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2.
Acta Anaesthesiol Scand ; 57(6): 737-44, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23379725

RESUMO

BACKGROUND: Tracheal intubation may cause vocal fold damage. The trial was designed to assess laryngeal morbidity comparing the Endoflex(®) tube with a conventional endotracheal tube with stylet. We hypothesised that laryngeal morbidity within the first 24 h after extubation would be lower with the Endoflex tube than with the conventional endotracheal tube with stylet because of less rigidity. METHODS: This randomised trial included 130 elective surgical patients scheduled for general anaesthesia with endotracheal intubation. Pre- and post-operative assessment of hoarseness, vocal fold pathology, and voice analysis using the Multidimensional Voice Program was performed. Induction of anaesthesia was standardised. After complete neuromuscular paralysis, intubation was done with an Endoflex tube or a conventional endotracheal tube with stylet. RESULTS: Post-operative hoarseness was found in 45% with the Endoflex tube and 55% with the endotracheal tube with stylet at 24 h after extubation (P = 0.44). Post-operative vocal fold injury was present in 23% in the Endoflex tube group and in 36% in the endotracheal tube with stylet group (P = 0.13). The increase in shimmer, the voice analysis variable reflecting vocal fold oedema, was 0.5% in the Endoflex tube group and 2.5% in the endotracheal tube with stylet group (P = 0.02). CONCLUSION: No significant difference was found in the incidence of hoarseness or vocal fold injury using the Endoflex tube. However, the statistically significant lower increase in the shimmer values in that group implies that the Endoflex may be associated with less laryngeal morbidity.


Assuntos
Intubação Intratraqueal/efeitos adversos , Intubação Intratraqueal/instrumentação , Complicações Pós-Operatórias/prevenção & controle , Prega Vocal/lesões , Adulto , Idoso , Extubação/efeitos adversos , Anestesia por Inalação/instrumentação , Procedimentos Cirúrgicos Eletivos , Feminino , Rouquidão/etiologia , Humanos , Edema Laríngeo/etiologia , Laringoscopia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Método Simples-Cego , Qualidade da Voz
3.
J Food Sci ; 74(6): E342-54, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19723198

RESUMO

Process engineering operations in food and nutraceutical industries pertaining to the design of extraction of value-added products from biomass using pressurized liquids involve a careful selection of the solvent and optimal temperature conditions to achieve maximum yield. Complex molecular structure and limited physical property data in the literature of biological solutes extracted from biomass compounds have necessitated the process modeling of such operations. In this study, we have applied the Hansen 3-dimensional solubility parameter concept to optimize the extraction of molecularly complex solutes using subcritical fluid solvents. Hansen solubility spheres characterized by the relative energy differences (RED) have been used to characterize and quantify the solute-subcritical solvent interactions as a function of temperature. The solvent power of subcritical water and compressed hydroethanolic mixtures above their boiling points has been characterized using the above-mentioned method. The use of group contribution methods in collaboration with computerized algorithms to plot the Hansen spheres provides a quantitative prediction tool for optimizing the design of extraction conditions. The method can be used to estimate conditions for solute-solvent miscibility, an optimum temperature range for conducting extractions under pressurized conditions, and approximate extraction conditions of solutes from natural matrices.


Assuntos
Catequina/isolamento & purificação , Flavonoides/isolamento & purificação , Tecnologia de Alimentos/métodos , Niacina/isolamento & purificação , Extratos Vegetais/química , Triterpenos/isolamento & purificação , Algoritmos , Betula/química , Etanol/química , Frutas/química , Concentração de Íons de Hidrogênio , Casca de Planta/química , Pressão , Saccharomyces cerevisiae/química , Solubilidade , Solventes , Temperatura , Vitis/química , Água/química
4.
Clin Diagn Lab Immunol ; 9(3): 731-5, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11986289

RESUMO

Seventeen volunteers received an intravenous bolus of endotoxin (2 ng/kg of body weight). Endotoxin-induced lymphopenia was constituted mainly by cells with an immature phenotype (CD45RA(+) CD45RO(-)) that were less likely to undergo apoptosis (CD28(+)), whereas cells with the highest rates of disappearance were characterized by an activated phenotype (CD45RA(-) CD45RO(+)) as well as a phenotype linked to apoptosis (CD95(+) CD28(-)). In conclusion, endotoxin-induced lymphopenia reflects the disappearance from the circulation of activated lymphocytes prone to undergo apoptosis.


