Biomedical subjects

D L Patton

Publications and source records attributed to D L Patton.

At least 37 records · Page 2Linked to original sources

PubMed1997

Effects of doxycycline and antiinflammatory agents on experimentally induced chlamydial upper genital tract infection in female macaques.

To evaluate the effects of antimicrobial and antiinflammatory drugs on oviductal pathology in chronic chlamydial upper genital tract infection, the fallopian tubes of 40 female Macaca nemestrina were inoculated with Chlamydia trachomatis and randomly assigned to treatment with doxycycline (n = 10), doxycycline plus ibuprofen (n = 10), doxycycline plus triamcinolone (n = 10), or placebo (n = 10). Before therapy, all animals were positive for culture or ligase chain reaction (or both), and laparoscopy demonstrated the presence of upper genital tract pathology. After therapy, cervical cultures remained positive in 5 animals given placebo versus 0 given doxycycline alone (P = .03), 0 given doxycycline plus ibuprofen (P = .03), and 1 given doxycycline plus triamcinolone (P = .14). At hysterectomy, neither gross nor histologic pathology was affected by any of the treatment regimens, but immunocytochemistry and in situ hybridization evidence of persistent tubal infection was significantly more frequent among animals given placebo or doxycycline plus antiinflammatory agents than among those given doxycycline alone.

Animals↗

PubMed1997

Repeated Chlamydia trachomatis infection of Macaca nemestrina fallopian tubes produces a Th1-like cytokine response associated with fibrosis and scarring.

Chlamydia trachomatis-associated female infertility and ectopic pregnancy are caused by postinflammatory fibrosis and scarring of the upper genital tract. Scarring of the upper genital tract is associated with multiple infectious episodes with C. trachomatis. To study the immune response that occurs with multiple infections of C. trachomatis in the female upper genital tract, a Macaca nemestrina model was used. Subcutaneous pockets containing autologous salpingeal tissue implants were inoculated three times with C. trachomatis. The inflammation after three inoculations was associated with a mononuclear infiltrate dominated by CD8 T-cell lymphocytes. Perforin mRNA was induced in infected pockets, demonstrating that activated cytolytic lymphocytes were present in the lesions. Fibrosis, as evidenced by fibroblast proliferation and connective tissue deposition, was observed by the third infection. Cytokine mRNAs induced by repeated chlamydial infection included gamma interferon, interleukin-2 (IL-2), IL-6, and IL-10 mRNAs, but IL-4 mRNA was not induced. Nearly identical findings were found in macaque fallopian tubes infected in situ repeatedly with C. trachomatis, validating the subcutaneous pocket model of chlamydial salpingitis. However, it was not possible to evaluate if there was an induction of perforin mRNA in infected salpingeal tubes in situ, because there was a high basal level of perforin mRNA in these tissues. These results suggest that repeated chlamydial infection of the female upper genital tract leads to CD8 T-cell predominance, a Th1-like cytokine milieu, and these inflammatory changes are associated with progression to fibrosis associated with female infertility.

Animals↗

PubMed1997

Evidence of genetic susceptibility to Chlamydia trachomatis-induced pelvic inflammatory disease in the pig-tailed macaque.

The macaque model of chlamydial pelvic inflammatory disease (PID) demonstrates individual variability in the time of onset of intrapelvic adhesions. Some animals develop adhesions rapidly, within 2 weeks after a single tubal inoculation with Chlamydia trachomatis, while in others, adhesions are not observed until 2 weeks after a second tubal inoculation. To test whether this variability correlates with major histocompatibility complex (MHC) class I haplotype, we used macaque alloantisera and mouse anti-HLA monoclonal antibodies to determine the MHC class I haplotypes of 44 C. trachomatis-infected macaques (Macaca nemestrina). Macaques developing gross tubal adhesions after the first chlamydial inoculation were classified as susceptible (n = 29), while those not developing adhesions until after the second chlamydial inoculation were classified as relatively resistant (n = 15), to adhesion formation. Three antibody specificities correlated with susceptibility (odds ratio [OR] 5.2, P < 0.01; OR 6.1 and 4.3, P < 0.05), and two correlated with relative resistance to adhesions (OR 0.1, P < 0.05; OR 0.2, P < 0.01). Because several of these antibodies are cross-reactive, as many as five different MHC class I alleles (three increasing and two decreasing ORs) or as few as two different MHC class I alleles (one increasing and one decreasing OR) could be correlated with risk of adhesion formation. We conclude that in macaques, susceptibility or relative resistance to rapid formation of tubal adhesions is correlated with expression of MHC class I alleles, consistent with reports of MHC class I restriction of chlamydial immunopathology in humans.

