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Serologic profile of some sexually transmitted diseases in women with squamous intraepithelial lesions.

UNLABELLED: The purpose of this study consisted of the evaluation of some sexually transmitted diseases in patients with cervical pathology, namely squamous intraepithelial lesions. METHODS: a prospective study was performed. Patients with an abnormal cervical smear were submitted to colposcopy, directed biopsy and an immunologic assay for Chlamydia, Herpes Simplex Virus (HSV) types 1 and 2, Cytomegalovirus, Treponema pallidum, Hepatitis B and Human Immunodeficiency Virus I and II. The same parameters were evaluated in women with normal cervical cytology in a matched control group. A comparative study was performed evaluating some epidemiological parameters and the referred immunologic assays. RESULTS: 118 patients were separated into four groups. Statistically significant differences were observed in the personal history of fungi infections, as well as Chlamydia and HSV 2 IgM. CONCLUSION: immunologic assays may prove useful in identifying sexually-transmitted diseases, especially Chlamydia and HSV 2 infections, in Human Papillomavirus infected women.

Adult↗

Antigenic complexity of Treponema pallidum: antigenicity and surface localization of major polypeptides.

The protein structure of Treponema pallidum was characterized by two-dimensional electrophoresis (2DE), consisting of isoelectric focusing (IEF, pH 5 to 7) in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the second dimension. Up to 85 major polypeptide species could be detected in the organisms in 2DE gels by Coomassie Blue staining. The antigenicity of the individual polypeptides was determined by transferring the 2DE pattern to nitrocellulose paper and utilizing a sensitive immunoperoxidase procedure to demonstrate the reactivity of immunoglobulins in sera obtained from rabbits infected intratesticularly at least 6 mo previously. The infected rabbit serum reacted with virtually every major polypeptide detectable by protein staining techniques, indicating that infected rabbits produce antibodies against nearly all major T. pallidum proteins at the time when the animals exhibit systemic resistance to reinfection. Surface radioiodination of freshly purified T. pallidum by an Iodogen procedure yielded preferential labeling of a major polypeptide with an apparent m.w. of 39,000. The results of this study indicate that the antigenic complexity of T. pallidum is much greater than described previously. The 39-kd polypeptide appears to be a major surface constituent of T. pallidum and as such may play an important role in the induction of immunity to syphilis.

Animals↗

Antibodies against Borrelia burgdorferi in Bavarian forest workers.

The sera of 496 forest workers (fw), 44 customs officials and 20 other persons in outdoor professions from different areas of Bavaria were tested for antibodies against Borrelia burgdorferi (strain B 31) by indirect immunofluorescence. In sera previously absorbed with Treponema phagedenis ultrasonicate, significantly elevated IgG antibody titers were found in 69 cases, in 68 fw (13.7%) and 1 custom agent. In accordance with previous observations the distribution of positive results showed a distinct age dependance: under 24 years (y) 1.6% (n = 64), 25-34 y 0 (n = 30), 35-44 y 10.1% (n = 79), 45-54 y 17.4% (n = 190). Infections without manifest illness seem to predominate. In 1 area the number of positive persons was significantly higher than in the other: In Donauries near Illertissen 14 (45%) of 31 probands had elevated IgG titers. This area and the high level regions excepted, no significant differences were demonstrable amongst the 13 regions of Bavaria included in this investigation.

Adolescent↗

Syphilitic seroreactivity among the Thai population aged 50 years and above: value of mass screening.

The present study is concerned with the evaluation of routine serologic screening for syphilis among the general population aged 50 and above living in a suburban area of Bangkok, Thailand. Among 941 subjects aged 50 years and above recruited in a cohort study named the CERB study, blood of 798 subjects was obtained and their sera were tested for syphilis using the passive particle agglutination test for detection of antibodies to Treponema pallidum (TPPA) and the rapid plasma reagin (RPR). Of 798 subjects, 132 (16.5%) were reactive to serum TPPA. Their mean age (standard deviation) was 61.4 (8.4) years. Fifty-six subjects (42.4%) were male. Prevalence of syphilitic seroreactivity increased with age (p = 0.004). Prevalence of syphilitic seroreactivity among male and female subjects was 18.3% and 15.4% respectively (p = 0.001). Prevalence of syphilitic seroreactivity among subjects with formal education (14.4%) was significantly lower than that among subjects without formal education (26.5%) (p = 0.001). Of 132 subjects, 10 (7.6%) had and a rapid plasma reagin (RPR) titer of 1:16 or higher. None of them reported symptoms of primary or secondary syphilis during the initial survey. Of 125 subjects who were interviewed in depth during the revisit survey, 24 subjects had known about their syphilitic infection prior to this study. Among these 24 subjects, 4 had not received any treatment for syphilis and 1 used herbal medicine. Therefore, 106 subjects (84.4%) were untreated or inadequately treated. These findings suggest the value of mass screening for syphilis among the Thai population aged 50 years and above.

