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Biomedical subjects

E Neter

Publications and source records attributed to E Neter.

At least 19 recordsLinked to original sources
PubMed1979

Gentamicin-resistant Staphylococcus aureus. Emergence in an intensive care nursery.

Gentamicin sulfate--resistant Staphylococcus aureus suddenly appeared in an intensive care nursery in December 1976 and became the dominant Staphylococcus; it accounted for 96% of the isolates by April 1977. All gentamicin-resistant strains were sensitive to amikacin sulfate, but 98% and 49% were resistant to kanamycin sulfate and tobramycin sulfate, respectively. All but one of the gentamicin-resistant strains were sensitive to methicillin sodium. The mechanism of gentamicin resistance appears to be plasmid mediated. Phage typing, used for epidemiologic purposes, also demonstrated that most gentamicin-resistant strains shared susceptibility to phages 29 and 52; however, 13% were completely different, indicating that gentamicin resistance is not solely related to a phage-susceptible factor.

Bacteriophage Typing↗
PubMed1979

Cell-mediated immune response to bacterial products in human tonsils and peripheral blood lymphocytes.

Lymphoproliferative responses of tonsillar tissue lymphocytes and peripheral blood lymphocytes to phytohemagglutinin and specific bacterial product antigens were studied in children undergoing tonsillectomy and adenoidectomy. Tonsillar tissue lymphocytes responded to optimal concentrations of phytohemagglutinin. Varidase, and streptolysin-O in a manner similar to peripheral blood lymphocytes. Higher base-line mitogenic activity in tonsillar lymphocytes was frequently associated with the presence of Staphylococcus aureus in the tonsils. Tonsillar tissue lymphocytes from 23% of the subjects with the highest base-line mitogenic activity manifested a decreased response to in vitro stimulation with mitogens or antigens. In subjects with such preactivated tonsillar lymphocytes, the proliferative responsiveness of blood lymphocytes to mitogen and antigens was markedly increased after tonsillectomy and adenoidectomy. These observations suggest the existence of in vitro correlates of cellular immunity to bacterial products in the mucosal surfaces. In addition, it is proposed that tonsils may possess immunosuppressive activity for peripheral blood lymphocytes, which may be related to local tonsillar infections.

Adenoidectomy↗
PubMed1979

Attachment to erythrocytes of uniform salt forms of lipopolysaccharides from Salmonella abortus-equi and its inhibition by various animal sera.

Lipopolysaccharides (LPS) readily attach to erythrocyte membranes in vitro, resulting in hemagglutination in the presence of the homologous bacterial antibodies. The attachment of LPS to red blood cells can be prevented by certain, but not all, animal sera. In this study, the attachment of uniform salt forms of LPS from Salmonella abortus-equi to erythrocytes from various animal species was investigated. The uniform salt preparations were significantly more active than the starting material. Similar findings were obtained with erythrocytes from man, sheep, rabbit, and guinea pig. These results were not due to differences in antibody neutralizing capacity, since all preparations showed essentially identical activity. When sera from various animal species were used as inhibitors of LPS attachment, inhibition of erythrocyte modification by equivalent, but not by identical, amounts of LPS was essentially the same.

Animals↗
PubMed1979

The antibody response to enterobacteriaceae and pseudomonas of patients with malignancies complicated by bacteremia.

The antibody response to the O antigens of the patients' own gram-negative bacteria causing bloodstream infection in patients with malignancies was investigated using the hemagglutination test. Of the 87 patients, 42 (48%) produced specific antibodies in significant titers. Differences were noted between the various microorganisms. Of 44 patients with E. coli bacteremia 26 (59%) had an antibody response, whereas only 5 (33%) out of 15 subjects with Pseudomonas aeruginosa infection did. The antibody response of patients with solid tumors (61%) was significantly better than that of subjects with RES malignancies (30%). Documentation of the humoral immune response of patients to isolates from blood cultures excludes laboratory contamination and supports the relevance of the isolated microorganisms. Thus, for diagnostic purposes documentation of the immunoglobulin response supplements bacteriologic findings.

Antibody Formation↗
PubMed1977

Meningitis due to two serotypes of Escherichia coli. An infant who recovered.

