Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0393754 (HSA)
 2,996 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

For the first time results of investigations on rats with radioactive compounds in autochtonal tumors of the central nervous system, induced via placenta by Ethyl-Nitrose-Urea (ENU), are reported. In contrast to transplantation tumors the tumors induced by ENU are comparable in regard to the szintigrafic results with human brain tumors. The radiopharmaceuticals 131I-HSA, 99mTc-Pertechnetate, 203Hg-Chlormerodrin and 113m/111In-DTPA are similar to human brain tumors taken up by the ENU-tumors. For these findings it may be important, that the ENU-tumors are of neurogenic origin and do not differ histologically from the human brain tumors. The accumulation of the radioactive substances in ENU-tumors can be explained with the lesion at the blood-brain-barrier and at the blood-nerv-barrier. Therefore, it is discussed that the mechanism of the uptake is similar in human brain neoplasms and in ENU-tumors of the brain. The ENU-tumor model is suitable for testing new radiopharmaceuticals before their application in men.
 ...
PMID:[Experimental investigations on the accumulation of radioactive compounds in autochtonal tumors in the rat (author's transl)]. 17 56

Radioactive tracers and immunofluorescence were employed to detect and quantitate fibrinogen/fibrin deposition in two types of cell-mediated hypersensitivity reactions in the guinea pig. Classic delayed hypersensitivity (DH) reactions to Old Tuberculin and to the azobenzenearsonate hapten were characterized by a progressive increase in the fibrinogen (125-I-HF) content which exceeded that of the albumin tracer (131-I-HSA) and paralleled the development of induration and erythema. Accumulation of 125-I-HF could be related both to increased vascular permeability to 125-I-HF and, more specifically, to retarded efflux of extra vascular 125-I-HF from tuberculin reaction sites. Warfarin inhibited 125-I-HF accumulation and the formation of urea-insoluble 125-I-HF (cross-linked fibrin) as well as induration in tuberculin reactions. Immunofluorescence studies revealed the site of Fib deposition to be extravascular, among the connective tissue fibers of the dermis, similar to that in DH reactions in man. In contrast, little 125-I-HF accumulated in cell-mediated reactions rich in basophils--cutaneous basophil hypersensitivity (CBH) reactions to keyhole limpet hemocyanin, ovalbumin, and dinitrochlorobenzene--due in part to less vascular leakage of macromolecules and to decreased formation of urea-insoluble fibrin. By immunofluorescence Fib deposits were found in CBH reactions in a pattern similar to that in DH reactions, but the intensity of staining was appreciably less. Thus, fibrin accumulation further distinguishes DH from CBH reactions and is very likely responsible for the induration characteristic of DH reactions.
 ...
PMID:Role of the clotting system in cell-mediated hypersensitivity. II. Kinetics of fibrinogen/fibrin accumulation and vascular permeability changes in tuberculin and cutaneous basophil hypersensitivity reactions. 109 Jun 56

Hydroxy-urea bearing albumin microspheres were prepared using the polymer dispersion method. Glycerol was used successfully in place of water as an internal phase of w/o emulsion, to prepare HSA based albumin microspheres. Silicone coated magnetite of nanometeric size was incorporated in the drug bearing microspheres. The process variables which could affect the physical characteristics with respect to in vitro and in vivo performance of the prepared microspheres were studied. The in vitro release of the drug from the microspheres followed a linear relationship when commulative per cent drug release was plotted against square root of time. Microspheres of average size 1-4 microns were studied for in vivo distribution and localization. It was established that 67 per cent of the drug enveloped in magnetic albumin microspheres could be localized in a rat tail target segment, on applying an external magnetic field of strength 8000 Oe. A remarkable stabilization of hydroxy urea in the prepared microspheres was recorded when t10% drug degradation was compared with the albumin microspheres prepared by a conventional emulsion polymerization method using water as an internal phase.
 ...
PMID:Hydroxy-urea bearing albumin microspheres--preparation, characterization and evaluation. 188 Jun 96

