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1.
Eur Rev Med Pharmacol Sci ; 17(12): 1561-8, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23832719

RESUMO

BACKGROUND: Social Anxiety Disorder (SAD) is one of the most prevalent anxiety disorders in Europe and comprises the fear of public speaking as its typical sub-type. Cognitive-Behavioural Therapy (CBT) is the intervention of choice for SAD, and it includes exposure to anxiety-provoking stimuli to induce systematic desensitization and reduce anxiety. Similarly, exposure therapy per se has been used and found effective, although it is not as specific as CBT for the treatment of SAD. Interestingly, exposure to anxiety-provoking situations can be achieved in Virtual Environments (VEs) through the simulation of social situations allowing individuals with public speaking anxiety to live and develop real exposure-like reactions. The Virtual Reality Exposure Therapy (VRET) is the treatment of anxiety disorders based on such VEs. AIM: This article aims to provide an overview of the scientific literature related to the applications of Virtual Reality to the treatment of fear of public speaking. MATERIALS AND METHODS: We conducted the literature review on PubMed and Google Scholar for studies including the fear-of-public-speaking VEs. RESULTS AND CONCLUSIONS: Reviewed studies addressed two main aspects: the design parameters of the VEs for adequate reactions to synthetic social stimuli, and the efficacy of VEs for fear of public speaking treatment. VEs resulted effective for triggering as-if-real reactions in relation to public speaking. VE-based exposures reduced public speaking anxiety measurements, decreased scores and maintained them at 3 month follow-up. Studies comparing VRET to pharmacological therapy are lacking, and there are few randomized controlled trials that compare VRET to CBT, especially on fear of public speaking treatment.


Assuntos
Transtornos Fóbicos/terapia , Fala , Terapia de Exposição à Realidade Virtual , Coleta de Dados , Medo/psicologia , Humanos
2.
Nat Genet ; 12(4): 455-7, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8630506

RESUMO

Lung cancer, a major cause of death in the Western world, has a poor prognosis. So far, therapeutic strategies have had only a limited effect. Lung cancer risk is strongly associated with cigarette smoking and lung cancer pedigrees are rare. However, a possible polygenic nature of inherited predisposition to this cancer has been envisaged. Mouse inbred strains with inherited predisposition and resistance to lung cancer provide an important tool for the dissection of the genetics of this complex disease. The A/J strain carries the pulmonary adenoma susceptibility 1 (Pas1) locus and develops many lung tumours. We have mapped the M. spretus-derived locus that strongly resists the lung tumorigenesis in Pas1/+ mice. This locus, pulmonary adenoma resistance 1 (Par1) maps to mouse chromosome 11, near the Rara locus, with a lod score of 5.3. In Pas1/+ mice Par1 accounts for 23% of the phenotypic variance and 10 fold reduction in total tumour volume. These results provide evidence for a major resistance locus affecting the expression of an inherited predisposition to lung cancer.


Assuntos
Adenoma/genética , Mapeamento Cromossômico , Genes Supressores de Tumor , Neoplasias Pulmonares/genética , Adenoma/patologia , Animais , Sequência de Bases , Cruzamentos Genéticos , Primers do DNA/genética , Feminino , Ligação Genética , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Endogâmicos A , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Muridae , Polimorfismo Conformacional de Fita Simples
3.
Eur Rev Med Pharmacol Sci ; 27(22): 11093-11102, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38039040

