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1.
Artigo em Chinês | MEDLINE | ID: mdl-36882271

RESUMO

Objective: To explore the characteristics and rules of blood pressure changes in oceanauts during simulated operation of manipulator and troubleshooting tasks with different difficulty. Methods: In July 2020, 8 deep-sea manned submersible oceanauts, 6 males and 2 females, were selected as objects. In the 1∶1 model of Jiaolong deep-sea manned submersible, the oceanauts performed manipulator operation tasks and troubleshooting tasks with different difficulties, measured the continuous blood pressure of the oceanauts, filled in the NASA Task Load Index (NASA-TLX scale) after the completion of a single mission, and the changes of systolic pressure (SBP), diastolic pressure (DBP), mean arterial pressure (MAP) and mental workload were analyzed. Results: In a single task, the SBP, DBP and MAP of the oceanauts increased first and then decreased. The blood pressure values at the third minute were significantly lower than those at the first minute (P<0.01), and those at the fifth minute were significantly higher than those at the third minute (P<0.01). When performing the same task, compared with the quiet state, SBP, DBP and MAP increased when the oceanauts performed low difficulty, high difficulty, high difficulty+2-back manipulator operation task and troubleshooting task (P<0.05). When the task difficulty was the same, the SBP and MAP of oceanauts performing manipulator operation tasks were higher than those of oceanauts performing troubleshooting tasks (P<0.05). Compared with low difficulty tasks, the scores of NASA-TLX scale for oceanauts performing high difficulty manipulator operationtasks were significantly higher (P<0.05). Compared with the low difficulty task and high difficulty task, the scale score of the high difficulty+2-back troubleshooting task was significantly higher (P<0.05). When the task difficulty was the same, the scale scores of low difficulty and high difficulty manipulator operation tasks were significantly higher than those of troubleshooting tasks (P<0.05). SBP, DBP, MAP of No. 1, No. 3, No. 4, No. 5, and No. 7 oceanauts (all of whom had 6 years of diving) were positively correlated with NASA-TLX scale scores (r>0.8, P<0.05) . Conclusion: In the process of manned deep-sea diving, when the oceanauts perform manipulator operation tasks and troubleshooting tasks, with the increase of task difficulty, the mental load of oceanauts increases, and the blood pressure index increases significantly in a short time. At the same time, improving the proficiency of operation can reduce the variation range of blood pressure indexes. Blood pressure can be used as an effective reference to evaluate the difficulty of operation and guide scientific training.


Assuntos
Mergulho , Feminino , Masculino , Humanos , Pressão Sanguínea , Carga de Trabalho
2.
Genet Mol Res ; 13(4): 9244-52, 2014 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-24615075

RESUMO

The relationship between gastric emptying dysfunction and blood glucose concentration in elderly with type 2 diabetes mellitus was investigated, and the effect of rehabilitation exercise prescription training on gastric emptying in the geriatric diabetic patients was evaluated. A total of 160 older type 2 diabetic adults and 30 cases of non-diabetic patients were studied with regard to the gastric half emptying time (GET1/2) of solid meals radiolabelled with 99mTc. Eighty delayed gastric emptying diabetic patients were randomly divided into 4 four groups: rehabilitation exercise + mosapride group (N = 20), rehabilitation exercise group (N = 20), mosapride group (N = 20), and control group (N = 20). The level of blood glucose was measured every six months in a two-year follow-up. The solid GET1/2 of regulated blood glycemic control patients showed no statistically significant differences from non-diabetic patients (P > 0.05). However, the value for poor blood glycemic control patients exhibited significant statistical differences compared with both non-diabetic (P < 0.01) and regulated blood glycemic control group patients (P < 0.01). It showed that the gastric emptying time improved in the rehabilitation exercise group, mosapride group and rehabilitation exercise group + mosapride group after two years of treatment (P < 0.05). Fasting blood glucose in both rehabilitation exercise group and rehabilitation exercise + mosapride group was significantly decreased. Postprandial blood glucose in the rehabilitation exercise group, mosapride group, rehabilitation exercise group + mosapride group was significantly decreased. High blood glucose level can delay gastric emptying in older type 2 diabetic patients. Gastric emptying and blood glucose control affect each other. It was shown that appropriate rehabilitation exercise combined with prokinetic agent may improve gastric emptying in some geriatric type 2 diabetic patients and help control their blood glucose.


