Biomedical subjects

C C Kuo

Publications and source records attributed to C C Kuo.

At least 163 records · Page 9Linked to original sources

PubMed1990

Structural and antigenic analysis of Chlamydia pneumoniae.

Several isolates of Chlamydia pneumoniae were compared with each other and to Chlamydia trachomatis and Chlamydia psittaci by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblots. Protein profiles of the C. pneumoniae isolates appeared to be the same and were distinct from the other Chlamydia species. A 39.5-kilodalton (kDa) protein, similar in molecular weight to the major outer membrane proteins (MOMP) of C. trachomatis and C. psittaci, was found in the Sarkosyl-insoluble fraction, demonstrating its association with the outer membrane complex. In the outer membrane complex, the MOMP was shown to exist in disulfide-linked protein complexes. Electron microscopy of the Sarkosyl-extracted elementary bodies showed that the structural rigidity and pear-shaped morphology remained intact. Rabbit immune sera prepared against C. pneumoniae demonstrated immunoreactive proteins of 98-, 77-, 75-, 66-, 60-, 39.5-, 28-, and 17.5-kDa proteins. Cross-reactivity experiments revealed that most of the antigenic reactivities shared between C. psittaci and C. trachomatis extend to C. pneumoniae and that the 98-kDa protein recognition appeared to be C. pneumoniae specific. In contrast to the other Chlamydia spp., the recognition of the C. pneumoniae MOMP by homologous immune sera was weak and was cross-reactive with the MOMPs of the other Chlamydia species. These results suggest that the C. pneumoniae MOMP is less immunogenic and antigenically complex than are the MOMPs of C. trachomatis and C. psittaci.

Antibodies, Bacterial↗

PubMed1990

Identification of lectin-binding proteins in Chlamydia species.

Lectin-binding proteins of chlamydiae were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. All three Chlamydia species tested expressed two proteins when whole-elementary-body lysates were reacted with the biotinylated lectin Dolichos biflorus agglutinin. The protein with a molecular mass of 18 kilodaltons (kDa) responded strongly compared with a higher-molecular-mass protein that varied from 27 to 32 kDa with each chlamydia strain tested. Among six lectins tested, including concanavalin A, D. biflorus agglutinin, Ulex europaeus agglutinin, soybean agglutinin, peanut agglutinin, and wheat germ agglutinin, the latter was the only lectin that did not recognize any chlamydial protein. For each lectin that reacted against the elementary body of serovar L2 of Chlamydia trachomatis, the same two peptides, an 18-kDa peptide and a 32-kDa peptide, were revealed. These two polypeptides adhered to HeLa cell surface components. Binding of a lectin to the L2 reticulate body resulted in a reduced response at the 18-kDa peptide. The 18- and 32-kDa peptides were purified from L2 serovar elementary bodies by affinity chromatography. The two proteins isolated from a concanavalin A-agarose column maintained their lectin-binding capacities and elicited hemagglutinating properties against mouse erythrocytes. Periodate oxidation abolished the abilities of the peptides to adhere to any of the lectins tested. These results suggest that these lectin-binding proteins are glycoproteins that may be an essential factor for attachment of chlamydial organisms to host cells.

Animals↗

PubMed1990

Cinematographic observations of growth cycles of Chlamydia trachomatis in primary cultures of human amniotic cells.

Time-lapse cinematography was used to study the growth cycle of Chlamydia trachomatis in primary cell cultures of human amnion. Twelve preterm and twelve term placentas were obtained within 8 h of delivery, and epithelial cells were dissociated from the amniotic membranes by trypsinization and grown in Rose chambers. The epithelial nature of the cultured cells was documented by morphology and by immunofluorescence staining for cytoskeletal proteins, which matched the staining of intact amnion. With regular feedings, uninfected cultures remained healthy for up to 30 days. Confluent cultures (7 to 10 days) were infected with a genital strain (E/UW-5/CX) of C. trachomatis at 10(5) infectious units per chamber. Infections were done in culture medium without cycloheximide, which is often used to induce susceptibility of the cells. Between 66 and 90% of the cells were infected. Intracytoplasmic inclusions were visible by 18 h post infection (p.i.) and grew larger as the organisms inside multiplied. By 72 h p.i., the inclusions occupied the entire cytoplasm of the host cells. Further growth of the inclusions overdistended and ruptured the host cells on days 3 to 7. Cells not infected by the original inoculum became infected on day 5 or 6 p.i. by the chlamydial particles released from the ruptured cells. No amniotic cell was ever observed to survive the infection. The data presented support the hypothesis that amniotic epithelium is susceptible to infection and damage by C. trachomatis. This culture system provided detailed and dynamic observations of chlamydial infection under conditions more nearly physiologic than previously reported.