Alleles↗

PubMed1996

Failure to detect Chlamydia pneumoniae in coronary atheromas of patients undergoing atherectomy.

To further investigate a proposed relationship between Chlamydia pneumoniae and coronary heart disease, coronary atheromas were collected from patients undergoing percutaneous atherectomy. Fifty-eight atheroma specimens were examined by culture and polymerase chain reaction (PCR) and 22 by electron microscopy. All were negative for C. pneumoniae, except a single specimen that was PCR-positive. These results differ from studies in other populations, in which this organism was identified by nonculture methods within coronary atheromas obtained at autopsy. Anti-C. pneumoniae antibody titers from 65 of the patients were compared with those of 28 asymptomatic controls. IgG titers were higher in controls than in patients. There is no evidence that C. pneumoniae exists within atheromas in this study population, nor does seroprevalence correlate with the presence of coronary disease in these patients.

Adult↗

PubMed1996

Analysis of lymphocyte phenotype and cytokine activity in the inflammatory infiltrates of the upper genital tract of female macaques infected with Chlamydia trachomatis.

Chlamydia trachomatis infects the upper genital tract of millions of women, causing infertility and pelvic inflammatory disease, yet the inflammatory response to C. trachomatis infection is poorly understood. The cytokine response and the phenotype of infiltrating lymphocytes during C trachomatis infection of fimbria and ampulla autografts in subcutaneous pockets in Macaca nemestrina were characterized. About two-thirds of the infiltrating lymphocytes were CD8 T cells, with the remainder being CD4 T cells and B cells. Interleukin (IL)-2, IL-6, IL-10, interferon-gamma (IFN-gamma), and perforin mRNA were produced by the infiltrating cells, but IL-4 mRNA was absent. The presence of CD8 T cells and perforin mRNA suggest that activated cytolytic T cells are present. The presence of IL-2 and IFN-gamma mRNA and the absence of IL-4 mRNA suggest that Th1-type cytokines predominate during the acute phase of C. trachomatis infection of the upper genital tract.

Animals↗

PubMed1996

Experimental rabbit models of Chlamydia pneumoniae infection.

Chlamydia pneumoniae (TWAR), a common cause of acute respiratory disease in humans, has recently been associated with coronary and aortic atherosclerosis. In this study, we evaluated rabbit models of chlamydial infection to investigate the pathogenesis of C. pneumoniae infection. New Zealand White rabbits were inoculated intranasally and intratracheally with C. pneumoniae, strain AR-39, and primary and repeated infection were assessed. After a single inoculation, lung pathology was characterized by a moderate self-resolving interstitial pneumonia with bronchiolitis of 21 days in duration. Chlamydial DNA was detected by polymerase chain reaction (PCR) intermittently in the upper respiratory tract and lung tissue through day 21 postinoculation, spleen tissue at day 14, and peripheral blood mononuclear cells at days 3 and 21. After repeated inoculations, chlamydial DNA was detected by PCR in the upper respiratory tract and lung tissue through day 42. Lung lesions consisted of multifocal interstitial mononuclear cell aggregates that persisted up to day 42. Watanabe heritable hyperlipidemic rabbits were less susceptible to C. pneumoniae infection. After multiple inoculations of Watanabe rabbits, C. pneumoniae was detected by PCR and/or immunocytochemistry until day 21. In conclusion, C. pneumoniae induced a moderate respiratory infection in these rabbit models.

Animals↗

PubMed1995

Detection of Chlamydia pneumoniae TWAR in human coronary atherectomy tissues.

