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Biomedical subjects

E Altman

Publications and source records attributed to E Altman.

At least 55 records · Page 3Linked to original sources
PubMed1997

Assessing substance use in multiproblem patients: reliability and validity of the Addiction Severity Index in a mental hospital population.

The Addiction Severity Index (ASI) is the most widely used measure of substance use in the field. Its reputation has been supported by reliability and validity studies. Despite its success, the psychometric properties of the ASI have not been examined in mental hospital populations. Our intent was to replicate prior studies and expand upon the validity of the ASI in a sample of 100 public psychiatric patients selected for a larger study. Findings revealed that a) reliability was acceptable, but there was only moderate agreement on the psychiatric scale severity score; b) the relationship between extent of rater training and reliability requires further study; c) despite some overlap, the scales were largely independent of each other; d) modification of the employment scale was necessary because of low correlations between the composite and severity score; e) raters are more responsive to client subjective ratings in psychiatric settings; f) ASI drug and alcohol scales correlate well with other substance use instruments and with DSM-III-R diagnoses; and g) the ASI can identify meaningful types of patient problems through cluster analysis. These findings, on the whole, support the use of the ASI drug and alcohol scales in public psychiatric hospitals.

Adult↗
PubMed1997

The expression of nonagglutinating fimbriae and its role in Proteus mirabilis adherence to epithelial cells.

Proteus mirabilis is a common causative agent of human urinary tract infections, especially in catheterized patients and in those patients with structural abnormalities of the urinary tract. In addition to the production of hemolysin and urease, fimbriae-mediated adherence to uroepithelial cells and kidney epithelium may be essential for virulence of P. mirabilis. A single P. mirabilis strain is capable of expressing several morphologically distinct fimbrial species, which can each be favoured by specific in vitro growth conditions. The fimbrial species reported to date include mannose-resistant/Proteus-like fimbriae, ambient temperature fimbriae, P. mirabilis fimbriae, and nonagglutinating fimbriae (NAF). Here, using intact bacteria or purified NAF as immunogens, we have generated the first reported NAF-specific monoclonal antibodies (mAbs). Bacteria expressing NAF as their only fimbrial species adhered strongly to a number of cell lines in vitro, including uroepithelial cell lines. Binding of P. mirabilis was markedly reduced following preincubation with NAF-specific mAbs and Fab fragments. The presence of NAF with highly conserved N-terminal sequences on all P. mirabilis strains so far examined, combined with the ability of both anti-NAF mAbs and purified NAF molecules to inhibit P. mirabilis adherence in vitro, suggests that NAF may contribute to the pathogenesis of P. mirabilis.

Antibodies, Bacterial↗
PubMed1997

Serodiagnosis of swine pleuropneumonia due to Actinobacillus pleuropneumoniae serotypes 7 and 4 using long-chain lipopolysaccharides.

A saline boiled extract (SBE), capsular polysaccharides (CPS) and long-chain lipopolysaccharides (LC-LPS) of Actinobacillus pleuropneumoniae serotype 7 have been evaluated in ELISA for the serodiagnosis of swine pleuropneumonia caused by this serotype. Mean optical densities (ODs) obtained with the 3 antigens using sera from negative herds as well as from animals experimentally and naturally exposed to A. pleuropneumoniae serotypes 7 or 4 were not statistically different. The positive ELISA reaction with anti-serotype 4 sera was unexpected with the CPS, which are supposed to be serotype-specific; LPS traces present in the CPS appeared to be responsible for this reaction. In addition, sera from animals exposed to A. pleuropneumoniae serotypes 5 or 10 presented cross-reactions with the SBE and the CPS, but not with the LC-LPS. Cross-reactions were mainly due to rough LPS, as shown by immunoblotting. The LC-LPS is easily obtainable and can be used for the detection of antibodies in animals infected with A. pleuropneumoniae serotypes 7 and 4.

Actinobacillus Infections↗
PubMed1996

Structural studies of the lipopolysaccharide O-antigen and capsular polysaccharide of Vibrio anguillarum serotype O:2.

