Biomedical subjects

R C Barnes

Publications and source records attributed to R C Barnes.

At least 37 records · Page 2Linked to original sources

PubMed1989

Enzyme immunoassay to determine exposure to Chlamydia pneumoniae (strain TWAR).

Recent studies suggest that a group of Chlamydia strains known as TWAR, which are now proposed to be a new species called Chlamydia pneumoniae, may be a frequent cause of respiratory disease in the United States and many other countries. Current serotesting methods do not allow rapid screening of large numbers of samples to distinguish C. trachomatis exposure from C. pneumoniae exposure. We developed an enzyme immunoassay to decrease cross-reactivity between immunoglobulin G antibodies reactive with C. trachomatis and C. pneumoniae. Elementary bodies of C. trachomatis or C. pneumoniae were treated with a detergent-chelating solution to decrease the reactivity of the common lipopolysaccharide antigens. Sera from four groups of patients, totaling 143 persons, were tested by this assay. The prevalences of titers of greater than or equal to 128 to C. trachomatis and C. pneumoniae, respectively, were as follows: (i) for 23 women seropositive for C. trachomatis by the microimmunofluorescence test, 21 (91%) and 18 (78%); (ii) for 50 adult blood donors, 13 (26%) and 39 (78%); (iii) for 40 sexually transmitted disease clinic patients, 20 (50%) and 32 (80%); (iv) for 30 healthy children 5 to 7 years old, 0 (0%) and 8 (27%). Western blots (immunoblots) of each antigen corroborated the differential reactivity of C. trachomatis-positive, C. pneumoniae-negative and C. trachomatis-negative, C. pneumoniae-positive serum samples. Western blots of serum samples from rabbits immunized with either C. trachomatis or C. pneumoniae elementary bodies revealed at least two protein bands (30 and 80 kilodaltons) which appeared to represent unique C. pneumoniae antigens.

Adult↗

PubMed1988

Antigenic heterogeneity in the 115,000 Mr major surface antigen of Trichomonas vaginalis.

The 115,000-molecular-weight antigen of Trichomonas vaginalis was characterized using monoclonal antibodies developed to three different strains of T. vaginalis and one strain of Tritrichomonas foetus. The antigen was found to be present on all strains or isolates of T. vaginalis examined and was demonstrated to be located on the external surface plasma membrane by agglutination assays and complement-mediated lysis assays. Characteristics of the antigen were assessed with a proteolytic enzyme and periodate oxidation. Periodate treatment of whole T. vaginalis abrogated binding for eight antibodies while use of pronase-treated antigen resulted in loss of antibody binding for two different antibodies. Screening of 19 axenized clinical isolates of T. vaginalis and one strain each of T. foetus and Giardia lamblia with type-specific antibodies delineated three major groups of T. vaginalis based on antigenic specificities (epitope distributions) within the 115,000-molecular-weight antigen. In addition, one epitope of the 115,000-molecular-weight antigen was found only on the immunizing strain. Two epitopes were present on all T. vaginalis isolates as well as T. foetus and G. lamblia. One epitope was common to all T. vaginalis except one. A minimum of six different epitopes of the 115,000-molecular-weight antigen were identified. Antigens purified with type-specific or "common" monoclonal antibodies shared the same partial peptide maps demonstrating relatedness.

Agglutination Tests↗

PubMed1988

Multicenter comparative evaluation of two rapid microscopic methods and culture for detection of Chlamydia trachomatis in patient specimens.

Four hundred and seventy-three men and women at high risk for sexually transmitted disease were tested for the presence of Chlamydia trachomatis in the urethra or the endocervix. Four groups were involved in this multicenter study of two direct fluorescent-antibody microscopy tests, Kallestad Pathfinder and Syva Microtrak, compared with culture techniques. Results from the test sites indicated that there was no significant difference overall in the sensitivity and specificity of the two test kits. However, there was some interlaboratory variation seen in the sensitivity of the microscopy, but little difference in the specificity. Either kit could be an effective screening method for C. trachomatis in high-risk populations.

Cervix Uteri↗

PubMed1988

Intentionality of college students regarding North Carolina's 21-year drinking age law.

The purpose of this study was to examine the intentions of underage students at a southeastern university as to a new 21-year drinking law. Students (N = 440) in introductory health classes were given a questionnaire prior to the law's enactment. Major findings included: 90% were alcohol users, with 85% beginning regular alcohol use by age 18. Only 6% intended to stop drinking, 70% planned to change their location of use, and 22% intended to use other drugs more. Seventy percent intended to obtain alcohol from their friends, and 21% intended to use a false or borrowed identification. Serious questions about potential negative impacts of the law are raised.

Adult↗

PubMed1987

Chlamydial infection of subcutaneous fimbrial transplants in cynomolgus and rhesus monkeys.

