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Biomedical subjects

B F Polk

Publications and source records attributed to B F Polk.

At least 109 records · Page 6Linked to original sources
PubMed1979

Identification of site of urinary-tract infections by antibody-coated bacteria assay.

Accurate identification of the site of urinary-tract infection (UTI) may be clinically and epidemiologically valuable. A review of the literature on the assessment of the antibody-coated bacteria (ACB) assay, a non-invasive technique introducted five years ago, shows that, compared with acceptable standards (bilateral ureteral catheterization or bladder washout), the overall sensitivity of the ACB assay is 83.1%, the specificity is 76.7%, the predictive value positive is 81.3%, and the predictive value negative is 78.8%. These findings suggest that the ACB assay has at present no role in the management of patients with UTI. Its usefulness as an epidemiological tool remains to be demonstrated.

Adult↗
PubMed1978

Cervical and vaginal bacterial flora: ecologic niches in the female lower genital tract.

The bacterial flora of the cervix and vaginal vault were compared by obtaining duplicate specimens for quantitative bacteriologic studies in 14 patients electively admitted for hysterectomy. There were a total of 137 isolates from the 28 specimens, including 71 aerobes and 66 anaerobes. Aggregate data showed that the flora of the two sample sites were similar by both qualitative and quantitative analysis. However, individual comparison of paired specimens showed considerable differences in that 75 of the 137 isolates were recovered from only the cervix or vaginal vault. Additional studies showed that neither low concentrations of bacteria nor the culture techniques accounted for these differences. It is concluded that most women harbor distinctive bacterial populations in the cervix and vaginal vault.

Aerobiosis↗
PubMed1977

Methods for quantitative vaginal flora studies.

Quantitative bacteriology of the vaginal flora was performed with two techniques: One was a quantitative loop of vaginal secretions and the second was duplicate swabs of the vaginal fornix with one swab for bacteriologic studies and the second to determine specimen weight. Both sampling methods were evaluated for accuracy in weight or volume measurements. Comparison of the two methods in eight volunteers showed reasonably good correlation although the duplicate swab technique gave somewhat higher mean counts and more bacterial species. Advantages and limitations of these methods for quantitative vaginal flora studies are discussed.

Bacteriological Techniques↗
PubMed1977

Isolation and identification of encapsulated strains of Bacteroides fragilis.

One hundred three clinical isolates of Bacteroides fragilis were identified during a two-year period. Most of these isolates were strains of B. fragilis subspecies fragilis, which constitutes a minor component of the fecal flora in comparison with the other subspecies of B. fragilis. By use of several techniques for demonstration of capsules, it was found that only B. fragilis strains classified as subspecies fragilis were encapsulated. An indirect immunofluorescence assay was developed for identification of clinical isolates possessing capsular material that was immunologically similar to that found in the reference strain of B. fragilis subspecies fragilis. All strains examined that were classified as subspecies fragilis were positive in this assay for the capsular material, whereas strains of the other subspecies were negative. This tests represents a rapid and sensitive means of identifying the most prevalent anaerobic gram-negative bacillus involved in human infections. The capsular polysaccharide of B. fragilis subspecies fragilis is a unique factor associated with the predominant subspecies of B. fragilis isolated from clinical material.

Antigens, Bacterial↗
PubMed1977

Bacteroides fragilis subspecies in clinical isolates.

Isolates of Bacteroides fragilis from 83 infected patients were collected during 2 years. Of 103 isolates, 68% were subspecies fragilis. This was the single most common subspecies isolated from blood (12/17), intra-abdominal (11/28), wound (17/20), perirectal (11/16), pelvic (6/10), and other (8/11) sites. Sixteen patients had B. fragilis isolated in pure culture. Of these, 9/12 blood cultures and 4/4 cultures from other sites were ss. fragilis. The recent observation that ss. fragilis organisms are encapsulated whereas the other subspecies are generally unencapsulated was supported by indirect fluorescent antibody studies using antibodies prepared to the capsular material of ss. fragilis. All 33 strains of ss. fragilis and none of 13 strains of other subspecies were positive. The predominance of ss. fragilis in clinical isolates compared to its relative infrequency in normal fecal flora and its predominance in pure cultures, especially of blood, indicate that this is the most virulent of B. fragilis subspecies. This virulence may be related to encapsulation.

Abdominal Injuries↗
PubMedDate not supplied

Decreasing seroprevalence of human immunodeficiency virus type 1 in a regional blood donor population.