Assuntos
Envelhecimento/imunologia , Apoptose/imunologia , Antígenos CD28/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Endotoxemia/imunologia , Antígenos Comuns de Leucócito/imunologia , Linfopenia/imunologia , Receptor fas/imunologia , Adulto , Idoso , Escherichia coli , Humanos , Células Matadoras Naturais/imunologia , Ativação Linfocitária/imunologia , Pessoa de Meia-Idade
5.
Eur J Anaesthesiol ; 18(9): 572-5, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11553251

RESUMO

BACKGROUND: and objective The aim of this study was to determine possible age-associated differences in human blood pressure regulation during an immunological challenge in healthy subjects. METHODS: Eight healthy young volunteers (median age 24 yr) and nine healthy elderly volunteers (median age 66 yr) received an intravenous bolus injection of Escherichia coli endotoxin (2 ng kg(-1)). Blood pressure, heart rate and core temperature were monitored during the first 7 h. Plasma catecholamine concentrations were measured at hourly intervals. RESULTS: The elderly showed a significantly more pronounced decrease in mean arterial pressure 4-7 h after endotoxin administration compared with the young controls (ANOVA; age x time; P < 0.0005). This mainly reflected a decrease in the systolic blood pressure in the elderly. The heart rate of both groups increased without difference between groups. Increased plasma epinephrine concentrations were found 2-3 h after endotoxin administration in both groups. Five hours after the endotoxin challenge, the epinephrine concentration had returned to control values in the elderly group only, in spite of decreased blood pressure. CONCLUSION: In conclusion, healthy elderly subjects fail to maintain a constant mean arterial pressure in response to the immunological challenge of endotoxemia.


Assuntos
Endotoxemia/complicações , Hipotensão/complicações , Adulto , Idoso , Temperatura Corporal , Endotoxinas/farmacologia , Epinefrina/sangue , Feminino , Frequência Cardíaca/fisiologia , Hemodinâmica/fisiologia , Humanos , Lipopolissacarídeos/farmacologia , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue
6.
J Cell Biochem ; 82(3): 422-36, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11500919

RESUMO

Several in vitro and in vivo experiments have demonstrated potent cell regulatory effects of vitamin D compounds in cancer cells. Moreover, a promising phase I study with the vitamin D analogue Seocalcitol (EB 1089) in patients with advanced breast and colon cancer has already been carried out and more clinical trials evaluating the clinical effectiveness of EB 1089 in other cancer types are in progress (Mørk Hansen et al. [2000a]). However, only little is known about the mechanisms underlying the actions of vitamin D or about the possible development of drug resistance in the patients. Therefore, in an attempt to gain more insight into these aspects, we have developed the MCF-7/VD(R) cell line, a stable subclone of the human MCF-7 breast cancer cell line, which is resistant to the growth inhibitory and apoptosis inducing effects of 1alpha,25(OH)(2)D(3). Despite this characteristic, receptor studies on the VDR have clearly demonstrated that the MCF-7/VD(R) cells contain fully functional VDRs, although in a lower number than seen with the parental MCF-7 cells. The regulation of the 24-hydroxylase enzyme appeared to be intact in the MCF-7/VD(R) cells and no differences with regard to growth rate and morphological appearance between the MCF-7/VD(R) cells and the parental MCF-7 cells were observed. Interestingly, however, the sensitivity of the MCF-7/VD(R) cells to the pure anti-estrogen ICI 182,780 was found to be increased. The MCF-7/VD(R) cell line shows characteristics different from those of previously described vitamin D resistant breast cancer cell lines but also some similarities. Together such vitamin D resistant cell lines therefore serve as a useful tool for studying the exact mechanism of action of vitamin D and the development of vitamin D resistance.


Assuntos
Células Tumorais Cultivadas/efeitos dos fármacos , Vitamina D/farmacologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proteínas de Ciclo Celular/metabolismo , Divisão Celular/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Resistência a Medicamentos , Moduladores de Receptor Estrogênico/farmacologia , Feminino , Humanos , Ligantes , Microscopia de Fluorescência , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Calcitriol/metabolismo , Receptores de Estrogênio/metabolismo , Esteroide Hidroxilases/genética , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/patologia
7.
Front Biosci ; 6: D820-48, 2001 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-11438443