RESUMO

OBJECTIVE: The aim of the preliminary pilot single-center retrospective cross-sectional study was to analyze and compare the presence of non-secretory salivary inflammatory biomarkers in pediatric patients with West syndrome, Noonan syndrome, and a healthy control group. PATIENTS AND METHODS: A total of 60 saliva samples were collected during dental check-ups. The saliva samples collected were analyzed by liquid chromatography. The results were analyzed with a t-test, and the statistical significance was given by a p-value lower than 0.05. RESULTS: We found statistical significance for defensin α1 (p=0.006) and thymosin ß4 (p=0.025) in the Noonan syndrome. In the West syndrome, only the defensin α1 had a statistically significant difference with the other groups (p=0.022). Proteomic analysis revealed an overexpression of peptides related to the innate (thymosin ß4) and acquired (defensin α1, α3) immunity. CONCLUSIONS: West and Noonan's syndromes showed the overexpression of molecular biomarkers involved in the pathogenesis of chronic periodontitis. The inflammatory status is triggered and amplified by the abnormal overgrowth of gingival tissues, the amplified release of proinflammatory cytokines from the immune cells, and the poor cooperation in maintaining adequate oral hygiene.


Assuntos
Síndrome de Noonan , Espasmos Infantis , Humanos , Criança , Estudos Retrospectivos , Proteômica , Estudos Transversais , Saliva/química , Biomarcadores/análise , Defensinas/análise
4.
ESMO Open ; 6(4): 100235, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34371384

RESUMO

BACKGROUND: Hereditary breast cancer (BC), ovarian cancer (OC), and pancreatic cancer (PC) are the major BRCA-associated tumours. However, some BRCA1/2-wild-type (wt) patients with a strong personal and/or family history of cancer need a further genetic testing through a multi-gene panel containing other high- and moderate-risk susceptibility genes. PATIENTS AND METHODS: Our study was aimed to assess if some BC, OC, or PC patients should be offered multi-gene panel testing, based on well-defined criteria concerning their personal and/or family history of cancer, such as earliness of cancer onset, occurrence of multiple tumours, or presence of at least two or more affected first-degree relatives. For this purpose, 205 out of 915 BC, OC, or PC patients, resulted negative for BRCA1/2 and with significant personal and/or family history of cancer, were genetically tested for germline pathogenic or likely pathogenic variants (PVs/LPVs) in genes different from BRCA1/2. RESULTS: Our investigation revealed that 31 (15.1%) out of 205 patients harboured germline PVs/LPVs in no-BRCA genes, including PALB2, CHEK2, ATM, MUTYH, MSH2, and RAD51C. Interestingly, in the absence of an analysis conducted through multi-gene panel, a considerable percentage (15.1%) of PVs/LPVs would have been lost. CONCLUSIONS: Providing a multi-gene panel testing to BRCA1/2-wt BC/OC/PC patients with a strong personal and/or family history of cancer could significantly increase the detection rates of germline PVs/LPVs in other cancer predisposition genes beyond BRCA1/2. The use of a multi-gene panel testing could improve the inherited cancer risk estimation and clinical management of patients and unaffected family members.


Assuntos
Neoplasias da Mama , Neoplasias Ovarianas , Neoplasias Pancreáticas , Proteína BRCA1/genética , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Feminino , Predisposição Genética para Doença , Testes Genéticos , Humanos , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/genética , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética
5.
Neurol Sci ; 31(6): 859-61, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20390435

RESUMO

Wernicke's encephalopathy (WE) is an acute or subacute syndrome that results from a deficiency in vitamin B1 (thiamine). The syndrome is characterised by a classical triad of symptoms: nystagmus and ophthalmoplegia,mental-status changes, and unsteadiness of stance and gait. When patients with WE are inappropriately treated with low doses of thiamine, mortality rates average out at 20% and Korsakoff's Psychosis develops in about 85% of survivors(Sechi and Serra in Lancet Neurol 6(5):442­455,2007). We report the case of a patient with a pyloric substenosis that developed a WE, and was treated with high doses of thiamine showing after few days of treatment a great improvement of neurological and neuroradiological assessment, even though cognitive impairment was still severe at discharge and at 6 months follow-up.