Assuntos
Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus Tipo 2/reabilitação , Esvaziamento Gástrico , Adulto , Idoso , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Feminino , Humanos , Masculino , Período Pós-Prandial , Cintilografia , Tecnécio/metabolismo , Fatores de Tempo
3.
Eur Rev Med Pharmacol Sci ; 27(19): 9396-9400, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37843351

RESUMO

OBJECTIVE: Linezolid is commonly used in intensive care units (ICU) but has the potential to interact with other drugs. This study aimed to evaluate the prevalence of potential drug-drug interactions in ICU patients receiving linezolid. PATIENTS AND METHODS: Data of ICU patients receiving linezolid were extracted and included in the Hospital Prescription Analysis Program of China, and the risk of potential drug-drug interactions between concomitant drugs and linezolid was evaluated using the Lexicomp database. RESULTS: A total of 3,712 ICU patients from 59 hospitals were included in the analysis, and patients received an average of 17 concomitant drugs. A total of 67.9% of patients had potential drug-drug interactions. Patients receiving concomitant drugs with risk ratings of "X", "D", and "C" categories were 20.8%, 30.4%, and 35.1%, respectively. Opioids were the most frequently prescribed drug class with drug-drug interactions (DDIs) in the "X" category, whereas butorphanol, metoclopramide, and sufentanil were the most contraindicated concomitant drugs. CONCLUSIONS: ICU patients receiving linezolid have a high prevalence of potential drug-drug interactions, and efforts should be made to better recognize and manage this risk.


Assuntos
Unidades de Terapia Intensiva , Humanos , Linezolida/efeitos adversos , Estudos Transversais , Prevalência , Interações Medicamentosas
4.
J Nanosci Nanotechnol ; 12(2): 1238-41, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22629929

RESUMO

The single phase ErFe(x)Mn1-xO3 (0 < or = x < or = 0.15) compounds were synthesized by the solid-state reaction method. The doping effects on the crystal structural, magnetic, thermal, and dielectric properties were systematically investigated. The XRD patterns show all samples crystallize in the hexagonal structure with P6(3)cm space group. The lattice parameters a and c first decrease with doping, which is followed by a subsequent increase at higher doping levels. Although both the Fe3+ and Mn3+ ions remain stable in high spin trivalent states in all samples, the magnetization is weakened with increasing Fe contents. The heat capacity data shows the antiferromagnetic transition slightly shifts from 77 K for ErMnO3 to 80 K for ErFe015Mn0.85O3, which can not be observed in the magnetic susceptibility data. The real part of complex impedance of these samples rises as the doping level increases, indicating the enhancement of insulativity of doped samples.