Nuclear proteins contain specific regions that are required for entry into the nucleus. Using ligand blotting, we have shown that a 67-kDa yeast nuclear envelope protein (p67) recognizes synthetic peptides containing the yeast histone H2B or simian virus 40 large tumor antigen nuclear localization sequence. Both free peptide and peptide conjugated to human serum albumin are recognized. The interaction between p67 and the nuclear localization sequences is specific; neither a mutant peptide that is incompetent for nuclear transport in vivo nor HSA can interact with p67 on blots. Moreover, although the wild-type peptide competes for binding to p67, the mutant peptides do not. p67 appears to be located at the nuclear envelope and is not present in other subcellular fractions. The nuclear localization sequence-binding protein is not extracted from the nuclear envelope with nonionic detergents and only partially extracted with high-salt buffer or 8 M urea, suggestive of a tight association with the nuclear envelope. Together our results are consistent with a role for p67 in nuclear transport.
 ...
PMID:Identification and characterization of a nuclear localization sequence-binding protein in yeast. 268 60

An enzyme-linked immunosorbent assay (ELISA) has been developed for unambiguous detection of antibodies against the sulphydryl drug D-penicillamine (PA) and its disulphide-conjugated metabolites. Disulphide-linked PA human serum albumin (PA-HSA) conjugates for use as coating antigens were prepared by a range of procedures employing oxidation with either potassium ferricyanide (0.1 M) or cupric sulphate (5 ppm). A satisfactory degree of conjugation was achieved by both oxidative procedures. Hapten density and antigenicity were increased when urea-denatured rather than non-denatured HSA was used. In 2 out of 3 rabbits, a specific IgG anti-PA response was detected following monthly injection of PA keyhole limpet haemocyanin (PA-KLH) in Freund's complete adjuvant. In the third rabbit, any anti-PA activity was obscured by a high level of binding to HSA. The anti-PA response was slow to develop in the 2 responder rabbits (requiring four injections) and was of low intensity (antibody titres less than 6,000). In contrast, the IgG antibody response to the structurally related drug captopril (CP), administered under identical conditions, was rapid in onset and of greater intensity (titres greater than 6,000 after one injection of CP-KLH). The hapten specificity of the IgG anti-PA-HSA antisera was defined by ELISA inhibition assays. Binding of IgG to PA-HSA was inhibited by PA, PA disulphide, PA cysteine and disulphide-linked PA-HSA conjugates, but not by PA acetone (thiazolidine ring-linked PA), CP, or unconjugated HSA. The inhibitory preparations were inactive in unrelated ELISAs.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:A specific enzyme-linked immunosorbent assay for definition of the IgG antibody response to disulphide-conjugated D-penicillamine in the rabbit. 330 11

A crossover study to compare the effects of seven different dialysers on intradialytic symptoms in 37 patients during dialysis with acetate-containing dialysate was performed at five centres in four countries. The same manufacturing lot of each dialyser and of blood line sets were used by all centres. The same clinical data (duration of dialysis, blood pressure, weights, temperature, drugs, symptoms, and treatments) and technical data (blood flow, dialyser clearance, and ultrafiltration rate) were collected. Kt/V for urea was used to determine dialysis prescribed. Intradialytic symptoms and signs were measured hourly or when observed by staff using the haemodialysis treatment form (see Introduction). After each week of treatment with a particular dialyser, patients completed a questionnaire relating to the presence and severity of symptoms. (Only presence or absence of symptoms are presented.) Wide differences in dialysis duration and blood flow between centres were noted. These may have contributed to the differences between centres in relationship to staff reported responses to different dialyser: Dialysers with the lowest incidence of both signs and symptoms and of chest pain, back pain, and itching (arbitrarily designated bioincompatibility symptoms) were the Duo-Flux and Filtral, with the G120 M, the CD 4000, and the T 150 having the highest incidence. By patient questionnaire the most biocompatible dialysers were the T 150, F 60, and the Filtral, with the most symptom producing being the G120 M and the G10-3N. Perceptions of symptoms between patients and staff differed substantially overall and between centres. Hypersensitivity reactions were noted in two patients, both occurring with cuprammonium cellulose hollow-fibre dialysis, despite adherence to manufacturers' instructions concerning saline priming and removal. Both patients showed antibody titres greater than 1:160 against ethylene oxide-HSA. Ethylene oxide was not detected (limit of detection 1 part per million) in dialysers, blood line sets, or fistula needles. The study suggests that dialysis symptom reporting is complicated by individual perceptions, staff reactions, and the efficiency of recording. In this study ethnic and cultural differences must be added to the haemodynamic differences and other prescription-related elements in influencing symptoms. Despite these problems a hierarchy of dialyser-related symptoms and signs could be discerned which largely paralleled laboratory findings of biocompatibility. Future comparative studies relating symptomatology to membrane and dialyser structure should consider the variables identified as influencing symptoms and their reporting.
 ...
PMID:Relationship between dialyser type and signs and symptoms. 827 50

