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Biomedical subjects

R L Wientzen

Publications and source records attributed to R L Wientzen.

At least 19 recordsLinked to original sources

Humoral immunity to commensal oral bacteria in human infants: salivary secretory immunoglobulin A antibodies reactive with Streptococcus mitis biovar 1, Streptococcus oralis, Streptococcus mutans, and Enterococcus faecalis during the first two years of life.

Secretory immunoglobulin A (SIgA) antibodies reactive with the pioneer oral streptococci Streptococcus mitis biovar 1 and Streptococcus oralis, the late oral colonizer Streptococcus mutans, and the pioneer enteric bacterium Enterococcus faecalis in saliva samples from 10 human infants from birth to age 2 years were analyzed. Low levels of salivary SIgA1 and SIgA2 antibodies reactive with whole cells of all four species were detected within the first month after birth, even though S. mutans and E. faecalis were not recovered from the mouths of the infants during the study period. Although there was a fivefold increase in the concentration of SIgA between birth and age 2 years, there were no differences between the concentrations of SIgA1 and SIgA2 antibodies reactive with the four species over this time period. When the concentrations of SIgA1 and SIgA2 antibodies reactive with all four species were normalized to the concentrations of SIgA1 and SIgA2 in saliva, SIgA1 and SIgA2 antibodies reactive with these bacteria showed a significant decrease from birth to 2 years of age. Adsorption of each infant's saliva with cells of one species produced a dramatic reduction of antibodies recognizing the other three species. Sequential adsorption of saliva samples removed all SIgA antibody to the bacteria, indicating that the SIgA antibodies were directed to antigens shared by all four species. The induction by the host of a limited immune response to common antigens that are likely not involved in adherence may be among the mechanisms that commensal streptococci employ to persist in the oral cavity.

Antibodies, Bacterial↗

Factors influencing pseudomonas colonization in cystic fibrosis.

In order to assess the relationship between various factors influencing Pseudomonas (Ps) colonization of the respiratory tract of patients with cystic fibrosis (CF) and the appearance of various strains of Ps, two groups of CF patients were studied during a 5-year period. Group A consisted of 24 Ps-negative patients, and Group B consisted of 32 Ps-positive patients, including eight patients who expired. Several clinical and laboratory parameters were evaluated. Although the precise mechanism causing the appearance of Ps in the respiratory tract of CF patients remains elusive, we analyzed several biologic characteristics of both host and organism. This study indicates that frequent use of antibiotics combined with the eradication of Staphylococcus aureus from the respiratory tract heralds the onset of persistent Ps colonization and a subsequent downhill course for CF patients.

Adolescent↗

Vulvovaginitis in prepubertal girls: the importance of group A Streptococcus.

We report four cases of group A streptococcal vulvovaginitis in prepubertal children. All cases were acute in onset. This illness presents with nonspecific signs and symptoms of labial inflammation. In a suburban community, streptococcal vulvovaginitis in prepubescent girls may be more common then genital infections due to Neisseria gonorrhoeae. Since media used for the selective isolation of N gonorrhoeae do not readily support the growth of streptococci, we suggest that the routine bacteriologic approach to the diagnosis of vulvovaginitis in young girls include inoculation of the culture swab on 5% sheep blood agar and the application of a bacitracin disk (taxo A disc) to detect any small beta-hemolytic, presumptively group A streptococcal colonies after overnight incubation. Penicillin therapy results in prompt cure.

Bacteriological Techniques↗

Occult bacteremia in toxic-appearing, febrile infants. A prospective clinical study in an office setting.

The prevalence of occult bacteremia was evaluated prospectively in two groups of infants: those with a toxic appearance and temperature greater than 38.8 C and a comparison group with similar fever but without a toxic appearance. All patients were diagnosed by one physician employed in a suburban, middle-class, private ambulatory pediatric practice. Toxicity scores were assigned based on the results of history and physical examination. Peripheral white blood cell (WBC) counts and blood cultures were obtained for every child. Of 52 toxic infants involved in the study, an infectious source, commonly otitis media, was found in 26 (50%). Eighteen patients (35%) had WBC counts above 15,000. Bacteremia was documented in six patients (12%), due to Streptococcus pneumoniae in five and to group C Streptococcus in one. Five bacteremic infants had toxic, febrile illnesses for which no overt focus could be identified. None of 31 febrile infants without a toxic appearance had bacteremia. We conclude that highly febrile, toxic-appearing infants are at risk for occult bacteremia even when they are seen in the pediatrician's office. Toxicity diagnosed on the basis of clinical findings in a febrile infant warrants obtaining a white blood cell count and a blood culture.

Ambulatory Care↗

Penicillin V for group A streptococcal pharyngotonsillitis. A randomized trial of seven vs ten days' therapy.

The effect of duration of orally administered penicillin V potassium on the bacteriologic and clinical cure of group A streptococcal pharyngitis was evaluated. One hundred ninety-one middle-class patients received either seven days (96 patients) or ten days (95 patients) of therapy. Compliance with taking penicillin was assessed by multiple methods, including penicillinuria. Throat cultures were obtained during therapy and three times in the three weeks after therapy. M-precipitin and T-agglutinin typing were done on paired isolates of group A streptococci from patients who had recurrences. Patients treated for seven days had a significantly greater failure rate (30/96 [31%]) compared with patients receiving ten days of penicillin (17/95 [18%]). Compliance rates were high; 66% to 81% of patients showed penicillinuria throughout the study period. Treatment failure was not a function of poor compliance in either treatment group. The data support the current recommendation for ten full days of penicillin therapy and suggest that persistence of streptococci in the throat after adequate therapy may be common.

Administration, Oral↗

Streptococcal pharyngitis in infants: a reappraisal of its prevalence.

The prevalence of group A streptococcal pharyngitis in children under 3 years of age was determined by retrospective review of the results of throat cultures taken from children seen in a middle-class, suburban, private pediatric practice. Of 2,200 throat cultures obtained, 7% (149) were from children in this age group, and 15% (23) of these were positive for group A streptococci. All children had pharyngeal injection and the majority were symptomatic, with fever, rash, or rhinitis. Exudative pharyngitis was rare. This study suggests that pharyngeal infection with this organism in infants and young children is not uncommon, and justifies the need for throat cultures in this population.

Child, Preschool↗

Localization and therapy of urinary tract infections of childhood.

One hundred four patients with 124 episodes of urinary tract infection were studied. Serum C-reactive protein (CRP) was determined on diagnosis of each patient. Children with a CRP equal to or greater than 30 micrograms/ml (CRP-pos) differed significantly from those with values less than 30 micrograms/ml (CRP-neg) in age, clinical presentation, K type of Escherichia coli causing disease, frequency or radiographic abnormalities, and presence of antibody coating of bacteria in the urinary sediment. E. coli K1 strains caused disease significantly more often in CRP-pos than in CRP-neg patients, and children with K1 infections were younger than those with non-K1 infections. The antibody-coated bacteria test was neither sensitive nor specific for localization of infection in pediatric patients. Determination of K1 antibody concentrations in serum and urine of E. coli K1-infected children provided data supporting the measurement of CRP as one means of localizing urinary tract infections. Patients with CRP-neg infections were treated as successfully with four days of antimicrobial therapy as with ten days.

Acute Disease↗