Amnion↗

PubMed1990

Amino acid requirements for growth of Chlamydia pneumoniae in cell cultures: growth enhancement by lysine or methionine depletion.

Amino acid requirements for growth of two isolates of Chlamydia pneumoniae were studied and compared with those for one strain of Chlamydia trachomatis in a HeLa 229 cell culture. It was shown that among 13 amino acids in Eagle minimum essential medium, C. pneumoniae required all amino acids except lysine. A true requirement for arginine, isoleucine, leucine, threonine, and valine could not be determined because depletion of 100% of these amino acids caused cell detachment. Consequently, a requirement for these amino acids was based on 90% depletion. C. trachomatis biovar trachoma required all amino acids except threonine, which was indeterminable. Depletion of 100 and 90% of the lysine and 90 to 70% of the methionine was shown to enhance the growth of C. pneumoniae. This phenomenon was shown to be a property of C. pneumoniae because the effect of lysine and methionine reduction was also demonstrated in another human line, HL cells, and a mouse line, McCoy cells.

Amino Acids↗

PubMed1990

Serological response to Chlamydia pneumoniae infection.

The human serological response was analyzed by using sera from patients who were serologically positive but isolation negative for Chlamydia pneumoniae and from patients with proven C. pneumoniae infection based on serology and isolation. To assess whether seroreactivity to C. pneumoniae proteins had potential diagnostic value, the cross-reactivities of these sera to other Chlamydia species and of sera from patients infected with C. trachomatis and C. psittaci to C. pneumoniae proteins were determined. In all serum samples from patients with proven C. pneumoniae infections, reactivities were seen with 98-, 68-, 60-, 39.5-, and 30-kilodalton proteins. Similar patterns were seen in sera from patients who were serologically positive and isolation negative. The onset of seropositivity for C. pneumoniae was accompanied by reactivities against presumably shared chlamydial antigens and a C. pneumoniae-specific 98-kilodalton protein.

Animals↗

PubMed1989

Current knowledge on Chlamydia pneumoniae, strain TWAR, an important cause of pneumonia and other acute respiratory diseases.

This article reviews current knowledge of Chlamydia pneumoniae strain TWAR, a newly recognized Chlamydia organism that causes acute respiratory infection, especially atypical pneumonia. Information is included on the microbiology, classification and laboratory diagnosis of the organism. Details of a series of studies of both endemic and epidemic respiratory infections are reviewed to present information on both the clinical and epidemiological characteristics of infection with strain TWAR. Laboratory studies of antibiotic sensitivity and recommendations for treatment are presented.

Adult↗

PubMed1989

Randomized treatment of mucopurulent cervicitis with doxycycline or amoxicillin.

A randomized trial of doxycycline versus amoxicillin was performed to treat mucopurulent cervicitis. Chlamydia trachomatis, the most common single agent associated with mucopurulent cervicitis, was isolated from 30 (47%) and Neisseria gonorrhoeae from five (8%) of 64 patients. Patients were followed up for 3 months, and the effect of treatment was assessed by clinical (presence of endocervical mucopus, cervicitis severity score, and number of polymorphonuclear leukocytes on Gram-stained smears of endocervical secretions) and microbiologic criteria. Doxycycline and amoxicillin were equally effective for treating chlamydial and nonchlamydial cervicitis. However, endocervical mucopus was still present in 18% of the patients in both treatment groups after 2 months and in 23% of the doxycycline group and 33% of the amoxicillin group after 3 months of therapy. The cause of persistent/recurrent mucopus after antimicrobial treatment was not explained by relapse or reinfection with Chlamydia trachomatis, Neisseria gonorrhoeae, genital mycoplasmas, or Gardnerella vaginalis, but persistence was associated with the degree of cervical ectopy.

Amoxicillin↗

PubMed1989

Experimental infection of baboons (Papio cynocephalus anubis) with Chlamydia pneumoniae strain 'TWAR'.

Two infant baboons (Papio cynocephalus anubis) were inoculated with Chlamydia pneumoniae strain 'TWAR', one in the conjunctiva, nasopharynx and oropharynx, the other in the trachea. Both remained well during 8 weeks of observation. C. pneumoniae infection persisted for at least 8 weeks after inoculation. Chlamydia pneumoniae seems to be of low virulence in baboons and capable of causing chronic infection.

Animals↗

PubMed1989

A proposed mouse model for acute epididymitis provoked by genital serovar E, Chlamydia trachomatis.

