormônio do Crescimento Humano/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Hipófise/metabolismo , Adulto Jovem
5.
Pituitary ; 13(3): 289-92, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18946740

RESUMO

In this report we emphasize the opportunity of considering the uncommon causes of chronic GH-excess in the initial diagnostic process, such as GHRH hypersecretion, especially in the presence of ambiguous pituitary neuroimaging. This topic may have an important clinical significance in order to plan the most cost-effective diagnostic procedures and management and to avoid unnecessary pituitary neurosurgery.


Assuntos
Acromegalia/diagnóstico , Neoplasias Brônquicas/diagnóstico , Tumor Carcinoide/diagnóstico , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Neoplasias Hipofisárias/diagnóstico , Feminino , Humanos , Pessoa de Meia-Idade
6.
Clin Endocrinol (Oxf) ; 69(4): 608-12, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18410544

RESUMO

OBJECTIVE: Long-term effects of trans-naso-sphenoidal surgery (TNS) or long-acting somatostatin analogs (SSA) on the function of hypothalamic-pituitary-adrenal (HPA) axis have been poorly investigated. Aim of this study was to evaluate HPA axis integrity during the follow-up in patients with GH-secreting pituitary adenomas and preserved HPA function post-TNS or prior SSA. DESIGN AND PATIENTS: This retrospective study investigated 36 acromegalic patients (16M and 20F, age: 47 +/- 13 years), 20 of whom cured by TNS and 16 controlled by SSA therapy (12 previously operated and 4 in primary medical therapy), before and after long-term follow-up (median: 72 months, range: 12-240). No patient previously underwent radiotherapy. MEASUREMENTS: HPA function was studied by morning circulating cortisol and ACTH levels, 24-h urinary free cortisol (UFC) and cortisol response to low-dose short Synacthen test (LDSST, 1 microg) with a peak > 500 nmol/l as cut-off for normal function. RESULTS: Serum basal cortisol, ACTH and UFC levels were in the normal range and did not significantly change over time. As far as the cortisol peak after LDSST is concerned, 12 patients (32%, 8 TNS and 4 SSA) developed biochemical hypoadrenalism. None of the patients in primary medical therapy showed cortisol peak < 500 nmol/l. No significant correlations between HPA axis deterioration and follow-up duration, serum GH/IGF-I levels, occurrence of other pituitary deficiencies, presence of secondary empty sella, changes in tumour or residual volume were observed. CONCLUSIONS: The HPA axis function must be carefully monitored over the time by dynamic testing in all acromegalic patients, independently from the type of treatment.


Assuntos
Acromegalia/fisiopatologia , Sistema Hipotálamo-Hipofisário/fisiologia , Sistema Hipófise-Suprarrenal/fisiologia , Acromegalia/metabolismo , Acromegalia/reabilitação , Acromegalia/terapia , Adenoma/tratamento farmacológico , Adenoma/metabolismo , Adenoma/fisiopatologia , Hormônio Adrenocorticotrópico/sangue , Hormônio Adrenocorticotrópico/metabolismo , Adulto , Idoso , Metabolismo Basal/fisiologia , Preparações de Ação Retardada , Progressão da Doença , Feminino , Seguimentos , Humanos , Hidrocortisona/sangue , Hidrocortisona/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/tratamento farmacológico , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/fisiopatologia , Sistema Hipófise-Suprarrenal/metabolismo , Estudos Retrospectivos , Somatostatina/administração & dosagem , Somatostatina/análogos & derivados , Fatores de Tempo
7.
Neurographics (2011) ; 8(3): 167-187, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35388375

