Identification and evaluation of outcome measurement instruments in pyoderma gangrenosum: a systematic review.

BACKGROUND: Pyoderma gangrenosum (PG) is a rare autoinflammatory skin condition that causes tissue destruction and subsequent painful ulcers. To date, there are no core domains or instruments for assessing PG severity in clinical trials, and current treatment paradigms rely on outcome measurements that have not been well characterized in the literature. OBJECTIVES: To perform two systematic reviews that (i) identify the outcome measurement instruments used in PG clinical trials and their corresponding domains and (ii) identify any associated validation studies and evaluate their measurement properties and methodological quality. METHODS: We systematically searched the MEDLINE and Embase databases for PG outcome measurement instruments. We also systematically searched for PG instrument validation studies. We evaluated the measurement properties and methodological quality of validation studies using the 2018 COSMIN Risk of Bias checklist. RESULTS: In total, seven clinical trials were included. These studies utilized a total of 20 different instruments, including 11 physician-reported instruments, eight patient-reported instruments and one composite instrument. Among these, 85% of the instruments lacked any validation data. Of the remaining three validated instruments (speed of healing, physician global assessment and resolution of inflammation), methodological quality was not available for half of the COSMIN categories. CONCLUSIONS: We identified 17 non-validated outcome measurement instruments used in PG clinical trials. We conclude that PG validation studies are required for existing instruments, and new instruments need to be developed to inform the consensus process for the development of a core outcome set for PG. What is already known about this topic? Pyoderma gangrenosum (PG) is a rare autoinflammatory skin condition that has been characterized by multiple outcome measurement instruments in clinical trials. However, there is no consensus on the most validated and appropriate outcome measurement instruments. What does this study add? This study identifies and evaluates 20 unique outcome measurement instruments for PG in the literature. Of these 20, 17 lack any instrument validation data, highlighting the need for future studies. What are the clinical implications of this work? Despite the current use of several outcome measurement instruments, future studies should explore the validation surrounding these instruments, as no instruments can currently be recommended.

STI/HIV Sexual Risk Behavior and Prevalent STI Among Incarcerated African American Men in Committed Partnerships: The Significance of Poverty, Mood Disorders, and Substance Use.

African Americans face disproportionate sexually transmitted infection including HIV (STI/HIV), with those passing through a correctional facility at heightened risk. There is a need to identify modifiable STI/HIV risk factors among incarcerated African Americans. Project DISRUPT is a cohort study of incarcerated African American men recruited from September 2011 through January 2014 from prisons in North Carolina who were in committed partnerships with women at prison entry (N = 207). During the baseline (in-prison) study visit, participants responded to a risk behavior survey and provided a urine specimen, which was tested for STIs. Substantial proportions reported multiple partnerships (42 %), concurrent partnerships (33 %), and buying sex (11 %) in the 6 months before incarceration, and 9 % tested positive for an STI at baseline (chlamydia: 5.3 %, gonorrhea: 0.5 %, trichomoniasis: 4.9 %). Poverty and depression appeared to be strongly associated with sexual risk behaviors. Substance use was linked to prevalent STI, with binge drinking the strongest independent risk factor (adjusted odds ratio: 3.79, 95 % CI 1.19-12.04). There is a continued need for improved prison-based STI testing, treatment, and prevention education as well as mental health and substance use diagnosis.

High HIV prevalence among men who have sex with men in Jamaica is associated with social vulnerability and other sexually transmitted infections.