5.
Poult Sci ; 99(10): 5047-5054, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988541

RESUMO

Caged layer osteoporosis (CLO) is a common bone metabolism diseases and poses a great threat to the production of laying hens. So far, there is no effective nutrition intervention to prevent CLO. The objective of this study was to evaluate the effects of dietary total flavonoids from Rhizoma Drynariae (TFRD), a Chinese herbal, on bone health, egg quality, and serum antioxidant capacity of caged laying hens. A total of two hundred sixteen, 54-wk-old Lohmann Pink-shell laying hens at were allocated to 3 groups with 6 replicates of 12 hens per replicate. The control group was fed a basal diet (BD) and 2 treatment groups additionally supplied with 0.5 or 2.0 g/kg TFRD, respectively. Results showed that supplying 2.0 g/kg TFRD enhanced the activities of serum total antioxidant capacity (P < 0.01) and glutathione peroxidase (P < 0.05) and had higher femur and tibia bone mineral density (both P < 0.05) compared with the control group. Dietary 2.0 g/kg TFRD also reduced the activities of serum alkaline phosphatase (P < 0.01), tartrate resistant acid phosphatase (P < 0.01), and the contents of osteocalcin (P < 0.01). Furthermore, tibia histomorphology observation showed that the microstructure of bone tissue was improved after TFRD treatment. Egg quality was not affected by TFRD while the egg weight significantly increased (P < 0.01). These findings suggested that TFRD has beneficial effects on bone health in older caged laying hens.


Assuntos
Osso e Ossos , Galinhas , Suplementos Nutricionais , Polypodiaceae , Ração Animal/análise , Animais , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Dieta/veterinária , Feminino , Flavonoides/farmacologia , Polypodiaceae/química
6.
Eur Rev Med Pharmacol Sci ; 23(12): 5285-5292, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31298380

RESUMO

OBJECTIVE: To explore whether micro ribonucleic acid (miR)-7 affects the resistance of breast cancer cells to adriamycin (ADR) through regulating the epidermal growth factor receptor (EGFR)/phosphatidylinositol 3-hydroxy kinase (PI3K) signaling pathway. MATERIALS AND METHODS: MiR-7 expression was compared among MCF-10A, MCF-7 and MCF-7/ADR cells. The MCF-7/ADR cells were divided into three groups, namely miR-7 control group (MCF-7/ADR drug-resistant strains), miR-7 inhibition group (miR-7-inhibited MCF-7/ADR drug-resistant strains) and miR-7 promotion group (MCF-7/ADR drug-resistant strains transfected with miR-7), and the messenger RNA (mRNA) and protein expression levels of MCF-7/ADR were evaluated via Western blotting. RESULTS: The expression level of miR-7 was substantially decreased in MCF-7 and MCF-7/ADR cells (p<0.05), and it was lowered more obviously in MCF-7/ADR cells than that in MCF-7 cells (p<0.05). Compared with that in miR-7 control group, miR-7 expression in miR-7 promotion group was notably raised (p<0.05), proving that the sensitivity of MCF-7/ADR cells to ADR was enhanced, while that in miR-7 inhibition group was significantly lowered (p<0.05). Compared with those in miR-7 control group, the mRNA and protein expression levels of EGFR and PI3K were elevated in miR-7 inhibition group (p<0.05), while they were lowered in miR-7 promotion group (p<0.05). Additionally, compared with those in miR-7 control group, the proliferation and apoptosis abilities of cells in miR-7 inhibition group were markedly enhanced (p<0.05) and weakened (p<0.05), respectively, while they were weakened (p<0.05) and significantly strengthened (p<0.05), respectively in miR-7 inhibition group. CONCLUSIONS: MiR-7 plays an important role in the resistance of breast cancer cells to ADR, and its over-expression can inhibit the EGFR/PI3K signaling pathway to raise their sensitivity to the chemotherapy drug ADR.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , MicroRNAs/metabolismo , Transdução de Sinais/genética , Antibióticos Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Regulação para Baixo , Doxorrubicina/uso terapêutico , Receptores ErbB/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , MicroRNAs/antagonistas & inibidores , Fosfatidilinositol 3-Quinases/metabolismo
7.
Biochim Biophys Acta ; 1509(1-2): 440-50, 2000 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-11118553