Vibriosis caused by Vibrio anguillarum affects salmonid and marine fish species worldwide and is considered to be one of the most serious threats to the success of commercial fish farming. In the course of this study, it was found that V. anguillarum serotype O:2 strains produce an acidic capsular polysaccharide having the identical structure to that of the O-chain polysaccharide. One-dimensional and two-dimensional nuclear magnetic resonance techniques, together with partial hydrolysis and various specific modifications, were used to determine the structure of these polysaccharides. It is proposed that both O-chain and capsular polysaccharide of V. anguillarum serotype O:2 are composed of linear tetrasaccharide repeating units having the following structure, in which Glc2NAc3NAN represents 2-acetamido-3-amino-2,3-dideoxy-D-glucuronamide, Man2NAc3AmA is 3-acetamidino-2-acetamido-2,3-dideoxy-D-mannuronic acid. Am represents an acetamidino group, Gal(NAc)2A is 2,3-diacetamido-2,3-dideoxy-L-galacturonic acid, Bac(NAc)2 is 2,4-diacetamido-2,4,6-trideoxy-D-glucose (N,N'-diacetylbacillosamine) and Fo is formyl.

Alanine↗
PubMed1996

Detection of antibodies against Streptococcus suis capsular type 2 using a purified capsular polysaccharide antigen-based indirect ELISA.

In the present study a purified capsular polysaccharide antigen-based indirect ELISA (CPS-ELISA) to detect antibodies against Streptococcus suis capsular type 2 was developed and compared with a whole cell antigen-based ELISA (WCA-ELISA). The WCA-ELISA presented a very low specificity when rabbit antisera to other capsular types were tested. Most of these cross-reactions were due to common proteins. The standardized CPS-ELISA gave satisfactory results using a concentration of 0.1 micrograms/well; most cross-reactions decreased significantly, with some exceptions, such as those shared by capsular types 1/2, 12 and 17. These cross-reactions were mainly due to common epitopes present in the capsule, as shown by immunoblotting. In a second experiment, the CPS-ELISA was used to detect antibodies in experimentally infected piglets. Despite the fact that capsular type 2 S. suis could be reisolated from all infected animals during and/or after the trial, antibody titers against a second infection. Sera from piglets experimentally infected were completely protected against a second infection. Sera from piglets experimentally infected with S. suis capsular types 1/2 or 12 presented cross-reactions at low dilutions, confirming data previously obtained with rabbit sera. Finally, sera of animals from herds with clinical signs associated with S. suis capsular type 2 did not present titers significantly different from those of disease free herds. From our results we concluded that the CPS-ELISA developed in this study can not be used as a diagnostic tool to identify infected animals.

Animals↗
PubMed1996

The HeLa cell receptor for enterovirus 70 is decay-accelerating factor (CD55).

Enterovirus 70 (EV70) is a recently emerged human pathogen belonging to the family Picornaviridae. The ability of EV70 to infect a wide variety of nonprimate cell lines in vitro is unique among human enteroviruses. The importance of virus receptors as determinants of viral host range and tropism led us to study the host cell receptor for this unusual picornavirus. We produced a monoclonal antibody (MAb), EVR1, which bound to the surface of HeLa cells and protected them against infection by EV70 but not by poliovirus or by coxsackievirus B3. This antibody also inhibited the binding of [35S]EV70 to HeLa cells. MAb EVR1 did not bind to monkey kidney (LLC-MK2) cells, nor did it protect these cells against virus infection. In Western immunoassays and in immunoprecipitations, MAb EVR1 identified a HeLa cell glycoprotein of approximately 75 kDa that is attached to the cell membrane by a glycosyl-phosphatidylinositol (GPI) anchor. Decay-accelerating factor (DAF, CD55) is a 70- to 75-kDa GPI-anchored membrane protein that is involved in the regulation of complement and has also been shown to function as a receptor for several enteroviruses. MAb EVR1 bound to Chinese hamster ovary (CHO) cells constitutively expressing human DAF. Anti-DAF MAbs inhibited EV70 binding to HeLa cells and protected them against EV70 infection. Transient expression of human DAF in murine NIH 3T3 cells resulted in binding of labelled EV70 and stably, transformed NIH 3T3 cells expressing DAF were able to support virus replication. These data indicate that the HeLa cell receptor for EV70 is DAF.

