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Biomedical subjects

A S Yeager

Publications and source records attributed to A S Yeager.

15 recordsLinked to original sources

Use of the serum bactericidal titer to assess the adequacy of oral antibiotic therapy in the treatment of acute hematogenous osteomyelitis.

Serum bactericidal titers against Staphylococcus aureus were measured in 63 children who were receiving mafcillin or methicillin intravenously, or dicloxacillin, penicillin, or cephalexin orally. The SBTs obtained following unit does of 25 mg/kg of dicloxacillin, 35 mg/kg of penicillin, or 25 mg/kg of cephalexin with probenecid were comparable to those seen following intravenous doses of 40 mg/kg nafcillin or methicillin. Twenty-two children with acute hematogenous osteomyelitis proven or presumed to be due to S. aureus were treated intravenously until point tenderness and fever had resolved, and then with oral therapy. The mean duration of intravenous therapy was 14 days. Oral doses were adjusted so that a peak SBT of greater than or equal to 1:16 and a trough SBT of greater than or equal to 1:2 were obtained in most children. No recurrences occurred. The SBT proved to be a practical means of assessing the adequacy of oral therapy in children with infections due to S. aureus.

Administration, Oral

Storage and transport of cultures for Herpes simplex virus, type 2.

Tryptic soy broth and brain-heart infusion broth maintained herpes simplex virus within +/- 1 serial dilution of the original titer in all of 51 samples held for one to three days at 4 C. In contrast, holding temperatures of -20 C or 22 C resulted in losses of titer of 10(2) or more. Holding periods as long as five days prior to inoculation did not delay the appearance of the cytopathic effect following inoculation. Unmodified tryptic soy broth or brain-heart infusion broth and holding periods as long as three days at 4 C prior to arrival in the laboratory give as satisfactory results as do traditional viral culture media and prompt inoculation of the specimen.

Cold Temperature

Antimicrobial susceptibilities of rough, smooth, and mucoid colony types of Pseudomonas isolated from cystic fibrosis patients.

Minimal inhibitory concentrations of carbenicillin, chloramphenicol, tetracycline, gentamicin, tobramycin, and trimethoprim-sulfamethoxazole were determined for rough, smooth, and mucoid Pseudomonas sp. isolates from sputa collected from 40 cystic fibrosis patients. Ninety-four percent of the minimal inhibitory concentrations obtained by using mixed inocula of colonies of different morphological types fell within one serial dilution of the most resistant minimal inhibitory concentration obtained when each colony type was tested separately.

Anti-Bacterial Agents

Comparison of a micromethod for performance of the serum bactericidal test with the standard tube dilution method.

A micromethod for performance of the serum bactericidal test is described, and the results obtained with this method are compared with those obtained with the standard tube dilution macromethod. An agreement within +/- 1 dilution was achieved in 23 of 25 (92%) determinations of the serum bactericidal titer. The micromethod used approximately one-third of the amount of pooled normal human serum and of the technician's time required for performance of the macromethod. The micromethod offers an accurate and economical alternative to the macromethod for the performance of the serum bactericidal test and is particularly useful with infants and children since it minimizes blood loss.

Anti-Bacterial Agents

Improved indirect hemagglutination test for cytomegalovirus using human O erythrocytes in lysine.

A modified indirect hemagglutination test for cytomegalovirus antibodies is described in which glutaraldehyde-fixed human O cells, rather than sheep cells, are used. Nonspecific hemagglutination was reduced by use of the optimal tannic acid concentration for each cell batch and the addition of 0.1 M lysine to the phosphate-buffered saline in which the fixed, tanned, sensitized cells were resuspended for use in the test. Three of 349 sera showed nonspecific hemagglutination by this technique. Antigen made by freezing phosphate-buffered saline (pH 7.2) over an infected monolayer can be used at dilutions of 1:8 to 1:15. Fixed, tanned, sensitized cells ready for use in the test can be stored in liquid nitrogen for up to 8 months. Use of cryoprotectants and washing after thawing is unnecessary. Simplification of the assay permits one person to screen 300 sera in 1 day or to determine the immune status of a potential donor or recipient in 45 min after the test is set up. The modified assay compares favorably in sensitivity with the complement fixation test and with previously described methods for performing the indirect hemagglutination test.

ABO Blood-Group System

Experimental brain abscess evolution: computed tomographic and neuropathologic correlation.