RESUMO

Radiation therapy is an integral part of the standard of care for many patients with brain and spine tumors. Stereotactic radiation surgery is increasingly being used as an adjuvant therapy as well as a sole treatment. However, despite newer and more focused techniques, radiation therapy still causes significant neurotoxicity. In this article, we reviewed the scientific literature, presented cases of patients who had developed different complications related to conventional radiation therapy or radiosurgery (gamma knife), demonstrated the imaging findings, and discussed the relevant clinical information for the correct diagnoses. Radiation therapy can cause injury in different ways: directly damaging the structures included in the radiation portal, indirectly affecting the blood vessels, and increasing the chance of tumor development. We also divided radiation complications according to the time of occurrence: acute (0 to 4 weeks), early delayed (4 weeks to months), and late delayed (months to years). With the increasing application of radiation therapy for the treatment of CNS tumors, it is important for the neuroradiologist to recognize the many possible complications of radiation therapy. Although this may cause significant diagnostic challenges, understanding the pathophysiology, time course of onset, and imaging features may help institute early therapy and prevent possible deleterious outcomes. Learning Objectives: To recognize the main complications of radiation therapy and stereotactic radiosurgery in the brain and spine, and to highlight the imaging findings to improve the diagnostic process and treatment planning.

8.
Arch Osteoporos ; 13(1): 93, 2018 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-30151698

RESUMO

Bone density impairment represents an established complication in adults with neurofibromatosis type 1, while few data exist in the pediatric population. Age- and gender-adjusted bone mass decreases with age and pubertal development, identifying childhood as the best time frame to introduce prevention strategies aiming at peak bone mass achievement. PURPOSE: The present study aims at evaluating bone mineral density (BMD) in a population of children with neurofibromatosis type I (NF-1), with particular focus on changes occurring during growth and pubertal development. METHODS: Bone metabolic markers and bone status [by dual-energy X-ray absorptiometry scans (DXA) of the total body and lumbar spine with morphometric analysis] were assessed in 50 children (33 males; mean age ± SD, 11.6 ± 4 years). Bone mineral apparent density (BMAD), trabecular bone score (TBS), and bone strain (BS) of the lumbar spine (LS) DXA were also obtained. RESULTS: In our cohort areal BMD (aBMD) Z-score was below the mean in 88% of the patients at LS (70% after correction for bone size) and in 86% considering total body (TB) DXA. However, aBMD Z-score was < - 2 in 12% after correction for bone size at LS and TB, respectively. Lumbar spine aBMD Z-score (r = - 0.54, P < 0.0001), LS BMAD Z-score (r = - 0.53, P < 0.0001), and TB Z-score (r = - 0.39, P = 0.005) showed a negative correlation with growth and pubertal development (P = 0.007, P = 0.02, P = 0.01, respectively), suggesting that patients failed to gain as much as expected for age. CONCLUSION: Bone density impairment becomes more evident with growth and pubertal development in NF-1 patients, thus identifying childhood as the best time frame to introduce prevention strategies aiming at peak bone mass achievement. TBS and BS, providing bone DXA qualitative information, could be useful during longitudinal follow-up for better characterizing bone impairment in these patients.


Assuntos
Absorciometria de Fóton/métodos , Envelhecimento/fisiologia , Doenças Ósseas/diagnóstico por imagem , Neurofibromatose 1/diagnóstico por imagem , Puberdade/fisiologia , Adolescente , Densidade Óssea , Desenvolvimento Ósseo , Doenças Ósseas/congênito , Osso Esponjoso/diagnóstico por imagem , Criança , Estudos de Coortes , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Neurofibromatose 1/complicações , Neurofibromatose 1/fisiopatologia
9.
Int J Pediatr Otorhinolaryngol ; 69(9): 1265-8, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15894386

RESUMO

A 6-year-old girl was diagnosed to suffer from clivus osteomyelitis secondary to Enterococcus faecium infection. On the basis of the magnetic resonance image, the abscess was drained via the posterior wall of the pharyngeal tract immediately. Subsequent antibiotic therapy allowed rapid improvement and long-term healing of the osteomyelitic process without any side effect. Osteomyelitis or abscess of the clivus is very rare in adult patients and extremely rare in children. Some etiopathogenetic hypotheses are discussed in this case.