Chlamydia pneumoniae TWAR has been associated with coronary heart disease by seroepidemiologic studies and direct detection of the organism in atheromatous lesions of coronary arteries and aorta. In this study, 38 fresh tissue specimens from patients with coronary artery lesions that were treated by directional coronary atherectomy were tested for C. pneumoniae. Twenty-three specimens were from patients with primary lesions and 15 were from patients with restenoses. C. pneumoniae was detected by polymerase chain reaction (PCR), immunocytochemical stain (ICC), or both in 20 of 38 specimens. Using cell identity markers, the organism was localized to macrophages. Ultrastructural evidence of the organism was found in the 2 specimens examined by transmission electron microscopy, which were also positive by both ICC and PCR. C. pneumoniae was found more frequently in tissues from restenoses than in primary lesions (P = .17). There was no relation between the frequency of detection of the organism and C. pneumoniae-specific antibody titers.

Adult↗

PubMed1995

The activity of azithromycin on the infectivity of Chlamydia trachomatis in human amniotic cells.

The effects of azithromycin on the infectivity and growth of Chlamydia trachomatis were investigated in primary human amniotic epithelial cells. Infection was prevented when cultures were exposed to the drug 6 h after inoculation and growth was completely inhibited when the drug was added to cultures 24, 48, 72 h or 7 days after infection. The same inhibition was observed at 0.5, 1.0 and 5.0 mg/L. Ultrastructural observations depicted interruption in the growth cycle of the chlamydia and ghost-like envelopes were present in the near empty inclusions. Azithromycin is effective in inhibiting chlamydial growth no matter when treatment is initiated after infection.

Amnion↗

PubMed1994

Detection of Chlamydia trachomatis in fallopian tube tissue in women with postinfectious tubal infertility.

OBJECTIVE: Biopsy tissues from women with postinfectious tubal infertility were studied for the presence of Chlamydia trachomatis. STUDY DESIGN: Tubal biopsy specimens from 25 women with postinfectious tubal infertility undergoing laparoscopy for repair of fallopian tubes were evaluated by culture, in situ hybridization. Immunocytochemistry, and transmission electron microscopy for the presence of Chlamydia trachomatis. Serum was also tested for Chlamydia trachomatis antibodies. RESULTS: Chlamydia trachomatis was detected in postinfectious tubal biopsy specimens in three of 25 patients by culture, 12 of 24 by in situ hybridization, 15 of 22 by immunoperoxidase stain, and two of 10 by transmission electron microscopy. Serum antibody against Chlamydia trachomatis was detected in 15 of 21 patients. CONCLUSION: Chlamydia trachomatis deoxyribonucleic acid or antigens were detected at a high percentage (19/24 women) in the biopsy tissues of the fimbrial and peritubal adhesions by in situ hybridization or immunoperoxidase stain, suggesting a persistent infection in these women even after antibiotic treatment.

Adult↗

PubMed1994

Detection of Chlamydia trachomatis deoxyribonucleic acid in monkey models (Macaca nemestrina) of salpingitis by in situ hybridization: implications for pathogenesis.

OBJECTIVE: Our purpose was to determine whether Chlamydia trachomatis persists in tubal tissues from monkey pocket models of chlamydial salpingitis and tubal infertility and to relate its presence to disease progression and histopathologic mechanisms. STUDY DESIGN: In situ hybridization was used to detect Chlamydia deoxyribonucleic acid in a monkey pocket model of salpingitis and in the direct tubal inoculation monkey model of tubal infertility. Results were correlated with culture and immunocytochemistry results and histopathologic characteristics. RESULTS: Chlamydia deoxyribonucleic acid was detected in the mucosa, submucosa, and deep tissues in the pocket model. In addition, it was present in peritubal adhesions from the direct inoculation model. Deoxyribonucleic acid was found at sites of inflammation and when culture and immunocytochemistry studies were negative. CONCLUSION: The presence of Chlamydia trachomatis deoxyribonucleic acid at sites of inflammation and tissue damage in monkey models of chlamydial salpingitis and tubal infertility suggests that Chlamydia persists and may be directly involved in the stimulation of the immune-mediated tissue destruction associated with Chlamydia trachomatis infections.

Animals↗

PubMed1994

Demonstration of delayed hypersensitivity in Chlamydia trachomatis salpingitis in monkeys: a pathogenic mechanism of tubal damage.