RESUMO

Today, it is well established that besides playing a crucial role in the establishment and maintenance of the calcium homeostasis in the body, the active form of vitamin D, 1,25(OH)2D3, also acts an effective regulator of cell growth and differentiation in a number of different cell types, including cancer cells. This has led to an increased interest in using 1,25(OH)2D3 in the treatment or prevention of cancer patients and to a substantial number of studies investigating the effect of 1,25(OH)2D3 on cancer cells. The results are encouraging, but clearly demonstrate that the therapeutic window of 1,25(OH)2D3 is extremely narrow due to the calcemic adverse effects of this compound. Much effort has consequently been directed into identifying vitamin D analogs with potent cell regulatory effects but with weaker effects on the calcium metabolism than those of 1,25(OH)2D3. In an attempt to clarify the mechanisms implicated in the cell regulatory effects of 1,25(OH)2D3 and eventually facilitate the process of developing new specific vitamin D analogs, numerous investigations have been carried out with 1,25(OH)2D3 and its analogs. The present review will focus on the results obtained in these studies and describe some of the synthetic analogs, which have shown to be of particular interest in relation to cancer.


Assuntos
Antineoplásicos/farmacologia , Calcitriol/análogos & derivados , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/fisiopatologia , Esteroide Hidroxilases/farmacologia , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Calcitriol/farmacologia , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Feminino , Substâncias de Crescimento/metabolismo , Humanos , Masculino , Invasividade Neoplásica/prevenção & controle , Metástase Neoplásica/fisiopatologia , Metástase Neoplásica/prevenção & controle , Neoplasias Experimentais/patologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/fisiopatologia , Esteroide Hidroxilases/metabolismo , Telomerase/metabolismo , Células Tumorais Cultivadas
8.
J Nutr ; 131(6): 1777-86, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11385067

RESUMO

The Recommended Dietary Allowance (RDA) of vitamin B-6 for young women was recently reduced from 1.6 to 1.3 mg/d based on an adequate plasma pyridoxal phosphate (PLP) concentration of 20 nmol/L. To assess vitamin B-6 requirements and suggest recommendations for intake, seven healthy young women consumed a controlled diet providing 1.2 g protein/kg body weight for a 7-d adjustment period (1.0 mg vitamin B-6/d) and three successive 14-d experimental periods (1.5, 2.1 and 2.7 mg/d, respectively). Direct and indirect vitamin B-6 status indicators were measured in plasma, erythrocytes and urine. Indicators most strongly correlated with vitamin B-6 intake [i.e., plasma and erythrocyte PLP, urinary 4-pyridoxic acid (4-PA) and total vitamin B-6] were regressed on vitamin B-6 intake and the dietary vitamin B-6 to protein ratio. Inverse prediction using adequate and baseline values estimated vitamin B-6 requirement. Adequate values were determined for plasma PLP and urinary 4-PA from baseline values of 60 previous subjects, using the statistical method suggested by Sauberlich. The current study suggests a vitamin B-6 Estimated Average Requirement (EAR) for young women of 1.1 mg/d or 0.016 mg/g protein, and a RDA of 1.5 mg/d or 0.020 mg/g protein. When results from this study are combined with data from four other recent studies, the combined data predict an EAR of 1.2 mg/d or 0.015 mg/g protein, and a RDA of 1.7 mg/d or 0.018 mg/g protein. This study suggests that the current vitamin B-6 RDA may not be adequate.


Assuntos
Dieta/normas , Estado Nutricional , Piridoxina/administração & dosagem , Administração Oral , Adulto , Alanina Transaminase/análise , Aspartato Aminotransferases/análise , Índice de Massa Corporal , Eritrócitos/metabolismo , Etnicidade , Feminino , Humanos , Política Nutricional , Fosfato de Piridoxal/sangue , Fosfato de Piridoxal/urina , Piridoxamina/análogos & derivados , Piridoxamina/sangue , Piridoxamina/urina , Ácido Piridóxico/sangue , Ácido Piridóxico/urina , Piridoxina/sangue , Piridoxina/urina
9.
Int J Cancer ; 93(2): 224-31, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11410870