Assuntos
Enterococcus faecium/isolamento & purificação , Infecções por Bactérias Gram-Positivas/microbiologia , Osteomielite/microbiologia , Abscesso Retrofaríngeo/microbiologia , Criança , Fossa Craniana Posterior , Drenagem/métodos , Feminino , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/cirurgia , Humanos , Imageamento por Ressonância Magnética , Osteomielite/etiologia , Osteomielite/cirurgia , Abscesso Retrofaríngeo/complicações , Abscesso Retrofaríngeo/cirurgia , Resultado do Tratamento
10.
Neurobiol Aging ; 16(2): 137-48, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7777132

RESUMO

Protein kinase C was studied in various brain areas in aging Wistar rats. Histone-directed kinase activity from the cortex, hippocampus and cerebellum did not change with aging. Using purified protein B-50 as a substrate, between 3 and 8 months a decrease in in vitro phosphorylation was detected in the membrane fraction of the cortex but after this age values remained stable. In hippocampal membranes, B-50 phosphorylation was increased in aged rats. PKC translocation was impaired in aged rats in both the cortex and the hippocampus. PKC alpha and beta mRNA decreased in the cortex between 3 and 8 months with no further decline in aged animals. Hippocampal mRNA for calcium-dependent PKC isoforms was not modified during aging, as assessed by Northern and in situ hybridization. Western blot analysis revealed a change in PKC gamma protein only, which was increased in hippocampal membranes from aged rats. The data indicate that the key PKC function that is impaired in aged rats is enzyme translocation irrespective of the brain area investigated.


Assuntos
Envelhecimento/metabolismo , Encéfalo/enzimologia , Isoenzimas/metabolismo , Proteína Quinase C/metabolismo , Animais , Northern Blotting , Western Blotting , Eletrofisiologia , Ativação Enzimática/efeitos dos fármacos , Proteína GAP-43 , Histonas/metabolismo , Hibridização In Situ , Masculino , Glicoproteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/metabolismo , Proteínas de Neurofilamentos/metabolismo , RNA Mensageiro/biossíntese , Ratos , Ratos Wistar , Acetato de Tetradecanoilforbol/farmacologia
11.
Neurobiol Aging ; 17(4): 549-55, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8832629

RESUMO

We have previously identified alterations of K+ channel function, IP3-mediated calcium release, and Cp20 (a memory-associated GTP binding protein) in fibroblasts from AD patients vs. controls. In the present study we introduce a scoring system based on these response alterations that integrates two or more alterations (and their degree) in AD vs. control fibroblasts. This scoring system generates an index that distinguishes AD patients from controls with both high specificity and sensitivity. We also show that low doses of bradykinin elicit intracellular calcium release almost exclusively in AD cell lines in an all or none fashion that provide a clear measurement of enhanced IP3-mediated function in AD vs. controls.


Assuntos
Doença de Alzheimer/metabolismo , Cálcio/metabolismo , Fibroblastos/metabolismo , Idoso , Idoso de 80 Anos ou mais , Bradicinina/farmacologia , Células Cultivadas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Neurology ; 43(12): 2581-6, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8255461

RESUMO

We attempted to determine whether changes in protein kinase C (PKC) activity in Alzheimer's disease (AD) brains are also present in cultured skin fibroblasts from living patients. Biopsies collected from shoulder skin were transferred to culture plates with an appropriate growth medium, and histone-directed PKC activity as well as phorbol ester binding were individually determined in soluble and particulate fractions prepared from AD and non-AD fibroblast cell lines. Binding experiments indicated that PKC was unevenly distributed between cytosol (78%) and particulate (22%). The Bmax values for phorbol ester binding in soluble and particulate fractions were similar in AD and non-AD patients. Kd values in the cytosol were 94% higher in AD patients, indicating lower affinity of the enzyme for the ligand. Accordingly, the soluble PKC activity was 30% lower in AD patients. The data suggest that the changes in PKC phosphorylating activity represent a diffuse cellular defect in AD and are not confined to the brain. The alterations of the enzyme may participate in the disregulation in processing of beta-amyloid precursor protein in AD.


