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1.
Eur Rev Med Pharmacol Sci ; 27(19): 9396-9400, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37843351

ABSTRACT

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.


Subject(s)
Intensive Care Units , Humans , Linezolid/adverse effects , Cross-Sectional Studies , Prevalence , Drug Interactions
2.
Article in Chinese | MEDLINE | ID: mdl-36882271

ABSTRACT

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.


Subject(s)
Diving , Female , Male , Humans , Blood Pressure , Workload
3.
Poult Sci ; 99(10): 5047-5054, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32988541

ABSTRACT

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.


Subject(s)
Bone and Bones , Chickens , Dietary Supplements , Polypodiaceae , Animal Feed/analysis , Animals , Bone Density/drug effects , Bone and Bones/drug effects , Diet/veterinary , Female , Flavonoids/pharmacology , Polypodiaceae/chemistry
4.
Eur Rev Med Pharmacol Sci ; 23(12): 5285-5292, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31298380

ABSTRACT

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.


Subject(s)
Antibiotics, Antineoplastic/pharmacology , Breast Neoplasms/drug therapy , Doxorubicin/pharmacology , Drug Resistance, Neoplasm/genetics , MicroRNAs/metabolism , Signal Transduction/genetics , Antibiotics, Antineoplastic/therapeutic use , Apoptosis/drug effects , Apoptosis/genetics , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Proliferation/drug effects , Cell Proliferation/genetics , Down-Regulation , Doxorubicin/therapeutic use , ErbB Receptors/metabolism , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , MCF-7 Cells , MicroRNAs/antagonists & inhibitors , Phosphatidylinositol 3-Kinases/metabolism
6.
Genet Mol Res ; 13(4): 9244-52, 2014 Jan 24.
Article in English | MEDLINE | ID: mdl-24615075

ABSTRACT

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.


Subject(s)
Diabetes Mellitus, Type 2/physiopathology , Diabetes Mellitus, Type 2/rehabilitation , Gastric Emptying , Adult , Aged , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnostic imaging , Female , Humans , Male , Postprandial Period , Radionuclide Imaging , Technetium/metabolism , Time Factors
7.
Int J Oral Maxillofac Surg ; 42(6): 707-10, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23535006

ABSTRACT

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.


Subject(s)
Dermatofibrosarcoma/complications , Dermatofibrosarcoma/surgery , Head and Neck Neoplasms/complications , Neck/pathology , Superior Vena Cava Syndrome/etiology , Adult , Antineoplastic Agents/therapeutic use , Dermatofibrosarcoma/drug therapy , Dermatofibrosarcoma/pathology , Head and Neck Neoplasms/drug therapy , Head and Neck Neoplasms/pathology , Head and Neck Neoplasms/surgery , Humans , Indoles/therapeutic use , Male , Neck/surgery , Neoplasm Recurrence, Local/surgery , Pyrroles/therapeutic use , Sunitinib , Superior Vena Cava Syndrome/pathology , Thorax/pathology , Vena Cava, Superior
8.
J Nanosci Nanotechnol ; 12(2): 1238-41, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22629929

ABSTRACT

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.

10.
Appl Spectrosc ; 57(2): 164-7, 2003 Feb.
Article in English | MEDLINE | ID: mdl-14610953

ABSTRACT

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.


Subject(s)
Algorithms , Models, Chemical , Models, Molecular , Spectroscopy, Fourier Transform Infrared/methods , Spectroscopy, Fourier Transform Infrared/standards , Statistics as Topic , Computer Simulation
11.
Eur J Clin Invest ; 32(2): 100-9, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11895456