BACKGROUND: Human immunodeficiency virus (HIV) prevalence among men who have sex with men (MSM) is thought to be high in Jamaica. The objective of this study was to estimate HIV prevalence and identify risk factors in order to improve prevention approaches. METHODS: With the help of influential MSM, an experienced research nurse approached MSM in four parishes to participate in a cross-sectional survey in 2007. Men who have sex with men were interviewed and blood taken for HIV and syphilis tests, and urine taken for gonorrhoea, chlamydia and trichomonas testing using transcription-mediated amplification assays. A structured questionnaire was administered by the nurse. RESULTS: One third (65 of 201; 32%, 95% Confidence Interval (CI) 25.2, 47.9) of MSM were HIV positive. Prevalence of other sexually transmitted infections (STI) was: chlamydia 11%, syphilis 6%, gonorrhoea 3.5% and trichomonas 0%. One third (34%) of MSM identified themselves as being homosexual, 64% as bisexual and 1.5% as heterosexual. HIV positive MSM were significantly more likely to have ever been told by a doctor that they had an STI (48% vs 27%, OR 2.48 CI 1.21, 5.04, p = 0.01) and to be the receptive sexual partner at last sex (41% vs 23%, OR 2.41 CI 1.21, 4.71, p = 0.008). Men who have sex with men who were of low socio-economic status, ever homeless and victims of physical violence were twice as likely to be HIV positive. The majority (60%) of HIV positive MSM had not disclosed their status to their partner and over 50% were not comfortable disclosing their status to anyone. CONCLUSIONS: The high HIV prevalence among MSM is an important factor driving the HIV epidemic in Jamaica. More effective ways need to be found to reduce the high prevalence of HIV among MSM including measures to reduce their social vulnerability, combat stigma and discrimination and empower them to practice safe sex.

Validity of self-reported 'safe sex' among female sex workers in Mombasa, Kenya--PSA analysis.

We assessed the validity of self-reported sex and condom use by comparing self-reports with prostate-specific antigen (PSA) detection in a prospective study of 210 female sex workers in Mombasa, Kenya. Participants were interviewed on recent sexual behaviours at baseline and 12-month follow-up visits. At both visits, a trained nurse instructed participants to self-swab to collect vaginal fluid specimens, which were tested for PSA using enzyme-linked immunosorbent assay (ELISA). Eleven percent of samples (n = 329) from women reporting no unprotected sex for the prior 48 hours tested positive for PSA. The proportions of women with this type of discordant self-reported and biological data did not differ between the enrolment and 12-month visit (odds ratio [OR] 1.1; 95% confidence interval [CI] 0.99, 1.2). The study found evidence that participants failed to report recent unprotected sex. Furthermore, because PSA begins to clear immediately after exposure, our measures of misreported semen exposure likely are underestimations.

Experimental vaccine induces Th1-driven immune responses and resistance to Neisseria gonorrhoeae infection in a murine model.

Female mice were immunized intravaginally with gonococcal outer membrane vesicles (OMVs) plus microencapsulated interleukin-12 (IL-12), and challenged using an established model of genital infection with Neisseria gonorrhoeae. Whereas sham-immunized and control animals cleared the infection in 10-13 days, those immunized with OMV plus IL-12 cleared infection with homologous gonococcal strains in 6-9 days. Significant protection was also seen after challenge with antigenically distinct strains of N. gonorrhoeae, and protective anamnestic immunity persisted for at least 6 months after immunization. Serum and vaginal immunoglobulin G (IgG) and IgA antibodies were generated against antigens expressed by homologous and heterologous strains. Iliac lymph node CD4+ T cells secreted interferon-γ (IFNγ), but not IL-4, in response to immunization, and produced IL-17 in response to challenge regardless of immunization. Antigens recognized by immunized mouse serum included several shared between gonococcal strains, including two identified by immunoproteomics approaches as elongation factor-Tu (EF-Tu) and PotF3. Experiments with immunodeficient mice showed that protective immunity depended upon IFNγ and B cells, presumably to generate antibodies. The results demonstrated that immunity to gonococcal infection can be induced by immunization with a nonliving gonococcal antigen, and suggest that efforts to develop a human vaccine should focus on strategies to generate type 1 T helper cell (Th1)-driven immune responses in the genital tract.