Assuntos
Doença de Alzheimer/metabolismo , Citosol/metabolismo , Proteína Quinase C/metabolismo , Pele/metabolismo , Idoso , Idoso de 80 Anos ou mais , Feminino , Fibroblastos/metabolismo , Humanos , Masculino , Dibutirato de 12,13-Forbol/metabolismo , Pele/patologia
13.
Neurology ; 47(4): 1069-75, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8857747

RESUMO

The present study investigates the ability of the pharmacologic activation of protein kinase C (PKC) to modulate amyloid precursor protein (APP) secretion in human skin fibroblasts from patients affected by Down's syndrome (DS). We assessed DS subjects at the Hospital Institute of Sospiro, Cremona, and at the Alzheimer's Disease Unit of the Sacred Heart Hospital in Brescia, and we subdivided them into nondemented (NDS) and demented (DDS) patients. All DS patients were trisomy 21 karyotype. DS fibroblasts had an increased content of APP immunoreactive material as revealed by immunocytochemistry analysis. The basal secretion of soluble APP was higher (+94.6%) in Down's cells with respect to controls. The observation on the fibroblasts prepared from DS is consistent with these patients' possessing an extra copy of the APP gene (mapped on chromosome 21) leading to increased APP expression. Phorbol-12,13-dibutyrate (PdBu, 9 to 150 nM) treatment promoted a dose-dependent increase of secreted APP in the conditioned medium of control fibroblasts. The peak response (+102.2%) was attained using 150 nM PdBu. In Down's fibroblasts, PdBu stimulated APP secretion already maximally at low concentrations (9 nM), but the peak response, due to the higher basal release, was lower on a percentage basis (+16.4%) than in control fibroblasts. The results indicate that in Down's fibroblasts the mechanisms controlling APP release are at least quantitatively altered. In addition, these results suggest caution when using information obtained from Down's patients to model Alzheimer's disease biochemical defects.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , Síndrome de Down/metabolismo , Fibroblastos/metabolismo , Proteína Quinase C/metabolismo , Adulto , Relação Dose-Resposta a Droga , Feminino , Humanos , Imuno-Histoquímica , Masculino
14.
Ann N Y Acad Sci ; 777: 332-7, 1996 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-8624109

RESUMO

The present study shows that cultured fibroblasts from sporadic AD patients present: a) reduced (-30%) cytosolic protein kinase C (PKC) activity; b) increased KD of phorbol ester binding (+94%) in cytosolic fractions; c) reduced (-30%) soluble protein kinase C alpha immunoreactivity; d) lower (-27.5%) basal soluble APP secretion and e) reduced soluble APP secretion in response to low phorbol ester concentrations (over threefold difference using 9 nM phorbol-12,13-dibutyrate-PdBu). Since the PKC-stimulated secretion of APP leads to the cleavage of the precursor within the amyloidogenic beta-A4 fragment, the reduced PKC activity in AD patients may lead to accumulation of potentially amyloidogenic or toxic APP fragments. A defect in the secretion of soluble amyloid beta-protein precursor is indeed suggested by literature data on familial AD fibroblasts as well as by the reported results.