RESUMO

The active form of vitamin D(3), 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), induces caspase-independent apoptosis in MCF-7 and T47D breast cancer cells. Before the appearance of apoptotic cells at Day 4 after the addition of 1,25(OH)(2)D(3), the MCF-7 cells are sensitized to the caspase-mediated apoptosis induced by TNF. We studied the mechanism underlying the cross talk between these 2 distinct death pathways in MCF-7 and T47D cells. Whereas 1,25(OH)(2)D(3) pre-treatment enhanced TNF-induced apoptosis of TNF sensitive MCF-7 cells, it failed to render TNF resistant T47D cells sensitive to this cytokine. Opposing to an earlier report suggesting that cytosolic phospholipase A(2) (cPLA(2)) mediates the 1,25(OH)(2)D(3)-induced sensitization to TNF, we could not detect any cPLA(2) protein in MCF-7 cells and its overexpression had no effect on cellular sensitivity to 1,25(OH)(2)D(3) or the combination with TNF. The sensitization of MCF-7 cells to TNF-induced apoptosis by pre-treatment with 1,25(OH)(2)D(3) may instead be partially explained by an increased surface expression of the TNF receptor 1 (TNF-R1). In line with this, not only the TNF-induced activation of caspases and apoptosis but also that of NF-kappaB was enhanced by 1,25(OH)(2)D(3) pre-treatment. Furthermore, 1,25(OH)(2)D(3) enhanced TNF-induced NF-kappaB activation in T47D cells suggesting that it potentiates TNF signaling in general. Interestingly, the lysosomal protease cathepsin B, which expression is up-regulated by 1,25(OH)(2)D(3), was released from the lysosomes upon TNF treatment, and inhibition of its activity rescued 1,25(OH)(2)D(3) treated MCF-7 cells from TNF-induced apoptosis. In conclusion, 1,25(OH)(2)D(3) may enhance TNF-induced apoptosis by increasing the expression of both the TNF-R1 and cathepsin B.


Assuntos
Antígenos CD/metabolismo , Apoptose , Catepsina B/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Esteroide Hidroxilases/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Caspases/metabolismo , Interações Medicamentosas , Ativação Enzimática/efeitos dos fármacos , Humanos , NF-kappa B/metabolismo , Fosfolipases A/biossíntese , Receptores Tipo I de Fatores de Necrose Tumoral , Células Tumorais Cultivadas , Regulação para Cima
10.
J Nutr ; 131(5): 1581-3, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11340119

RESUMO

Pyridoxal 5'-phosphate (PLP) stimulation of erythrocyte alanine and aspartate aminotransferase (EALT, EAST) activities is a frequently used functional measure of vitamin B-6 status. Stability of enzyme activities and activity coefficients (AC, stimulated / unstimulated) was assessed in packed erythrocytes frozen at -20, -80 degrees C and under liquid nitrogen (-196 degrees C). Activities of EALT and EAST, with and without added PLP, were determined in fresh erythrocytes (d 0) and frozen samples on d 1, 7, 14, 28, 58 and 84. In -20 degrees C samples, EALT basal activity decreased 17 and 22% (P < or = 0.05 for both) by d 58 and 84, respectively, and EAST basal activity decreased 40% (P < or = 0.05) by d 58. In -80 and -196 degrees C samples, EALT and EAST basal activities did not change significantly. Activity coefficients did not differ significantly from d 0 at any storage temperature, but EAST-AC increased 9-19% (nonsignificant) in samples stored at -20 and -80 degrees C for 7 to 84 d. Additionally, EAST-AC was significantly higher in -20 than -80 and -196 degrees C samples on d 1 and 58, respectively. Erythrocytes may be frozen for 28 d at -20 degrees C and 84 d at -80 degrees C before analysis for EALT; for EAST, activity should be measured on fresh erythrocytes.


Assuntos
Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Criopreservação , Piridoxina/farmacologia , Adulto , Alanina Transaminase/efeitos dos fármacos , Aspartato Aminotransferases/efeitos dos fármacos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
11.
J Steroid Biochem Mol Biol ; 77(1): 1-11, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11358669

RESUMO

Several studies have demonstrated that vitamin D regulates growth and differentiation in bone cells in vitro. In addition, in vivo studies have shown that vitamin D stimulates bone formation, increases the number of osteoblast precursor cells and prevents bone mineral loss. These observations indicate that vitamin D may have anabolic effects on bone, and thus therapeutic potential in the treatment of osteoporosis. However, little is known about the effects of vitamin D on apoptosis in bone cells and about the contribution of this process to the effect of vitamin D on bone mineral loss. To investigate this aspect in more detail, we studied the effect of 1alpha,25(OH)(2)D(3) and a series of analogues on apoptosis in human osteosarcoma cells. No significant induction of apoptosis was observed with any of the compounds after a 5 day treatment period. In contrast, some of the analogues showed a tendency to protect the cells from undergoing apoptosis. This anti-apoptotic effect of vitamin D was further confirmed by the ability of 1alpha,25(OH)(2)D(3) to suppress camptothecin- and staurosporin-induced DNA fragmentation in the cells. In cultures treated simultaneously with 1alpha,25(OH)(2)D(3) in combination with camptothecin or staurosporin, the level of DNA fragmentation was markedly reduced compared with cultures treated with camptothecin or staurosporin alone. On the basis of the present results, it is therefore concluded that vitamin D displays anti-apoptotic effects in human osteoblast-like osteosarcoma cells in vitro. This observation suggests that besides regulating growth and differentiation, vitamin D exerts its anabolic effects on bone by protecting osteoblastic cells from undergoing apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Osteossarcoma/patologia , Vitamina D/farmacologia , Camptotecina/antagonistas & inibidores , Camptotecina/farmacologia , Humanos , Estaurosporina/antagonistas & inibidores , Estaurosporina/farmacologia , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologia
12.
J Invest Dermatol ; 116(5): 785-92, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11348471