This study was conducted to determine the efficacy of the male mouse as a model for epididymitis caused by human genital serovar E, Chlamydia trachomatis. C. trachomatis was reisolated from all tissues removed on Days 3, 5, and 7 post inoculation (pi). Although some infected epididymides removed on Days 10, 14, and 21 pi were positive, control tissues remained negative. Histopathology of tissues showed a heavy, mixed inflammatory infiltrate consisting of polymorphonuclear cells and lymphocytes. Serum antibody to C. trachomatis was detected in the infected mice only (titer greater than or equal to 1:32). Chlamydial inclusions and individual elementary bodies were confirmed by immunofluorescent and immunoperoxidase staining up to Day 7 pi. These data show that the male mouse is susceptible to C. trachomatis infection and is appropriate for studies dealing with the effect of C. trachomatis on male fertility.

Acute Disease↗

PubMed1989

Isolation of a gene encoding a Chlamydia sp. strain TWAR protein that is recognized during infection of humans.

Chlamydia sp. strain TWAR is a unique Chlamydia sp. that causes acute respiratory disease. A gene bank consisting of TWAR isolate AR-39 DNA in pUC19 was screened with anti-AR-39 rabbit immune sera. Two positive clones were isolated that contained 7.3-kilobase (pLC1) and 14.9-kilobase (pLC2) plasmids. Restriction mapping and hybridization studies showed that both pLC1 and pLC2 contained a common 4.2-kilobase PstI fragment. Plasmids were used as templates of in vitro transcription-translation. All three plasmids had a novel protein product of ca. 75 kilodaltons not found in the vector alone. Western blots showed that this protein reacted with anti-TWAR rabbit immune sera and with human immune serum from an individual who had proven TWAR infection. Whole-cell lysates of TWAR demonstrated a protein having the same molecular weight and immunoreactivity as the recombinant gene product. This protein was also recognized by rabbit immune serum against Chlamydia psittaci or Chlamydia trachomatis. Southern hybridizations with the cloned fragment as a probe of digests of other Chlamydia spp. showed weakly hybridizing fragments. These results suggest that we have isolated a gene encoding a protein recognized during human TWAR infection that contains some sequences shared among Chlamydia spp.

Animals↗

PubMed1989

Histopathology of Chlamydia trachomatis salpingitis after primary and repeated reinfections in the monkey subcutaneous pocket model.

Monkeys with subcutaneously autotransplanted salpingeal fimbrial tissues were subjected to primary and repeated infections with Chlamydia trachomatis. The inflammatory response after primary inoculation was characterized by infiltration with polymorphonuclear leucocytes in the acute phase and mononuclear cells in the chronic phase. However, the inflammatory response after repeated infections was dominated by a mononuclear cell infiltration with a conspicuous absence of the initial phase of polymorphonuclear leucocyte infiltration. The remarkable findings of repeated infections were plasma cell infiltration, lymphoid follicle formation, and increased fibroblast activity resulting in extensive fibrosis. These findings are similar to those described for monkeys inoculated directly into the oviducts with C. trachomatis and support our original hypothesis that, after chlamydial infection, the tissue damage is provoked by immune-mediated mechanisms.

Animals↗

PubMed1989

Experimentally induced ocular chlamydial infection in infant pig-tailed macaques.

Four Macaca nemestrina monkeys were inoculated in the conjunctiva with Chlamydia trachomatis (strain E) at 6 weeks of age. A fifth monkey was inoculated with HeLa cell materials only. Ten weeks later, all monkeys were reinoculated with either strain E or strain C. All inoculated monkeys were susceptible to infection with C. trachomatis as documented by fluorescent antibody staining of smears and reisolation of the organism from conjunctival and nasopharyngeal swab specimens. Rectal and vaginal swab specimens remained negative throughout the study. Three of four inoculated animals responded with IgM titers reaching a peak of 1:16 (M#3) and 1:32 (M#1, M#4) 2 weeks after the primary inoculation. IgG appeared in all inoculated animals and titers rose to peak levels of 1:64 (M#2), 1:128 (M#1, M#3), and 1:256 (M#4). Histopathology documented a dramatic difference in immunological response following secondary inoculation. Primary inoculation elicited a typical inflammatory response characterized by moderate stromal infiltration of polymorphonuclear and mononuclear leukocytes. Plasma cells appeared by week 3 postinoculation (pi). Following a secondary inoculation, classic follicle formation was evident by 1 week pi. Mononuclear markers identified a germinal center composed of B cells and a T cell cap. Epithelial thinning near the cap of the follicle was accompanied by a complete loss of goblet cells. This model may be useful for studying the immunopathology of infant chlamydial infections.

Animals↗

PubMed1989

Chlamydia trachomatis oculogenital infection in the subcutaneous autotransplant model of conjunctiva, salpinx and endometrium.