Age Factors↗

Marijuana, immunity and infection.

The influence of marijuana cannabinoids on immune function has been examined extensively over the last 25 yr. Various experimental models have been used employing drug-abusing human subjects, experimental animals exposed to marijuana smoke or injected with cannabinoids, and in vitro models employing immune cell cultures treated with various cannabinoids. For the most part, these studies suggest that cannabinoids modulate the function of T and B lymphocytes as well as NK cells and macrophages. In addition to studies examining cannabinoid effects on immune cell function, other reports have documented that these substances modulate host resistance to various infectious agents. Viruses such as herpes simplex virus and murine retrovirus have been studied as well as bacterial agents such as members of the genera Staphylococcus, Listeria, Treponema, and Legionella. These studies suggest that cannabinoids modulate host resistance, especially the secondary immune response. Finally, a third major area of host immunity and cannabinoids is that involving drug effects on the cytokine network. Employing in vivo and in vitro models, it has been determined that cannabinoids modulate the production and function of acute phase and immune cytokines as well as modulate the activity of network cells such as macrophages and T helper cells, Th1 and Th2. These results are intriguing and demonstrate that under certain conditions, cannabinoids can be immunomodulatory and enhance the disease process. However, more studies are needed to determine both the health risk of marijuana abuse and the role of the cannabinoid receptor/ligand system in immune regulation and homeostasis.

Animals↗

Dental plaque revisited: bacteria associated with periodontal disease.

Between 3-12 weeks after the beginning of supragingival plaque formation, a distinctive subgingival microflora predominantly made up of gram-negative, anaerobic bacteria and including some motile species, becomes established. In order to establish in a periodontal site, a species must be able to attach to one of several surfaces including the tooth (or host derived substances adhering to the tooth), the sulcular or pocket epithelium, or other bacterial species that are attached to these surfaces (Socransky and Haffajee 1991). Bacterial adhesion has demonstrated specificity in the mechanisms involved and studies have shown that there is a diversity of receptors on tooth surfaces, epithelial or other host cells and other bacteria. Recent studies have described bacterial complexes that are present in subgingival plaque and these studies are likely to help in current understanding of the complex ecology observed in dental plaque biofilm (Socransky, Haffajee et al. 1998). Bacterial interactions play important roles in species survival. Some interspecies relationships are favourable, in that one species produces growth factors for, or facilitates attachment of, another species. Other relationships are antagonistic due to competition for nutrients and binding sites, or to the production of substances that limit or prevent the growth of another species (Socransky and Haffajee 1991). A number of different bacterial interactions within plaque biofilm have been discussed. In the last 30-40 years, a vast amount of evidence has been published to suggest that bacteria are the primary aetiological agents of periodontal diseases. In the 1950s and early 1960s, periodontal treatment was based on the non-specific plaque hypothesis. However, the non-specific plaque hypothesis gave way after studies suggested that not all organisms in plaque are equally capable of causing destructive periodontal disease. Thus the concept of specificity re-emerged. Criteria for defining periodontal pathogens have been developed and include association, elimination, host response, virulence factors, animal studies and risk assessment (Haffajee and Socransky 1994). Until recently there were few consensus periodontal pathogens and trying to discriminate pathogenic from non-pathogenic species has been a difficult task for dental researchers for a variety of reasons. A discussion of the specific microbiota associated with gingivitis, chronic and aggressive periodontitis, NUG, HIV-associated periodontitis and implantitis has been presented. The bacteria associated with periodontal diseases are predominantly gram-negative anaerobic bacteria and may include A. actinomycetemcomitans, P. gingivalis, P. intermedia, B. forsythus, C. rectus, E. nodatum, P. micros, S. intermedius and Treponema sp. The bacterial numbers associated with disease are up to 10(5) times larger than those associated with health.