RESUMO

MC903 (calcipotriol) is a synthetic, low calcemic analog of the nuclear hormone 1alpha,25-dihydroxyvitamin D3 and used in the treatment of psoriasis. The beneficial effects of MC903 on psoriasis are based on gene regulatory events. The genomic actions of 1alpha,25-dihydroxyvitamin D3 and its analogs are primarily mediated by a complex of the vitamin D3 receptor and the retinoid X receptor bound to a 1alpha,25-dihydroxyvitamin D3 response element that can be considered as the molecular switch of 1alpha,25-dihydroxyvitamin D3 signaling. In this study, the interaction of MC903 and two new analogs, GS1500 and EB1213, with this molecular switch was compared with that of 1alpha,25-dihydroxyvitamin D3. In DNA-dependent limited protease digestion assays, ligand-dependent gel shift assays and mammalian-one-hybrid assays, all four ligands appeared to be equally sensitive VDR agonists that activated vitamin D3 receptor-retinoid X receptor-1alpha,25-dihydroxyvitamin D3 response element complexes at a concentration of approximately 0.2 nM. The analyzed VDR agonists, however, also showed individual molecular properties, such as a reduced sensitivity in HaCaT cells (MC903), a selectivity for DNA-bound vitamin D3 receptor-retinoid X receptor heterodimers (GS1500) and a long-lasting stabilization of vitamin D3 receptor-retinoid X receptor-1alpha,25-dihydroxyvitamin D3 response element complexes (EB1213). This molecular evaluation demonstrated that the sensitivity in activating the vitamin D3 receptor is already optimal for MC903, but the analog may not be ideal in keeping the receptor active and in selectively triggering 1alpha,25-dihydroxyvitamin D3 signaling pathways.


Assuntos
Receptores de Calcitriol/agonistas , Dermatopatias/tratamento farmacológico , Administração Tópica , Calcitriol/análogos & derivados , Calcitriol/farmacologia , Linhagem Celular , Fármacos Dermatológicos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Estabilidade de Medicamentos , Células HeLa , Humanos , Receptores de Calcitriol/genética , Receptores do Ácido Retinoico/metabolismo , Elementos de Resposta/fisiologia , Receptores X de Retinoides , Tecnologia Farmacêutica , Fatores de Transcrição/metabolismo
13.
Clin Diagn Lab Immunol ; 8(2): 333-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11238217

RESUMO

The purpose of this study was to investigate whether an age-associated impaired acute-phase response exists. Nine healthy elderly volunteers (median, 66 years; range, 61 to 69 years) and eight young controls (median, 24 years; range, 20 to 27 years) were given an intravenous bolus of endotoxin (2 ng/kg). The rectal temperature was monitored continuously, and blood samples for cytokine measurements were obtained before endotoxin administration as well as 0.5, 1, 1.5, 2, 3, 4, 8, 12, and 24 h after the injection. The elderly subjects showed a more prolonged fever response compared to the young controls. Levels of tumor necrosis factor alpha (TNF-alpha), soluble TNF receptors (sTNFR-I), interleukin-6 (IL-6), IL-8, IL-10, and IL-1 receptor antagonist (IL-1ra) in plasma increased markedly following endotoxin administration in both groups. The elderly group showed larger initial increases in TNF-alpha and sTNFR-I levels and prolonged increased levels of sTNFR-I. Monocyte concentrations decreased in both groups, with the elderly group showing a more rapid decrease and a slower subsequent increase than did the young group. Furthermore, the elderly group had a more rapid increase in C-reactive protein levels than did the young group. In conclusion, ageing is associated with an altered acute-phase response including initial hyperreactivity, prolonged inflammatory activity, and prolonged fever response.


