Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human blood cells were washed and treated by PEG 6 000 (40% solution in BME) at 37 degrees for 15 min. A strong agglutination was observed. After dilution with 3 vol. of BME and shaking, microscopic examination at low magnification revealed small aggregates disseminated in dispersed population of erythrocytes. These aggregates were shown to be formed by a polymorphonuclear cell closely surrounded by erythrocytes. The possible explanation of the formation of such "Rosettes" was briefly discussed.
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PMID:[Formation of "Rosettes" induced by polyethylene glycol]. 77 62

Hepatocytes from isolated rat livers were hypothermically incubated (5 degrees C) in an oxygenated environment with continuous shaking (to simulate organ perfusion preservation). The incubation solution was either a tissue culture medium (L-15), an organ preservation perfusate (UW gluconate), or a simple cold-storage solution used for organ preservation (UW lactobionate). Hepatocyte viability was assessed from the release of lactate dehydrogenase (LDH) into the incubation medium. Cell swelling (due to the uptake of water) was also measured. Within 24 hr, hepatocytes hypothermically stored in each of the three incubation solutions became swollen (30 to 40% water gain) and lost a significant amount of LDH (as much as 60%). The addition of polyethylene glycol (PEG; relative molecular mass 8000; 5 g%) to the solutions suppressed cell swelling and allowed the incubated hepatocytes to remain relatively well preserved (30% LDH release) for as long as 120 hr. Adding either dextran (relative molecular mass 10,000 to 78,000; 5 g%) or saccharides (100 mmol/liter) instead of PEG neither prevented cell swelling nor prevented the cells from dying. The results of this study suggest (i) there is a direct correlation (r = 0.873) between hypothermia-induced cell swelling and cell death (i.e., the suppression of cell swelling prevents cell death); (ii) the mechanism by which PEG prevents cell swelling (and thus maintains cell viability) is not related to the osmotic or oncotic properties of the molecule but instead is apparently related to some unknown interaction between PEG and the cell, an interaction that provides stability during hypothermic incubation; and (iii) hypothermia-induced cell swelling must be prevented if isolated hepatocytes are to be used as a model for studying the mechanism by which cell damage occurs during hypothermic organ preservation. By eliminating cell death due to cell swelling, the biochemical mechanisms of cell death can be studied.
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PMID:Hypothermic preservation of hepatocytes. I. Role of cell swelling. 248 Aug 65

Isothermal gas chromatography with flame ionization detection was used to determine residual ethylene oxide (EtO), ethylene chlorohydrin, and ethylene glycol in soft rubber catheters that had been sterilized with EtO. Catheter samples were extracted by shaking with carbon disulfide, and the extract was analyzed on a 3% Carbowax 20M on 80-100 mesh Chromosorb 101 column, using nitrogen as the carrier gas. Ten replicate injections of a mixed standards solution gave coefficients of variation of 1.91, 1.23, and 4.74% for EtO, ethylene chlorohydrin, and ethylene glycol, respectively. A linear response was obtained with concentrations ranging from 1.0 to 7.9 micrograms EtO, 14.0 to 88.0 micrograms ethylene chlorohydrin, and 31.0 to 98.5 micrograms ethylene glycol. The proposed method detected as little as 0.5, 5.0, and 16.5 ng EtO, ethylene chlorohydrin, and ethylene glycol, respectively.
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PMID:Rapid gas chromatographic determination of ethylene oxide, ethylene chlorohydrin, and ethylene glycol residues in rubber catheters. 401 75

Several separation phases were tested for effectiveness in the gas chromatographic determination of residues of sym-triazine herbicides in officinal drugs. Carbowax 20 M, OV 225 and OV 330 are well suited for separating this group of active agents. A NP-FID was used as a gas chromatographic detector. Sample preparation was optimized. Chloroform (as an extracting agent) and the shaking method were best suited for extracting. The samples were purified by column chromatography, DMSO/petroleum ether partition and purification by extraction from a hydrochloric solution being performed subsequently if necessary. The recovery rates and the reproducibility observed for various drugs and different extraction methods were compared. The limit of detection of the method laid at 0.02 mg/kg.
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PMID:[Gas chromatographic determination of sym-triazine herbicides in drugs from vegetable sources (author's transl)]. 711 66