Assuntos
Estenose Pilórica/complicações , Tiamina/administração & dosagem , Complexo Vitamínico B/administração & dosagem , Encefalopatia de Wernicke/complicações , Encefalopatia de Wernicke/tratamento farmacológico , Relação Dose-Resposta a Droga , Humanos , Masculino , Pessoa de Meia-Idade , Estenose Pilórica/diagnóstico , Estenose Pilórica/tratamento farmacológico , Encefalopatia de Wernicke/diagnóstico
6.
Oncogene ; 26(45): 6546-59, 2007 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-17471236

RESUMO

The RET gene encodes two main isoforms of a receptor tyrosine kinase (RTK) implicated in various human diseases. Activating germ-line point mutations are responsible for multiple endocrine neoplasia type 2-associated medullary thyroid carcinomas, inactivating germ-line mutations for Hirschsprung's disease, while somatic rearrangements (RET/PTCs) are specific to papillary thyroid carcinomas. SH2B1beta, a member of the SH2B adaptors family, and binding partner for several RTKs, has been recently described to interact with proto-RET. Here, we show that both RET isoforms and its oncogenic derivatives bind to SH2B1beta through the SRC homology 2 (SH2) domain and a kinase activity-dependent mechanism. As a result, RET phosphorylates SH2B1beta, which in turn enhances its autophosphorylation, kinase activity, and downstream signaling. RET tyrosine residues 905 and 981 are important determinants for functional binding of the adaptor, as removal of both autophosphorylation sites displaces its recruitment. Binding of SH2B1beta appears to protect RET from dephosphorylation by protein tyrosine phosphatases, and might represent a likely mechanism contributing to its upregulation. Thus, overexpression of SH2B1beta, by enhancing phosphorylation/activation of RET transducers, potentiates the cellular differentiation and the neoplastic transformation thereby induced, and counteracts the action of RET inhibitors. Overall, our results identify SH2B1beta as a key enhancer of RET physiologic and pathologic activities.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Proteínas Proto-Oncogênicas c-ret/metabolismo , Animais , Diferenciação Celular , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Células Cultivadas , Humanos , Camundongos , Fosforilação , Isoformas de Proteínas/fisiologia , Ratos , Transdução de Sinais , Neoplasias da Glândula Tireoide/metabolismo , Domínios de Homologia de src/fisiologia
7.
Cancer Res ; 57(19): 4164-6, 1997 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-9331067

RESUMO

Mouse inbred strains with inherited predisposition and resistance to lung cancer provide a tool for the dissection of the complex genetics of this disease. In the present report, we have crossed the BALB/c with the SWR/J strain and performed whole-genome scanning for loci affecting lung tumor development in their F2 progeny. Both parental strains carry the pulmonary adenoma susceptibility 1 (Pas1) locus, a major locus affecting predisposition to lung cancer in mice. On distal chromosome 18 and on centromere of chromosome 6, we have mapped two pulmonary adenoma resistance loci (Par2 and Par4, respectively), which reduce lung tumor multiplicity strongly, up to 15-fold. Par2 and Par4, however, do not affect lung tumor size, which is instead controlled by an additional locus that we have mapped on the central region of chromosome 4. We designated this locus as "pulmonary adenoma progression 1" (Papg1), because it specifically modifies lung tumor size but not multiplicity. The present results, therefore, provide evidence for the existence of cancer modifier loci acting on specific stages of lung tumorigenesis.


Assuntos
Neoplasias Pulmonares/genética , Adenoma/genética , Adenoma/patologia , Animais , Mapeamento Cromossômico , Progressão da Doença , Suscetibilidade a Doenças , Feminino , Escore Lod , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos , Neoplasias Primárias Múltiplas/genética , Neoplasias Primárias Múltiplas/patologia
8.
Leukemia ; 11(12): 2150-6, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9447834