Cooperative effects of gamma interferon and 1-alpha,25-dihydroxyvitamin D3 in inducing differentiation of human promyelocytic leukemia (HL-60) cells.

Various agents induce differentiation of human leukemia cells in vitro. Most of these agents cause myeloid differentiation, but phorbol diesters, 1-alpha,25-dihydroxyvitamin D3 (1,25[OH2]D3), and certain lymphokines cause differentiation to monocyte-like cells. The purpose of this study was to determine the cooperative effects of 1,25(OH2)D3 and the lymphokine gamma interferon (IFN-gamma) on HL-60 cell differentiation. The recombinant human IFN-gamma or 1,25(OH2)D3 caused a slight reduction in the proliferation of the HL-60 cells (30%-40% reduction at doses of 100-200 U/ml [0.25-0.50 nM] IFN-gamma, or 5-25 nM 1,25[OH2]D3). HL-60 cells treated with 100 U/ml IFN-G had an eightfold increase in expression of nonspecific esterase (NSE) and a twofold increase in H2O2 production in response to phorbol myristate acetate (PMA). 1,25(OH2)D3 enhanced NSE expression eight- to 30-fold and H2O2 secretion twofold in response to PMA. There was also enhanced expression of HLA-DR and the receptor for C3bi. The 1,25(OH2)D3- and IFN-gamma-differentiating effects appeared to be additive or synergistic. Populations of IFN-gamma-treated HL-60 cells (but not the 1,25[OH2]D3-treated cells) had multinucleated giant cells. The polykaryons had NSE activity and had some properties of macrophage polykaryons or osteoclasts. 1,25(OH2)D3 did not augment the IFN-gamma-induced polykaryon formation.

Microassay for the photometric quantitation of cell-associated plasminogen activator using a chromogenic tripeptide substrate.

Plasminogen activator (PA), a neutral protease whose primary function is to convert plasminogen to plasmin, is produced by various cells including macrophages, monocytes, endothelial cells, and tumor cells. This study reports the use of the chromogenic tripeptide substrate D-Val-Leu-Lys-p-nitroanilide (S-2251) and an automated microtiter plate reader spectrophotometer for the determination of PA activity in cells and fluids. There was a linear relationship between the time of incubation at 37 degrees C and the square root of the absorbance measured at 405 nm when urokinase was incubated with the substrate in the presence of plasminogen. There was no activity in the absence of plasminogen. The slopes of the lines (square root A 405/time) were directly related to the concentrations of urokinase, up through 0.05 CTA units. Using this assay, we determined the cellular activity of PA in human promyelocytic cells HL-60 (1.33 +/- 0.12 CTA units/mg), human monocytoid cells U937 (1.27 +/- 0.12 CTA units/mg), mouse myeloid leukemia cells RFM/UN (0.70 +/- 0.07 CTA units/mg), freshly isolated normal human monocytes (0.00 +/- 0.00 CTA units/mg), and human monocytes after 7 days in culture (5.66 +/- 0.38 CTA units/mg). There was a variable amount of activity expressed in freshly isolated cells or cell lysates of peritoneal macrophages from normal mice, or mice that had gotten intraperitoneal injections of peptone, thioglycollate, or NaIO4, but after 24 or 48 h of culture, these activities, in general, increased. Using this assay, PA levels in the euglobulin precipitates from human plasma prepared without venous occlusion (0.03 +/- 0.02 CTA units/mg protein) or after 5 min of venous occlusion of the arm (0.18 +/- 0.01 CTA units/mg) were comparable to those reported by others using different assays. Thus, this represents a simple, rapid, accurate assay of PA that should be useful to those in immunology, cell biology, and clinical medicine.

Antimicrobial susceptibility and molecular typing of MRSA in cystic fibrosis.