A newborn infant with hyaline membrane disease and aspiration pneumonia developed purulent meningitis on day 19, three days after discontinuation of ampicillin sodium and gentamicin sulfate therapy. Therapy with gentamicin, both systemically and intrathecally, for two weeks was ineffective. During this time each of four specimens of cerebrospinal fluid contained two serotypes of Escherichia coli, namely, O83:H4 and O75:H5. The antibiograms of the two strains were identical, both being susceptible to gentamicin and ampicillin. Treatment with ampicillin resulted in prompt disappearance of the infecting microorganisms and recovery from the infection. One of the strains (O75:H5) produced an antigen cross-reacting with the capsular antigen of Haemophilus influenzae type B; the other did not. The patient developed O antibodies in substantial titers against E coli O83 but not against E coli O75.

Ampicillin↗
PubMed1977

The effect of attapulgite and charcoal on enterotoxicity of Vibrio cholerae and Escherichia coli enterotoxins in rabbits.

Vibrio cholerae and certain strains of Escherichia coli produce heat-labile enterotoxins which play a significant role in the pathogenesis of the intestinal disease. Activated attapulgite, a heated magnesium aluminum silicate, was previously shown to prevent the toxic effects of endotoxin. The present study has revealed that this drug inhibits the toxic effects of cholera and E. coli enterotoxins in the intestinal loop of rabbits, when toxin and attapulgite are pre-incubated prior to injection. Up to 50 to 100 minimal effective doses are inhibited. Attapulgite is effective also when injected separately, albeit simultaneously, into the intestinal loops, but not when administered after the toxin. Since supernates of toxinattapulgite mixtures are non-toxic, it is postulated that attapulgite acts by adsorption and that the attached enterotoxin is no longer toxic to the rabbit intestine. The previously reported effect of charcoal on V. cholerae enterotoxin paralleling that of attapulgite, was confirmed. In contrast to the effects of these absorbents on isolated toxin, both failed to prevent enterotoxicity in the rabbit model of an enterotoxin-producing strain of E. coli.

Aluminum Silicates↗
PubMed1977

Pasteurella multocida infection of urinary tract in patient with ileal loop.

Pasteurella multocida infection in the ileal loop and in the pelvis of a hydronephrotic kidney of a patient whose other kidney had been removed at age six months was documented by the repeated isolation of this patthogen. Two episodes occurred, the first terminated after a dose of gentamicin and the other without chemotherapy. Since the patient prior to infection was in severe renal failure necessitating hemodialysis, the effect of this infection on renal function could not be ascertained. The probable source was a cat present in the household.

Adolescent↗
PubMed1977

Effect of heat on antigenicity and immunogenicity of the antigenic determinant shared by Haemophilus influenzae type b and Escherichia coli K100.

Escherichia coli K100 produces an antigenic determinant similar to, or identical with, the capsular antigen of Haemophilus influenzae type b. Studies of the effects of heat on the immunogenicity, erythrocyte-modifying capacity, and antigenicity of this cross-reacting antigen (CRA) revealed the following findings. Immunization of rabbits with viable or formaldehyde-killed suspensions of E. coli K100, producing CRA, engendered CRA antibodies in significant titers, as demonstrated by hemagglutination of erythrocytes modified by H. influenzae type b antigen. Heating of the suspensions for 1 h at 56 or 100 degrees C destroyed the immunogenicity of CRA, and the heated suspensions did not prime for a secondary antibody response. Supernatants of heated suspensions also were non-immunogenic. Repeated freezing and thawing of heated suspensions of E. coli K100 or their supernatants did not restore immunogenicity. Heat also abolished the immunogenicity of H. influenzae type b. The loss of immunogenicity of CRA of E. coli K100 by heat was not due to alteration of the antigenic determinant, since heated suspensions and supernatants thereof modified erythrocytes for agglutination by H. influenzae type b antiserum. The latter supernatants also inhibited hemagglutination by H. influenzae type b antibodies and absorbed the latter. We conclude that striking differences exist in the effects of heat on CRA on the one hand and of enterobacterial common antigen and lipopolysaccharide O antigen of enteric bacteria on the other. Heating of the latter two antigens does not abolish their priming effect, and repeated freezing and thawing restores the immunogenicity of heated antigens.

Antibodies, Bacterial↗
PubMed1977

Effect of serum from various animal species on erythrocyte attachment of endotoxins and other bacterial antigens.