Animals↗

[Overview of endemic treponematoses].

Endemic treponematoses including yaws, bejel, pinta are distinguished from venereal syphilis on the basis of epidemiological characteristics and clinical manifestations. They cannot be differentiated by morphological and serological methods. A few minor genetic differences have been identified among the subspecies (Treponema pallidum sp. pallidum, pertenue, endemicum, carateum). Although penicillin therapy is effective, these infectious diseases have yet to be eliminated.

Diagnosis, Differential↗

Function and protective capacity of Treponema pallidum subsp. pallidum glycerophosphodiester phosphodiesterase.

Infectious syphilis, caused by the spirochete bacterium Treponema pallidum subsp. pallidum, remains a public health concern worldwide. The immune-response evasion mechanisms employed by T. pallidum are poorly understood, and prior attempts to identify immunoprotective antigens for subsequent vaccine design have been unsuccessful. Previous investigations conducted in our laboratory identified the T. pallidum glycerophosphodiester phosphodiesterase as a potential immunoprotective antigen by using a differential immunologic expression library screen. In studies reported here, heterologous expression of the T. pallidum glycerophosphodiester phosphodiesterase in Escherichia coli yielded a full-length, enzymatically active protein. Characterization of the recombinant molecule showed it to be bifunctional, in that it exhibited specific binding to human immunoglobulin A (IgA), IgD, and IgG in addition to possessing enzymatic activity. IgG fractionation studies revealed specific binding of the recombinant enzyme to the Fc fragment of human IgG, a characteristic that may play a role in enabling the syphilis spirochete to evade the host immune response. In further investigations, immunization with the recombinant enzyme significantly protected rabbits from subsequent T. pallidum challenge, altering lesion development at the sites of challenge. In all cases, animals immunized with the recombinant molecule developed atypical pale, flat, slightly indurated, and nonulcerative reactions at the challenge sites that resolved before lesions appeared in the control animals. Although protection in the immunized rabbits was incomplete, as demonstrated by the presence of T. pallidum in the rabbit infectivity test, glycerophosphodiester phosphodiesterase nevertheless represents a significantly immunoprotective T. pallidum antigen and thus may be useful for inclusion in an antigen cocktail vaccine for syphilis.

Animals↗

Monoclonal antibody with hemagglutination, immobilization, and neutralization activities defines an immunodominant, 47,000 mol wt, surface-exposed immunogen of Treponema pallidum (Nichols).

Radioimmunoprecipitation (RIP) analyses performed on 125I-surface-labeled Treponema pallidum cells using various immune sera revealed the presence of six major surface antigens (immunogens) with apparent molecular weights of 47 K, 36 K, 34 K, 32 K, 29 K, and 13 K. Among these, the 47 K surface antigen was most abundant. Radioimmunoprecipitation assays using 125I-labeled T. phagedenis biotype Reiter or immunoblot analyses using the same strain, failed to reveal the presence of the 47 K mol wt antigen in the representative nonpathogenic treponeme. Preabsorption of anti-T. pallidum immune rabbit serum (IRS) with the Reiter organism did not remove anti-T. pallidum antibodies from immune serum that reacted with the 47 K mol wt immunogen or other immunogens of T. pallidum present in the characteristic antigenic profile. Monoclonal antibodies (mAb) directed specifically against the 47 K mol wt immunogen of T. pallidum also failed to react with an analogous 47 K mol wt component in Treponema phagedenis biotype Reiter, further suggesting the unique presence of this antigen in pathogenic treponemes. The presence of the 47 K mol wt surface immunogen in pathogenic treponemes other than T. pallidum subspecies pallidum was also observed (43). Anti-47 K immunogen mAb was nonreactive against rabbit IgG or IgM. mAb directed specifically against the 47 K mol wt immunogen of T. pallidum was examined for strategic functional activities. It was found to be reactive in the microhemagglutination assay for T. pallidum antibodies, the T. pallidum immobilization test, and was found to be capable of significant blockage of attachment of virulent T. pallidum to host cells in tissue culture. Additional significant biological activity for the anti-47 K mol wt immunogen mAb was revealed through results of the in vitro-in vivo neutralization test of Bishop and Miller, in which a 99% or 100% neutralizing activity was demonstrated. The combined data of this study suggest that the 47 K mol wt immunogen of T. pallidum represents an abundant, immunodominant, surface-exposed immunogen possessing potential biological importance in the pathogenesis and immunology of T. pallidum infection. These studies serve to establish the first functionally defined immunogen for T. pallidum, which may represent the major immunogen of the organism.