OBJECTIVES: The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in cystic fibrosis (CF) patients in the United States is approximately 25%. Little is known about the relative proportion of hospital- versus community-associated strains or the antimicrobial susceptibility of MRSA in different CF centers. We hypothesized that the majority of MRSA isolates obtained from children with CF are those endemic in the hospital and that those associated with community acquisition (SCCmec IV) would be more resistant than typically seen in non-CF MRSA isolates. METHODS: We studied MRSA strains from seven pediatric CF centers to determine the clonal distribution based on DNA sequencing of the staphylococcal protein A gene (spa typing), the type of staphylococcal chromosomal cassette mec (SCCmec), and the proportion of strains with Panton-Valentine leukocidin (PVL). Antimicrobial susceptibility to systemic and topical antibiotics was compared between different MRSA types. RESULTS: We analyzed 277 MRSA isolates from unique patients (mean age 11.15 ± 4.77 years, 55% male). Seventy % of isolates were SCCmec II PVL negative and the remainder SCCmec IV. Overall 17% MRSA strains were PVL positive (all SCCmec IV). Spa typing of 118 isolates showed most of the SCCmec II strains being t002, while SCCmec IV PVL positive isolates were t008, and SCCmec IV PVL negative isolates represented a variety of spa-types. The proportions of SCCmec II strains and spa-types were similar among centers. Overall rates of resistance to trimethoprim-sulfamethoxazole (4%), tetracycline (7%), tigecycline (0.4%), linezolid (0.4%) as well as fosfomycin (0.4%), fusidic acid (3%), and mupirocin (1%) were low. No strains were resistant to vancomycin. SCCmec II strains had higher rates of resistance to ciprofloxacin and clindamycin (P < 0.001) than SCCmec IV strains. CONCLUSIONS: In this U.S. study, most MRSA isolates in the pediatric CF population were SCCmec II PVL negative. Rates of resistance were low, including to older and orally available antibiotics such as trimethoprim-sulfamethoxazole.

Phenotypic characterization of gamma interferon-induced human monocyte polykaryons.

Multinucleated giant cells of mononuclear phagocyte origin (monocyte or macrophage polykaryons [MPs] ) are seen in numerous different normal and pathologic states. We have previously shown that gamma interferon (IFN-gamma) induces fusion of uninuclear monocytes (UMs) to form MPs. This study was designed to characterize these IFN-gamma-induced MPs. Control and IFN-gamma-treated UMs and MPs did not have peroxidase activity, but they stained intensely for nonspecific esterase and acid phosphatase. The esterase of UMs and MPs was abolished by fluoride, but the acid phosphatase of UMs and MPs was only minimally decreased by tartrate. The phagocytosis of polystyrene spheres and glutaraldehyde-fixed erythrocytes by MPs was moderately depressed as compared with control or treated UMs, whereas the phagocytosis of IgG-coated erythrocytes was markedly depressed. Populations of control monocytes produced less H2O2 in response to 200 nmol/L of phorbol myristate acetate than did IFN-gamma-treated monocytes (37 +/- 7 v 199 +/- 29 nmol/h per milligram of cell protein). However, when examined microscopically, individual MPs had less ability to reduce NBT (18% +/- 5% positive for MP, 91% +/- 3% for treated UMs, and 67% +/- 3% for control UMs). The surface membrane antigens Leu M3, OKM1 (C3bi receptor), DU-HL60-3, DU-HL60-4, TE5, and V1 were not expressed or were expressed poorly in MPs; they were expressed normally in control and treated UMs. However, HLA-DR expression was increased in treated UMs and MPs. The binding of the lectins RCA, Con A, WGA, DBA, UEA, and PNA was equivalent in all cells. Thus, MPs formed by fusion of UMs in vitro after culture with IFN-gamma differ in several features from UMs.

Recombinant human gamma-interferon induces human monocyte polykaryon formation.