ABSTRACT

BACKGROUND: Insulin sensitivity and insulin clearance are compromised in end-stage renal disease but it has not been fully established whether they are altered in earlier stages of diabetic nephropathy. DESIGN: We studied three groups of patients with type 1 diabetes; 10 with no sign of nephropathy, 11 with albuminuria (> 20 microg min-1) but normal glomerular filtration rate (GFR) and eight with a small reduction in GFR, (43-73 mL min-1 1.73 m-2). The groups were matched for age (range 36-61 years), body mass index (BMI), diabetes duration and glycaemic control. The euglycaemic hyperinsulinaemic clamp technique was utilized to study insulin sensitivity (M-value) and metabolic clearance rate for insulin. Needle biopsies from abdominal subcutaneous fat tissue were obtained to study insulin binding, insulin degradation, insulin-stimulated glucose uptake and anti-lipolysis in adipocytes in vitro. RESULTS: Patients with reduced GFR were more insulin-resistant (M-value 5.7 +/- 0.7 mg kg LBM-1 min-1) than those without nephropathy (9.6 +/- 0.7, P = 0.001) and those with only albuminuria (8.9 +/- 1.2, P = 0.044). In all subjects taken together there was a strong association between insulin sensitivity and GFR (r = 0.46, P = 0.012). Patients with reduced GFR displayed no significant difference in insulin clearance (12.2 +/- 1.6 mL kg-1 min-1) compared to controls (13.8 +/- 1.3) but a slightly lower insulin clearance than patients with only albuminuria (16.6 +/- 1.0, P = 0.027). There were no significant differences between patient groups in the adipocyte studies in vitro, i.e. with respect to insulin binding, insulin degradation and the effects of insulin on glucose uptake and lipolysis. This is compatible with humoral factors causing whole-body insulin resistance and in the group with reduced GFR, we found that serum parathyroid hormone, interleukin-6 and tumour necrosis factor-alpha levels were elevated whereas the morning cortisol was decreased. CONCLUSIONS: In type 1 diabetes, the appearance of albuminuria does not seem to alter insulin sensitivity and clearance. A marked insulin resistance but no consistent impairment in insulin clearance seems to accompany progression to a stage with a slight reduction in GFR. These alterations are not accompanied by general defects in insulin target cells. Instead, alterations in the regulation of insulin-antagonistic hormones and cytokines could potentially contribute to the development of insulin resistance in diabetic nephropathy.


Subject(s)
Diabetes Mellitus, Type 1/physiopathology , Diabetic Nephropathies/physiopathology , Glomerular Filtration Rate/physiology , Insulin Resistance/physiology , Adipose Tissue/metabolism , Adult , Albuminuria/physiopathology , Cytokines/blood , Female , Glucose/metabolism , Glucose Clamp Technique , Hormones/blood , Humans , In Vitro Techniques , Male , Middle Aged
12.
Biochim Biophys Acta ; 1535(2): 174-85, 2001 Feb 14.
Article in English | MEDLINE | ID: mdl-11342006

ABSTRACT

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.


Subject(s)
Adipocytes/drug effects , Cyclic AMP/pharmacology , Glucose/pharmacology , Insulin/pharmacology , Monosaccharide Transport Proteins/metabolism , Muscle Proteins , 3T3 Cells , Adipocytes/metabolism , Animals , Blotting, Western , Culture Media , Deoxyglucose/metabolism , Enzyme Inhibitors/pharmacology , Gene Expression Regulation/drug effects , Glucose/analysis , Glucose Transporter Type 4 , Insulin Resistance/genetics , Mice , Monosaccharide Transport Proteins/analysis , Monosaccharide Transport Proteins/genetics , Protein Tyrosine Phosphatases/antagonists & inhibitors , RNA, Messenger/analysis , Vanadates/pharmacology
13.
Biophys Chem ; 89(2-3): 231-8, 2001 Feb 15.
Article in English | MEDLINE | ID: mdl-11254215

ABSTRACT

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.


Subject(s)
Glycerol/chemistry , Phosphatidylethanolamines/chemistry , Calorimetry, Differential Scanning , Cryoprotective Agents/chemistry , Crystallization , Gels/chemistry , Kinetics , Temperature
14.
Biochim Biophys Acta ; 1509(1-2): 440-50, 2000 Dec 20.
Article in English | MEDLINE | ID: mdl-11118553

ABSTRACT

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.