RESUMO

The thermotropic phase behaviour and structure of a nonbilayer-forming lipid, 1-palmitoyl-2-oleoyl-phosphatidylethanolamine, dispersed in water and in aqueous solutions of up to 50 wt% dimethyl sulphoxide (DMSO) have been characterised using synchrotron X-ray diffraction methods. It was found that the presence of DMSO in the solvent induced an increase in the temperature of lamellar-gel to lamellar-liquid-crystal phase transition and a decrease in the temperature of the lamellar-liquid-crystal to inverted-hexagonal phase transition of the phospholipid. The presence of DMSO also caused a decrease in the X-ray repeat spacings of all the phases studied. Electron density profiles of the phospholipid dispersed in water and 50 wt% DMSO in the bilayer gel state were calculated. The presence of 50 wt% DMSO caused the apparent disappearance of the solvent layer separating phospholipid bilayers in the gel state. The results suggest that DMSO contributes to the bilayer electron density profile and that the amphiphilic solvent molecules partition into the interfacial region.


Assuntos
Dimetil Sulfóxido/química , Bicamadas Lipídicas/química , Fosfatidiletanolaminas/química , Géis/química , Estrutura Molecular , Temperatura , Água/química , Difração de Raios X
8.
Biochim Biophys Acta ; 1282(1): 57-62, 1996 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-8679660

RESUMO

To further elucidate the mechanisms for short-term regulation of the receptor for insulin-like growth factor II (IGF-II), we investigated effects of insulin, cAMP and phosphatase inhibitors on cell surface 125I-IGF-II binding in rat adipocytes. Preincubation with the serine/threonine phosphatase inhibitor okadaic acid (OA, 1 microM) or the non-hydrolysable cAMP analogue N6-mbcAMP (4 mM) markedly impaired insulin-stimulated 125I-IGF-II binding. Furthermore, addition of OA enhanced the inhibitory effect exerted by N6-mbcAMP. N6-mbcAMP also induced an insensitivity to insulin which was normalized by concomitant addition of the tyrosine phosphatase inhibitor vanadate (0.5 mM). In contrast, vanadate did not affect the impairment in maximal insulin-stimulated 125I-IGF-II binding produced by either OA or N6-mbcAMP. Phospholipase C (PLC), which cleaves phospholipids at the cell surface, markedly enhanced cell surface 125I-IGF-II binding in a concentration-dependent manner. Scatchard analysis demonstrated that the effect of PLC was due to an increased number of binding sites suggesting that "cryptic' IGF-II receptors are associated with the plasma membrane (PM). PLC (5 U/ml) also reversed the N6-mbcAMP-induced decrease of 125I-IGF-II binding at a low insulin concentration (10 microU/ml). Taken together, these data indicate that cAMP, similar to its effects on the glucose transporter GLUT 4 and the insulin receptor, may increase the proportion of functionally cryptic IGF-II receptors in the PM through mechanisms involving serine phosphorylation, possibly of a docking or coupling protein. Tyrosine phosphorylation appears to exert an opposite effect promoting the full cell surface expression of receptors.


Assuntos
Adipócitos/metabolismo , Membrana Celular/metabolismo , Resistência à Insulina , Receptor IGF Tipo 2/metabolismo , Adipócitos/ultraestrutura , Animais , Bucladesina/análogos & derivados , Bucladesina/farmacologia , Inibidores Enzimáticos/farmacologia , Éteres Cíclicos/farmacologia , Insulina/farmacologia , Fator de Crescimento Insulin-Like II/metabolismo , Radioisótopos do Iodo , Masculino , Ácido Okadáico , Monoéster Fosfórico Hidrolases/antagonistas & inibidores , Fosfosserina/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor IGF Tipo 2/efeitos dos fármacos , Fosfolipases Tipo C/metabolismo , Fosfolipases Tipo C/farmacologia , Vanadatos/farmacologia
9.
Biochim Biophys Acta ; 1310(1): 103-9, 1996 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-9244182