Brain abscess evolution was studied in dogs by correlating the CT appearance with the neuropathologic findings. The abscess, produced by direct inoculation, progressed from an area of cerebritis to a well encapsulated abscess over 14 days. Ring enhancement was seen in the cerebritis stage prior to capsule formation. The ring reached its maximum size at this stage and correlated best with the area of cerebritis surrounding the developing necrotic center; the rim of this ring increased in thickness, resulting in progressive diminution of the central lucent area on scans delayed up to 60 min. The diameter of the ring decreased as cerebritis receded. Once the capsule had formed, the central lucent area was similar and no longer filled in on delayed scans.

Animals

Spontaneous resolution of severe aplastic anemia associated with viral hepatitis A in a 6-year-old child.

Recovery from acquired aplastic anemia associated with hepatitis is rare. This case of a 6-year-old boy with severe aplastic anemia is the first reported association of this disease with a hepatitis A infection. Antibody to hepatitis A (anti-HA) was not detected on admission, but was detected three weeks later. Infection with hepatitis B virus, cytomegalovirus (CMV), and Epstein-Barr virus (EBV) were excluded. The peak titer of anti-HA was higher than would be expected for passive transfer of antibody resulting from transfusions. The persistence of antibody for more than 20 months after the last transfusion was not consistent with passive antibody, which would be expected to disappear over that time. This child had indications for allogeneic marrow transplant and a sibling donor who was histocompatible. However, the transplant was postponed because the prognosis was considered to be poor in the presence of active hepatitis. There was a spontaneous remission without the necessity of the transplantation procedure.

Anemia, Aplastic

Measles immunization. Successes and failures.

As a result of a large outbreak of measles, measles hemagglutination inhibition (HI) titers were measured in 465 immunized children. Titers of less than 1:4 were found in 14.6% of children immunized at 12 months of age as compared to 5.2% of those immunized at 13 months of age or later. Measles antibody titers were higher in the mothers of seronegative children who had been immunized at 11 or 12 months of age than in the mothers of seroposotive children. Measles HI titers of 1:4 or more were present in 94% of children immunized at 13 months of age or later between 1962 and 1964. The findings suggest that vaccine failure and not waning antibody accounts for the majority of titers of less than 1:4 in immunized children. Reimmunization programs should be considered for those who were immunized before 13 months of age.

Adolescent

Respiratory syncytial virus in early infancy. Circulating antibody and the severity of infection.

Forty-one children less than 6 months of age from whom respiratory syncytial virus (RSV) was isolated were divided into groups of varying severity of illness. No relationship was demonstrated between severity of illness and the complement fixation titer to RSV in cord sera, acute sera, or convalescent sera. An increase in IgM level of greater or equal to 15 mg/100 ml in association with the RSV infection was seen more frequently in infants who had higher IgM levels in their acute sera than in infants who had lower levels.

Antibodies, Viral

Effect of leukocyte interferon on urinary excretion of cytomegalovirus by infants.

Five infants with symptomatic cytomegalovirus infections and high urinary titers of cytomegalovirus were treated with interferon in doses of 1.7-3.5 X 10(5) reference units/kg per day for seven to 14 days. Six courses of treatment were given. One of two infants treated with the largest dose of interferon had transient suppression of viruria; no suppression was noted during the other five courses of treatment. Adverse effects noted included a low rate of weight gain, a transient elevation of serum aspartate aminotransferase and fever. Further trials are needed to determine whether larger doses of a more purified preparation of interferon will eliminate viruria in infants with sytomegalovirus infection, but careful assessment of toxicity will be necessary in this population of patients.

Cytomegalovirus

Longitudinal, serological study of cytomegalovirus infections in nurses and in personnel without patient contact.

Sera were obtained at intervals from 172 hospital employees for measurement of cytomegalovirus (CMV) complement fixation (CF) and indirect hemagglutination antibody. No fourfold rises or falls in titer were seen over a 19- to 27-month period among 71 employees with initially positive CMV CF titers. The concurrence rate between the CMV CF and the indirect hemagglutination antibody tests in identifying seronegative personnel was 96%. Five seroconversions were identified during an average follow-up period of 15 to 17 months per person among 65 pediatric nurses whose CMV CF titers had initially been less than 1:8. No seroconversions were seen during an average follow-up period of 29 months per person among 27 hospitad little patient contact. The rate of acquisition of CMV infections in seronegative pediatric nurses was 4.1 to 7.7% per year. Sera from 9 of the 172 employees studied (5.2%) gave inconsistent results at the lower limits of the CF test.

Adult