The present report describes application of advanced analytical methods to establish correlation between changes in human serum proteins of patients with coronary atherosclerosis (protein metabolism) before and after moderate beer consumption. Intrinsic fluorescence, circular dichroism (CD), differential scanning calorimetry and hydrophobicity (So) were used to study human serum proteins. Globulin and albumin from human serum (HSG and HSA, respectively) were denatured with 8 m urea as the maximal concentration. The results obtained provided evidence of differences in their secondary and tertiary structures. The thermal denaturation of HSA and HSG expressed in temperature of denaturation (Td, degrees C), enthalpy (DeltaH, kcal/mol) and entropy (DeltaS kcal/mol K) showed qualitative changes in these protein fractions, which were characterized and compared with fluorescence and CD. Number of hydrogen bonds (n) ruptured during this process was calculated from these thermodynamic parameters and then used for determination of the degree of denaturation (%D). Unfolding of HSA and HSG fractions is a result of promoted interactions between exposed functional groups, which involve conformational changes of alpha-helix, beta-sheet and aperiodic structure. Here evidence is provided that the loosening of the human serum protein structure takes place primarily in various concentrations of urea before and after beer consumption (BC). Differences in the fluorescence behavior of the proteins are attributed to disruption of the structure of proteins by denaturants as well as by the change in their compactability as a result of ethanol consumption. In summary, thermal denaturation parameters, fluorescence, So and the content of secondary structure have shown that HSG is more stable fraction than HSA.
 ...
PMID:Structure characterization of human serum proteins in solution and dry state. 1190 9

The urea-induced unfolding of 'N' isomer (occurring at pH 7.0) and 'B' isomer (occurring at pH 9.0) of human serum albumin was studied by fluorescence and circular dichroism spectroscopic measurements. Urea-induced destabilization in different domains of both the isomers was monitored by using domain specific ligands, hemin (domain-I), chloroform, bilirubin (domain-II), and diazepam (domain-III). Urea-induced denaturation of N and B isomers of HSA showed a two-step, three-state transition with accumulation of intermediates around 4.8-5.2M and 3.0-3.4M urea concentrations, respectively. During first transition (0-4.8M urea for N isomer and 0-3.0M urea for B isomer) a continuous decrease in diazepam binding suggested major conformational changes in domain-III prior to intermediate formation. On the other hand, binding of hemin, a ligand for domain-IB and chloroform, whose binding site is located in domain-IIA remains unchanged up to 5.0M urea for N isomer and 3.0M urea for B isomer. Similarly, fluorescence intensity of Trp-214 that resides in domain-IIA remained unchanged up to the above-said urea concentrations and decreased thereafter. Absence of any decrease in hemin binding, chloroform binding, and Trp-214 fluorescence suggested the non-involvement of domain-IB and domain-IIA in intermediate formation. A significant increase in bilirubin binding prior to intermediate formation showed favorable conformational rearrangement in bilirubin binding cavity formed by loop 4 of domain-IB and loop 3 of domain-IIA. Further, a nearly complete abolishment of bilirubin binding to both isomers around 7.0M and 6.0M urea concentrations, respectively, indicated complete separation of domain-I from domain-II from each other. From these observations it can be concluded that N to B transition of human serum albumin shifted the intermediate formation towards lower urea concentration (3.0-3.4M urea for B isomer as against 4.8-5.2M urea for N isomer). Further both the intermediates were found to possess similar alpha-helical (approximately 39%) content and ligand binding properties.
 ...
PMID:Intermediate formation at lower urea concentration in 'B' isomer of human serum albumin: a case study using domain specific ligands. 1471 61