RESUMO

The effects of vanadate and the stable peroxovanadate compound bpV(pic) on insulin binding and degradation were investigated in rat adipocytes under conditions of ongoing receptor cycling. Both bpV(pic) and vanadate increased 125I-insulin binding to intact cells through an increase in apparent receptor affinity. The maximal effect of bpV(pic) was to increase binding approximately 4-fold (EC50 0.06 +/- 0.01 mM), whereas vanadate increased binding approximately 2-fold (EC50 1.4 +/- 0.2 mM). Removal of cell surface insulin-receptor complexes with trypsin showed that the effects on binding exerted by bpV(pic) and vanadate were due to a similar increase in both cell surface binding and intracellular accumulation of radioactivity. Both bpV(pic) and vanadate inhibited the degradation of 125I-insulin in medium containing 1% bovine serum albumin. The ratio of degraded/intact intracellular 125I-insulin was also markedly reduced by these agents, suggesting that they inhibit intracellular insulin-degrading proteases. Similar to previous findings with vanadate, bpV(pic) stimulated glucose transport and, at low concentrations, enhanced insulin sensitivity. Taken together, these data demonstrate that both bpV(pic) and vanadate inhibit insulin degradation. In addition, they significantly enhance cell surface insulin binding in rat fat cells and this is associated with an improved insulin sensitivity.


Assuntos
Adipócitos/efeitos dos fármacos , Insulina/metabolismo , Receptor de Insulina/efeitos dos fármacos , Vanadatos/farmacologia , 3-O-Metilglucose/metabolismo , Adipócitos/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Membrana Celular/metabolismo , Insulina/farmacologia , Masculino , Inibidores de Proteases/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor de Insulina/isolamento & purificação , Receptor de Insulina/metabolismo
10.
Biochim Biophys Acta ; 1237(2): 135-42, 1995 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-7632706

RESUMO

The phase behaviour of 1,2-distearoylphosphatidylethanolamine in glycerol has been examined using differential scanning calorimetry and real-time synchrotron X-ray diffraction methods. Dry phospholipid and phospholipid dispersed in glycerol over the concentration range 2.4%-90% (w/w) was equilibrated for 30 min at 20 degrees C and thermal and structural parameters on the temperature range 60 degrees C to 110 degrees C recorded during an initial heating and subsequent reheating. The characteristic feature of the initial heating scan was a direct lamellar crystalline to inverted hexagonal phase transition. In the subsequent cooling scan a lamellar gel structure was formed from the non-lamellar phase which transformed, on reheating, to a lamellar crystalline phase in which the acyl chain packing was titled with respect to the bilayer plane. The mechanism of the formation of the two crystalline phases was examined in the context of a relaxation model, where the liquid-crystal phase below the transition temperature from lamellar crystalline phase is metastable. A binary phase diagram over the temperature range 60 degrees C to 110 degrees C has been constructed.


Assuntos
Glicerol/química , Fosfatidiletanolaminas/química , Termodinâmica , Difração de Raios X
11.
Biochim Biophys Acta ; 1535(2): 174-85, 2001 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-11342006