3T3 Cells↗
PubMed1996

Utility of the chemical use, abuse, and dependence scale in screening patients with severe mental illness.

The Chemical Use, Abuse, and Dependence (CUAD) Scale was administered with other scales to 100 consecutive admissions to a psychiatric hospital. Moderately high correlations with other measures of drug and alcohol use were obtained. Although more research with the CUAD is necessary, it may be potentially useful in screening for substance use among severely mentally ill patients.

Adult↗
PubMed1995

Evidence for the extended helical nature of polysaccharide epitopes. The 2.8 A resolution structure and thermodynamics of ligand binding of an antigen binding fragment specific for alpha-(2-->8)-polysialic acid.

The antigen binding fragment from an IgG2a kappa murine monoclonal antibody with specificity for alpha-(2-->8)-linked sialic acid polymers has been prepared and crystallized in the absence of hapten. Crystals were grown by vapor diffusion equilibrium with 16-18% polyethylene glycol 4000 solutions. The structure was solved by molecular replacement methods and refined to a conventional R factor of 0.164 for data to 2.8 A. The binding site is observed to display a shape and distribution of charges that is complementary to that of the predicted conformation of the oligosaccharide epitope. A thermodynamic description of ligand binding has been compiled for oligosaccharides ranging in length from 9 to 41 residues, and the data for the largest ligand has been used in a novel way to estimate the size of the antigen binding site. A model of antigen binding is presented that satisfies this thermodynamic data, as well as a previously reported requirement of conformational specificity of the oligosaccharide. X-ray crystallographic and thermodynamic evidence are consistent with a binding site that accommodates at least eight sialic acid residues.

Antibodies, Monoclonal↗
PubMed1995

Characterization of the glycan structure of a major glycopeptide from the surface layer glycoprotein of Clostridium thermosaccharolyticum E207-71.

The squarely arranged surface layer (S-layer) glycoprotein of Clostridium thermosaccharolyticum E207-71 was isolated from bacterial cells which were grown under defined culture conditions. By sodium dodecyl sulfate polyacrylamide gel electrophoresis, the S-layer showed a series of distinct bands with apparent molecular masses in the range 83-210 kDa. Upon deglycosylation by trifluoromethanesulfonic acid, only the single band at 83 kDa remained unchanged. After pronase digestion of the intact S-layer glycoprotein, the degradation products were isolated by gel-permeation chromatography, cation-exchange chromatography and isoelectric focusing. Three main fractions and an amino sugar containing minor fraction were obtained. The main fractions, which showed identical carbohydrate compositions, were further purified by reverse-phase chromatography and characterized by monosaccharide analysis, Smith degradation, methylation analysis, and one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy. The combined chemical and spectroscopical evidence suggest the following glycan structure for the main fractions: [Sequence: See text]

Amino Acid Sequence↗
PubMed1995

Expression of a nonagglutinating fimbria by Proteus mirabilis.

We have clarified growth conditions and isolation strategies for the nonagglutinating fimbriae from Proteus mirabilis. Nonagglutinating fimbriae were expressed by all P. mirabilis strains we examined, and the major subunit proteins, which ranged from 23 to 29 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, had highly conserved N-terminal sequences.

Agglutination Tests↗
PubMed1995

Structural elucidation of the lipopolysaccharide core region of the O-chain-deficient mutant strain A28 from Pseudomonas aeruginosa serotype 06 (International Antigenic Typing Scheme).