Monocyte or macrophage polykaryons (MP) are seen in different tissues in various inflammatory states and in normal bone (osteoclasts). The factors controlling the formation and the function of MP are not completely understood. This study was designed to evaluate the effects of the lymphokine gamma-interferon (IFN-gamma) on human monocyte function in vitro. Purified recombinant IFN-gamma [20-200 units/ml (0.1-1.0 nM)] caused the appearance of MP in cultures of normal human monocytes cultured in 10% unheated autologous serum. The MP were noted by as early as 36 hr of culture with fusion indices of 40%-60% and up to 160 nuclei per cell. The effect was seen with both recombinant IFN-gamma and natural IFN-gamma produced by Staphylococcal enterotoxin A-stimulated lymphocytes, but IFN-alpha (leukocyte-derived and recombinant) and IFN-beta did not induce MP formation. The activity of the IFN-gamma was destroyed by heating at 56 degrees C for 4 hr, incubating at pH 2 for 3 hr, or incubating with antibody against IFN-gamma. Populations of monocytes incubated 3 days with 100 units of IFN-gamma per ml (0.5 nM) had enhanced capacity to produce H2O2 in response to phorbol 12-myristate 13-acetate and increased content of acid phosphatase and plasminogen activator. As determined by autoradiography, the MP did not incorporate [3H]dThd into their nuclei. Thus, the IFN-gamma appears to induce MP formation by a process of monocyte fusion, and to "activate" monocytes, as judged by various parameters.

Microevolution within a clonal population of pathogenic bacteria: recombination, gene duplication and horizontal genetic exchange in the opa gene family of Neisseria meningitidis.

Opacity (Opa) proteins are a family of antigenically variable outer-membrane proteins of Neisseria meningitidis. Even among clonally related epidemic meningococcal isolates, there is greater variation of Opa protein expression than can be accounted for by the opa gene repertoire of any individual strain. We characterized the opa genes of eight closely related isolates of serogroup A N. meningitidis (subgroup IV-1) from a recent meningitis epidemic in West Africa. DNA sequence analysis and Southern blot experiments indicated that changes occurred in the opa genes of these bacteria as they spread through the human population, over a relatively short period of time. Such changes in one or a few loci within a clonal population are referred to as microevolution. The distribution of sequences present in hypervariable (HV) regions of the opa genes suggests that duplication of all or part of opa genes into other opa loci changed the repertoire of Opa proteins that could be expressed. Additional variability in this gene family appears to have been introduced by horizontal exchange of opa sequences from other meningococcal strains and from Neisseria gonorrhoeae. These results indicate that processes of recombination and genetic exchange contributed to variability in major surface antigens of this clonal population of pathogenic bacteria.

Cerebrospinal fluid macrophage response to experimental cryptococcal meningitis: relationship between in vivo and in vitro measurements of cytotoxicity.

The functional abilities of macrophages from cerebrospinal fluid (CSF) have so far been little studied. We examined the acquisition of activation characteristics by CSF macrophages during the course of experimental cryptococcal meningitis. CSF macrophages developed the ability for increased reactive oxidative intermediate (H2O2) production and tumor and fungal cytotoxicity. Despite having been activated, CSF macrophages could not inhibit the growth of Cryptococcus neoformans in vitro. Immunosuppression with cyclosporine, which eliminates the natural resistance of rabbits to cryptococcal meningitis, did not prevent or diminish H2O2 production by CSF macrophages but did reduce their tumoricidal activity. Activation of CSF macrophages appears to be an integral part of the central nervous system immune response to C. neoformans in this model, but alone is insufficient to eliminate C. neoformans from the central nervous system.

Treatment of experimental disseminated candidiasis with cilofungin.

The efficacy of cilofungin treatment of experimental disseminated candidiasis in rabbits was examined. Cilofungin treatment reduced yeast counts, especially in the kidney, with activity comparable to that of amphotericin B. The peak level of cilofungin in serum was measured at 5 min after administration of a single dose, with no drug detectable after 90 min.

Periplasmic copper-zinc superoxide dismutase protects Haemophilus ducreyi from exogenous superoxide.