RESUMO

UNLABELLED: It is well-established that high levels of cAMP or glucose can produce insulin resistance. The aim of this study was to characterize the interaction between these agents and insulin with respect to adipose tissue/muscle glucose transporter isoform (glucose transporter 4, GLUT4) gene regulation in cultured 3T3-F442A adipocytes and to further elucidate the GLUT4-related mechanisms in insulin resistance. Insulin (10(4) microU/ml) treatment for 16 h clearly increased GLUT4 mRNA level in cells cultured in medium containing 5.6 mM glucose but not in cells cultured in medium with high glucose (25 mM). 8-Bromo-cAMP (1 or 4 mM) or N(6)-monobutyryl cAMP, a hydrolyzable and a non-hydrolyzable cAMP analog, respectively, markedly decreased the GLUT4 mRNA level irrespective of glucose concentrations. In addition, these cAMP analogs also inhibited the upregulating effect of insulin on GLUT4 mRNA level. Interestingly, the tyrosine phosphatase inhibitor vanadate (1-50 microM) clearly increased GLUT4 mRNA level in a time- and concentration-dependent manner. Furthermore, cAMP-induced inhibition of the insulin effect was also prevented by vanadate. In parallel to the effects on GLUT4 gene expression, both insulin, vanadate and cAMP produced similar changes in cellular GLUT4 protein content and cAMP impaired the effect of insulin to stimulate (14)C-deoxyglucose uptake. In contrast, insulin, vanadate or cAMP did not alter insulin receptor (IR) mRNA or the cellular content of IR protein. IN CONCLUSION: (1) Both insulin and vanadate elicit a stimulating effect on GLUT4 gene expression in 3T3-F442A cells, but a prerequisite is that the surrounding glucose concentration is low. (2) Cyclic AMP impairs the insulin effect on GLUT4 gene expression, but this is prevented by vanadate, probably by enhancing the tyrosine phosphorylation of signalling peptides and/or transcription factors. (3) IR gene and protein expression is not altered by insulin, vanadate or cAMP in this cell type. (4) The changes in GLUT4 gene expression produced by cAMP or vanadate are accompanied by similar alterations in GLUT4 protein expression and glucose uptake, suggesting a role of GLUT4 gene expression for the long-term regulation of cellular insulin action on glucose transport.


Assuntos
Adipócitos/efeitos dos fármacos , AMP Cíclico/farmacologia , Glucose/farmacologia , Insulina/farmacologia , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas Musculares , Células 3T3 , Adipócitos/metabolismo , Animais , Western Blotting , Meios de Cultura , Desoxiglucose/metabolismo , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/análise , Transportador de Glucose Tipo 4 , Resistência à Insulina/genética , Camundongos , Proteínas de Transporte de Monossacarídeos/análise , Proteínas de Transporte de Monossacarídeos/genética , Proteínas Tirosina Fosfatases/antagonistas & inibidores , RNA Mensageiro/análise , Vanadatos/farmacologia
12.
Diabetes Care ; 21(8): 1217-20, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9702422

RESUMO

CASE HISTORY: A woman born in 1949 was diagnosed in 1990 with systemic lupus erythematosus. She was treated with prednisolone, and < 1 year later she presented with marked hyperglycemia. Large doses of insulin were given four times per day. Even though the patient was thin (BMI 17.4 kg/m2), very little improvement was seen. INVESTIGATIONS AND TREATMENT: Serum insulin levels were high, and a euglycemic clamp investigation confirmed severe insulin resistance. The patient's serum contained insulin receptor antibodies inhibiting insulin binding, and thus the patient had a type B syndrome of insulin resistance. After diet and exercise, glycemic control stabilized and insulin treatment was withdrawn. However, in late 1993 she was in a catabolic and hyperglycemic state even though prednisolone doses were increased and azathioprin was added. In early 1994 she was treated with plasmapheresis and cyclophosphamide i.v. Subsequently, cyclosporin A was started as a maintenance therapy in addition to azathioprin. There was a rapid and sustained clinical improvement. Since late 1994 and onward, there is no sign of diabetes or glucose intolerance and there are no demonstrable insulin receptor antibodies in the patient's serum. DISCUSSION: Severe type B insulin resistance may respond favorably to treatment with plasmapheresis and cyclophosphamide followed by cyclosporin A in combination with azathioprin.


Assuntos
Ciclofosfamida/uso terapêutico , Ciclosporina/uso terapêutico , Imunossupressores/uso terapêutico , Resistência à Insulina , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Plasmaferese , Receptor de Insulina/imunologia , Adipócitos/metabolismo , Animais , Autoanticorpos/sangue , Terapia Combinada , Feminino , Humanos , Hiperglicemia/induzido quimicamente , Hiperglicemia/tratamento farmacológico , Insulina/metabolismo , Insulina/uso terapêutico , Lúpus Eritematoso Sistêmico/sangue , Pessoa de Meia-Idade , Prednisolona/efeitos adversos , Prednisolona/uso terapêutico , Ratos
13.
Biophys Chem ; 70(1): 35-9, 1998 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9474761