Assuntos
Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Proteína Quinase C/metabolismo , Doença de Alzheimer/patologia , Linhagem Celular , Citosol/metabolismo , Fibroblastos/metabolismo , Humanos , Fosforilação , Valores de Referência , Solubilidade
15.
Brain Res ; 402(2): 359-61, 1987 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-3828802

RESUMO

We investigated the effect of acute ethanol administration on voltage-sensitive calcium channels (VSCC) by measuring [3H]nitrendipine ([3H]NTP) binding to crude synaptosomal membrane preparations from different rat brain areas, i.e. cerebral cortex, hippocampus and striatum. Ethanol enhances the number of binding sites shortly after the administration (40 min), then Bmax returns towards control values while the binding affinity increases. Kd decreased peaks 8 h after the oral administration and returns within the range of control values at 36 h. The in vitro addition of ethanol has no effect on [3H]NTP binding at various concentrations up to 600 mM. These results suggest that acute ethanol treatment modifies VSCC supporting the concept that the short-term neurochemical alterations induced by in vivo ethanol administration involve calcium channels.


Assuntos
Encéfalo/metabolismo , Bloqueadores dos Canais de Cálcio/metabolismo , Etanol/farmacologia , Nitrendipino/metabolismo , Animais , Masculino , Ratos , Ratos Endogâmicos , Sinaptossomos/metabolismo , Fatores de Tempo , Trítio
16.
Neurosci Lett ; 236(1): 13-6, 1997 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-9404940

RESUMO

Fibroblasts from Alzheimer's disease (AD) patients displayed decreased cytochrome c oxidase (complex IV) activity (P < 0.05). The basal oxygen consumption rate (QO2) and the response to an uncoupler of oxidative phosphorylation did not differ between AD and control fibroblasts. The QO2 of AD fibroblasts was more susceptible (P < 0.05) to inhibition by azide in the range 0.5-5 mM. The basal intracellular pH (pHi) in AD fibroblasts was significantly more acidic than in control ones. The results support the hypothesis that subtle dysfunctions of oxidative energy-producing processes are present in fibroblasts from sporadic AD patients. The alterations observed scantly influence the fibroblasts functioning even in stressful conditions; however in tissues, such as the brain, that rely heavily on oxidative metabolism for their function, similar alterations may trigger molecular mechanisms leading to cell damage.


Assuntos
Doença de Alzheimer/metabolismo , Metabolismo Energético/fisiologia , Consumo de Oxigênio/fisiologia , Periodicidade , Idoso , Doença de Alzheimer/patologia , Estudos de Casos e Controles , Células Cultivadas , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Fibroblastos/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Oxirredução
17.
Neurosci Lett ; 201(1): 1-5, 1995 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-8830300

RESUMO

The present study shows that cultured fibroblasts from sporadic Alzheimer's disease patients are deficient in protein kinase C-regulated secretion of amyloid precursor protein. In particular, Alzheimer fibroblasts show a reduced basal secretion and a reduced response at low concentrations of phorbol-12,13-dibutyrate, with an EC50 twofold higher than control fibroblasts. Furthermore, we observed that such defective regulation of the amyloid precursor secretion can possibly be correlated to a specific defect in protein kinase C alpha in fibroblasts from Alzheimer patients.


Assuntos
Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/farmacologia , Dibutirato de 12,13-Forbol/farmacologia , Idoso , Western Blotting , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Isoenzimas/metabolismo , Masculino , Pessoa de Meia-Idade , Proteína Quinase C/metabolismo , Pele/citologia , Pele/metabolismo , Estimulação Química
18.
Pharmacol Biochem Behav ; 39(4): 835-40, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1662399

RESUMO

The present study investigates the effect of the administration of alpha-glycerylphosphorylcholine (alpha-GPC) on scopolamine-induced amnesia and on brain acetylcholine (ACh) levels and release in rats. The results indicate that alpha-GPC, when administered orally, reverses the amnesia caused by scopolamine in passive avoidance. The peak effect is observed using 600 mg/kg IG, 5 h before training. The effect of the drug is long lasting (up 30 h) in accordance with its pharmacokinetic characteristics. Since, alpha-GPC administered IG is cleaved within the gut mucosal cells to glycerophosphate and free choline, it is tempting to speculate that this drug acts by increasing the ACh precursor pool. This view is supported also by the observation that alpha-GPC partially counteracts the decrease of brain ACh levels elicited by scopolamine administration. The effect is observed in the hippocampus and cortex, but not in the striatum. Moreover, in ex vivo experiments, alpha-GPC is able to increase the amount of ACh released by rat hippocampus slices following potassium stimulation.