Animals↗

Acute bacterial suppurative parotitis: microbiology and management.

The parotid gland is the salivary gland most commonly affected by inflammation. The most common pathogens associated with acute bacterial parotitis are Staphylococcus aureus and anaerobic bacteria. The predominant anaerobes include gram-negative bacilli (including pigmented Prevotella and Porphyromonas spp.), Fusobacterium spp., and Peptostreptococcus spp. Streptococcus spp. (including S. pneumoniae) and gram-negative bacilli (including Escherichia coli) have also been reported. Gram-negative organisms are often seen in hospitalized patients. Organisms less frequently found are Arachnia, Haemophilus influenzae, Klebsiella pneumoniae, Salmonella spp., Pseudomonas aeruginosa, Treponema pallidum, cat-scratch bacillus, and Eikenella corrodens. Mycobacterium tuberculosis and atypical mycobacteria are rare causes of parotitis. Therapy includes maintenance of hydration and administration of parenteral antimicrobial therapy. Once an abscess has formed surgical drainage is required. The choice of antimicrobial depends on the etiologic agent. Maintenance of good oral hygiene, adequate hydration, and early and proper therapy of bacterial infection of the oropharynx may reduce the occurrence of suppurative parotitis.

Abscess↗

Biological basis for syphilis.

Syphilis is a chronic sexually transmitted disease caused by Treponema pallidum subsp. pallidum. Clinical manifestations separate the disease into stages; late stages of disease are now uncommon compared to the preantibiotic era. T. pallidum has an unusually small genome and lacks genes that encode many metabolic functions and classical virulence factors. The organism is extremely sensitive to environmental conditions and has not been continuously cultivated in vitro. Nonetheless, T. pallidum is highly infectious and survives for decades in the untreated host. Early syphilis lesions result from the host's immune response to the treponemes. Bacterial clearance and resolution of early lesions results from a delayed hypersensitivity response, although some organisms escape to cause persistent infection. One factor contributing to T. pallidum's chronicity is the paucity of integral outer membrane proteins, rendering intact organisms virtually invisible to the immune system. Antigenic variation of TprK, a putative surface-exposed protein, is likely to contribute to immune evasion. T. pallidum remains exquisitely sensitive to penicillin, but macrolide resistance has recently been identified in a number of geographic regions. The development of a syphilis vaccine, thus far elusive, would have a significant positive impact on global health.

Amino Acid Sequence↗

DNA probe detection of periodontopathogens in advanced periodontitis.

Species-specific DNA probes were used to determine the presence of Actinobacillus actinomycetemcomitans (A.a.), Porphyromonas (Bacteroides) gingivalis, Prevotella intermedia, Treponema denticola, Eikenella corrodens, Fusobacterium nucleatum, and Wolinella recta in subgingival plaque from deep pockets/sites of patients with advanced periodontitis. The subjects were 20 patients with severe adult periodontitis, 13 men and 7 women (mean age 45.6 +/- 6.7 yr). For each subject, 9-10 subgingival sites with the deepest probing depths from each quadrant were sampled by the paper point method, a total of 198 sites, with mean probing depth 7.2 +/- 1.6 mm and clinical attachment level 9.5 +/- 2.7 mm. A.a. was present in at least one site in 75% of the subjects; P. gingivalis was found in 95%; P. intermedia and W. recta were found in 90%, respectively; and T. denticola, E. corrodens, and F. nucleatum were found in all subjects. In the 198 samples, A.a. was detected in 25.8%, P. gingivalis in 51.5%, P. intermedia in 64.1%, T. denticola in 60.6%, E. corrodens in 72.9%, F. nucleatum in 74.7%, and W. recta in 65.7%. The predominant combination was the simultaneous presence of P. intermedia, T. denticola, E. corrodens, F. nucleatum, and W. recta in 89.5% of the subjects and 46.8% of the sites. Of these sites, 51.1% showed the combined presence of P. gingivalis and 28.4% that of both A.a. and P. gingivalis. None of the seven bacteria could be detected in 14.4% of the total sites sampled. The present study indicates that severe destructive adult periodontitis is a multibacterial infection and that certain combinations of periodontopathogens seem to be important in the pathogenesis of the disease.