Blood banks have intensified their efforts to discourage donations from individuals at risk for the human immunodeficiency virus (HIV-1). Since the onset of HIV-1 donor screening in April 1985, a marked reduction in seroprevalence has been seen at the authors' institutions: from 51 cases per 100,000 donors in 1985 to 13 per 100,000 in the first 6 months of 1988. Data from 3.5 years have been analyzed for temporal trends in the association of HIV-1 seroprevalence with donation site (urban vs. non-urban) and donor gender. The association of HIV-1 seropositivity with an urban donation site decreased through 1987 as the urban-to-nonurban donation odds ratio declined from 6.48 in 1985 to 2.54 in 1987. Despite this decrease, both men and women who donated in urban areas had a significantly higher seroprevalence than those in nonurban areas. Male donors had a higher overall HIV-1 seroprevalence than female donors. However, the male-to-female odds ratio declined from 2.94 in 1985 to 1.96 in 1988, and male gender was no longer significantly associated with HIV-1 seropositivity. This change in the donor profile appears to reflect declining numbers of seropositive men who acknowledge risk factors and greater numbers of women with no identified risks for HIV-1. This study documents a dramatic decrease in HIV-1-seropositive donors and suggests that the deferral of high-risk individuals has become increasingly successful.

Blood Donors↗
PubMedDate not supplied

Surface antigens as virulence factors in infection with Bacteroides fragilis.

Organisms of the genus Bacteroides represent the major group of obligate anaerobes involved in human infections. Bacteroides usually cause either bacteremia or localized abscesses. Of the numerous species of Bacteroides, Bacteroides fragilis is the single most frequent clinical isolate. B. fragilis and Bacteroides melaninogenicus have chemically incomplete lipopolysaccharides as compared with the lipopolysaccharides (endotoxins) of aerobic bacteria, and the lipopolysaccharides of Bacteroides lack the biologic potency characteristic of endotoxin. This inactivity may account for the very infrequent occurrence of disseminated intravascular coagulation or purpura that can accompany sepsis due to these organisms. Furthermore, strains of B. fragilis have an immunologically common capsular polysaccharide. In an animal model of intraabdominal sepsis, the encapsulated strains caused abscesses when given without other organisms, but abscess formation from unencapsulated strains of Bacteroides generally required the administration of a synergistic aerobe. The abscesses caused by encapsulated strains were shown to be directly attributable to the capsular polysaccharide, which is an important virulence factor of this organism. Patients or experimental animals infected with B. fragilis develop antibodies to the capsular polysaccharide, and these antibodies can be detected in a radioactive antigen-binding assay.

Animals↗
PubMedDate not supplied

Seal finger.

Explore the source record for details and available documents.

Adult↗
PubMedDate not supplied

Single-dose antimicrobial therapy for urinary tract infections in women.

Single-dose antimicrobial therapy for uncomplicated urinary tract inductions in women has been reported and evaluated by several investigators. A review of the results of these studies suggest that amoxicillin, sulfisoxazole, and trimethoprim-sulfamethoxazole are effective single-dose regimens in this setting. These results should not be extrapolated to other populations, such as pregnant women or children, or to other antimicrobial agents. The limited data available suggest that cephalosporins are less effective than the regimens recommended. When the infecting organism is sensitive, failure to eradicate bacteriuria with one of these single-dose regimens may be indicative of a more invasive infection, perhaps in the kidney.

Amoxicillin↗
PubMedDate not supplied

Bacterial flora of the vagina: quantitative study.

Quantitative analysis of cultures of the vaginal flora was performed on 118 specimens from 68 women of reproductive age. Aerobic bacteria in concentrations greater than 10(5) organisms/g were recovered in all specimens. The mean concentration of aerobes was 10(8.1) organisms/g, and lactobacilli were the most common isolates. Anaerobes were recovered from 86% of the specimens, and the mean concentration of these organisms, when present, was 10(8.6) organisms/g. The most commonly occurring anaerobes were peptococci and anaerobic gram-positive bacilli. Analysis of specimens obtained sequentially during a menstrual cycle showed significant qualitative and quantitative changes. Cervical cultures showed bacteriologic patterns that were similar to those noted with vaginal cultures. However, duplicate samplings of the cervix and vagina in individual patients showed substantial differences in the bacteria recovered. These observations suggest that the vaginal flora is a dynamic ecosystem that is subject to change and that the cervix represents a unique ecologic niche.

Adolescent↗
PubMedDate not supplied

Human immunodeficiency virus infection in women attending an inner-city prenatal clinic: ineffectiveness of targeted screening.

Women attending an inner-city prenatal clinic between February, 1987 and August, 1988 completed a questionnaire to assess risk factors for human immunodeficiency virus (HIV) infection. Women with risk factors were offered HIV testing. Testing was available to women without risk factors upon their request. Stored sera were obtained for anonymous HIV testing on patients not consenting for testing. Overall, 30 of 622 women (5%) tested HIV positive. Ten per cent of women acknowledging risk factors were seropositive vs 3% denying risk factors (P less than .001). Intravenous (IV) drug use was reported in 40% of seropositive women. However, 47% (14/30) of HIV seropositive women denied risk factors for infection. Limiting prenatal HIV screening to women acknowledging risk factors may fail to identify a substantial number of infected women. Screening for HIV infection, counseling, and education on risk reduction should be offered to all pregnant women.

Adolescent↗