RESUMO

The effect of dimethylsulphoxide (DMSO), a widely used solvent in life sciences to stabilise biological membrane structures at low temperatures, on the structure of model membranes has been examined using X-ray diffraction methods. It was found that increasing concentrations of DMSO in water caused a progressive decrease in lamellar repeat spacings of multilamellar dispersions of both saturated and mono-unsaturated phosphatidylcholines. The lamellar repeat spacings were temperature-dependent but with dispersions in excess 40 wt.% DMSO, repeat spacings were less than that of the phospholipids in the dry state. One dimensional electron density profiles of the lipid bilayers were calculated and the thickness of the phosphatidylcholine bilayers were determined. It was inferred from the data that the thickness of liquid-crystal bilayers decreases in the presence of DMSO and that the DMSO molecules penetrate between the polar head groups of the phosphatidylcholines, resulting in an increase in area occupied by phospholipid at the bilayer surface.


Assuntos
Dimetil Sulfóxido/farmacologia , Bicamadas Lipídicas/metabolismo , Fosfolipídeos/metabolismo , 1,2-Dipalmitoilfosfatidilcolina/metabolismo , Temperatura , Difração de Raios X
14.
Biophys Chem ; 89(2-3): 231-8, 2001 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11254215

RESUMO

Phase behavior of distearoylphosphatidylethanolamine dispersed in excess glycerol has been examined by differential scanning calorimetry. Transformation from lamellar-gel to lamellar crystalline phase was found to take place at temperatures near 74.9 degrees C upon cooling and near 76.3 degrees C during heating scans. The transition can also be observed under isothermal conditions at temperature in this range. The kinetics of the transformation from lamellar-gel to lamellar-crystal phase was analyzed by the well-known Avrami equation. The apparent Avrami exponents were found to be approximately 1.6. The effective dimensionality of the growth pattern can then be set as 1, after taking into account the contribution of nucleation at the examination temperatures. The activation energy of the phase transition was estimated as approximately 255 kJ mol(-1). The data are discussed in terms of development of successful cryoprotective strategies using glycerol.


Assuntos
Glicerol/química , Fosfatidiletanolaminas/química , Varredura Diferencial de Calorimetria , Crioprotetores/química , Cristalização , Géis/química , Cinética , Temperatura
15.
Biosci Rep ; 14(6): 259-81, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7620078

RESUMO

Dimethyl sulphoxide is a water miscible solvent that has wide applications in cell biology. It acts as a cryoprotective agent in a variety of cells and tissues allowing prolonged storage at subzero temperatures. The action of dimethyl sulphoxide on the stability of the liquid matrix of cell membranes appears to be responsible for its effects and this appears also to be true for related effects on membrane permeability and fusion. Dimethyl sulphoxide is also known to act as an inducer of cellular differentiation and as a free radical scavenger and radioprotectant. A review of the underlying molecular basis of all these effects of dimethyl sulphoxide is presented.


Assuntos
Dimetil Sulfóxido , Animais , Dimetil Sulfóxido/química , Dimetil Sulfóxido/farmacologia , Humanos
16.
Appl Spectrosc ; 57(2): 164-7, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14610953

RESUMO

Data pretreatment is of importance in two-dimensional (2D) correlation analysis when composition is used as a perturbation parameter. For composition-oriented studies, different normalization methods based on both external parameters (i.e., concentration) and internal parameters (i.e., absorbance from individual components) have been compared. It was found that when there is no overlapping between absorption bands of interest, no normalization is needed for data pretreatment. When overlapped bands must be used for 2D correlation analysis, the mean-centered normalization method could be used to obtain correct signs in synchronous spectra for a transformation process in the specific form of A-->kC. The intensity of the 2D spectrum, however, may not accurately reflect quantitative information of the overall extent of spectral intensity variation observed during experiments.