Assuntos
Envelhecimento/imunologia , Endotoxemia/imunologia , Febre/imunologia , Reação de Fase Aguda/imunologia , Adulto , Idoso , Temperatura Corporal , Proteína C-Reativa/metabolismo , Endotoxinas/administração & dosagem , Feminino , Febre/induzido quimicamente , Humanos , Proteína Antagonista do Receptor de Interleucina 1 , Interleucina-10/sangue , Interleucina-6/sangue , Interleucina-8/sangue , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Receptores do Fator de Necrose Tumoral/sangue , Sialoglicoproteínas/sangue , Fator de Necrose Tumoral alfa/metabolismo
14.
Cancer Res ; 60(19): 5578-83, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11034106

RESUMO

Tumor cells and their surrounding microenvironment produce a variety of factors that promote tumor growth and metastasis. We recently identified a nuclear factor, termed com1, that is up-regulated in human breast carcinoma cells on formation of experimental metastatic tumors and is assumed to act as a growth-promoting factor in breast cancer. 1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] is a potent inhibitor of growth in breast cancer both in vitro and in vivo. We compared the growth-regulatory mechanisms of nontumorigenic and estrogen-dependent MCF-7 cells with those of the tumorigenic and tamoxifen-resistant subline MCF7/ LCC2 in the presence of 1,25(OH)2D3. Proliferation of MCF7/LCC2 cells, which revealed constitutive com1 expression, was inhibited by 1,25(OH)2D3 (10(-7) M). This was strongly associated with cell cycle arrest in G1 phase, consistent with accumulation of the hypophosphorylated form of the retinoblastoma protein as well as the induction of the cyclin-dependent kinase inhibitor p21. These cell cycle events were preceded by a transient up-regulation (5-8-fold) of com1 mRNA. Furthermore, clonal growth of the MCF7/LCC2 cells was also inhibited by 1,25(OH)2D3 (10(-7) M), and when the com1-negative MCF-7 cells were stably transfected with com1, the resulting MCF7/com1 cells showed a significant decrease in colony formation. These results seem to indicate that rather than promoting growth, com1 may participate in the regulatory pathway involved in cellular growth inhibition when recruited by inhibitory signals.


Assuntos
Neoplasias da Mama/metabolismo , Calcitriol/farmacologia , Proteínas de Ligação a DNA , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Proteínas de Neoplasias/biossíntese , Neoplasias Hormônio-Dependentes/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Células Clonais/efeitos dos fármacos , Células Clonais/patologia , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/biossíntese , Ciclinas/genética , Dexametasona/farmacologia , Estradiol/farmacologia , Estrogênios/fisiologia , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/fisiologia , Neoplasias Hormônio-Dependentes/genética , Neoplasias Hormônio-Dependentes/patologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Tretinoína/farmacologia , Células Tumorais Cultivadas , Regulação para Cima/efeitos dos fármacos
15.
Curr Pharm Des ; 6(7): 803-28, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10828309

RESUMO

It is well established that the metabolically active form of vitamin D, 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3) plays a key role in the establishment and maintenance of the calcium metabolism in the body. In addition to this classic effect of 1alpha,25(OH)2D3, substantial evidence has emerged demonstrating that 1alpha,25(OH)2D3 is able to regulate cell growth and differentiation in a number of different cell types, including cancer cells. However, the clinical usefulness of 1alpha,25(OH)2D3 is limited by its tendency to cause hypercalcaemia. Much effort has therefore been directed to identifying new vitamin D analogues with potent cell regulatory effects, but with weaker effects on the calcium metabolism than those of 1alpha,25(OH)2D3. One of these new synthetic analogues is Seocalcitol (EB 1089). Despite being 50-200 times more potent than 1alpha,25(OH)2D3 with respect to regulation of cell growth and differentiation in vitro as well as in vivo, EB 1089 displays a reduced calcaemic activity in vivo compared to that of 1alpha, 25(OH)2D3. These characteristics make EB 1089 a potentially useful compound for the treatment of cancer. Recent clinical evaluation of EB 1089 has focused mainly on establishing a maximum tolerated dose in cancer patients. Early results confirm that the low calcaemic activity observed in animals can be reproduced in the clinic. Furthermore, EB 1089 has been shown to induce regression of tumours, especially in hepatocellular carcinoma where complete remission has been obtained. In conclusion, the development of EB 1089 as an anti-cancer drug holds promise. However, its final evaluation must await the completion of ongoing controlled clinical trials.