Haemophilus ducreyi causes chancroid, a sexually transmitted genital ulcer disease implicated in increased heterosexual transmission of HIV. As part of an effort to identify H. ducreyi gene products involved in virulence and pathogenesis, we created random TnphoA insertion mutations in an H. ducreyi 35000 library cloned in Escherichia coli. Inserts encoding exported or secreted PhoA fusion proteins were characterized by DNA sequencing. One such clone encoded a Cu-Zn superoxide dismutase (SOD) enzyme. The Cu-Zn SOD was periplasmic in H. ducreyi and accounted for most of the detectable SOD activity in whole-cell lysates of H. ducreyi grown in vitro. To investigate the function of the Cu-Zn SOD, we created a Cu-Zn SOD-deficient H. ducreyi strain by inserting a cat cassette into the sodC gene. The wild-type and Cu-Zn SOD null mutant strains were equally resistant to excess cytoplasmic superoxide induced by paraquat, demonstrating that the Cu-Zn SOD did not function in the detoxification of cytoplasmic superoxide. However, the Cu-Zn SOD null strain was significantly more susceptible to killing by extracellular superoxide than the wild type. This result suggests that the H. ducreyi Cu-Zn SOD may play a role in bacterial defence against oxidative killing by host immune cells during infection.

Complementation of an Escherichia coli proC mutation by a gene cloned from Treponema pallidum.

Little is known concerning the biosynthetic and metabolic capabilities of the syphilis agent, Treponema pallidum, because of the inability to cultivate continuously the organism in vitro. To circumvent the problem of cultivation, researchers have used recombinant DNA technology to express treponemal protein antigens in Escherichia coli. However, with a few notable exceptions, the specific cellular roles of these cloned treponemal proteins have not been determined. In this study, a cosmid library of T. pallidum genomic DNA was constructed and amplified by repackaging infective lambda bacteriophage particles in vivo. Recombinant clones capable of complementing a null mutation in the E. coli proC gene encoding 1-pyrroline-5-carboxylate (P5C) reductase (EC 1.5.1.2) were subsequently identified. The complementing activity was eventually localized to a 2.3-kilobase BglII-HindIII fragment that hybridized to the same-size fragment of a BglII-HindIII digest of T. pallidum DNA. Two proteins of 41 and 27 kilodaltons (kDa) were encoded by this fragment, as determined by maxicell analysis. Although only the 41-kDa protein could be specifically precipitated by experimental syphilitic rabbit antisera, it was the 27-kDa protein that was responsible for the proC-complementing activity. The recombinant P5C reductase differed from the native E. coli enzyme by a number of biochemical properties. The cloning of a T. pallidum gene encoding P5C reductase strongly suggests that this pathogen has the ability to synthesize proline and possibly other amino acids.

Opsonic activity of cerebrospinal fluid in experimental cryptococcal meningitis.

The role of antibody in protection against infection with Cryptococcus neoformans is undefined. In this paper we describe the development of opsonic activity in the cerebrospinal fluid (CSF) of rabbits in response to cryptococcal meningitis. The opsonin appeared to be immunoglobulin G (IgG); the activity was heat stable, copurified with the IgG fraction during protein A separation, and could be absorbed by encapsulated cryptococci. Immunosuppression with cyclosporine could be administered to prevent or allow in vivo deposition of IgG on the polysaccharide capsule of yeast in the CSF. Both early and late cyclosporine regimens resulted in prolonged, severe meningeal infections corresponding to the complete absence of in vitro opsonic activity in the CSF. While the production of opsonic antibody is part of the successful host response against C. neoformans in the central nervous system of rabbits, the presence of specific immunoglobulin by itself is insufficient for complete protection.

Treatment of experimental cryptococcal meningitis and disseminated candidiasis with SCH39304.