RESUMO

We have identified by MEDLINE search the cases of gammaglobinopathy and plasma cell malignancy in HIV-positive patients reported in the English language literature. The average age at presentation among HIV-positive patients with plasma cell disorders is 33 years, far younger than the average age of presentation in the general population. Some of these patients present with transient paraproteinemias, while others have persistent paraproteins, which may or may not be associated with true plasma cell malignancies. In most cases in which it has been examined, the paraprotein contains high-titer anti-HIV activity. The presence of high-titer anti-HIV activity in the paraproteins of AIDS patients suggests that an antigen-driven process in response to HIV infection may contribute to the early development of plasma cell disorders in these patients. Recent work in plasma cell tumorigenesis has indicated that transformation at a single point in the B lymphocyte lineage can give rise to either lymphoma or myeloma, dependent upon environmental factors such as T cell function, which may be required for directing transformed lymphocytes from lymphoma and towards plasma cell differentiation. This may explain why B lineage oncogenesis in AIDS patients favors the development of lymphoma over that of myeloma.


Assuntos
Infecções por HIV/complicações , Mieloma Múltiplo/etiologia , Paraproteinemias/etiologia , Plasmocitoma/etiologia , Adulto , Humanos , Pessoa de Meia-Idade
9.
Obstet Gynecol ; 87(1): 142-9, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8532252

RESUMO

OBJECTIVE: To summarize clinical features and treatments in reported cases of actinomycotic pelvic abscess occurring in women using intrauterine contraceptive devices (IUD), and to review detection of Actinomyces by cervical smear. DATA SOURCES: The English-language medical literature accessed through MEDLINE. METHODS OF STUDY SELECTION: We identified 92 cases of actinomycotic abscesses associated with IUD use in 63 case reports. In addition, 31 studies of Actinomyces detection were found, 16 of which were studies of Papanicolaou smear-based detection. DATA ABSTRACTION AND SYNTHESIS: Data regarding clinical presentation and treatment were culled from case reports, whereas detection rates of Papanicolaou smear and other methods were obtained from studies of Actinomyces detection. The average patient was 37 years old, had been using an IUD for 8 years, and presented with abdominal pain, weight loss, vaginal discharge, and fever. Laboratory studies commonly revealed anemia, leukocytosis, and an elevated erythrocyte sedimentation rate. Most of these patients underwent operative procedures, usually hysterectomy and salpingoophorectomy. High-dose penicillin was found to be an effective antibiotic. Detection rates of organisms on Papanicolaou smear were somewhat variable; use of other detection methods, including endometrial biopsy, culture, and immunofluorescence, did not improve this variability. CONCLUSIONS: Pelvic actinomycosis associated with the use of IUDs can mimic pelvic malignancy; for that reason, it is often treated surgically. However, if the diagnosis of actinomycosis can be obtained preoperatively, antibiotic treatment may lead to complete resolution. The Papanicolaou smear may be useful in evaluating such patients.


Assuntos
Abscesso/etiologia , Actinomicose/etiologia , Dispositivos Intrauterinos/efeitos adversos , Abscesso/diagnóstico , Abscesso/microbiologia , Abscesso/terapia , Actinomyces/isolamento & purificação , Actinomicose/diagnóstico , Actinomicose/microbiologia , Actinomicose/terapia , Adulto , Feminino , Humanos , Teste de Papanicolaou , Pelve , Esfregaço Vaginal
10.
J Control Release ; 65(1-2): 105-19, 2000 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10699275

RESUMO

Camptothecin (CPT) is a potent, antitumour drug acting mainly through inhibition of topoisomerase I during the S-phase of the cell cycle. Despite its impressive antitumour activity, clinical development was halted for unpredictable toxic events. Two soluble N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers were synthesised to contain CPT (5 wt.% and 10 wt.%). CPT was covalently linked at its alpha-hydroxyl group to the polymers through a Gly-Phe-Leu-Gly- spacer. In-vitro, CPT-conjugates were fairly resistant to hydrolysis in plasma as in buffer at neutral pH (0.2-0. 4% free CPT/h), while elastase and cysteine-proteases were able to release the active drug. Plasma levels in mice after intravenous administration of CPT-conjugates confirmed the modest hydrolysis in plasma. Plasma levels were approximately 5-fold lower than those observed at the highest tolerated dose of CPT administered in classical vehicles. Biodistribution in HT29 human colon carcinoma bearing mice was carried out after i.v. injection of [3H]CPT-conjugate and free [3H]CPT. Radioactivity uptake in tumour was evident only after [3H]CPT-conjugate treatment. Repeated intravenous administration of CPT-conjugates to HT29-bearing mice gave more than 90% tumour inhibition, some complete tumour regressions and no toxic deaths. The improved pharmacological profile on HT29 human colon carcinoma xenografts of the first poly(HPMA)-CPT conjugates might be ascribed to their prolonged intra-tumour retention and sustained release of the active drug.


Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Antineoplásicos Fitogênicos/uso terapêutico , Camptotecina/farmacocinética , Camptotecina/uso terapêutico , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Autorradiografia , Soluções Tampão , Camptotecina/administração & dosagem , Preparações de Ação Retardada , Células HT29 , Humanos , Hidrólise , Injeções Intravenosas , Cinética , Metacrilatos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Polímeros , Distribuição Tecidual , Transplante Heterólogo
11.
In Vitro Cell Dev Biol Anim ; 34(3): 247-58, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9557943

RESUMO

We have isolated a conditionally transformed liver progenitor cell line with phenotypic similarities to both hepatoblasts (bipotent embryonic liver cells that give rise to hepatocytes and intrahepatic biliary epithelial cells) and liver epithelial cells (primitive hepatic cells isolated from adult livers capable of generating both hepatocytic and biliary lineages). Cell line L2039 was derived from E14 fetal mouse liver after transformation with temperature-sensitive SV-40 large T antigen. At 33 degrees C, these cells have an epithelial morphology with a high nucleocytoplasmic ratio and express both hepatocytic and biliary genes, including albumin, alpha-fetoprotein, glutamine synthetase, insulinlike growth factor II receptor, fibronectin and laminin, and cytokeratins 8 and 19, a set of markers characteristic for hepatoblasts. The presence of cytokeratin 14, vimentin, and several oval-cell antigens link cell line L2039 to nonparenchymal liver epithelial cell populations thought to contain progenitor cells. Serum-free, hormonally defined media conditions and extracellular matrix requirements were determined for growth and differentiation of this cell line. During culture on type IV collagen at 39 degrees C, L2039 cells cease dividing and demonstrate hepatocytic differentiation with the assumption of a hepatocytelike morphology and glucocorticoid-dependent regulation of liver-specific genes, including albumin, alpha-fetoprotein, phosphoenolpyruvate carboxykinase, and liver-enriched transcription factors. The number of albumin-positive cells increases during culture at 39 degrees C, indicating that L2039 cells convert from a prehepatocytic to a hepatocytic phenotype. Under conditions specific for hepatocytic differentiation, C/EBPs were expressed and differentially regulated, with C/EBPbeta and C/EBPdelta upregulated early and C/EBPalpha only slightly expressed after 7 d, indicating that C/EBPalpha may not be a crucial factor in commitment to the hepatocytic phenotype.


Assuntos
Diferenciação Celular , Regulação da Expressão Gênica , Fatores de Transcrição/genética , Animais , Divisão Celular , Linhagem Celular Transformada , Fígado/embriologia , Camundongos , Células-Tronco , Temperatura
12.
Eur J Clin Nutr ; 65(4): 501-7, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21285968