Subject(s)
Dimethyl Sulfoxide/chemistry , Lipid Bilayers/chemistry , Phosphatidylethanolamines/chemistry , Gels/chemistry , Molecular Structure , Temperature , Water/chemistry , X-Ray Diffraction
15.
Horm Metab Res ; 32(8): 310-5, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10983626

ABSTRACT

The aim of this study was to further characterize the rapid effects of insulin and the tyrosine phosphatase inhibitor vanadate to amplify cell surface insulin binding capacity in isolated rat adipocytes. The effect of 20 min insulin treatment (1000 microU/ml) was 2- to 3-fold (p < 0.01) when cells were treated in medium containing 5.6 mM D-glucose, but it was totally absent in glucose-free medium. Other carbon energy sources, such as fructose and pyruvate, could only partly substitute for D-glucose, with an approximately 1.5-fold insulin effect. Moreover, inhibiting transmembrane glucose transport with cytochalasin B completely blocked the effect of insulin to enhance cell surface binding. The effect of vanadate was only partly glucose-dependent, since a submaximal effect (1.5- to 2-fold, p<0.05) was seen also in the absence of glucose. The tyrosine kinase inhibitor genistein markedly blunted the effect of vanadate (from 3- to 4-fold to approximately 2-fold, p < 0.05) also indicating the importance of tyrosine phosphorylation-related mechanisms in the upregulation of cell surface insulin binding. Glycosylation of insulin receptors as a mechanism for this effect appears unlikely since neither the effect of insulin nor that of vanadate was altered by the glycosylation inhibitor tunicamycin. The time course for the insulin effect displayed a long duration (at least 6 h), suggesting a maintenance role of insulin keeping its receptors accessible for ligand binding at the cell surface. In conclusion, the effect of insulin and vanadate to upregulate cell-surface insulin receptors is energy-dependent and to some extent specifically glucose-dependent.


Subject(s)
Adipocytes/metabolism , Energy Metabolism , Glucose/pharmacology , Insulin/pharmacology , Receptor, Insulin/drug effects , Vanadates/pharmacology , Animals , Biological Transport/drug effects , Cell Membrane/metabolism , Cytochalasin B/pharmacology , Enzyme Inhibitors/pharmacology , Genistein/pharmacology , Glucose/metabolism , Glycosylation/drug effects , Humans , Insulin/metabolism , Kinetics , Male , Phosphotyrosine/metabolism , Protein-Tyrosine Kinases/antagonists & inhibitors , Rats , Rats, Sprague-Dawley , Receptor, Insulin/metabolism , Tunicamycin/pharmacology
16.
Se Pu ; 18(1): 39-41, 2000 Jan.
Article in Chinese | MEDLINE | ID: mdl-12541452

ABSTRACT

Amylose-tris(3,5-dimethylphenylcarbamate) (ADMPC) and aminopropylated silica gel(APS) were prepared after the reported methods. ADMPC was immobilized on APS from tetrahydrofuran solution with a coating amount of 15%. The chiral stationary phase was packed in a stainless-steel column(150 mm x 4.6 mm i.d.) by slurry method. The column was used for the enantioseparation of 6 glycerin monosulfides and 4 glycerin bisulfides. Mixtures of hexane and 2-propanol were used as mobile phases. The enantiomers of the monosulfides could be separated quite well, while those of the bisulfides could not at all. This phenomenon shows that the ether oxygen atom of the monosulfides plays a key role in the chiral discrimination process. The retention time of the solutes increases significantly as the amount of 2-propanol decreases. This shows the main interaction between the solutes and the chiral stationary phase is hydrogen bonding. A dynamic model is presented to account for the chiral discrimination mechanism.


Subject(s)
Amylose/analogs & derivatives , Carbamates , Chromatography, High Pressure Liquid/instrumentation , Glycerol/analogs & derivatives , Glycerol/isolation & purification , Phenylcarbamates , Chromatography, High Pressure Liquid/methods , Silicon Dioxide , Stereoisomerism
17.
Se Pu ; 18(4): 287-90, 2000 Jul.
Article in Chinese | MEDLINE | ID: mdl-12541499

ABSTRACT

A chiral stationary phase was prepared by coating cellulose-tris(3, 5-dimethylphenylcarbamate) onto aminopropylated silica gel. A series of enantiomeric acidic biphenyl drugs were directly resolved on the chiral stationary phase (CSP) by normal-phase high performance liquid chromatography (HPLC). A hexane-2-propanol eluting system containing 1% of trifluoroacetic acid was used as mobile phase. Efficient optical resolution of the acidic biphenyl drugs has been attained. The factors that influence chiral discrimination such as structural characeristic of the samples and mobile phase were investigated. An interaction model between the stationary phase and the samples was discussed. The results showed that efficient optical resolution of racemic carboxylic acids could be attained by normal-phase HPLC on CSP using a hexane-2-propanol eluting system containing 1% of trifluoroacetic acid.