Acute infection with Chlamydia trachomatis serotype E was established in monkey fallopian tube fimbriae by subcutaneous implantation. Depending upon monkey species, from eight to 20 implants could be established in each animal. Animals were given estrogen before percutaneous inoculation of the autografts with Chlamydia. Acute inflammatory changes were found in homografts examined in the first week after infection, with chronic inflammatory changes noted thereafter. Chlamydial inclusions were detected within fimbrial epithelial cells up to seven days postinoculation by fluorescent-antibody staining and immunoperoxidase staining with C. trachomatis-specific monoclonal antibody. Organisms were recovered from autografts up to five days after infection. Analysis of serum antibody by microimmunofluorescence revealed that serotype E-specific antibody of both IgM and IgG classes was produced after infection. We conclude that subcutaneously implanted fallopian tube autografts may provide a useful primate model for kinetic studies of chlamydial infection and immunity.

Animals↗

PubMed1987

Comparison of Chlamydia trachomatis serovars causing rectal and cervical infections.

We used monoclonal antibodies capable of distinguishing serovars of Chlamydia trachomatis to compare 314 cervical isolates with 150 rectal isolates from homosexual men. The isolates were obtained from patients attending a sexually transmitted diseases clinic over a two-year study period. The serovar distribution of cervical and rectal isolates differed significantly. Serovar D/D' was found in 53% of the rectal isolates but in only 18% of cervical isolates (P less than .0001). Serovar E was the predominant serovar in cervical isolates (32%) but was found in only 6% of rectal isolates (P less than .0001). Serovars B, I/I', H, and K were isolated from 2%-7% of cervical specimens but were not found in rectal isolates. There was a significant decline in the proportion of rectal infections caused by serovar D/D' over the study period, and clustering of infections caused by other serovars was observed. Serotyping using monoclonal antibodies provides a powerful tool for investigating the epidemiology of sexually transmitted C. trachomatis infections.

Bisexuality↗

PubMed1987

Sexually transmitted diseases. Urethritis in men.

Gonococcal and nongonococcal urethritis (NGU) are among the most common syndromes afflicting men. NGU is caused primarily by Chlamydia trachomatis and Ureaplasma urealyticum, but the cause is unknown in approximately 20 to 30 percent of cases. Evaluation of a gram-stained urethral smear is generally sufficient to distinguish between gonococcal and nongonococcal urethritis. Owing to the frequent coexistence of Neisseria gonorrhoeae and C. trachomatis in heterosexual men, treatment regimens for gonococcal urethritis should generally include an effective antichlamydial regimen. Complications of urethritis are uncommon, but the causative pathogens produce serious morbidity in women. Prevention of urethritis is based on identification of asymptomatically infected persons who serve as the major reservoir of infection with both N. gonorrhoeae and C. trachomatis.

Male↗

PubMed1987

Sexually transmitted diseases. Genital ulceration with regional adenopathy.

The specific agent causing genital ulceration is difficult to identify without laboratory confirmatory testing including darkfield microscopy, syphilis and lymphogranuloma venereum serology, and culture for Haemophilus ducreyi and herpes simplex virus. Empiric antimicrobial therapy risks masking clinical or serologic diagnosis of syphilis.

Female↗

PubMed1986

Urinary-tract infection in sexually active homosexual men.

14 of 280 young, sexually active men with acute urinary symptoms had pronounced bacteriuria--13 with Escherichia coli and 1 with Staphylococcus saprophyticus. 12 of the 14 bacteriuric men were homosexual or bisexual, compared with 3 of 22 non-bacteriuric control patients. Pyuria and symptoms of cystitis were more common in the bacteriuric men, and these men frequently had a urethral discharge on examination, and non-gonococcal urethritis on gram stain of the discharge. The E coli strains causing cystourethritis in these men showed properties previously associated with acute-urinary-tract infection in women, including O serotype, haemolysin production, mannose-resistant haemagglutination of human erythrocytes, and P-fimbriation. Sexually active homosexual men are a newly identified group at increased risk of acute urinary-tract infection, and E coli may contribute to non-gonococcal urethritis in this population.

Acute Disease↗

PubMed1986

Distribution of an antigenically related iron-regulated protein among the Neisseria spp.

