Erwin Neter

Escherichia coli Hemagglutinin Response of Adult Volunteers to Ingested E. coli 055 B5

Summary The E. coli hemagglutinin response of adult volunteers to ingestion of E. coli 055 and a “normal” strain of E. coli, respectively, was determined. 1. Increase in E. coli 055 hemagglutinin titers was observed in all subjects following administration of living organisms in large numbers and in two-thirds of individuals who received smaller numbers. 2. None of the controls who received milk without E. coli showed such an antibody response, nor did the volunteers who ingested large numbers of killed 055 organisms or viable bacteria of a “normal” strain of E. coli. 3. Good correlation was found between increases of E. coli 055 hemagglutinin titers and the appearance of bacterial O agglutinins. 4. The E. coli hemagglutination test proved to be more sensitive than the conventional bacterial agglutination test, inasmuch as the former method with the postfeeding serum specimens yielded antibody titers which were from 5 to 20 times higher and detected antibodies in prefeeding serum specimens which were not demonstrated by the latter method.

Effect of Salmonella enteritidis Endotoxin Preparations and Lipid A on Dermal Reactivity in Rabbits to Epinephrine.

Summary Minute amounts of aqueousether extracted S. enteritidis endotoxin, upon intravenous injection into rabbits, alter dermal reactivity to intradermally injected epinephrine. The lipid A component is only approximately 1/2000 as active as the endotoxin when potent endotoxins are tested. Phenol-water treatment of aqueous-ether extracted endotoxin reduces this activity.

Necrotizing Effects of Staphylococcus aureus Extract on Mouse Sarcoma 180.

Summary 1) A trichloracetic acid extract of Staphylococcus aureus, strain D (5 to 40 μg/mouse), in 24 hours caused extensive hemorrhagic necrosis of Sarcoma 180 in HaICR Swiss mice when injected intraperi-toneally 7 days after tumor implantation. The extract was ineffective against tumors 1 to 4 days after implantation. 2) The effect was also produced in Sarcoma 180 grown in C57B1/6, C3H, AKR and DBA2 mice. 3) Epinephrine, dibenzyline and the antihistaminic drug Benadryl, in the doses used, did not alter the necrotizing activity of the extract. Cortisone, however, reduced the incidence of the effect. The authors are indebted to Dr. Lenore Simpson Englander for excellent histological studies and to Miss Aurelie Mulhern, Mr. Kalman Bercsenyi and Mr. Gabor Papp for proficient technical assistance.

Respiratory infections in infants on mechanical ventilation: The immune response as a diagnostic aid

A prospective study was undertaken in 41 newborn infants receiving artificial respiration for evaluation of the incidence of respiratory infections. Clinical and radiologic evidence of pneumonia was compared with the appearance of serum antibodies against antigens prepared from microorganisms isolated from bronchial aspirates, and with serum and bronchial immunoglobulin M values. A significant specific immune response was documented in 24% of the patients studied. The data indicate that by correlating the clinical and radiographic findings with specific antibodies and IgM antibody responses, it is possible to document a significant number of respiratory infections. One implication of this study is that subclinical infections may not be uncommon. The significance of the presence and changes in concentration of IgM in bronchial aspirate requires further study.

Effects of pyribenzamine and benadryl on chick embryo and on vascular phenomenon induced by normal serum.

Discussion and Summary The experiments reported here revealed that the anti-histaminic compounds pyribenzamine, bena-dryl and hetramine in the 3-day-old chick embryo cause bradycardia, stoppage of the heart beat and occasionally hemorrhages. It appears likely that the chick embryo can be used to advantage in studies on the relative toxicity of various antihistaminic compounds. The drugs do not prevent the inverted ana-phylactic shock, which is due to factors other than histamine.

1307 RESPIRATORY INFECTIONS IN INFANTS ON MECHANICAL VENTILATION: THE IMMUNE RESPONSE AS A DIAGNOSTIC AID

Bronchial aspirates for bacterial and viral cultures and bronchial IgM were obtained weekly in 41 patients receiving artificial ventilation. Mean birth weight 1,680 grams ± 875grams GA 32.6 weeks ±4.4. The mean duration of ventilation was 28 days (maximum 137 days). Weekly blood samples were also obtained for serum IgM and hemagglutination antibodies against O antigens prepared from the patients own microorganisms. Clinicoradiographic evidence of pneumonia was compared with the demonstration of specific immune responses (rise in titer of at least four fold) or a significant rise in serum or bronchial IgM levels. Significant specific immune response was documented in 24% of the patients studied. Altogether there were 35 clinicoradio-graphic pneumonic episodes. Abnormal serum IgM was found in 60%, bronchial IgM in 42% and specific antibodies in 34% of those episodes. Combining the three parameters studied pneumonia was documented in 30 out of the 35 purported episodes. Patients with severe bronchopulmonary dysplasia had significantly elevated levels of both bronchial (p <.001) or serum IgM (p <.001) even during asymptomatic periods. No correlation was found between paired samples of bronchial and serum IgM (r=0.16). The data on bronchial aspirate IgM are compatible with local production by the lung. We conclude that the immune response of the host is helpful in documenting respiratory infections in infants receiving prolonged respirator therapy.

COMPARATIVE INHIBITORY EFFECTIVENESS OF CHOLESTRYAMINE RESIN AND ACTIVATED ATTAPULGITE ON VIBRIO CHOLERAE ENTEROTOXIN

Cholestyramine resin, an anion exchange material binding bile acids, and activated attapulgite, composed of magnesium silicate particles adsorbing bacterial toxins, have been used in the treatment of diarrheal diseases. The relative effectiveness of cholestyramine and attapulgite in inhibiting the toxicity (fluid accumulation) of V. cholerae enterotoxin in the ligated intestinal loop of rabbits was determined. Toxin was mixed with equal amounts of a 10% suspension of either drug or physiologic saline and incubated for 1 hour at room temperature prior to injection into the loops. The animals were sacrificed 18 hours following surgery. The mean index of fluid accumulation (ml/cm per loop) with toxin alone was 1.7; with toxin-cholestyramine 1.6; with toxin-attapulgite only 0.32: and with the drugs alone 0.30. Attapulgite neutralized 8 to 10 minimally effective doses of toxin. Preliminary studies with other drugs revealed that 10% suspension of activated charcoal and 10% suspension of kaolin were effective; bismuth subsalicylate in the form of pepto-bismolR was less efficacious than attapulgite. The clinical implications for the prevention of enterotoxin-induced diarrheal disease by available drugs are obvious.

Salmonella choleraesuis (variety Kunzendorf) bacteriemia complicating streptococcal sore throat

Summary A case of S. choleraesuis (variety Kunzendorf) bacteriemia complicating or concomitant with streptococcal sore throat is described. The relationship of the two diseases is discussed.