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PubMed1996

In vivo behavior of liposomes modified with a novel galactosyllipid derivative.

We studied the in vivo behavior of galactosyllipid-modified liposomes for targeting the asialoglycoprotein receptor present on the surface of liver parenchymal cells. We examined the effects of the lipid composition of liposomes on the in vivo behavior of galactosyllipid-modified liposomes, and found good accumulation in the liver of liposomes of a high cholesterol content and liposomes made of lipids of a high gel-liquid crystalline phase transition temperature. The amount of modification with the galactosyllipid derivative required for effective targeting to the liver was found to be more than 5% of the total lipids. The concentration of galactosyllipid-modified liposomes was lower than that of control liposomes in all the organs except for the liver, showing high selectivity of galactosyllipid-modified liposomes for the liver. Hepatic accumulation of liposomes was inhibited by preinjection of asialofetuin. This result suggests that hepatic accumulation of ¿8-(2-hexadecyloctadecanoylamido)-3,6-dioxaoctyl¿-beta-D-gal actoside (Gal-t-psa) liposome was involved with the asialoglycoprotein receptor in the liver. Therefore, it was concluded that our neogalactolipid-modified liposomes are useful for selective delivery to the liver.

Animals↗
PubMed2007

Characterization of novel mixed polyethyleneglycol modified liposomes.

In our previous paper, mixed polyetheleneglycol (PEG) modification of liposomes by a mixture of 1-monomethoxypolyethyleneglycol-2,3-distearoylglycerol (PEG-DSG) with short polyoxyethylene chain and PEG-DSG with long one was shown to increase fixed aqueous layer thickness (FALT) around the liposomal membrane, and this was useful in vivo. In this study, we investigated the characterization of mixed PEG modification of liposomes with different anchors (PEG2000-DSG and PEG2000-cholesterol (CHO)). When the liposomes was modified by a mixture of PEG2000-DSG and PEG2000-CHO, FALT was increased compared to that of each single PEG-lipids modification and the most suitable mix modification (PEG2000-DSG:PEG2000-CHO = 3:1) showed a maximum FALT. This phenomenon was speculated to be based on the difference in the insertion state of the PEG anchor unit in the liposomal membrane. PEG-CHO-modified liposomes (single or mixed PEG-modified liposomes) were easily incorporated into the liposomal membranes compared with that of single PEG-DSG-modified liposomes. Namely, it was considered that the cholesterol anchor as a single chain was able to be easily introduced, compared with the DSG anchor as two chains, and induced some interaction with both PEG modification. In conclusion, it is expected that novel PEG-modified liposomes with PEG2000-DSG and PEG2000-CHO (3:1) had superior physicochemical properties.

Cholesterol↗
PubMed1989

A comparison of bovine serum albumins, modified with a variety of carboxyl group agents, as stimulators of tissue-type plasminogen activator-catalyzed activation of plasminogen.

Bovine serum albumins (BSA), modified with a variety of carboxyl group agents, stimulated the tissue-type plasminogen activator (t-PA)-catalyzed activation of human plasminogen. Modification with taurine (tau) and putrescine (put) provided the best stimulants. The tauBSA and putBSA were effective at a concentration of 5 micrograms/ml and enhanced the Lys-plasminogen activation by two-chain t-PA in a dose-dependent manner to a maximum of 44- to 46-fold at 200 micrograms/ml. The Km values for the activation of Glu-plasminogen by t-PA in the presence of tauBSA and putBSA (100 micrograms/ml) were 1.7 and 1.8 microM, while the kcat values were 0.059 and 0.062 s-1, respectively. T-PA was bound to both tauBSA and putBSA, which were immobilized on agarose beads, with KD values of 163 and 138 nM, respectively. The two modified BSAs were good substrates for plasmin and were hydrolyzed by the enzyme to small peptides. All of these modified BSA-related actions were inhibited by lysine analogs (e.g. tranexamic acid) which were adjusted to the concentrations required for the inhibition of the plasminogen (Kringle 1 domain) binding to fibrin. On the other hand, acetylation or succinylation of the amino groups of BSA was not effective, while alkylation of the thiol groups of this protein resulted in a moderate stimulation of the plasmin generation. The present results show that t-PA and plasminogen form complexes with certain charge-modified BSAs via their lysine-binding sites. The different stimulation potency of modified BSAs may provide a model for in vivo counterparts of fibrin.