The adhesion and growth of two pathogenic bacteria (Escherichia coli and Staphylococcus aureus) on the surface of a heparinized hydrophilic polymer were studied. Heparinized hydrophilic polymer is composed of poly(vinyl chloride) grafted with poly(ethylene glycol) monomethacrylate, diethylaminoethyl methacrylate, and ionically bound heparin. Poly(vinyl chloride) was used as a control. Plasma protein pre coated polymers were also prepared to evaluate the effect of proteins on bacterial adhesion. Polymer films were stored in bacterial suspensions under gentle shaking at 37 degrees C for 24 hr. The amount of adherent bacterial cells was measured by the bioluminescent assay of bacterial adenosine triphosphate. Their structure was observed by use of a scanning electron microscope. These evaluations demonstrated that a large amount of bacterial adhesion and biofilm formation was found on the surface of poly(vinyl chloride), whereas significant reductions in bacterial adhesion and no biofilm formation were observed on heparinized hydrophilic polymer. Bacterial adhesion onto plasma protein pre coat polymer films were also investigated, and it was clear that the bacterial adhesion on these surfaces was dependent upon the amount and species of absorbed proteins.
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PMID:Inhibition of bacterial adhesion and biofilm formation by a heparinized hydrophilic polymer. 857 26

The aim of this work was to increase sensitivity in the detection of antigens from HIV-infected patients, through a process of immune complex dissociation without loss of antigenicity. 500 microliters of sera were mixed with 100 microliters of PEG 12%, stored one night in refrigerator, and centrifuged at 2000 g during 20 minutes. 200 microliters of buffer AcH/Ac- (pH 3.5) were added to the sediment, and incubated at 37 degrees C during one hour with periodic shaking. This was neutralized with 100 microliters of buffer TRIS/CIH (pH 8.6). The antigen was investigated in the original sample, supernatant and sediment. Samples of 105 patients with positive serology, confirmed by Western Blot following CDC criteria, were processed. The antigen was detected in 62 (59%) samples precipitated with PEG, but only 35 (33%) when conventional methods were used. Applying statistics X2: 13.97, P < 0.001, a highly significant association can be observed between PEG dissociation treatment and antigen detection. 27 negative sera by the standard method became positive in the whole sediment, and only 8 in the supernatant. In addition, 40 negative sera were processed, which had not become positive for the antigen by PEG treatment.
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PMID:[Detection of human immunodeficiency virus antigen both free and in immune complexes]. 858 50

Cucurbita maxima trypsin inhibitor I (CMTI-I), a member of the squash-type protease inhibitor family, is composed of 29 amino acids and shows strong inhibition of trypsin by its compact structure. To study the structure-function relationship of this inhibitor using protein engineering methods, we constructed an expression system for CMTI-I as a fused protein with porcine adenylate kinase (ADK). A Met residue was introduced into the junction of ADK and CMTI-I to cleave the fusion protein with CNBr, whereas a Met at position 8 of authentic CMTI-I was replaced by Leu. Escherichia coli JM109 transformed with the constructed plasmid expressed the fused protein as an inclusion body. After cleavage of the expressed protein with CNBr, fully reduced species of CMTI-I were purified by reversed-phase HPLC and then oxidized with air by shaking. For efficient refolding of CMTI-I, we used 50 mM NH4HCO3 (pH 7.8) containing 0.1% PEG 6000 at higher protein concentration. Strong inhibitory activity toward trypsin was detected only in the first of three HPLC peaks. The inhibitor constant of CMTI-I thus obtained, in which Met8 was replaced by Leu, was 1.4 x 10(-10) M. The effect of replacement of Met with Leu at position 8 was shown to be small by comparison of the inhibitor constant of authentic CMTI-III bearing Lys at position 9 (8.9 x 10(-11) M) with that of its mutant bearing Leu at position 8 and Lys at position 9 (1.8 x 10(-10) M). To investigate the role of the well conserved hydrophobic residues of CMTI-I in its interaction with trypsin, CMTI-I mutants in which one or all of the four hydrophobic residues were replaced by Ala were prepared. The inhibitor constants of these mutants indicated that those with single replacements were 5-40 times less effective as trypsin inhibitors and that the quadruple mutant was approximately 450 times less effective, suggesting that the hydrophobic residues in CMTI-I contribute to its tight binding with trypsin. However, each mutant was not converted to a temporary inhibitor.
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PMID:Synthesis of a squash-type protease inhibitor by gene engineering and effects of replacements of conserved hydrophobic amino acid residues on its inhibitory activity. 901 Sep 39