The lipopolysaccharide (LPS) of the Pseudomonas aeruginosa serotype 06 rough-type mutant A28 was isolated by a modified phenol-chloroform-petroleum ether extraction method. Deoxycholate-polyacrylamide gel electrophoresis indicated a single band with mobility similar to that of the complete core region of the wild-type parent serotype 06 (International Antigenic Typing Scheme) strain. Compositional analysis of the LPS indicated that the core oligosaccharide was composed of D-glucose (three units), L-rhamnose (one unit), 2-amino-2-deoxy-D-galactose (one unit), L-glycero-D-manno-heptose (two units), 3-deoxy-D-manno-octulosonic acid (two units), L-alanine (one unit), and phosphate (two units). Under the mild conditions of hydrolysis with methanolic hydrogen chloride, a 7-O-carbamoyl substituent was observed on the second heptose residue. The glycan structure of the LPS was determined by employing one- and two-dimensional nuclear magnetic resonance spectroscopy and mass spectrometry-based methods with a backbone oligosaccharide that was obtained from the LPS by deacylation, dephosphorylation, and reduction of the terminal glucosamine. On the basis of the results of the present study and our earlier work with the P. aeruginosa 06-derived core-defective mutant R5 (H. Masoud, E. Altman, J. C. Richards, and J. S. Lam, Biochemistry, 33:10568-10578, 1994), a structural model for the complete core oligosaccharide is proposed.

Carbohydrate Sequence↗
PubMed1995

Production and characterization of monoclonal antibodies to Actinobacillus pleuropneumoniae serotype 5b.

Monoclonal antibodies specific for capsular polysaccharide (CPS) and lipopolysaccharide (LPS) of A. pleuropneumoniae serotype 5b were generated by hybridoma cells and selected by indirect ELISA of culture supernatants with purified and structurally defined LPS and CPS preparations and their synthetic conjugates. It was shown in this study that at least one monoclonal antibody, 3B4, presented 100% specificity and recognized all A. pleuropneumoniae serotype 5 field strains tested in a dot-ELISA assay.

Actinobacillus pleuropneumoniae↗
PubMed1994

General strategy for structural analysis of the oligosaccharide region of lipooligosaccharides. Structure of the oligosaccharide component of Pseudomonas aeruginosa IATS serotype 06 mutant R5 rough-type lipopolysaccharide.

A general NMR-based strategy for the structural analysis of rough-type lipopolysaccharides, i.e., lipooligosaccharides, is introduced that involves initial deacylation of the glycolipids. The approach is illustrated here with the lipooligosaccharide (LOS) of the Pseudomonas aeruginosa serotype 06 rough-type mutant R5, which consists of a single major low molecular weight component. The LOS was isolated by using a modified phenol/chloroform/petroleum ether extraction method. Chemical analysis of the core oligosaccharide obtained from this LOS indicated that it was composed of D-glucose (D-Glc), 2-amino-2-deoxy-D-galactose (D-GalN), L-glycero-D-manno-heptose (L,D-Hep), 3-deoxy-D-manno-octulosonic acid (KDO), L-alanine (Ala), and phosphate. The glycan structure of the LOS was elucidated by employing a novel strategy that involved the use of one- and two-dimensional nuclear magnetic resonance techniques and mass spectrometric based methods on the backbone oligosaccharide obtained from the LOS by deacylation, dephosphorylation, and reduction of the terminal glucosamine. The location of phosphomonoester groups was unambiguously established by a 2D 1H-31P chemical shift correlation experiments on an O-deacylated sample of the LOS (LOS-OH). The LOS-OH carries amide-linked 3-hydroxydodecanoic acid groups and Ala on the two D-glucosamine residues and the D-galactosamine residue, respectively.

Antigens, Bacterial↗
PubMed1994

Primary structure of the O-glycosidically linked glycan chain of the crystalline surface layer glycoprotein of Thermoanaerobacter thermohydrosulfuricus L111-69. Galactosyl tyrosine as a novel linkage unit.