The role of delayed hypersensitivity in the pathogenesis of Chlamydia t trachomatis salpingitis was studied in the monkey "pocket" model. Pigtailed monkeys (Macaca nemestrina) were sensitized by inoculation of live C. trachomatis organisms (E/UW-5/Cx) into subcutaneous pockets containing salpingeal autotransplants. At 21 days, affinity-purified recombinant C. trachomatis heat-shock protein (rhsp60) was injected into pockets either previously sensitized with C. trachomatis or not sensitized in the same monkey. Delayed-type hypersensitivity reaction was observed, characterized by mononuclear cell infiltration with peak reaction at 48 h. Injection of rhsp60 into the pockets of a naive animal did not induce inflammation. This study showed that C. trachomatis infection in monkeys induced delayed hypersensitivity, which is mediated by hsp60. Histologic findings of the salpinx were consistent with delayed hypersensitivity reaction observed in ocular C. trachomatis infection, further suggesting a similar pathogenesis for both salpingitis and trachoma.

Animals↗

PubMed1994

Ultrastructural lung pathology of experimental Chlamydia pneumoniae pneumonitis in mice.

The ultrastructural lung pathology of Swiss Webster mice on days 2, 4, 7, 11, 15, and 21 after intranasal inoculation of Chlamydia pneumoniae AR-39 is described. The inflammatory infiltrate was predominantly polymorphonuclear leukocytes on day 2. By day 7, mononuclear cells were most prominent in the infiltrate. On day 2, chlamydial inclusions were found frequently in the bronchial ciliated epithelial cells and less frequently in the interstitial cells that appeared to be macrophages. Free particles of all developmental forms of the chlamydial microorganism were found in the bronchial lumen and alveolar space. These particles were likely organisms released from infected cells. Inclusions as well as free particles were difficult to find after day 4. These ultrastructural observations suggest an immunopathologic basis for the acute phase of the disease process.

Acute Disease↗

PubMed1993

Demonstration of Chlamydia pneumoniae in atherosclerotic lesions of coronary arteries.

Chlamydia pneumoniae is a human respiratory pathogen that causes acute respiratory disease and approximately 10% of community-acquired pneumonia. The infections are geographically widespread. Antibody prevalence studies have shown that virtually everyone is infected with the C. pneumoniae organisms at some time and that reinfection is common. In addition to respiratory disease, seroepidemiologic studies have shown an association of this organism with coronary artery disease. C. pneumoniae was detected in coronary artery atheromas by immunocytochemistry (15/36) and by polymerase chain reaction (PCR) (13/30) in 20 of 36 autopsy cases from Johannesburg, South Africa. Sequence analysis of the C. pneumoniae rRNA genes amplified by PCR confirmed that the amplified gene products were C. pneumoniae. Electron microscopy revealed typical pear-shaped C. pneumoniae elementary bodies in 6 of 21 atheromatous plaques. These findings support the seroepidemiologic studies and offer further evidence that C. pneumoniae may be involved in the atherosclerotic process.

Adult↗

PubMed1993

Effects of quinolone analog CI-960 in a monkey model of Chlamydia trachomatis salpingitis.

Several quinolones have been shown to have antichlamydial activity in vitro and in vivo. We evaluated the effects of the quinolone CI-960 (Parke-Davis) on primary or repeated chlamydial infection in the monkey salpinx pocket model. The antichlamydial effect was evaluated in the tissues, and we tested for the presence of the organism by culture, immunocytochemical stains, in situ hybridization, and histopathology. An intravenous dosage of 5 mg/kg of body weight produced therapeutic concentrations in plasma (blood sera and pocket fluids) of at least 0.25 microgram/ml at 2 h posttreatment. In monkeys with primary infections, treatment was started 2 days after inoculation and was continued for 7 days. After CI-960 treatment, all animals became culture negative. One of two control animals was culture positive through day 10 postinoculation. In monkeys with repeated infections five inoculations were given within 2 weeks. A 7-day intravenous treatment was started on day 2 postinoculation following the last inoculation. Isolation of Chlamydia trachomatis prior to treatment was positive intermittently for all monkeys. After treatment, isolation of C. trachomatis was negative for all monkeys. In monkeys with both primary and repeated infections, no significant differences were noted in the inflammatory responses in the tissues of treated and untreated animals. All tissues tested were positive by immunoperoxidase staining and/or in situ hybridization. After CI-960 therapy, C. trachomatis organisms were no longer recoverable by cell culture. The persistent finding of chlamydial DNA throughout the observation periods following drug therapy may indicate the presence of dead organisms or viable organisms in an unculturable state.