Animals↗
PubMed2004

Catalytic activity for decomposition of hydrogen peroxide by metal complexes of water-soluble thiacalix[4]arenetetrasulfonate on the modified anion-exchangers.

The catalytic activity for the decomposition of hydrogen peroxide by anion-exchangers modified with metal complexes of thiacalix[4]arenetetrasulfonate (Me(n+)-TCAS[4], Me(n+)=Mn(3+), Mn(2+), Fe(3+), Co(3+), Co(2+), Cu(2+), Zn(2+) and Ni(2+)) was investigated. As a reference, calix[4]arenetetrasulfonate, calix[6]arenehexasulfonate and calix[8]areneoctasulfonate were also examined. Mn(3+)- and Fe(3+)-TCAS[4] on the modified anion-exchangers showed high catalytic activity in alkaline buffer solutions among metal complexes tested. Mn(3+)- and Fe(3+)-TCAS[4] on the modified anion-exchangers exhibited high and constant levels of catalytic activity even after having been used 5 times, and showed catalytic activity in the presence of an excess of H(2)O(2) over Mn(3+)- and Fe(3+)-TCAS[4] on the modified anion-exchangers. Only Mn(3+)-TCAS[4] on the modified anion-exchangers exhibited high catalytic activity at around a neutral pH.

Anion Exchange Resins↗
PubMed2006

Amperometric sensor for the determination of ascorbic acid based on Cobalt hexacyanoferrate modified electrode fabricated through a new route.

A new approach was attempted to prepare a chemically modified electrode using Cobalt hexacyanoferrate (CoHCF) as the redox mediator and to study its stability and electrocatalytic activity for ascorbic acid (AA) oxidation. The basic principle underlying the electrode modification is the coordination of cobalt ion with the amino nitrogen of aniline adsorbed on the surface of a graphite rod. This surface was subsequently derivatized with ferrocyanide to get CoHCF film on the electrode surface. The CoHCF modified electrode as prepared above was characterized using cyclic voltammetry. The effect of scan rate, supporting electrolyte and pH of the medium on the performance of the modified electrode was investigated. The CoHCF modified electrode exhibited good electrocatalytic activity towards the oxidation of ascorbic acid and gave a linear response from 5.52 x 10(-5) M to 3.23 x 10(-2) M with a correlation coefficient of 0.9929. The detection limit was found to be 3.33 x 10(-5) M. Hydrodynamic voltammetry and chronoamperometry studies for the oxidation of ascorbic acid were also carried out. The electrode was highly stable and exhibited good reproducibility. This modified electrode was also applied for the determination of ascorbic acid in commercial samples.

Ascorbic Acid↗
PubMed1988

Modified Fontan operation for complex cardiac anomalies--postoperative hemodynamics, cardiac function and clinical status.

