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Biomedical subjects

A S Yeager

Publications and source records attributed to A S Yeager.

At least 37 records · Page 2Linked to original sources
PubMed1982

Neonatal herpes simplex infection in the absence of mucocutaneous lesions.

Six infants with disseminated HSV had no mucocutaneous lesions at any time during the course of the illness. These infants presented with lethargy, poor feeding, apnea, acidosis, and hepatomegaly. The diagnosis of HSV was made by culturing the infant's oropharynx and blood, and the maternal cervix. Eight infants with HSV encephalitis had no skin, eye, or mucous membrane lesions. These infants presented with lethargy and low-grade fever, followed within 24 hours by the onset of focal partial motor seizures. The seizures were refractory to anticonvulsant therapy. The mean CSF white cell count was 131 cells/mm3;the glucose and protein concentrations were in the normal range. Brain biopsy was required for the early diagnosis of HSV encephalitis. These 14 cases presented 70% (14/20) of all infants with neonatal HSV diagnosed during the study period. HSV infection should be considered in infants with no mucocutaneous lesions who have signs usually associated with bacterial sepsis or who develop focal seizures during the first three weeks of life.

Encephalitis↗
PubMed1982

The effect of short-term corticosteroid treatment on the CT appearance of experimental brain abscesses.

The effect of short-term corticosteroid treatment on contrast enhancement was investigated in an experimental brain abscess model. The degree of enhancement was reduced in the cerebritis stage, unaffected in the capsule stage, and intermediate in the transitional stage. The area and pattern of enhancement were also altered in the cerebritis stage. Although the magnitude of the entire cerebritis time-density curve (extended for 60 minutes) was decreased by the steroids, its configuration was unchanged. Prior to steroid administration, the 10- and 60-minute components of the curve discriminated between cerebritis and capsule stages, with the latter exhibiting a far lower 60-minute value. Implications for treatment of brain abscesses are discussed.

Animals↗
PubMed1982

Neutralization of herpes simplex virus by antibody in amniotic fluid.

The ability of amniotic fluid to neutralize herpes simplex virus type 2 (HSV-2) was quantitated and compared with the serum neutralization titer in 158 pregnant women. Neutralizing activity was expressed as the ability of 0.1 ml of amniotic fluid to reduce the expected number of plaque-forming units (pfu) in the inoculum by 99%. All amniotic fluid samples from 32 women with serum titers of 1:40 or greater neutralized 5 pfu or more; at term, 96% of these fluid samples neutralized 50 pfu or more, 83% neutralized 500 pfu or more, and 61% neutralized 5000 pfu or more. Only 76% of the amniotic fluid samples obtained at term from women with serum titers of 1:5 to 1:39 contained detectable neutralizing activity and only 8% neutralized 5000 pfu or more. None of the amniotic fluid samples from 30 women with serum titers less than 1:5 neutralized 5 pfu or more. All neutralizing activity was removed when immunoglobulin G was removed from the amniotic fluid samples. Sera were obtained from 51 pregnant women 4 to 8 weeks prior to delivery. All women with serum titers of 1:40 or higher gave birth to infants who also had serum titers of 1:40 or higher. Therefore, it is possible to predict the neutralization titer in amniotic fluid and in the infant's serum by measuring the mother's titer in the third trimester.

Amniotic Fluid↗
PubMed1981

Prevention of transfusion-acquired cytomegalovirus infections in newborn infants.

Transfusion-acquired cytomegalovirus infections occurred in 13.5% of 74 infants of seronegative mothers who were exposed to one or more blood donors who had a CMV indirect hemagglutination titer of 1:8 or higher. None of 90 infants of seronegative mothers exposed only to donors with CMV IHA titers of less than 1:8 became infected. Ten of 41 (24%) infants of seronegative mothers who received more than 50 ml of packed red blood cells and who were exposed to at least one seropositive donor became infected. None of 23 infants of seronegative mothers who received this amount of blood but who were exposed only to seronegative donors became infected. Fatal or serious symptoms developed in 50% of the infected infants of seronegative mothers and in none of the 32 infected infants of seropositive mothers. Acquired CMV infections occurred in 15% of infants of seropositive mothers who were exposed to the red blood cells of seropositive donors and in 17.6% of infants of seropositive mothers exposed only to seronegative donors. Use of seronegative donors reduced the prevalence of excretion of CMV among hospitalized infants who were 4 weeks of age or older from 12.5 to 1.8% and eliminated acquired CMV infections in infants of seronegative mothers.

Antibodies, Viral↗
PubMed1981

Neuropathological and computerized tomographic findings in experimental brain abscess.

The neuropathological progression of brain abscess formation was studied experimentally at sequential stages in dogs, and the findings correlated with the appearance on computerized tomographic (CT) brain scans. The evolution of brain-abscess formation was divided into four stages based on histological criteria: early cerebritis (Days 1 to 3); late cerebritis (Days 4 to 9); early capsule (Days 10 to 13); and late capsule (Days 14 and later). The cerebritis stage was characterized by prominent perivascular cuffing by inflammatory cells in the area adjacent to the developing necrotic center. However, the early elements of capsule formation appeared with the presence of fibroblasts by Day 5. The CT scans showed ring-shaped contrast enhancement by Day 3. Delayed scans at 30 minutes revealed diffusion of the contrast material into the developing necrotic center, forming a solid lesion. In lesions that were well encapsulated (14 days and older), five distinct histological zones were apparent: 1) a well formed necrotic center; 2) a peripheral zone of inflammatory cells, macrophages, and fibroblasts; 3) the dense collagenous capsule; 4) a layer of neovascularity associated with continuing cerebritis; and 5) reactive astrocytes, gliosis, and cerebral edema external to the capsule. The CT appearance of well encapsulated abscesses showed a typical ring-shaped contrast-enhancing lesion. On the delayed scans, the "ring" did not fill in with contrast enhancement. The diameter of the ring correlated best with the presence of cerebritis (perivascular infiltrates in the adventitial sheaths of vessels surrounding the abscess). The discussion focuses on the relevance of this study to the current management of patients with brain abscess.