Animals↗

PubMed1993

Detection of Chlamydia trachomatis deoxyribonucleic acid in women with tubal infertility.

OBJECTIVE: To determine the presence of Chlamydia trachomatis by in situ hybridization in fallopian tube tissues of women with distal tubal occlusion. PATIENTS: Subjects were selected from a Seattle-based study of infertility in women with distally occluded fallopian tubes undergoing reconstructive surgery. For comparison, six specimens were obtained from women undergoing surgery for noninfertility-related conditions who had normal appearing tubes. METHODS: Tissue specimens from 16 of these patients were selected for analysis by in situ hybridization and immunoperoxidase (IP) staining. RESULTS: C. trachomatis was detected in 9 of 16 women by either in situ hybridization or IP. Six of the nine were seropositive with titers ranging from 1:16 to 1:64. Tissue from 6 women with normal appearing fallopian tubes were negative by in situ hybridization. CONCLUSIONS: The demonstration of C. trachomatis deoxyribonucleic acid and/or antigens in fallopian tube tissue from infertile women with distal tubal disease suggests that C. trachomatis can persist in these tissues in an uncultivable state.

Biopsy↗

PubMed1992

In vitro activity of nonoxynol 9 on HeLa 229 cells and primary monkey cervical epithelial cells infected with Chlamydia trachomatis.

Nonoxynol 9 (non-9) is the active ingredient in a wide variety of vaginal contraceptive preparations. The manufacturer recommendation for optimal contraceptive practice is repeated application every 6 h. We studied the in vitro activity of non-9 against Chlamydia trachomatis (E/UW-5/Cx) and its toxicity against HeLa 229 cells and monkey cervical epithelial cells. With a contact time of 6 h, non-9 was toxic to HeLa cells at concentrations of 50 micrograms/ml or greater and to monkey cervical cells at 100 micrograms/ml or greater. Inhibitory effects of non-9 on extracellular chlamydiae were observed at concentrations of 50 micrograms/ml or greater. Inhibition of intracellular growth of chlamydiae in monkey cervical cells was observed at a nontoxic concentration of 50 micrograms/ml. Our studies show that non-9 has antichlamydial activity. However, owing to its toxicity to cervical cells in vitro, the effects of prolonged use of non-9 in vivo should be further studied.

Animals↗

PubMed1992

Effects of ascorbic acid on Chlamydia trachomatis infection and on erythromycin treatment in primary cultures of human amniotic cells.

Ascorbic acid (vitamin C) is an essential nutrient for humans. It may also be needed by Chlamydia trachomatis, an intracellular bacterium. We investigated the effects of vitamin C on the growth of C. trachomatis E/UW-5/Cx in a primary culture of human amniotic epithelial cells. The results showed that vitamin C enhances C. trachomatis infection at concentrations of 0.2, 0.6, and 1.2 mg/dl (P less than 0.001). These three concentrations represent the in vivo concentrations of deficiency, normal, and overload levels in serum, respectively. The enhancement was dose dependent. However, the growth of C. trachomatis was inhibited at vitamin C concentrations of 120 and 1,200 mg/dl. The inhibitory effect of erythromycin against C. trachomatis was shown to be reduced in the presence of vitamin C at the three concentrations tested (P less than 0.025-0.001), and MICs were four times greater (1.6 versus 0.4 micrograms/ml). Human amniotic cells were tolerant to vitamin C concentrations of up to 1,200 mg/dl. The results show that vitamin C may be an important nutrient for C. trachomatis and that incorporation of vitamin C in the culture medium may enhance the isolation and propagation of C. trachomatis in cell cultures.

Amnion↗

PubMed1992

Detection of Chlamydia pneumoniae in coronary arterial fatty streaks and atheromatous plaques.

There is serological evidence that a recently described new strain of Chlamydia, namely Chlamydia pneumoniae TWAR, is associated with coronary artery disease. This study describes the detection of TWAR organisms in the coronary arterial fatty streaks and atheromatous plaques in 7 autopsy cases. TWAR-like organisms were observed ultrastructurally in the lipid-rich core area of fibrolipid plaques and in intimal smooth-muscle cells. In 5 cases, immunoperoxidase staining showed positive reactions to Chlamydia genus- and C. pneumoniae species-specific monoclonal antibodies.

Adult↗