RESUMO

BACKGROUND/OBJECTIVES: Live-attenuated influenza vaccine (LAIV) protects against influenza by mucosal activation of the immune system. Studies in animals and adults have demonstrated that probiotics improve the immune response to mucosally delivered vaccines. We hypothesized that Lactobacillus GG (LGG) would function as an immune adjuvant to increase rates of seroconversion after LAIV administration. SUBJECTS/METHODS: We conducted a randomized double-blind placebo-controlled pilot study to determine whether LGG improved rates of seroconversion after administration of LAIV. We studied 42 healthy adults during the 2007-2008 influenza season. All subjects received LAIV and then were randomized to LGG or placebo, twice daily for 28 days. Hemagglutinin inhibition titers were assessed at baseline, at day 28 and at day 56 to determine the rates of seroconversion. Subjects were assessed for adverse events throughout the study period. RESULTS: A total of 39 subjects completed the per-protocol analysis. Both LGG and LAIV were well tolerated. Protection rates against the vaccine H1N1 and B strains were suboptimal in subjects receiving LGG and placebo. For the H3N2 strain, 84% receiving LGG vs 55% receiving placebo had a protective titer 28 days after vaccination (odds of having a protective titer was 1.84 95% confidence interval 1.04-3.22, P=0.048). CONCLUSION: Lactobacillus GG is potential as an important adjuvant to improve influenza vaccine immunogenicity. Future studies of probiotics as immune adjuvants might need to specifically consider examining vaccine-naïve or sero-negative subjects, target mucosal immune responses or focus on groups known to have poor response to influenza vaccines.


Assuntos
Adjuvantes Imunológicos/metabolismo , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Lactobacillus/imunologia , Adolescente , Adulto , Anticorpos Antivirais/sangue , Método Duplo-Cego , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Vacinas contra Influenza/efeitos adversos , Influenza Humana/imunologia , Masculino , Projetos Piloto , Probióticos/metabolismo , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologia , Adulto Jovem
13.
Yale J Biol Med ; 69(6): 517-23, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9436295

RESUMO

At one time, when antacids were the primary medical means of treating peptic ulcer disease, the milk-alkali syndrome was not an uncommon cause of hypercalcemia. The simultaneous occurrence of hypercalcemia, alkalosis, and renal failure, in conjunction with the appropriate history of ingestion fof antacids, was suggestive of the syndrome. With the advent of antisecretory therapy, however, the milk-alkali syndrome has become an uncommon diagnosis. I report a case of milk-alkali syndrome and review the history of this syndrome as reported in the medical literature. Contemporary reports have focused on understanding the pathophysiology of the syndrome. Recent series have identified a shifting demographic profile, as increasing numbers of elderly women consume calcium carbonate as an anti-osteoporosis measure.


Assuntos
Alcalose , Hipercalcemia , Idoso , Feminino , Humanos , Masculino
14.
Brain Res Brain Res Rev ; 22(3): 258-64, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8957563

RESUMO

Over the past 30 years, significant progress has been made in understanding the physiologic mechanisms of sleep. Insomnia, a common complaint in general medical practice, and other sleep disorders have become increasingly recognized. In 1986, a heritable total insomnia was described and termed fatal familial insomnia; since then, the pathology of this disease has been shown to involve an accumulation of prion particles in the brains of affected patients. Prions have been more commonly associated with the transmission of spongiform encephalopathies such as scrapie (in sheep), Creutzfeldt-Jakob disease and Kuru. We briefly review the physiological and biochemical characteristics of normal sleep, describe the typical clinical characteristics of fatal familial insomnia and describe the current understanding of how prions cause neurodegenerative diseases, including fatal familial insomnia.


Assuntos
Doenças Priônicas/genética , Doenças Priônicas/mortalidade , Doenças Priônicas/fisiopatologia , Sono/fisiologia , Humanos , Degeneração Neural/fisiologia
15.
Ann Intern Med ; 128(10): 839-47, 1998 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-9599197