Assuntos
Antineoplásicos/uso terapêutico , Calcitriol/análogos & derivados , Desenho de Fármacos , Animais , Apoptose/efeitos dos fármacos , Calcitriol/síntese química , Calcitriol/farmacologia , Calcitriol/uso terapêutico , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Humanos , Neoplasias/tratamento farmacológico
16.
Anticancer Res ; 20(6B): 4211-20, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11205250

RESUMO

The cyanoguanidine CHS 828 was recently shown to possess potent anti-tumour effects both in vitro and in vivo. The exact mechanism of action of CHS 828 is not known, but recent results have indicated that induction of programmed cell death may be one mechanism by which CHS 828 exerts its anti-tumour effects. To investigate this aspect in more detail, we studied the effect of CHS 828 and the reference compound Taxol beta on programmed cell death in human breast cancer cells in vitro. Both compounds were found to induce DNA fragmentation in the cells. However, microscopic examination of the cells demonstrated that CHS 828 and Taxol triggered different types of cell death. In the CHS 828-treated cultures most cells were found to be Annexin-V positive, indicating that these cells were early apoptotic cells, while no morphological characteristics of classical apoptosis were seen. In contrast, the cells in the Taxol-treated cultures displayed morphological features characteristic of classical apoptotic cells, but no Annexin-V positive cells could be observed. These findings together with the previously reported potent effects of CHS 828 on tumour cells, makes CHS 828 a promising new agent for the treatment of cancer patients.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Cianetos/farmacologia , Fragmentação do DNA , DNA de Neoplasias/efeitos dos fármacos , Guanidinas/farmacologia , Paclitaxel/farmacologia , Anexina A5/análise , Apoptose/fisiologia , Neoplasias da Mama/química , Neoplasias da Mama/genética , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Proteínas de Neoplasias/análise , Células Tumorais Cultivadas/efeitos dos fármacos
17.
J Nutr ; 129(10): 1915-9, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10498768

RESUMO

The bootstrap procedure is a versatile statistical tool for the estimation of standard errors and confidence intervals. It is useful when standard statistical methods are not available or are poorly behaved, e.g., for nonlinear functions or when assumptions of a statistical model have been violated. Inverse regression estimation is an example of a statistical tool with a wide application in human nutrition. In a recent study, inverse regression was used to estimate the vitamin B-6 requirement of young women. In the present statistical application, both standard statistical methods and the bootstrap technique were used to estimate the mean vitamin B-6 requirement, standard errors and 95% confidence intervals for the mean. The bootstrap procedure produced standard error estimates and confidence intervals that were similar to those calculated by using standard statistical estimators. In a Monte Carlo simulation exploring the behavior of the inverse regression estimators, bootstrap standard errors were found to be nearly unbiased, even when the basic assumptions of the regression model were violated. On the other hand, the standard asymptotic estimator was found to behave well when the assumptions of the regression model were met, but behaved poorly when the assumptions were violated. In human metabolic studies, which are often restricted to small sample sizes, or when statistical methods are not available or are poorly behaved, bootstrap estimates for calculating standard errors and confidence intervals may be preferred. Investigators in human nutrition may find that the bootstrap procedure is superior to standard statistical procedures in cases similar to the examples presented in this paper.


Assuntos
Modelos Estatísticos , Piridoxina/metabolismo , Adulto , Feminino , Humanos , Modelos Lineares , Método de Monte Carlo , Necessidades Nutricionais , Ácido Piridóxico/urina , Piridoxina/administração & dosagem
18.
Aviat Space Environ Med ; 69(11): 1083-6, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9819166

RESUMO

BACKGROUND: Recent investigation into the push-pull effect (PPE), the reduction of +Gz tolerance when preceded by less than +1 Gz, has focused on centrifuge studies to demonstrate the presence of adverse cardiovascular responses. Maneuvers found to cause the Push-Pull Effect (PPEM) have not been studied previously in U.S. Air Force (USAF) fighter aircraft. The frequency of and extent to which PPEMs are performed in fighter aircraft are unknown. METHODS: Head-up display (HUD) videotapes from F-15 and F-16 air combat training missions were reviewed for the presence of PPEMs. The frequency of engagements containing PPEMs and the magnitude of the Gz profiles were noted. RESULTS: PPEMs were found in 11 to 67%, of engagements reviewed, depending on the nature of the training mission, with an overall average of 32%. The PPEMs that were observed contained segments of less than +1 Gz, ranging on average from 0.0 to 0.5 Gz for an average of 3.5 to 5 s duration. CONCLUSIONS: PPEMs are present in air combat training missions performed by today's USAF fighter aircraft and represent an operationally significant source of risk for accidents. These findings support continued research into the physiologic response to PPE and the development of countermeasures.