The human serum albumin is known to undergo N <==> F (neutral to fast moving) isomerization between pH 7 and 3.5. The N < ==> F isomerization involves unfolding and separation of domain III from rest of the molecule. The urea denaturation of N isomer of HSA shows two step three state transition with accumulation of an intermediate state around 4.8-5.2 M urea concentration. While urea induced unfolding transition of F isomer of HSA does not show the intermediate state observed during unfolding of N isomer. Therefore, it provides direct evidence that the formation of intermediate in the unfolding transition of HSA involves unfolding of domain III. Although urea induced unfolding of F isomer of HSA appears to be an one step process, but no coincidence between the equilibrium transitions monitored by tryptophanyl fluorescence, tyrosyl fluorescence, far-UV CD and near-UV CD spectroscopic techniques provides decisive evidence that unfolding of F isomer of HSA is not a two state process. An intermediate state that retained significant amount of secondary structure but no tertiary structure has been identified (around 4.4 M urea) in the unfolding pathway of F isomer. The emission of Trp-214 (located in domain II) and its mode of quenching by acrylamide and binding of chloroform indicate that unfolding of F isomer start from domain II (from 0.4 M urea). But at higher urea concentration (above 1.6 M) both the domain unfold simultaneously and the protein acquire random coil structure around 8.0 M urea. Further much higher KSV of NATA (17.2) than completely denatured F isomer (5.45) of HSA (8.0 M urea) suggests the existence of residual tertiary contacts within local regions in random coil conformation (probably around lone Trp-214).
 ...
PMID:Urea induced unfolding of F isomer of human serum albumin: a case study using multiple probes. 1592 4

In recent studies, the cytotoxic activity of NO has been investigated for its potential use in anticancer therapies. Nitrosated human serum albumin (NO-HSA) may act as a reservoir of NO in vivo. However, there are no published reports regarding the effects of NO-HSA on cancer. Therefore, the present study investigated the antitumor activity of NO-HSA. NO-HSA was prepared by incubating HSA, which had been sulfhydrylated using iminothiolane, with isopentyl nitrite (6.64 mol NO/mol HSA). Antitumor activity was examined in vitro using murine colon 26 carcinoma (C26) cells and in vivo using C26 tumor-bearing mice. Exposure to NO-HSA increased the production of reactive oxygen species in C26 cells. Flow cytometric analysis using rhodamine 123 showed that NO-HSA caused mitochondrial depolarization. Activation of caspase-3 and DNA fragmentation were observed in C26 cells after incubation with 100 muM NO-HSA for 24 h, and NO-HSA inhibited the growth of C26 cells in a concentration-dependent manner. The growth of C26 tumors in mice was significantly inhibited by administration of NO-HSA compared with saline and HSA treatment. Immunohistochemical analysis of tumor tissues demonstrated an increase in terminal deoxynucleotidyl transferase dUTP nickend labeling-positive cells in NO-HSA-treated mice, suggesting that inhibition of tumor growth by NO-HSA was mediated through induction of apoptosis. Biochemical parameters (such as serum creatinine, blood urea nitrogen, aspartate aminotransferase, and alanine aminotransferase) showed no significant differences among the three treatment groups, indicating that NO-HSA did not cause hepatic or renal damage. These results suggest that NO-HSA has the potential for chemopreventive and/or chemotherapeutic activity with few side effects.
 ...
PMID:Design and evaluation of S-nitrosylated human serum albumin as a novel anticancer drug. 1821 31


1 2 3 Next >>