RESUMO

PURPOSE: To briefly review the role of calcium in the pathophysiology of atherosclerosis and to comprehensively review and analyze studies of coronary artery calcium detected by electron-beam computed tomography (CT). DATA SOURCES: The English-language literature located through MEDLINE and Current Contents. STUDY SELECTION: All studies of electron-beam CT in symptomatic and asymptomatic patients with and without known coronary artery disease were selected. DATA EXTRACTION: Significant findings on the association of cardiac risk factors and angiographically evident coronary artery disease with coronary artery calcium detected on electron-beam CT were compared. Prospective data on clinical outcomes in patients with coronary artery calcium were assessed. DATA SYNTHESIS: Coronary artery calcium is common in patients with known coronary artery disease or risk factors for coronary artery disease, and it becomes more common with increasing age. Coronary artery calcium detected by electron-beam CT is a sensitive but not a specific indicator of angiographically evident atherosclerosis; sensitivity is increased and specificity is decreased for angiographically significant disease. Test characteristics can be adjusted to improve specificity at the cost of sensitivity. Very limited data suggest that patients with coronary artery calcium are more likely to have cardiac events. CONCLUSIONS: Electron-beam CT is a promising new tool for the evaluation of coronary artery disease because patients who have coronary artery calcium are likely to have angiographically evident atherosclerosis. However, too few data currently exist to support the broad use of this tool in clinical decision making during the evaluation of patients with known or suspected coronary artery disease.


Assuntos
Calcinose/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Calcinose/patologia , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/patologia , Vasos Coronários/patologia , Humanos
16.
J Chromatogr ; 476: 83-92, 1989 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-2777998

RESUMO

A method for the simultaneous determination of imino and amino acids is reported. The method, based on the derivatization of amino acids, separated by ion-exchange chromatography, by reaction with alkaline hypochlorite and o-phthalaldehyde-3-mercaptopropionic acid, increases the sensitivity towards imino acids to the picomole level. The use of 3-mercaptopropionic acid gives intensely fluorescent derivatives and improves the stability of primary and secondary amino acid fluorophores towards oxidation. The accuracy and reproducibility of the method are increased by using three internal standards. The determination of all amino and imino acids present in protein hydrolysates, including tryptophan, in a single run is demonstrated.


Assuntos
Aminoácidos/análise , Iminoácidos/análise , Proteínas/análise , Ácido 3-Mercaptopropiônico , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Quimotripsinogênio/análise , Hidrólise , Indicadores e Reagentes , Proteínas do Leite/análise , Espectrometria de Fluorescência , Extratos do Timo/análise , o-Ftalaldeído
17.
Cell Biol Int ; 20(7): 489-99, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8931316

RESUMO

We have investigated the effects of altered cell shape on the regulation of the 92 kDa type IV collagenase. In MDCK cells, anti-E-cadherin antibodies alter cell shape by disrupting normal cell-cell contacts, while sodium butyrate causes a marked flattening and spreading of cells. The disruption of cell-cell contacts led to a faint expression of the 92 kDa collagenase. This effect was enhanced by sodium butyrate, which by itself did not induce collagenase expression. In contrast, stromelysin expression was not regulated in these conditions. Although mRNA expression was enhanced, the secreted collagenase activity was not altered in these conditions in either cell line. Examination of cytoskeletal and extracellular matrix proteins and cell-cell and cell-matrix adhesion proteins by immunofluorescence and Western blot revealed a disruption of the actin network, tight junctions, and fibronectin deposition by anti E-cadherin antibodies, and alterations in actin, cytokeratin 8, cytokeratin 14, laminin and beta 1 integrin induced by sodium butyrate. Thus, the induction of collagenase expression in epithelial cells by disrupted cell-cell adhesion and sodium butyrate is associated with changes in cell shape and structure.


Assuntos
Butiratos/farmacologia , Caderinas/metabolismo , Colagenases/biossíntese , Animais , Ácido Butírico , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Tamanho Celular/efeitos dos fármacos , Cães , Células Epiteliais , Epitélio/metabolismo , Metaloproteinase 9 da Matriz
18.
J Biomed Mater Res ; 26(12): 1619-31, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1484066

RESUMO

When magnetic fields were applied to polymer matrices of ethylene-vinyl acetate copolymer embedded with drug and a small magnet, drug release was increased up to 30-fold above baseline levels. It has been hypothesized that the effect of magnetic stimulation on the release of drugs from these matrices is the transduction of the applied magnetic field into a mechanical deformation of the matrix through motion of the magnet within the matrix. This current study provides support for this hypothesis by demonstrating that repeated pulsatile mechanical deformation of matrices can enhance the release of macromolecules from ethylene-vinyl acetate copolymer matrices. Furthermore, similar modulated release kinetics were obtained with mechanically compressed and magnetically stimulated matrices. We also established that modulation was dependent on the ratio of compression area to matrix volume and that modulation was maximized when this ratio was optimized.