Assuntos
Aceleração/efeitos adversos , Medicina Aeroespacial , Gravitação , Militares , Acidentes Aeronáuticos/estatística & dados numéricos , Aeronaves/classificação , Aeronaves/estatística & dados numéricos , Fenômenos Fisiológicos Cardiovasculares , Humanos , Estudos Retrospectivos , Fatores de Risco , Estados Unidos
19.
J Cell Biochem ; 71(3): 340-50, 1998 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-9831071

RESUMO

The nuclear hormone 1alpha,25-dihydroxyvitamin D3 (VD) has important cell-regulatory functions but also a strong calcemic effect. Therefore, various VD analogues have been synthesized and screened for their biological profile. In order to gain more insight into the molecular basis of the high antiproliferative but low calcemic action of the VD analogue EB1089, we characterized this compound in comparison to five structurally related VD analogues. The activities of the six VD analogues in in vitro assays (limited protease digestion assays for determining interaction with monomeric vitamin D receptor (VDR), ligand-dependent gel shift assays for showing the increase of DNA binding of VDR-retinoid X receptor (RXR) heterodimers, and reporter gene assays on different types of VD response elements for demonstrating the efficacy in nuclear VD signalling) were found to represent their biological potency (antiproliferative effect on different malignant cell lines). In this series, EB1089 proved to be the most potent VD analogue; that is, every structural modification (20-epi configuration, cis-configuration at position C24, or changes at the ethyl groups at position C25) appeared to reduce the determined activities mediated through the VDR of these analogues. Moreover, the modifications of EB1089 resulted in a loss of VD response element selectivity, suggesting that this parameter is very critical for the biological profile of this VD analogue.


Assuntos
Calcitriol/análogos & derivados , Receptores de Calcitriol/metabolismo , Vitamina D/farmacologia , Calcitriol/química , Calcitriol/farmacologia , Divisão Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Dimerização , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Ligantes , Regiões Promotoras Genéticas/genética , Conformação Proteica/efeitos dos fármacos , Receptores de Calcitriol/química , Receptores de Calcitriol/genética , Receptores do Ácido Retinoico/metabolismo , Elementos de Resposta/genética , Receptores X de Retinoides , Fatores de Transcrição/metabolismo , Transfecção , Tripsina/metabolismo , Células Tumorais Cultivadas , Vitamina D/análogos & derivados
20.
Ugeskr Laeger ; 160(39): 5640-4, 1998 Sep 21.
Artigo em Dinamarquês | MEDLINE | ID: mdl-9771055

RESUMO

In Denmark, only few studies have addressed the problem of severe trauma. In relation to establishing a trauma manual at our hospital we studied trauma patients requiring immediate anaesthesiological assistance. Patients from the preceeding years, 1994-1995 were identified. The injuries were scored according to the Abbreviated Injury Scale (AIS), and Injury Severity Scores (ISS) were calculated. Two hundred and fifty-eight trauma patients were identified, 132 of these were severely injured, defined as having ISS > or = 15. Of these, 75 patients were multitraumatised, defined as AIS > or = 3 in at least two regions. None of the patients with ISS < or = 15 died. Mortality was 49% among severely injured but not multitraumatised patients, while mortality was 56% among the multitraumatised patients. Head injuries were the most frequently found severe injury (AIS > or = 3), followed by injuries to the thorax and extremities. The anaesthesiologist and the orthopaedic surgeon were involved in initial diagnosis and treatment in all patients, and beyond these a variety of medical specialties were involved. In the light of this study we have revised our procedures and registration concerning severe trauma patients.


Assuntos
Traumatismo Múltiplo , Ferimentos e Lesões , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Dinamarca/epidemiologia , Serviço Hospitalar de Emergência/organização & administração , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Mortalidade Hospitalar , Humanos , Lactente , Escala de Gravidade do Ferimento , Masculino , Pessoa de Meia-Idade , Traumatismo Múltiplo/diagnóstico , Traumatismo Múltiplo/mortalidade , Traumatismo Múltiplo/terapia , Ferimentos e Lesões/diagnóstico , Ferimentos e Lesões/mortalidade , Ferimentos e Lesões/terapia
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