The purpose of this paper is to compare and define the postoperative hemodynamics, cardiac function and clinical status after the modified Fontan operation in patients with complex cardiac anomalies. Thirteen consecutive patients (6 with double-outlet right ventricle [DORV] [SLL : 4, SDL : 2], 5 with single ventricle [SV] [A-III : 3, B-III : 1, C-III : 1] and 2 with tricuspid atresia [TA] [Ib : 1, IIb : 1]) underwent the modified Fontan operation. These 13 patients ranging in age from 7 to 42 years of age (mean 18) were catheterized at 7 to 46 months (mean 8 months) postoperatively. Pressure tracings at rest demonstrated a dominant "a" wave in both the right atrium and the pulmonary artery suggesting a marked right atrial contraction after this operation. Left ventricular filling pressure was significantly decreased after the modified Fontan operation in DORV and SV. The ejection fraction and left ventricular end-diastolic volume index were unchanged or slightly increased after the modified Fontan operation. Cardiac index in 6 patients with DORV was significantly increased from rest to exercise by +48% (p less than 0.05) with a significant increase in the stroke volume (p less than 0.05) and with a slight increase in heart rate, but this index in 5 patients with SV and in 2 patients with TA was not significantly increased from rest to exercise. In the postoperative clinical status, 11 of 13 patients were in NYHA class I and 2 in class II at follow-up periods ranging from 4 to 75 months (mean 48 months). These results suggest that the modified Fontan operation can be of value and can provide excellent exercise tolerance for patients with complex cardiac lesions.

Adolescent↗
PubMed1993

[Dietary fiber intake and intake patterns among the general population in Aomori, calculated using modified Southgate and Prosky methods].

Based on the result of the Aomori Nutrition Survey, we have calculated daily dietary fiber (DF) intake using modified Southgate and Prosky methods. Result obtained were as follows: DF intake in Aomori was 23.7 +/- 8.4g by the modified Southgate method, and 22.2 +/- 8.5g by the modified Prosky method. As for supply sources of DF, 32.3% was from grains; 22.7%, vegetables; 15.6%, beans; and 7.8%, fruits calculated by the modified Southgate method, and 31.3%, vegetables; 19.0%, grains; 18.0%, beans; and 11.6%, fruits by the modified Prosky method. As to types of DF, intake of hemicellulose was 11.5 +/- 4.2g, cellulose 7.8 +/- 3.0g and lignin 4.4 +/- 2.3g. In the group with DF intake below 10.0g, DF came mainly from grains and fruits, while the group with DF intake above 30.0g took DF from various foods.

Adolescent↗
PubMed2001

Small-angle X-ray scattering analysis of stearic acid modified lipase.

Stearic acid modified lipase (from Rhizopus japonicus) exhibited remarkable interesterification activity in n-hexane, but crude native lipase did not. The structure of the fatty acid modified lipase had not been analyzed until now. We analyzed the modified lipase by small-angle X-ray scattering (SAXS) measurements in order to clarify the structure. SAXS measurements showed that the modified lipase consisted of a lipid lamellar structure and implied that the lipase was incorporated into the lamellar structure of stearic acid. The long spacings in the lamellar structures of the modified lipase and stearic acid were measured.

Algorithms↗
PubMed2003

A modified ultrasensitive assay to detect quantified HIV-1 RNA of fewer than 50 copies per milliliter.

We compared the sensitivity and specificity of versions 1.0 and 1.5 and a modified version 1.5 of the AMPLICOR HIV-1 MONITOR ultrasensitive RNA assay (Roche, Indianapolis, IN) by using a virus stock dilution series and plasma samples from HIV-1-infected and uninfected subjects. The modified assay was linear and consistently positive down to 12 copies per milliliter vs 25 copies per milliliter for the other 2 assays. Versions 1.0, 1.5, and modified 1.5, respectively, detected 9 (23%) of 39, 11 (28%) of 40, and 43 (61%) of 71 replicates of a 4-copy-number and 11 (28%) of 40, 17 (46%) of 37, and 88 (90%) of 98 replicates of a 10-copy-number standard. Of 44 patient samples with undetectable levels using version 1.0, 32 (73%) had detectable levels on the modified assay, and 5 (25%) of 20 had detectable levels on version 1.5. None of the assays detected HIV-1 RNA in HIV-1 antibody-negative samples. The modified version 1.5 of the RNA assay is more sensitive for detecting HIV-1 RNA in significantly more patients than are versions 1.0 and 1.5.

Gene Dosage↗
PubMed1995

A modified Abrams needle biopsy technique.