Several iron-regulated proteins of Neisseria gonorrhoeae have been reported. One of these, a 37,000-molecular-weight protein (37K protein), appears to be common to all gonococcal isolates. Recently, the occurrence of a similar protein has also been noted in N. meningitidis. The gonococcal 37K protein has been purified and used to produce both rabbit monospecific antiserum and murine monoclonal antibodies. Using these antibody reagents, we analyzed 57 strains from nine species of Neisseria and the closely related organism Branhamella catarrhalis for the presence of proteins antigenically related to the gonococcal 37K protein. Strains grown on medium with low iron content were probed for antigenic reactivity by Western blot techniques and an enzyme-linked immunosorbent assay. Proteins which cross-reacted with the rabbit monospecific antiserum were designated as AgR-37K proteins. The data indicated that the AgR-37K proteins were conserved among the 40 strains of N. gonorrhoeae, N. meningitidis, N. lactamica, and N. cinerea tested. Seventeen strains from other species of Neisseria and Branhamella did not express AgR-37K proteins with the exception of one N. subflava isolate. All AgR-37K proteins appeared to be regulated by the amount of available iron in the growth medium. Murine monoclonal antibodies were used to probe the antigenic heterogeneity of the AgR-37K proteins from different Neisseria spp. Two of seven monoclonal antibodies were broadly cross-reactive, recognizing the AgR-37K proteins from all species examined. The remaining five monoclonal antibodies were more discriminating, recognizing the AgR-37K proteins from certain species. The antigenic conservation of these AgR-37K proteins, particularly among the pathogenic members of the genus Neisseria, may imply that these proteins serve a common function in pathogenicity.

Antibodies, Bacterial↗

PubMed1986

Prevalence of antibody to LAV/HTLV-III among homosexual men in Seattle.

The prevalence of antibody to LAV/HTLV-III among homosexual men attending a community clinic and a sexually transmitted disease clinic in Seattle, Washington in early 1985 was 42 per cent and 32 per cent, respectively. Seropositivity was apparently not related to age or number of sexual partners. The high prevalence of LAV/HTLV-III seropositivity in an area where overt AIDS (acquired immune deficiency syndrome) is still relatively uncommon suggests that public health measures to prevent acquisition and transmission of LAV/HTLV-III should be a high priority even in areas with low incidences of AIDS.

Acquired Immunodeficiency Syndrome↗

PubMed1985

Immunotyping of Chlamydia trachomatis with monoclonal antibodies.

Rapid and precise immunotyping of Chlamydia trachomatis was achieved by testing whole organisms (elementary bodies) in the microimmunofluorescence test with monoclonal antibodies. Monoclonal antibodies were produced with standard techniques by using an immunization schedule that encouraged the development of immunotype-specific antibodies. Fifteen monotypic or multitypic (subspecies) monoclonal antibodies were chosen for use in a two-step typing system that required strains of C. trachomatis to be tested against six to eight monoclonal antibodies for classification. Immunotyping with monoclonal antibodies was studied by testing 313 strains, typed with the previous method that utilized immunized mouse antisera, that represented each of the 15 established serovars. The two-step monoclonal antibody method resulted in a classification similar to the current one. Only one strain typed differently with the two methods. With the monoclonal antibody method, available lymphogranuloma venereum (LGV) serovars L1 and L3 could not be differentiated from trachoma serovars E and G, respectively, unless the strains had been identified as LGV. Monoclonal antibody typing was simpler to perform and more precise; it allowed easy differentiation between closely related serovars. Three new types were discovered among the strains previously classified as serovars D, I, and L2. These are tentatively being considered subtypes and are labeled D', I', and L2'.

Animals↗

PubMed1985

Detection of multiple serovars of Chlamydia trachomatis in genital infections.

Eight genital isolates of Chlamydia trachomatis that each contained two different serovars were identified by typing with serovar-specific monoclonal antibodies. Mixed infections were confirmed by using serovar-specific monoclonal antibodies in an indirect immunofluorescence assay. For some isolates, fluorescein/rhodamine double-label indirect immunofluorescence with mixtures of IgM and IgG monoclonal antibodies to Chlamydia provided direct visual confirmation of mixed infection. Two isolates contained serovars D and F, and two E and F; one isolate contained serovars Ba and E, one D and J, one I' and F, and one E and J. In a sample of 352 genital isolates of C. trachomatis consecutively typed by dot ELISA with monoclonal antibodies, seven (2%) demonstrated mixed serovars.

Antibodies, Bacterial↗

PubMed1985

Rapid immunotyping of Chlamydia trachomatis with monoclonal antibodies in a solid-phase enzyme immunoassay.

The technical complexity of determining the serovar of Chlamydia trachomatis strains has limited the use of serotyping in clinical and epidemiologic studies. We developed a simple method for rapidly serotyping isolates of C. trachomatis by using monoclonal antibodies in a dot-enzyme-linked immunosorbent assay (ELISA) system. Isolates were passaged three to six times in shell vial cultures to greater than 50% monolayer infection, and chlamydial elementary bodies were isolated by sonication and microcentrifugation. Chlamydial antigen was spotted onto a series of replicate nitrocellulose membrane patches and reacted with C. trachomatis-specific monoclonal antibodies. Bound antibody was detected visually by a color reaction by using peroxidase-conjugated anti-mouse immunoglobulins. This method can be routinely applied to 60 or more specimens concurrently. We compared dot-ELISA serotyping with monoclonal antibody microimmunofluorescence serotyping of 124 clinical C. trachomatis isolates and found that dot-ELISA has sensitivity and serotyping accuracy comparable to that of monoclonal antibody microimmunofluorescence.