The products of Pronase digestion of the crystalline surface layer (S-layer) glycoproteins of Thermoanaerobacter thermohydrosulfuricus strains L111-69 and L110-69 were isolated by gel permeation chromatography, cation exchange chromatography, chromatofocusing, and reversed phase high performance liquid chromatography. Four compounds were obtained which were analyzed by monosaccharide analysis, one- and two-dimensional 500 and 600 MHz 1H and 13C NMR spectroscopy, methylation analysis, gas-liquid chromatography/mass spectrometry, and matrix-assisted laser desorption ionization mass spectrometry. For all glycopeptides we propose the following glycan structure with galactose as the linkage sugar. [formula: see text] The isolated glycopeptides resulted from Pronase cleavage at the glycosylated tyrosine residues. Tyrosine was found as the linkage amino acid in all fractions but the remaining amino acid sequences varied, indicating the presence of different glycosylation sites in the intact S-layer glycoprotein.

Bacterial Proteins↗
PubMed1994

Evaluation of a saline boiled extract, capsular polysaccharides and long-chain lipopolysaccharides of Actinobacillus pleuropneumoniae serotype 1 as antigens for the serodiagnosis of swine pleuropneumonia.

A saline boiled extract (SBE), capsular polysaccharides (CPS) and long-chain lipopolysaccharides (LC-LPS) of Actinobacillus pleuropneumoniae serotype 1 have been evaluated in ELISA for the serodiagnosis of swine pleuropneumonia caused by this serotype. Mean optical densities (ODs) obtained with the three antigens using sera from negative herds as well as from animals experimentally and naturally exposed to A. pleuropneumoniae serotypes 1, 9 or 11 were not significantly different. The positive ELISA reaction with anti-serotypes 9 and 11 was unexpected with the CPS, which are supposed to be serotype-specific; LPS, and to a lesser extent proteins, were present in the CPS and appeared to be responsible for this reaction. In addition, sera from animals exposed to a field strain of A. pleuropneumoniae serotype 3 and to Actinobacillus suis presented a significantly lower mean OD (P < 0.001) when LC-LPS were used. Cross-reacting antigens consisted mainly of LPS core-lipid A present in the SBE and CPS. The specificity and the sensitivity of the ELISA were evaluated using three different cut-off values (the OD plus two, three and four times the standard deviation or SD) obtained with 667 negative sera. The diagnostic sensitivity was of 81% with the three antigens and the different thresholds. The diagnostic specificity was of 84, 86 and 88% for the mean plus two, three and four times the SD respectively using the SBE and the CPS, while that obtained with the LC-LPS was of 96, 98 and 99% using the same thresholds. In conclusion, LC-LPS make an easily obtainable antigen and seem to retain the best specificity while minimizing losses of sensitivity.

Actinobacillus Infections↗
PubMed1994

Characterization of lipopolysaccharide-deficient mutants of Pseudomonas aeruginosa derived from serotypes O3, O5, and O6.

Well-characterized rough mutants are important for the understanding of structures, functions, and biosynthesis of lipopolysaccharide (LPS) in gram-negative organisms. In this study, three series of Pseudomonas aeruginosa LPS-deficient mutants, namely PAC strains derived from serotype O3, AK strains derived from strain PAO1 (serotype O5), and serotype O6-derived mutants were subjected to biochemical analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining as well as immunochemical characterization using LPS-specific monoclonal antibodies. The O-side-chain deficiency among the O6-derived mutants was also examined, and three mutants, A28, R5, and H4, were subsequently chosen for the elucidation of component sugars of the core structure of serotype O6 LPS. LPS of strain A28 has L-rhamnose and proportionally higher amounts of D-glucose, a feature shared by the O5-derived mutant, strain AK1401 (previously demonstrated as a mutant with a core-plus-one O repeat). In contrast strains R5 and H4 were shown to be devoid of L-rhamnose and have low and undetectable amounts of D-glucose, respectively, which indicated their core deficiency. The LPS-deficient or -sufficient characteristics of the P. aeruginosa strains examined correlated will with serum sensitivity data. This report represents a comprehensive analysis of rough mutants derived from O3 and O5 strains that have been used by others in many studies and a first look at the core oligosaccharide region of serotype O6 LPS obtained with the O6-derived mutants generated in this study.

Antibodies, Monoclonal↗