Lipopolysaccharide O antigens (endotoxins) and other bacterial antigens readily attach to erythrocytes in vitro. This attachment is prevented by certain mammalian and avian sera. In this study, the inhibitory capacity of sera from lower animals was compared with that of higher animals for a total of 30 species. Antigens and the corresponding antisera included both crude O antigens and purified lipopolysaccharide preparations, the common enterobacterial antigen from Escherichia coli O14, the Vi antigen from Citrobacter ballerup, the polyribose-phosphate antigen from Haemophilus influenzae type b, and the crude teichoic acid antigen from Staphylococcus aureus. Antigen and serum mixtures were incubated at 37 degrees C for 30 min and used for erythrocyte modification; failure of hemagglutination by homologous bacterial antiserum provided evidence of inhibitory capacity. Sera from the classes Mammalia and Aves were very strong inhibitors; those of Reptilia and Osteichthyes were moderate in activity, displaying variation within the classes; those of Amphibia and Chondrichthyes were minimal inhibitors; and those of Merostomata, Crustacea, and Lamellibranchiata displayed questionable or no inhibitory capacity. Inhibitory sera were active with all antigens tested. The findings suggest evolution of inhibitory factors consistent with the theory of two diverging lines of animal phylogeny based on embryological criteria and closely parallel the observations of an endotoxin-altering capacity in vertebrate sera that is not found in invertebrate sera or hemolymph.

Amphibians↗
PubMed1977

Antibody response to Serratia marcescens isolated from patients with malignant diseases.

Sixty-four patients with malignant diseases from whom Serratia marcescens was isolated from various sources were studied regarding their antibody responses to somatic O antigens of this microorganism. Antibodies were titrated by the passive hemagglutination test. An antibody response was considered present when either a fourfold or greater rise in antibody titers between two consecutive serum specimens was demonstrated, or when elevated titers (greater than or equal to 40 for serogroup O14 and greater than or equal to 160 for all others) were present in the first available specimen. Overall, 31% of subjects mounted an immune response, but there were differences depending upon the infection site. Seventy-one percent of patients with S. marcescens bacteremia responded immunologically; whereas the percentage for patients with Serratia present in the respiratory tract was only 22%, in the urinary tract, 31%, and in wounds, 26%. Documentation of an immune response to the patient's own infecting strain of Serratia aids in the differentiation between infection and contamination and possibly also between clinical disease and colonization. In addition, immunoglobulin samples collected in different decades were examined to determine whether the background level of antibodies to S. marcescens had changed in the general population over the years. No difference in antibody titers to 13 O antigens was observed in immunoglobulin preparations from 1951, 1962, 1971, and 1975.

Adult↗
PubMed1976

Strain-related differences in immunosuppressive effects of Enterobacteriaceae and their lipopolysaccharides on production in rabbits of antibody to enterobacterial common antigen.

Certain polysaccharides have been shown to inhibit the antibody response of rabbits to the common enterobacterial antigen (CA). The present investigation revealed that striking differences exist in the immunosuppressive effects of enteric bacteria and their lipolysaccharides (lps), depending upon CA production by the strains. Mixtures of immunogenic strains (Escherichia coli F2378 [R4], E. coli F470 [R1], or Shigella boydii F3140 [R]) and non-immunogenic CA-producing strains, such as E. coli O1, E. coli O113, Salmonella montevideo, and S. minnesota, as well as the R mutants E. coli F614 (R1), E. coli F757 (R1), and S. typhimurium his 642 (Ra), failed to elicit CA antibodies. In contrast, mixtures of the immunogen and CA-negative strains S. typhimurium his 386 (Ra) and S. minnesota P595 (Re) or R555 (Ra) yielded antibodies in titers similar to those elicited by the immunogen alone. Further, LPS of CA-positive but not of CA-negative strains exerted this immunosuppressive effect. Quantitative studies revealed that LPS of S. minnesota in amounts of 100 mug/ml was strongly immunosuppressive, in amounts of 20 mug/ml slightly effective, and in amounts of 4 mug/ml ineffective. It is postulated that hitherto unknown differences exist, either in composition or in configuration, between LPS obtained from different microorganisms to account for the strain-related differences in immunosuppressive effects and, further, that the immunosuppressive LPS interacts with immunogenic CA.

Animals↗