STUDY OBJECTIVE: To compare the diagnostic sensitivity of a modified Abrams needle pleural biopsy technique (A1) with the standard Abrams (A2) and Cope needle biopsy methods. The modified Abrams pleural biopsy technique consisted of suctioning each tissue sample into a syringe without removing the needle completely from the chest until the completion of the entire procedure. Both the standard Abrams and Cope needle techniques required needle removal from the chest after each pleural biopsy. DESIGN: Retrospective chart analysis. SETTING: Community teaching hospital affiliated with Stanford University. PATIENTS: Forty-seven patients (30 men and 17 women) with a mean age 44.5 years (range, 19 to 81 years) who were referred to a pulmonary consultation service for pleural biopsy. INTERVENTIONS: Two of us (C. M. K. and F. T. K.) used the modified Abrams technique and two of us (W. A. J. and A. C. C.) used the standard Abrams technique. The Cope needle was used as originally described. MEASUREMENTS: We recorded the type of pleural biopsy needle and technique used in each patient. Biopsy specimen diameter and number of tissue samples obtained, final diagnoses, and complications were recorded. RESULTS: The diagnostic sensitivity for tuberculous pleurisy was 82% for the modified Abrams method, 71% for the standard Abrams method, and 88% for the standard Cope technique (p > or = 0.3). There was no difference in size of tissue sample obtained (A1 vs A2), number of biopsies, or complications among the three methods of pleural biopsy. CONCLUSIONS: The modified method of Abrams needle biopsy demonstrates a diagnostic sensitivity for pleural tuberculosis (82%) that is equivalent to that for the standard Abrams or Cope methods.

Adult↗
PubMed2004

Detection and quantification of modified nucleotides in RNA using thin-layer chromatography.

Identification of a modified nucleotide and its localization within an RNA molecule is a difficult task. Only direct sequencing of purified RNA molecules and high-performance liquid chromatography mass spectrometry analysis of purified RNA fragments allow determination of both the type and location of a given modified nucleotide within an RNA of 50-150 nt in length. The objective of this chapter is to describe in detail a few simple procedures that we have found particularly suited for the detection, localization, and quantification of modified nucleotides within an RNA of known sequence. The methods can also be used to reveal the enzymatic activity of a particular RNA-modifying enzyme in vitro or in vivo. The procedures are based on the use of radiolabeled RNA (with [32P], [14C], or [3H]) or [32P]-postlabeled oligonucleotides and two-dimensional thin-layer chromatography of labeled nucleotides on cellulose plates. This chapter provides useful maps of the migration characteristics of 70 modified nucleotides on thin-layer cellulose plates.

5' Untranslated Regions↗
PubMed2002

A modified hMG-GnRH method for the induction of ovulation in infertile women with severe hypogonadotropic amenorrhea.

The objective of this study was to compare, in infertile women suffering from severe hypogonadotropic amenorrhea, the therapeutic utility and the incidence of complications arising from fertility treatment by the conventional human menopausal gonadotropin/human chorionic gonadotropin (hMG-hCG) method, the hMG step-down method, the sequential hMG/gonadotropin-releasing hormone (GnRH) method and a new, modified hMG-GnRH method that has been developed by us. In the step-down method, the daily dose of hMG was decreased from 150 IU to 75 IU when the follicle diameter reached 11-13 mm. In the sequential hMG-GnRH, hMG injection was switched to pulsatile GnRH administration (20 microg/120 min SC), when the follicle diameter reached 11-13 mm. In our new modified hMG-GnRH, pulsatile GnRH was injected together with hMG. Daily hMG was stopped and the GnRH dosage was changed from 10 microg to 20 microg when the follicle diameter reached 11-13 mm. Initially, the three established methods were applied randomly to treat 34 cycles in 20 women; and subsequently, five patients who failed to conceive following treatment by sequential hMG-GnRH were then treated by the modified hMG-GnRH method. More than eight growing follicles and multiple pregnancies were observed during treatment by the conventional method. The incidence of ovarian hyperstimulation syndrome (OHSS) was 25.7% with the conventional method, 20.0% with the step-down method and 0% with the sequential hMG-GnRH method; however, the rate of ovulation was only 50% with the sequential hMG-GnRH method. By contrast, with the modified hMG-GnRH method, less than three growing follicles occurred in 81.8% of patients, there was a 100% rate of ovulation, and neither OHSS nor multiple pregnancies were observed. Moreover, the modified hMG-GnRH method induced pregnancy in 3 out of 5 patients. These data indicate that this new method is favorable for the treatment of severe hypogonadotropic amenorrhea.