Animals↗
PubMed1981

Atypical mycobacterial cervical lymphadenitis--treatment with surgery and antibiotics.

Five patients, ages 2 to 5 years, were successfully treated for cervical lymphadenitis caused by the avium intercellulari complex of atypical bacteria. Preoperative treatment with standard antituberculosis therapy had been unsuccessful. Extensive surgery requiring a conservative radical neck dissection was sometimes required. Three patients had such extensive and progressive disease that immediate excision was impossible. These patients received a course of Amikacin with considerable improvement, permitting adequate excision and reconstruction. A fourth patient who received Amikacin did not respond, although sufficient excision was possible. This preliminary data indicates that a combined treatment of Amikacin and surgery in extensive cases may be useful in the treatment of cervical lymphadenitis due to atypical mycobacteria.

Amikacin↗
PubMed1980

Relationship of antibody to outcome in neonatal herpes simplex virus infections.

Neutralizing antibody titers to herpes simplex virus type 1 (HSV-1) and HSV-2 were measured at birth in normal infants and uninfected infants of mothers with genital HSV infections during pregnancy and at the onset of infection in 5 infants with mild infections and 11 infants with severe infections. Thirty-eight percent of premature and 29% of term infants had neutralization titers of <1:5. High titers ([unk]1:40) were found in 55% of infants of mothers with primary infections during pregnancy and in 76% of infants of mothers with recurrent infections. The mean titers to HSV-1 and -2 in 5 infected infants with mild infections were 1:56 and 1:65 at the time of onset of infection, whereas the mean titers in 11 infants with severe infections were 1:11 and 1:12. Six natally exposed infants who remained asymptomatic were also studied and had a mean titer to HSV-1 of 1:85 and to HSV-2 of 1:69. Therefore, infants with high titers of transplacentally derived antibody had a more favorable outcome than infants with lower titers. Ninety-five percent of the infants of mothers with recurrent infections had a Rawls index of more than 85, suggesting that the antibody response was to HSV-2. However, low levels of antibody with this type specificity failed to protect four infants from infection with HSV-2. Augmentation of the neutralization titer to HSV-2 by the amount of complement present in cord serum was less than twofold. The study suggests that the quantity of antibody derived transplacentally affects the outcome of infection after natal exposure to herpes simplex virus. Complete neutralization of virus by antibody may occur in some infants, and prolongation of the incubation period and modification of the infection may occur in others.

Age Factors↗
PubMed1980

Diagnostic significance of immunoglobulin M antibodies to Toxoplasma gondii detected after separation of immunoglobulin M from immunoglobulin G antibodies.

Failure to demonstrate immunoglobulin M (IgM) antibodies by indirect immunofluorescence (IgM-IFA) in sera from some patients with acute acquired toxoplasmosis has recently been attributed to an inhibitory effect of high titers of IgG antibodies in these sera (Pyndiah et al. J. Clin. Microbiol. 9:170-174, 1979). To confirm these findings and define their importance for diagnosis, we used gel filtration to separate IgM from IgG antibodies in a series of sera that were negative in the IgM-IFA test. A total of 68 sera were from patients with acquired toxoplasmosis, 13 were from uninfected adults, 13 were from infants with congenital toxoplasmosis, and 7 were from uninfected neonates. Of the 68 sera from patients with acquired toxoplasmosis, IgM preparations (from the separated sera) were positive in the IgM-IFA test in 36 (53%). There was a significant (P = 0.00003) association between high titers of IgM-IFA antibodies in the IgM preparations (corrected for dilution of IgM antibodies by the gel filtration procedure) and recent acquisition of infection. IgM antibodies were also detected in 5 (38%) of the IgM preparations of 13 sera from congenitally infected infants but not in any of the IgM preparations of sera from uninfected neonates. IgG antibodies to Toxoplasma gondii were shown to interfere with demonstration of IgM antibodies in the IgM-IFA test. Treatment of sera with protein A resulted in greater dilution of IgM antibodies and less efficient separation of IgM from IgG antibodies than did separation of sera by gel filtration. Treatment of sera with protein A did not result in increased detection of IgM antibodies to T. gondii. Testing of IgM preparations (obtained by gel filtration) resulted in a significant increase in sensitivity of the IgM-IFA test for the diagnosis of recently acquired and congenital toxoplasmosis.

Adult↗
PubMed1980

Anticomplement immunofluorescence test that uses isolated fibroblast nuclei for detection of antibodies to human cytomegalovirus.

Cytomegalovirus antibodies were measured in human sera by a nuclear anticomplement immunofluorescence test that used as antigen the isolated nucleic of virus-infected fibroblasts cells lysed in distilled water. The method exhibited less nonspecific fluorescence than either a conventional whole-cell anticomplement immunofluorescence test or an indirect fluorescent antibody test applied to the same isolated nuclear substrate. The assay detected 97.5% of 40 antibody-positive sera, compared with 92.5 and 90% detection rates by indirect hemagglutination and complement fixation, respectively. In addition, antibody titers obtained by this technique were significantly higher than those obtained by either indirect hemagglutination (P < 0.02) or complement fixation with a glycine-extract antigen (P < 0.001).

Antibodies, Viral↗
PubMed1979

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↗
PubMed1979

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↗
PubMed1979

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↗
PubMed1979

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↗