Assuntos
Implantes de Medicamento , Polímeros , Animais , Bovinos , Campos Eletromagnéticos , Cinética , Polivinil , Soroalbumina Bovina
19.
Experientia ; 41(10): 1332-5, 1985 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-3899711

RESUMO

A thiol: protein disulfide oxidoreductase from bovine liver was isolated after separation from protein disulfide isomerase. The enzyme, after activation (reduction) with glutathione, was reacted with stoichiometric amounts of insulin and the sulfhydryl groups of the partially reduced hormone were labeled with iodo (l-14C)acetamide. After separation of the insulin chains, the radioactivity was found in both the peptides, with a ratio A-chain/B-chain equal to 2/1.


Assuntos
Dissulfetos/metabolismo , Insulina/metabolismo , Oxirredutases/metabolismo , Proteína Dissulfeto Redutase (Glutationa)/metabolismo , Aminoácidos/análise , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Fígado/enzimologia , Peso Molecular
20.
Am J Physiol ; 263(2 Pt 1): G139-48, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1325126

RESUMO

We propose that the liver is a stem cell and lineage system with many parallels to lineages in the bone marrow, gut, and epidermis, varying from them only in kinetics. All are organized with three compartments: a slow cycling stem cell compartment with cells expressing a fetal phenotype and responding slowly to injury; an amplification compartment with cells of intermediate phenotype rapidly proliferating in response to regenerative stimuli or acute injuries; and a terminal differentiation compartment in which cells increasingly differentiate and gradually lose their ability to divide. In all systems, both those with slow or rapid kinetics, the various compartments are positioned in a polarized organization, are associated with a gradient in the chemistry of the extracellular matrix, and show lineage-position-dependent growth responses, gene expression, pharmacological and toxicological responses, and reaction to viruses and radiation. In general, known oncogens selectively kill cells in the differentiation compartment inducing chronic regenerative responses of the cells in stem cell and/or amplification compartment. Tumors arise by subsequent transformation of the activated stem cells or early precursor cells. The evidence for a lineage model consists of the data implicating gradients in cell size, ploidy, growth potential, and antigenic and gene expression in the liver parenchyma along the sinusoidal plates. The traditional explanation for this heterogeneity is that it represents adaption of cells to a changing sinusoidal microenvironment dictated by the direction of blood flow. However, we review the extant data and suggest that it more readily supports a lineage model involving a maturation process beginning with stem cells and precursors in the periportal zone and ending with sensescing parenchyma near the central vein. Support for this theory is provided by the studies on phenotypic heterogeneity in liver, investigations into the embryology of the liver, and analyses of the responses of liver to chemical and viral oncogens that induce rapid proliferation of small cells with oval-shaped nuclei, "oval cells," now thought to be closely related to liver stem cells. The lineage model provides clarity and insights into many aspects of liver biology and disease including the limited proliferative ability of in vitro parenchymal cultures, liver regeneration, gene expression, viral infection, hepatocellular carcinogenesis, liver cell transplantation, and aging.


Assuntos
Fígado/citologia , Células-Tronco/fisiologia , Envelhecimento/fisiologia , Animais , Carcinoma Hepatocelular/etiologia , Linhagem Celular , Expressão Gênica , Terapia Genética/métodos , Humanos , Fígado/microbiologia , Fígado/fisiologia , Neoplasias Hepáticas/etiologia , Transplante de Fígado , Células-Tronco/citologia , Replicação Viral
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