Adult↗
PubMed2002

[Calcium-oxygen modified amorphous and nanocrystalline carbon layers as biomaterials].

Undoped and Ca-O-modified diamond-like carbon coatings were deposited by a direct current discharge. Hardness and Young's modulus of Ca-O-modified DLCs were reduced in comparison with the undoped DLC, but the adherence of the Ca-O-modified films is improved. Ca-O-modified DLCs have a higher fraction of nano-crystalline regions with carbon in sp2 hybridisation. In addition, an increased oxygen content and CaCO3 was identified in Ca-O-modified DLCs. While mouse fibroblasts of the type L929 attach and grow on unmodified diamond-like carbon coatings synthesized by the decomposition of hydrocarbon, the addition of CaO-H2O into the precursor gas improves the coatings biological acceptance by the cells.

Animals↗
PubMed2005

Antibody titer against malondialdehyde-modified LDL compares with HDL cholesterol concentration in identifying angiographically verified coronary artery disease. Comparison of tests by ROC analysis.

Antibody titer against malondialdehyde (MDA)-modified low-density lipoprotein (LDL) has been found to be associated with atherosclerosis, but it has not been established whether it would detect subjects with coronary artery disease (CAD). In the present study, receiver-operating characteristic (ROC) analysis was used to compare the diagnostic accuracy of the antibody titer against MDA-modified LDL and high-density lipoprotein (HDL) and LDL cholesterol levels in discrimination between subjects with (n = 51) and without (n = 35) angiographically verified 3-vessel CAD. As a result, the antibody titer against MDA-modified LDL was lower in subjects with CAD compared with subjects without CAD (p < 0.0001). The area under the ROC plot was 0.822 (95% CI, 0.727 to 0.918) for the antibody titer and 0.769 (95% CI, 0.661 to 0.876) for the HDL cholesterol concentration. Both the antibody titer and the plasma HDL cholesterol level were more accurate markers of CAD than the LDL cholesterol level. As a conclusion, our results indicate that the antibody titer against MDA-modified LDL discriminates between subjects with widespread CAD and those without CAD similarly as the HDL cholesterol concentration. Moreover, the antibody titer against MDA-modified LDL is inversely correlated with the risk of severe CAD.

Antibodies↗
PubMed2006

A modified method of prothrombin time/International Normalised Ratio determination in capillary blood and monitoring oral anticoagulant therapy.

BACKGROUND: Oral anticoagulant therapy is monitored by a prothrombin time (PT) assay. The PT is standardised by the International Normalised Ratio (INR). The purpose of this study was to work out a modified method of PT/INR measurement in capillary blood for monitoring anticoagulation treatment. METHODS: Healthy donors, subjects with high or low haematocrit values, and oral anticoagulant-treated patients were included in the study. Plasma and capillary blood PT/INRs were determined by the standard Quick clotting assay, by the modified approach and with the CoaguChek S analyser. RESULTS: The performance characteristics of the developed method were accuracy, due to taking into account whole capillary blood haematocrit values, and precision, due to a decrease in the viscosity of the analysed samples. Implementation of the modified method showed that it is possible to use PT values of normal plasma for capillary blood INR calculation. The developed method allowed the determination of PT in capillary blood within the haematocrit value range from 0.15 up to 0.7. For capillary blood, the results of the modified method closely correlated with PT/INR values determined by the reference Quick method in venous plasma (r=0.99) and with the CoaguChek S analyser (r=0.97). CONCLUSIONS: The modified method of capillary blood PT/INR determination could be recommended for oral anticoagulant therapy monitoring.