Adult↗

Similar serological response to conventional therapy for syphilis among HIV-positive and HIV-negative women.

OBJECTIVES: To compare characteristics of syphilis serological reactivity in HIV positive (+) and HIV negative (-) female sex workers, as well as the serological response to therapy after treatment with intramuscular benzathine penicillin, 2.4 million U weekly, for three consecutive weeks. METHODS: Rapid plasma reagin (RPR) and Treponema pallidum haemagglutination assay (TPHA) results of 72 HIV-positive and 121 HIV-negative women reactive in both tests were assessed. The response to therapy was prospectively monitored with quantitative RPR serology in 47 HIV-positive and 73 HIV-negative patients. Cumulative probabilities of becoming nonreactive by RPR were compared at six months, one and two years after therapy. RESULTS: At enrolment, the geometric mean titres of RPR and TPHA were lower in HIV-positive patients (RPR, 1:2.6) than in HIV-negative patients (RPR, 1:3.8; p < 0.01). The evolution over time of RPR titres was similar among HIV-positive patients as compared to HIV-negative patients. Among patients with an initial RPR titre of < 1:8, 53% of HIV-positive and 44% of HIV-negative patients became RPR negative two years after therapy. Among patients with an RPR titre of 1:8 or greater at enrolment, 83% of HIV-positive and 90% of HIV-negative patients had reached at least a fourfold decline of RPR titres two years after therapy. CONCLUSIONS: Syphilis serology findings (both RPR and TPHA) may be altered in the presence of HIV infection, but the serological response to therapy was similar in HIV-positive and HIV-negative patients.

Adult↗

The influence of different sera on the in vitro immobilisation of Percoll purified Treponema pallidum, Nichols strain.

OBJECTIVES: Investigation of sera, especially rabbit serum, in preventing in vitro immobilisation of Percoll purified T. pallidum. MATERIALS AND METHODS: The immobilisation of Percoll purified T. pallidum (Nichols) was studied after pre-incubations with basal reduced medium (BRM), heat-inactivated serum of seven different species of animals, heat-inactivated normal human serum (NHS) and rabbit sera containing a different level of antitreponemal antibodies. Also increasing percentages of heat-inactivated normal rabbit serum (NRS) were studied. RESULTS: The rapid immobilisation of purified treponemes by NHS is delayed by pre-incubation with NRS in a dose-dependent manner. The treponemes from 5-day infections were immobilised significantly more slowly than treponemes from 7- and 8-day infections. Compared with NRS, pre-incubations with a high-titred, low-titred and "autologous" serum resulted in significantly more rapid immobilisation of the treponemes. With most other animal sera resistance to immobilisation was slight compared with that produced by NRS. Immunofluorescent studies revealed that the treponemes were covered with a layer of the human third complement factor (C3b), within an hour of incubation. With two sequential pre-incubations, a delay of the immobilisation was only noted in those test mixtures in which NRS had been present in both preincubations. CONCLUSION: Rabbit serum delays the rapid in vitro immobilisation of Percoll purified treponemes by normal human serum. There was no evidence that this was caused by preventing access of antibodies (in vivo as well as in vitro) to, or preventing the activation of complement on, the treponemal surface. The evidence points to a mechanism in the fluid phase, suggesting participation of a third factor in the immobilisation process, for instance an enzyme, which can be partially inhibited by rabbit serum component(s).

Animals↗

[Clinical characteristics and therapy of neurosyphilis in patients who are negative for human immunodeficiency virus].