We studied the pharmacokinetics and in vivo antifungal action of SCH39304, a new antifungal azole compound, in rabbits. It crossed the blood-cerebrospinal fluid barrier in the presence or absence of meningeal inflammation, reaching approximately 60% of the simultaneous concentrations in serum. In the treatment of experimental cryptococcal meningitis, SCH39304 was as effective as fluconazole in reducing yeast counts in the subarachnoid space. SCH39304 and fluconazole both were highly effective against candida endophthalmitis, sterilizing the vitreous humor and the choroid and retina. SCH39304 suppressed candida endocarditis and reduced yeast counts in the kidney at all doses tested. SCH39304 was effective in the treatment of experimental cryptococcal meningitis and disseminated candidiasis. Further investigations in humans are warranted.

Trichomoniasis: clinical manifestations, diagnosis and management.

Trichomonas vaginalis was originally considered a commensal organism until the 1950s when the understanding of its role as a sexually transmitted infection (STI) began to evolve. Trichomoniasis has been associated with vaginitis, cervicitis, urethritis, pelvic inflammatory disease (PID), and adverse birth outcomes. Infection with T vaginalis could have an important role in transmission and acquisition of HIV. T vaginalis is site specific for the genitourinary tract and has been isolated from virtually all genitourinary structures. Asymptomatic disease is common in both men and women, thus screening for disease is important. Various sociodemographic factors have been correlated with presence of T vaginalis, and may be used to predict infection. Diagnosis is usually made from wet mount microscopy and direct visualisation, which are insensitive. DNA amplification techniques perform with good sensitivity, but are not yet approved for diagnostic purposes. In areas where diagnostic methods are limited, management of trichomoniasis is usually as part of a clinical syndrome; vaginal discharge for women and urethral discharge for men. A single dose of metronidazole is effective in the majority of cases. Outside of the United States, other nitroimidazoles may be used and are as effective as metronidazole. Metronidazole resistance is an emerging problem, but its clinical importance is not yet clear. Concomitant treatment of sexual partners is recommended.

Haemophilus ducreyi infection causes basal keratinocyte cytotoxicity and elicits a unique cytokine induction pattern in an In vitro human skin model.

Haemophilus ducreyi is the etiologic agent of the sexually transmitted genital ulcer disease chancroid. Predominantly a cutaneous pathogen, H. ducreyi is present in chancroid ulcers that are characterized by extensive neutrophil accumulation in intraepidermal lesions accompanied by a mononuclear infiltrate in the dermis. We used an in vitro human skin model composed of foreskin fibroblasts and keratinocytes to examine host skin cell interactions with H. ducreyi 35000. Bacteria replicated and persisted in artificial skin for at least 14 days. We observed H. ducreyi inside suprabasal keratinocytes using transmission electron microscopy. Although no bacteria were seen in the basal keratinocyte region, these cells were disrupted in infected cocultures. H. ducreyi infection stimulated increased secretion of interleukin-6 (IL-6) and IL-8 by skin cells. Conversely, tumor necrosis factor alpha and IL-1alpha levels were not elevated. IL-8 produced in response to H. ducreyi infection may be involved in recruiting polymorphonuclear leukocytes and other inflammatory cells, thereby contributing to the tissue necrosis and ulcer formation characteristic of chancroid.

Selection for expression of the gonococcal hemoglobin receptor during menses.

All gonococci encode a hemoglobin (Hgb) receptor, but it is phase variable, and most laboratory and clinical isolates are in the Hgb receptor "off" phase. In the present study, we address the question of whether there is a selective advantage to expressing the Hgb receptor during early phases of the menstrual cycle, when Hgb is readily available from menstrual blood. Inclinical isolates collected from women, Hgb use in vitro (Hgb receptor "on" phase) was associated with a shorter time since the onset of the last menstrual cycle, (P=.031, Wilcoxon rank-sum test). Thus, there may be a selective advantage to expression of the gonococcal Hgb receptor during infection of women in the early phases of their menstrual cycles.