Antibodies, Bacterial↗

PubMed1984

Moxalactam plus piperacillin versus moxalactam plus amikacin in febrile granulocytopenic patients.

In a prospective randomized trial, febrile granulocytopenic patients received either moxalactam plus piperacillin or moxalactam plus amikacin as initial empiric antimicrobial therapy. Most patients were also given prophylactic vitamin K. The overall response rates for the two regimens were similar (105 of 136, or 77 percent, for moxalactam plus piperacillin versus 107 of 136, or 79 percent, for moxalactam plus amikacin). For Pseudomonas aeruginosa infections, the response rate was better in patients receiving moxalactam plus amikacin (seven of nine versus one of five, p = 0.06); two patients treated with moxalactam plus piperacillin experienced relapse of P. aeruginosa bacteremia in association with the emergence of beta-lactam-resistant P. aeruginosa isolates. On the other hand, bacteremic enterococcal superinfections occurred in seven patients receiving moxalactam plus amikacin but in none given moxalactam plus piperacillin (p = 0.02). Serious side-effects were minimal with both regimens, and nephrotoxicity was less common in patients receiving moxalactam plus piperacillin (two of 136 versus six of 136, p = 0.28). There was no antibiotic-related hemorrhage. These results suggest that the overall efficacy and toxicity of moxalactam plus piperacillin and moxalactam plus amikacin are similar. Moxalactam/piperacillin therapy may be limited in certain patients by the emergence of beta-lactam-resistant P. aeruginosa, whereas enterococcal superinfections may complicate moxalactam/amikacin therapy.

Adolescent↗

PubMed1984

Epidemiology of gonorrhea: current perspectives.

Once considered a public nuisance of the developed countries, gonorrhea is now established as a leading worldwide public health problem. The rapid increase in reported disease in many developed countries noted in the 1960s and 1970s has been followed by stable or declining disease rates. This may reflect improved gonorrhea control programs or changes in sexual behavior. The assault on the developed countries by imported antibiotic-resistant strains of N. gonorrhoeae has increased, however, indicating the need for intensive control programs. New methods of identifying strains of gonococci have allowed investigation of the distribution and patterns of transmission of gonorrhea. Future studies using these methods will provide valuable knowledge of the ecology and epidemiology of gonorrhea. Within the developing countries, gonorrhea caused by resistant strains of N. gonorrhoeae has become hyperendemic. The current decreases of gonorrhea incidence in the developed countries may not be maintained unless some success is attained in the control of gonorrhea in developing countries.

Adolescent↗

PubMed1984

Tubulin and high-molecular-weight polypeptides as Giardia lamblia antigens.

We determined the antigenic specificities of nine murine monoclonal antibodies to Giardia lamblia. Four distinct antibody reaction patterns were detected by immunofluorescence with G. lamblia trophozoites. Four monoclonal antibodies which reacted with the body but not the flagella of the whole trophozoites recognized two polypeptides of 170,000 and 155,000 molecular weights by immunoblotting. Two antibodies reacting with both the flagella and body also reacted with 170,000- and 155,000-molecular-weight antigens. An antibody specific for the G. lamblia attachment disk and two specific for flagella by immunofluorescence were found to react with 53,000- and 55,000-molecular-weight polypeptides by immunoblotting. These antigens comigrated with purified bovine brain tubulin, and their respective antibodies reacted in immunoblots with purified bovine brain tubulin. The antigens identified in this report were found to be present in Giardia cytoskeletal preparations. All antigens were pronase labile and heat stable. Four strains of G. lamblia reacted similarly in immunofluorescence assays as well as in immunoblotting assays.

Animals↗

PubMedDate not supplied

Treatment of Chlamydia trachomatis genital infection.

Chlamydia trachomatis infections are the most frequent bacterial sexually transmitted diseases in the United States, with an estimated 4 million cases occurring annually. The mainstay of treatment for chlamydial infections has been the tetracyclines. Doxycycline, comparable in cost to tetracycline and with a less frequent dosage schedule, is the drug of first choice. Erythromycins are the drugs of choice for infections in pregnant women, nursing mothers, infants, children, and adults unable to tolerate tetracyclines. beta-Lactam antibiotics have had variable efficacy against C. trachomatis infections, although recent studies suggest that amoxicillin may be an effective alternative for C. trachomatis infection during pregnancy. Quinolones are currently being tested and may be used in alternative regimens in the future. The effectiveness of current antimicrobial regimens in preventing long-term complications of chlamydial infections should be determined in research studies.

4-Quinolones↗