INTRODUCTION: Neurosyphilis is still a significant medical problem in developing countries and its occurrence in HIV infection is the reason for a growing number of new cases in developed countries [1-4]. Personality changes are the commonest symptom of late neurosyphilis [5]. Neurologic deficits are usually due to syphilitic vasculitis with lacunar infarctions [6]. The laboratory confirmation of neurosyphilis must depend on a cluster of tests (Venereal Disease Research Laboratories--VDRL; Fluorescent Treponemal Antibody-Absorption--FTA-ABS; Treponema Pallidum Immobilization--TPI or Nelson-Mayer). The diagnosis of active neurosyphilis also requires an inflammatory cerebrospinal fluid (CSF) test [4]. METHODS: A retrospective study of hospitalized neurosyphilitic patients at the Institute of Neurology, Belgrade, Serbia, was carried out. Between 1990 and 1996 seven cases were found: five males and two females, aged from 22 to 66 years, mean 56 years. All were in tertiary stage and HIV negative. None of them reported previous veneral disease and only one reported meningitis. In all patients neurological examination, VDRL and TPI in blood and CSF, CT or MRI of the brain, Mini Mental State (MMS) test [11] and psychiatric evaluation were performed. To patients with active disease 24 million units of crystalline penicillin were administered, in divided daily doses in continuous intravenous infusions for three weeks. RESULTS: Symptoms. Five patients (71%) had gait disturbances, four (57%) headache, three (43%) hearing loss, speech complaints, forgetfulness, mood changes, and two (29%) seizures and stroke-like episodes. Malaise, diplopia, visual loss, vertigo, loss of sphincter control and paresthesia were noticed in one patient (14%). Neurologic findings. Five patients (71%) had pupillary changes. In four (57%) of them we found hemiparesis, gait disturbances and signs of cerebellar involvement, in three (43%) hearing loss, dysarthria, paraparesis, hypesthesia for light touch, mood disorders (depression in two, hypomania in one), mild cognitive decline and tremor of the tongue and hands. Lesion of the second and the sixth cranial nerve, position sense and positive release signs were recorded in one patient (14%). Gonarthrotic changes were observed in two (29%) patients. Cerebrospinal fluid. Elevated cell count and high protein level were detected in four (57%) patients. Three had also positive oligoclonal bands. Serological tests. In six patients (86%) serological tests for syphilis were positive (VDRL and/or Nelson-Mayer Test) in serum and in three (43%) in CSF. Results in one patient were negative both regarding serum and CSF, as he was treated for secondary syphilis in his twenties (now 65 years old) presumably as a "burnt out" case with neurologic sequelae. Neuroimaging. CT and MRI of the brain showed cortical and subcortical reduction in the brain parenchyma in four (57%) and multiischaemic changes in two (29%) patients. Therapy. Crystalline penicillin was administered to five patients with no side effects. Improvement of mood and cognitive status were noted in three patients, improvement of neurologic status in two subjects and arrest of progression in two patients. DISCUSSION: None of our patients reported previous venereal disease. They complained of impaired gait, headache, hearing loss, speech difficulties, forgetfulness, and mood changes. Pupillary changes, hemiparesis, gait disturbances and cerebellar signs, hearing loss, dysarthria, paraparesis, hypesthesia, mood disorders, mild cognitive decline and tremor of the tongue and hands were found during the examination. Pupillary signs are the most important symptoms because they can point to neurosyphilis. A two-step approach is recommended for establishing the diagnosis of syphilis with simple nontreponemal tests for screening purpose, and specific treponemal tests for its confirmation [21]. In our patients all but one were positive for syphilis in serum-tests and/or CSF. (ABS

Adult↗

Mechanisms of clearance of Treponema pallidum from the CSF in a nonhuman primate model.