Subject(s)
Carbamates , Cellulose/analogs & derivatives , Chromatography, High Pressure Liquid/instrumentation , Dioxoles/isolation & purification , Phenylcarbamates , Chromatography, High Pressure Liquid/methods , Dioxoles/chemistry , Drugs, Chinese Herbal/chemistry , Stereoisomerism
18.
Mol Membr Biol ; 15(2): 59-68, 1998.
Article in English | MEDLINE | ID: mdl-9724923

ABSTRACT

Dimethyl sulphoxide is a widely used agent in cell biology. It is well known as a cryoprotectant, cell fusogen and a permeability enhancing agent. These applications depend, to a greater or lesser extent, on the effect of dimethyl sulphoxide on the stability and dynamics of biomembranes. The aim of this review is to examine progress of the research which has been directed towards studies of the interactions between dimethyl sulphoxide and membranes, particularly that with the lipid components of cell membranes, as seen in its effects on model membrane systems. Models are proposed to explain the mechanism whereby dimethyl sulphoxide may mediate its effects on biological functions by its effects on the stability and properties of the membrane lipid matrix.


Subject(s)
Cell Membrane/chemistry , Cell Membrane/drug effects , Dimethyl Sulfoxide/pharmacology , Models, Biological , Solvents/pharmacology , Animals , Humans
19.
Diabetes Care ; 21(8): 1217-20, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9702422

ABSTRACT

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.


Subject(s)
Cyclophosphamide/therapeutic use , Cyclosporine/therapeutic use , Immunosuppressive Agents/therapeutic use , Insulin Resistance , Lupus Erythematosus, Systemic/drug therapy , Plasmapheresis , Receptor, Insulin/immunology , Adipocytes/metabolism , Animals , Autoantibodies/blood , Combined Modality Therapy , Female , Humans , Hyperglycemia/chemically induced , Hyperglycemia/drug therapy , Insulin/metabolism , Insulin/therapeutic use , Lupus Erythematosus, Systemic/blood , Middle Aged , Prednisolone/adverse effects , Prednisolone/therapeutic use , Rats
20.
Biochemistry ; 37(6): 1540-50, 1998 Feb 10.
Article in English | MEDLINE | ID: mdl-9484224

ABSTRACT

The surface force apparatus was used to determine the fundamental forces governing the adhesion between mixed bilayer membranes comprising lactosyl ceramide (LacCer) and di-tridecanoyl-phosphatidyl choline. Forces between membranes were quantified as a function of the glycolipid surface densities, which ranged from 0 to 30 mol %. Control measurements of the forces between pure phosphatidylcholine membranes and mixed bilayers of lactosyl ceramide with phosphocholine showed that the steric thickness of the carbohydrate headgroups increased from 19 to 25 A when the glycolipid density increased from 10 to 20 mol %. The layer compressibility also decreased with increasing carbohydrate coverage, but the corresponding adhesion between lactosyl ceramide-containing membranes increased with increasing amounts of glycosphingolipid in them. The nonspecific van der Waals forces accounted for the attraction measured in the control experiments and that between identical 10 mol % LacCer bilayers. However, the increase in the adhesion with increasing glycolipid density was 2-4 times greater than predicted by Lifschitz theory. Additionally, the forces measured during separation of membranes containing 20 and 30 mol % glycosphingolipid indicated that the headgroups bind and rearrange during bilayer detachment. The interactions between the carbohydrates are weak and apparently dynamic, and they generate an additional density-dependent intermembrane attraction that is on the order of the van der Waals force.


Subject(s)
Carbohydrates/chemistry , Lactosylceramides/chemistry , Lipid Bilayers/chemistry , Adsorption , Animals , Calorimetry, Differential Scanning , Cattle , Glycolipids/chemistry , Hydrogen-Ion Concentration , Interferometry , Membranes/chemistry , Particle Size , Phosphatidylcholines/metabolism , Surface Properties
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