A total of 498 porcine embryos at various stages of development collected from superovulated gilts was used to investigate cryopreservation. First, blastocysts (BL), expanded blastocysts (ExB), and hatched blastocysts (HB) were used to determine the effect of exposure to concentrated solutions of ethylene glycol as cryoprotective additives (CPAs) on embryo survival. Then, survival of other embryos after vitrification by rapid cooling was determined. Based on their development after 48 h in culture, embryos were not injured by being exposed to 2.0 M ethylene glycol (EG) for 15 min or to 2.0 M EG for 5 min and then to a solution of 8.0 M EG in 7% polyvinylpyrrolidone (PVP) for 1 min. The CPAs were removed from the embryos by diluting them with 1.7 M galactose. To vitrify the embryos, they were exposed to 2.0 M EG for 5 min and then were pipetted directly into short columns of 8.0 M EG-PVP contained within (1.25-ml plastic straws and separated from long columns of 1.7 M galactose by an air bubble. The straws were plunged directly into LN2. After the straws were warmed rapidly in a 25 degrees C water bath, the embryos were immediately mixed with galactose within the straws by shaking them vigorously to mix the contents. In sequential experiments, three methods were used to dilute the CPA solutions. Method 1: Embryos in the EG-PVP-galactose mixture were expelled from the straws and rinsed and cultured in modified CZB medium (mCZB). Method II: Embryos in the mixture were placed briefly into 1.5 M EG and then rinsed and cultured in mCZB. Method III: Embryos in the mixture were rinsed in 1.0 M EG and then in 0.5 M EG and finally rinsed with mCZB and cultured. After 48 h in culture, the respective percentages of survival of embryos vitrified as BL, ExB, or HB were: Method I, 21, 32, and 13%; Method II, 9, 40, and 24%; Method III, 35, 85, and 71%. Of 20 additional ExB vitrified embryos diluted by Method III and transferred into a recipient, four developed into live piglets; two other recipients failed to litter although one had been pregnant for 65 days. These results demonstrate that porcine embryos can be successfully cryopreserved by rapid cooling in EG-PVP and by careful dilution of the CPA after warming.
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PMID:Piglets produced by transfer of vitrified porcine embryos after stepwise dilution of cryoprotectants. 950 Sep 30

Liquid-liquid equilibrium (LLE) compositions and interfacial tensions of the aqueous two-phase system containing poly(ethylene glycol) (PEG 4000, average Mr=3500; PEG 6000, average Mr=7500; and PEG 20000, average Mr =20000) and dipotassium hydrogenphosphate were experimentally determined by using a shaking flask method and a drop volume method at 288.15, 298.15 and 308.15 K, respectively.
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PMID:Interfacial tension of aqueous two-phase systems containing poly(ethylene glycol) and dipotassium hydrogenphosphate. 970 1

Busulphan (Bu) is an alkylating agent used in preparative regimen before stem cell transplantation (SCT). Bu has a narrow therapeutic window, and underdosing or overdosing may have a fatal outcome for the patient. Therapeutic drug monitoring (TDM) combined with dose adjustment is currently used to optimize and individualize therapy with Bu. However, this approach is limited to centers with laboratory facilities. An automated and easy method for measurement of Bu plasma concentrations may facilitate TDM for Bu and thus improve the clinical outcome. A solid-phase microextraction (SPME) on line with gas chromatography (GC) and mass-spectrometric detection to quantify Bu in human plasma samples was developed using in-vial derivatization. Bu was mixed with reagent in a 2-mL vial and shaken for 15 minutes at 80 degrees C; subsequently, the SPME fiber was immersed into the vial for 15 minutes. The fiber was washed in water for 10 seconds before injection. Several parameters influencing the extraction and recovery were studied, such as absorption and desorption times, the effects of the temperature on the reaction, and the shaking time on the derivatization yield. Carbowax-divinylbenzene, polyacrylate, and polydimethylsiloxane fibers were tested. The carbowax-divinylbenzene fiber resulted in the highest recovery in plasma samples. The validation of the method showed a high chromatographic selectivity and a good sensitivity (LOQ = 20 ng/mL). Coefficient of variation for SPME was less than 15%. The results showed good correlation between Bu concentrations and response within the range of 40 to 2500 ng/mL (R2 = 0.999). The accuracy ranged from 94% to 106%. This is well in line with the international criteria for validation. The present method was applied to patient plasma. The obtained results were comparable with the results obtained from GC with electron capture detection. The authors conclude that this method has shortened the analysis time considerably and is fully automated, which benefits TDM of Bu in SCT patients.
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PMID:On-line derivatization utilizing solid-phase microextraction (SPME) for determination of busulphan in plasma using gas chromatography-mass spectrometry (GC-MS). 1276 72


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