OBJECTIVES: To establish a model of CNS invasion by Treponema pallidum and to use it to investigate the immune mechanisms responsible for clearance. METHODS: Four macaques were intrathecally inoculated with 0.6 to 2.1 x 10(8) T. pallidum and underwent clinical examinations and blood and CSF collections every 1 to 2 weeks for 12 to 13 weeks. The following were determined: serum Venereal Disease Research Laboratory (VDRL) and microhemagglutination-T. pallidum reactivities, CSF-VDRL, CSF white blood cell (WBC) count, and the presence of viable T. pallidum in CSF by the rabbit infectivity test (all animals), as well as the presence of T. pallidum in CSF by reverse transcriptase (RT)-PCR, WBC phenotype by fluorescence-activated cell sorter, WBC cytokine production by RT-PCR, and brain MRI at 10 weeks (two animals). RESULTS: All animals became systemically infected and developed CSF pleocytosis that resolved after 8 weeks. CSF T. pallidum was detected from 2 to 8 weeks. CSF T lymphocytes were predominantly CD4+. Interferon-gamma (IFN-gamma) mRNA was consistently detected in CSF WBCs, but interleukin (IL)-4 and IL-5 were not. All animals remained clinically well. MRIs were normal. CONCLUSIONS: In this model, T. pallidum is cleared from the CNS just as in most humans with early syphilis. Local production of IFN-gamma likely participates in this process. This model could be used to clarify the effect of retrovirus-induced immunodeficiency on clearance of T. pallidum from the CNS and on the local CNS immune response.

Animals↗

Evaluation of the Determine Rapid Syphilis TP assay using sera.

The Abbott Determine Rapid Syphilis TP assay is a treponemal test that can be used in resource-poor settings that lack laboratory facilities. However, this test has not been extensively evaluated. We measured its sensitivity and specificity by using stored serum specimens (n = 567) from all persons who tested Treponema pallidum hemagglutination assay (TPHA) positive (n = 250) or TPHA indeterminate (n = 17) in the year 2001 and the first 300 patients in 2001 who tested TPHA negative at the Evandro Chagas Research Institute in Rio de Janeiro, Brazil. This rapid assay was independently interpreted by three different observers. With TPHA results as the reference, sensitivity ranged between readers from 95.6 to 98.4% and specificity ranged from 97.3 to 95.7%. There was little interreader variability in the interpretation of results, with approximately 98% agreement for all reader combinations. Of samples from persons with human immunodeficiency virus (HIV) infection (n = 198), sensitivity was 96.9 to 99.2% and it was 94.4 to 96.3% among HIV-negative persons (n = 127). Specificity was 92.4 to 95.5% among HIV-positive persons and 97.2 to 100% among HIV-negative persons. We found this test to have high sensitivity and specificity and little interreader variability, indicating that it may be easily used in resource-poor settings without laboratory facilities. Further studies are needed using this test on whole blood and under the clinical conditions for which it is intended.

Antibodies, Bacterial↗

Purification and general properties of an oligopeptidase from Treponema denticola ATCC 35405--a human oral spirochete.

An endo-acting oligopeptidase (OPase) was purified to homogeneity from the cells of Treponema denticola ATCC 35405--a human oral spirochete--by a procedure that comprised a mild Triton X-100 extraction (which disintegrates the outer membrane but leaves the cells morphologically intact) and four successive fast protein liquid chromatographic steps of the extract. The activity of this oligopeptidase (formerly named "trypsin-like" enzyme and "BANA-peptidase") together with the proteinase activities of T. denticola and Porphyromonas gingivalis is utilized in a diagnostic test for human periodontal infections, but the enzyme's chemical nature has not been studied. The enzyme is a cell-associated 78-kDa protein with an isoelectric point of 6.1, and its estimated minimum peptide length was 688 amino acid residues. The OPase does not hydrolyze proteins, but hydrolyzes -X-Arg-p-nitroaniline peptides between arginine and the chromogen, the optimum pH of hydrolysis covering a broad pH range (7 to 9). The OPase is not a metalloenzyme, although 1.0 mmol/liter Ca(II) increases the rate of the hydrolysis of all substrates. Ca(II) did not affect the values of the Michaelis constant. The OPase activity is not dependent on reactive SH-groups, but is suggested to depend on the catalytic triad COOH. . .His. . .Ser. The N-terminal sequence for the first 29 amino acid residues is MKQSDFEKPPIAEIKETRFEKFGKTRIDN. The purified enzyme is very sensitive to chlorhexidine acetate (mixed inhibition; Ki = 0.85 microM) and somewhat less sensitive to bacitracin (Ki(app) = 27.5 microM). The present OPase is considered to belong to the serine peptidases, functionally resembling trypsin except that the OPase does not hydrolyze proteins. The OPase may be regarded as an oligopeptidase, the substrate specificity profile of which resembles to a certain extent that of some members of the coagulation cascade.

Amino Acid Sequence↗