Administration, Oral↗
PubMed2006

Enhanced degradation of carbon tetrachloride by surfactant-modified zero-valent iron.

Sorption of carbon tetrachloride (CT) by zero-valent iron (ZVI) is the rate-limiting step in the degradation of CT, so the sorption capacity of ZVI is of great importance. This experiment was aimed at enhancing the sorption of CT by ZVI and the degradation rate of CT by modification of surfactants. This study showed that ZVI modified by cationic surfactants has favorable synergistic effect on the degradation of CT. The CT degradation rate of ZVI modified by cetyl pyridinium bromide (CPB) was higher than that of the unmodified ZVI by 130%, and the CT degradation rate of ZVI modified by cetyl trimethyl ammonium bromide (CTAB) was higher than that of the unmodified ZVI by 81%. This study also showed that the best degradation effect is obtained at the near critical micelle concentrations (CMC) and that high loaded cationic surfactant does not have good synergistic effect on the degradation due to its hydrophilicity and the block in surface reduction sites. Furthermore degradation of CT by ZVI modified by nonionic surfactant has not positive effect on the degradation as the ionic surfactant and the ZVI modified by anionic surfactant has hardly any obvious effects on the degradation.

Carbon Tetrachloride↗
PubMed1996

Role of Amadori-modified nonenzymatically glycated serum proteins in the pathogenesis of diabetic nephropathy.

Accelerated nonenzymatic glycation in diabetes, resulting in Amadori-modified proteins and the later-developing advanced glycation end-products, has been mechanistically linked to the pathogenesis of diabetic nephropathy. Recent focus on putative AGE-induced pathophysiology has shifted attention from the possible role of Amadori-modified proteins in the development of diabetic complications. Ample experimental evidence has demonstrated that Amadori-modified serum proteins adversely affect renal glomerular capillary function, structure, and metabolism. Previous studies from the laboratories of this study's authors have shown that human serum containing diabetic concentrations of albumin modified by Amadori-glucose adducts inhibits the replication of murine mesangial cells in culture and stimulates the production and gene expression of type IV collagen. Monoclonal antibodies (A717) specific for Amadori-glycated albumin prevent these abnormalities. In other studies, it has also been shown that in vivo administration of A717 (Fab fragments) retards the progression of diabetic nephropathy in diabetic db/db mice. Neutralizing the effects of the elevated circulating glycated albumin concentration is associated with reduction in proteinuria and mesangial matrix expansion, and prevention of the overexpression of mRNA encoding type IV collagen and fibronectin in the renal cortex. The renoprotective effects of A717 are independent of any change in blood glucose concentrations. These studies implicate Amadori-modified glycated albumin in the pathogenesis of diabetic nephropathy. It is proposed in this study that abrogating the biologic effects of increased glycated albumin in diabetes has novel therapeutic potential in the management of diabetic renal complications.

Aging↗
PubMed2004

Ion-exchange selectivity of anion exchange resin modified with polystyrenesulfonic acid.

In order to change the ion-exchange selectivity of anion-exchange resin, the surface of a gel-type anion exchange resin was modified with anionic polyelectrolyte, polystyrenesulfonic acid. Using this modified resin, the ion-exchange rate of nitrate was little decreased, but that of sulfate was evidently decreased. It is considered that the ion-exchange reaction of the multivalent anion is suppressed by the greater electrostatic repulsive force against the modification layer than that against the monovalent anion. Thus, this modified resin may be suitable for the selective separation of monovalent anions. The influence of the modified condition on the ion-exchange rate was examined. Furthermore, this modified resin was used to separate nitrate ions from sulfate ions in the aqueous solution.

Anion Exchange Resins↗