Assuntos
Algoritmos , Modelos Químicos , Modelos Moleculares , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/normas , Estatística como Assunto , Simulação por Computador
17.
Zhonghua Zhong Liu Za Zhi ; 9(6): 451-3, 1987 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-2454786

RESUMO

187 patients with subclinical hepatic cancer (SHC), collected by mass screening or follow-up of the hepatic diseases in our hospital from Dec. 1972 to Dec. 1984, are reported. The age ranged from 18 to 76 years with a median of 47. The sex ratio of male and female was 1.97:1. 143 (76.5%) patients had a positive pathology. The exploration rate was 60.4% and resection rate was 77.9%. Of them, there were 72 (81.8%) small liver cancers with lesions equal to or less than 5 cm in diameter. For patients with resection, the 1, 3 and 5 year survival rates were 77.3%, 39.3% and 34.6%, markedly higher than those treated by other means. B-ultrasonography gave a significantly higher positive rate (96.4%) in the localization of SHC, compared with nuclide imaging (17.6%). Basing on analysis of 187 patients with SHC, close follow-up of the subjects with low level persistent positive alpha-fetoprotein without active liver disease plays an important role in the early detection of SHC.


Assuntos
Carcinoma Hepatocelular/mortalidade , Neoplasias Hepáticas/mortalidade , Adolescente , Adulto , Idoso , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/cirurgia , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/cirurgia , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Ultrassonografia , alfa-Fetoproteínas/análise
18.
Zhonghua Nei Ke Za Zhi ; 28(7): 394-6, 442, 1989 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-2556248

RESUMO

The results of determination of serum alpha-L-fucosidase (AFU) in healthy individuals, in patients with various liver diseases and non-liver malignant diseases were reported. In primary hepatic carcinoma the level of serum AFU was significantly higher than that in various other diseases and healthy persons (P less than 0.001). The serum AFU level was independent of AFP level (x = 1.24, P greater than 0.25). These data suggest that AFU may be a useful marker for the diagnosis of primary hepato cellular carcinoam with negative AFP.


Assuntos
Biomarcadores Tumorais/sangue , Carcinoma Hepatocelular/diagnóstico , Ensaios Enzimáticos Clínicos , Neoplasias Hepáticas/diagnóstico , alfa-L-Fucosidase/sangue , Humanos , Hepatopatias/diagnóstico
19.
Int J Oral Maxillofac Surg ; 42(6): 707-10, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23535006

RESUMO

Dermatofibrosarcoma protuberans (DFSP) is an uncommon dermal soft tissue tumour of intermediate malignancy. A 44-year-old man presented to the hospital with a large lesion on the right upper chest and neck. Despite eight previous surgical excisions, the tumour had continued to recur. Contrast-enhanced computed tomography showed recurrence of the tumour, associated with superior vena cava (SVC) syndrome. He declined radical surgical resection of the recurrent tumour, which may have required right upper limb amputation. Targeted therapy with sunitinib malate was therefore introduced. This case demonstrates the recurrent nature of DFSP and the association of this lesion on the upper chest/neck with SVC syndrome. Primary wide radical resection is essential for better local control and to avoid the development of SVC syndrome.


Assuntos
Dermatofibrossarcoma/complicações , Dermatofibrossarcoma/cirurgia , Neoplasias de Cabeça e Pescoço/complicações , Pescoço/patologia , Síndrome da Veia Cava Superior/etiologia , Adulto , Antineoplásicos/uso terapêutico , Dermatofibrossarcoma/tratamento farmacológico , Dermatofibrossarcoma/patologia , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Indóis/uso terapêutico , Masculino , Pescoço/cirurgia , Recidiva Local de Neoplasia/cirurgia , Pirróis/uso terapêutico , Sunitinibe , Síndrome da Veia Cava Superior/patologia , Tórax/patologia , Veia Cava Superior
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