Assuntos
Acetilcolina/metabolismo , Amnésia/tratamento farmacológico , Química Encefálica/efeitos dos fármacos , Cognição/efeitos dos fármacos , Psicotrópicos/farmacologia , Escopolamina , Amnésia/induzido quimicamente , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Técnicas In Vitro , Masculino , Sistema Nervoso Parassimpático/efeitos dos fármacos , Cloreto de Potássio/farmacologia , Ratos , Ratos Endogâmicos , Transmissão Sináptica/efeitos dos fármacos
19.
Alcohol ; 5(4): 337-40, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-2852497

RESUMO

The present study investigates the effect of acute ethanol and acetaldehyde administration on neuronal L-type calcium channels by measuring the binding of 3H-nitrendipine (3H-NTP). Acute ethanol (3 g/kg orally) transiently increases (+40% at 40 min) 3H-NTP binding. Acetaldehyde has a similar effect, but the onset of action is shorter; in fact the binding increase peaks 15 min following administration and is completely reversible within 2 hours. Disulfiram pretreatment does not modify the effect produced by acute ethanol on 3H-NTP binding. The results indicate that acetaldehyde may participate in mediating the action of ethanol on voltage sensitive L-type calcium channels with consequent alterations of neuronal excitability.


Assuntos
Acetaldeído/farmacologia , Encéfalo/efeitos dos fármacos , Canais de Cálcio/efeitos dos fármacos , Etanol/farmacologia , Nitrendipino/metabolismo , Acetatos/farmacologia , Animais , Encéfalo/metabolismo , Química Encefálica/efeitos dos fármacos , Canais de Cálcio/metabolismo , Córtex Cerebral/efeitos dos fármacos , Cinética , Masculino , Ratos , Ratos Endogâmicos , Receptores Nicotínicos/efeitos dos fármacos
20.
Alcohol ; 12(6): 497-503, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8590609

RESUMO

The effect of prolonged (72 h) ethanol (200 mM) exposure on the labeling of L-type (using tritiated PN 200-110) and N-type (using iodinated omega-conotoxin) voltage-dependent calcium channels was investigated in cultured NG 108-15 cells. In undifferentiated cells ethanol produced an 80% increase in PN 200-110 Bmax and no changes in omega-conotoxin binding. Differentiation had a profound effect on the response of cells to ethanol, which in differentiated neuron-like cells decreased omega-conotoxin binding (-53.5%) leaving PN 200-110 labeling of L-type channels unaffected. The effect was time dependent and reversible upon ethanol withdrawal. The decreased omega-conotoxin binding was accompanied by a reduced ability of omega-conotoxin to inhibit K+ -stimulated calcium uptake. The results demonstrate that in cultured NG 108-15 cells ethanol differentially affects DHP and omega-conotoxin-sensitive, voltage-dependent calcium channels and that the effect is also modulated by differentiation of the cell to a neuronal phenotype.


Assuntos
Canais de Cálcio/efeitos dos fármacos , Depressores do Sistema Nervoso Central/farmacologia , Etanol/farmacologia , Ativação do Canal Iônico/efeitos dos fármacos , Neurônios/metabolismo , Animais , Bucladesina/farmacologia , Bloqueadores dos Canais de Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Diferenciação Celular , Eletrofisiologia , Fura-2 , Células Híbridas/efeitos dos fármacos , Isradipino/metabolismo , Isradipino/farmacologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Peptídeos/metabolismo , Peptídeos/farmacologia , Cloreto de Potássio/farmacologia , Ratos , Células Tumorais Cultivadas , ômega-Conotoxina GVIA
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