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Biomedical subjects

E Neter

Publications and source records attributed to E Neter.

At least 37 records · Page 2Linked to original sources
PubMed1981

Comparison of the quantitative direct plating method and the BACTEC procedure for rapid diagnosis of Haemophilus influenzae bacteremia in children.

The efficacy and reproducibility of the quantitative direct plating (QDP) method and the semi-automated BACTEC radiometric system (BBL Microbiology Systems, Cockeysville, Md.) were analyzed for the rapid diagnosis of Haemophilus influenzae bacteremia on the basis of 41 positive cultures from 35 patients. The QDP method detected 61% and BACTEC only 19% of the positive cultures within the first 12 h. Similarly, the QDP procedure yielded growth of H. influenzae in 56% of the cultures before a positive growth index reading was obtained with the BACTEC method. The observation that the quantitative procedure recovered H. influenzae in 88% of all positive cultures, using only 1 ml or less of blood, is attributed to the fact that 68% of the cultures had counts in excess of 100 colony-forming units per ml. The reproducibility of the QDP method was documented by the fact that duplicate blood cultures taken within a few hours of each other yielded comparable results on the number of bacteria at low (1 to 100/ml), moderate (100 to 1,000/ml), and high (greater than 1,000/ml) levels of bacteremia. We concluded that the QDP method is a valuable, simple, and inexpensive supplementary technique to the semi-automated BACTEC procedure for the rapid diagnosis of H.influenzae bacteremia in children.

Bacteriological Techniques↗
PubMed1981

Aminoglycosides and polymyxin B as inhibitors of antigen attachment to erythrocytes for agglutination by Salmonella antibodies.

Previous investigations indicate that polymyxin B inhibits attachment of lipopolysaccharides (O antigens) to erythrocytes and subsequent hemagglutination by the corresponding bacterial antibodies. In this study the effect of this antibiotic was compared to that of the aminoglycosides gentamicin, tobramycin, and amikacin. Using both crude O antigens and highly purified lipopolysaccharides, polymyxin B was at least 100 times more effective than the aminoglycosides. Amikacin proved to be less effective than gentamicin and tobramycin.

Aminoglycosides↗
PubMed1980

The effects of ampicillin and trimethoprim/sulfamethoxazole on the periurethral flora of children with urinary tract infection.

Ampicillin and trimethoprim/sulfamethoxazole were shown to be of similar efficacy in the treatment of acute urinary tract infection of children. It was of interest to determine the effects of these antimicrobial drugs on the periurethral flora and recurrence rates. To this end, seventeen girls with twenty-two separate infections of the urinary tract were treated randomly with a ten-day course of either ampicillin or trimethoprim/sulfamethoxazole. Cultures of the urine and periurethral area were obtained before, during (third day), and after (seventeenth day) therapy. All Escherichia coli strains were serotyped. Both treatments resulted in the disappearance of the pathogens from the urine by the third day in all cases, and in all but one patient on the seventeenth day. The causative agents persisted more frequently in the periurethral area than in the urine on both the third and seventeenth days in patients treated with either ampicillin or trimethoprim/sulfamethoxazole. The recurrence rates by the seventeenth day were 50% (4/8) in the ampicillin group, and 14% (2/14) in the trimethoprim/sulfamethoxazole group. Although suggestive in favor of the latter treatment, the difference is not statistically significant. In two of the three re-infections in the ampicillin group the microorganisms causing the second attack were present in the periurethral area on the third day. Sixteen of the seventeen girls were studied radiologically; six (37%) had radiologic abnormalities.

Adolescent↗
PubMed1980

Immunoglobulin G and immunoglobulin M antibody responses of patients with malignancies to the O antigens of bacteria causing bacteremia.

Malignancy may be associated with impairment of the immune system. In children with acute leukemia, an impaired immunoglobulin M (IgM) antibody response to poliovirus was documented previously. It was of interest, therefore, to determine the immunoclass of antibodies produced against the O antigens of bacteria causing bacteremia in patients with leukemia and other malignancies. For control purposes, parallel studies were carried out in patients without maligancies but with infections caused by gram-negative bacteria. The patients with malignancies were adults, and those without malignancies were children. The serum specimens were selected from patients mounting an antibody response. IgG and IgM antibodies were identified by mercaptoethanol reduction and chromatography. Antibody titers against the O antigens of enteric bacteria were determined by the hemagglutination procedure. Antibodies of both IgM and IgG immunoclasses were produced by all but 1 of 16 patients with leukemia and by all but 1 of 12 subjects with other malignancies. Thus, a specific IgM immune deficiency in adult patients with leukemia or other malignancies complicated by bacteremia was not present; however, the magnitude of the antibody response of the patient with leukemia was less than that of the subjets with other maligancies, with the median antibody titers of the former being 320 and those of the latter being 2,560.

Adult↗
PubMed1980

Detection of endotoxin in ear specimens from patients with chronic otitis media by means of the limulus amebocyte lysate test.

The limulus amebocyte lysate (LAL) test is the most sensitive procedure for the detection of endotoxic lipopolysaccharides. The test was applied to middle ear fluids, cholesteatomas, and granulation tissue specimens from 31 patients in parallel with bacteriologic examination. The LAL test and bacteriologic examination yielded concordant results with 26 out of 28 specimens. A positive LAL test was obtained with 11 specimens containing endotoxin-producing organisms. The test became positive within 60 min of incubation in 10 out of 11 specimens and in 1 specimen between 1 and 24 h, suggesting that, in the majority of specimens, endotoxin was present in the specimen itself and that the result was not due to the in vitro multiplication of the microorganisms. All negative tests remained negative for 24 h. It is conceivable that endotoxin present in ear fluids may contribute to the pathologic changes in chronic otitis media.

Adolescent↗
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↗