The subcutaneous pocket model of salpingeal, endometrial, and conjunctival autografts for studying Chlamydia trachomatis infection in monkeys is described. Portions of the salpinx that were transplanted included fimbria, ampulla, and isthmus. The model is an extension of the original model which consists of either salpingeal fimbria or conjunctive autografts. Transplantation of the ampulla portion of the Fallopian tube enabled us to increase the number of pockets or test sites. Salpingeal and conjunctival autografts could be established during a single surgery. In addition, it is possible to autotransplant endometrium and provoke endometritis. The autografts were shown to be susceptible to C. trachomatis infection. Preliminary rechallenge experiments showed infection of the subcutaneous transplants may induce immunity, indicating the model may be used for immunity and vaccine studies. Simultaneous transplantation of different parts of the oviduct, endometrium, and conjunctive should expand the usefulness of the subcutaneous model in other studies on mixed infections or immune responses to infection.

Animals↗

PubMed1989

Myasthenia gravis and insulin-dependent diabetes mellitus in two adolescents.

Insulin-dependent diabetes mellitus (IDDM) has rarely, if ever, been reported to be an autoimmune disease associated with myasthenia gravis (MG). Two Chinese patients, one of whom was successfully treated with cyclosporin A (CyA) are reported, with discussion of pathophysiologic mechanisms involved and rationale for the treatment used.

Adolescent↗

PubMed1988

Local antibody in semen for rapid diagnosis of Chlamydia trachomatis epididymitis.

Etiologic studies including micro-immunofluorescence serology for Chlamydia trachomatis were done on 45 consecutive men with acute epididymitis. Of the men 21, all less than 35 years old, had type specific Chlamydia trachomatis antibody in the semen. All patients with semen antibody also had Chlamydia trachomatis antibody in the serum, while only a few of the patients without semen antibody had serum antibody. Chlamydia antibody titers in the semen specimens were higher than those in the sera and they persisted longer. In only 1 patient with semen antibody was another potential etiological agent for epididymitis demonstrated, while most of the patients without semen antibody had bacterial causes for the epididymitis. It was concluded that measurement of Chlamydia trachomatis antibody in semen offered a noninvasive, sensitive and specific method, useful despite prior antibiotic therapy, for diagnosis of the etiology of epididymitis in young men.

Acute Disease↗

PubMed1988

In vitro drug susceptibility of Chlamydia sp. strain TWAR.

The in vitro susceptibilities of eight Chlamydia sp. strain TWAR isolates were tested against tetracycline, erythromycin, penicillin, ampicillin, sulfisoxazole, and a new drug, trospectomycin. The ranges of inhibitory concentrations of these antimicrobial agents, except for sulfonamide, were similar to those for Chlamydia trachomatis. Sulfisoxazole was not inhibitory at the highest nontoxic concentration tested.

Ampicillin↗

PubMed1988

Ultrastructural study of entry of Chlamydia strain TWAR into HeLa cells.

Ultrastructural studies of the entry of Chlamydia strain TWAR into HeLa cells showed that the elementary bodies first attach to host cells by the pointed end, secure other binding sites on the host cells by forming cell wall protrusions, enter host cells by invaginating the host cell membrane, and form vacuolated endocytic vesicles. Differences were demonstrated between TWAR and other chlamydiae in the mode of attachment and endocytosis.

Bacterial Adhesion↗

PubMed1988

Factors affecting viability and growth in HeLa 229 cells of Chlamydia sp. strain TWAR.

Two prototype isolates (TW-183 and AR-39) of Chlamydia sp. strain TWAR were used to study factors affecting growth of this organism in HeLa 229 cells. The results showed that an incubation temperature of 35 degrees C was better than one of 37 degrees C for growth. The burst size after 3 days of incubation at 35 degrees C was found to be small (13 to 52), which partially explains the difficulty of serial passage in cell culture. Application of a higher centrifugal force (1,700 X g versus 900 X g) at the time of inoculation enhanced growth 2.2 to 3.6 times. Infectivity was enhanced by treatment of cells with DEAE-dextran (2.4 times) or poly-L-lysine (1.6 times), but not with Polybrene or polyethylene glycol. The viability of the TWAR organism in chlamydia transport medium SPG was also studied. It was shown that the organism was rapidly inactivated at room temperature (22 degrees C); only 1% remained viable after storage for 24 h. The viability was preserved at 4 degrees C, and 70% remained viable after storage for 24 h. Freezing at -75 degrees C inactivated 23% of the organisms when the organisms were frozen within 4 h after harvesting and stored at 4 degrees C before freezing.

Centrifugation↗