Analysis of multiple restriction fragment length polymorphisms of the gene for the human complement receptor type I. Duplication of genomic sequences occurs in association with a high molecular mass receptor allotype.

Human CR1 exhibits an unusual form of polymorphism in which allotypic variants differ in the molecular weight of their respective polypeptide chains. To address mechanisms involved in the generation of the CR1 allotypes, DNA from individuals having the F allotype (250,000 Mr), the S allotype (290,000 Mr), and the F' allotype (210,000 Mr) was digested by restriction enzymes, and Southern blots were hybridized with CR1 cDNA and genomic probes. With the use of Bam HI and Sac I, an additional restriction fragment was observed in 20 of 21 individuals having the S allotype with no associated loss of other restriction fragments. Southern blot analysis with a noncoding genomic probe derived from the S allotype-specific Bam HI fragment showed hybridization to this fragment and to two other fragments that were also present in FF individuals. Thus, an intervening sequence may be repeated twice in the F allele and three times in the S allele. A restriction fragment length polymorphism (RFLP) unique to two individuals expressing the F' allotype was seen with Eco RV, but the absence of persons homozygous for this rare allotype prevented further comparisons with the F and S allotypes. Analysis of the CR1 transcripts associated with the three CR1 allotypes indicated that these differed by 1.3-1.5 kb and had the same rank order as the corresponding allotypes. Taken together, these findings suggest that the S allele was generated from the F allele by the acquisition of additional sequences, the coding portion of which may correspond to a long homologous repeat of approximately 1.4 kb that has been identified in CR1 cDNA. We saw two other RFLPs with Hind III and Pvu II that were in linkage dysequilibrium with the Bam HI-Sac I RFLPs associated with the S allotype, and a third polymorphism was seen with Eco RI that was not in linkage dysequilibrium with the other polymorphisms. Thus, 10 commonly occurring CR1 alleles can be defined, making this locus a useful marker for the long arm of chromosome 1 to which the CR1 gene maps.

Structure of the human CR1 gene. Molecular basis of the structural and quantitative polymorphisms and identification of a new CR1-like allele.

Structural and quantitative polymorphisms have been described in human CR1. In the former, the S allotype is larger than the F allotype by 40-50 kD, the size of a long homologous repeat (LHR). In the latter, homozygotes for a 7.4-kb Hind III fragment express fourfold more CR1 per erythrocyte than do homozygotes for the allelic 6.9-kb restriction fragment. The basis for these genomic polymorphisms has been determined by restriction mapping the entire S allele and part of the F allele. The S allele is 158 kb and contains 5 LHRs of 20-30 kb, designated -A, -B/A, -B, -C, and -D, respectively, 5' to 3'. Extensive homology was found among the LHRs in their restriction maps, exon organization, and the coding and noncoding sequences. The presence of LHR-B/A in the S allele but not in the F allele accounts for the longer transcripts and polypeptide associated with the former allotype. At least 42 exons are present in the S allele, with distinct exons for the leader sequence, the transmembrane and cytoplasmic regions and most of the SCRs comprising the extracellular portion of CR1. Consistent with the mapping of the ligand binding site to the first two SCRs in each LHR, the second SCRs in LHR-A, -B/A, -B, and -C are encoded by two exons, reflecting a specialized function for this unit. The allelic 7.4/6.9-kb Hind III fragments extend from the 3' region of LHR-C to LHR-D. The 6.9-kb restriction fragment is the result of a new Hind III site generated by a single base change in the intron between the exons encoding the second SCR of LHR-D. A second cluster of genomic clones has been identified by hybridization to CR1 probes. Although they contain regions of hybridization to the cDNA and genomic probes derived from CR1, these cannot be overlapped with the structural gene owing to their distinct restriction maps. Three genomic polymorphisms previously identified by CR1 cDNA probes map to this region. These additional clones may represent part of a duplicated allele located nearby within the CR1 locus.

Molecular characterization of Irish E. coli O157:H7 isolates of human, bovine, ovine and porcine origin.

AIMS: To determine the degree of relatedness between isolates of Escherichia coli O157:H7 of human, bovine, ovine and porcine origin. METHODS AND RESULTS: Escherichia coli O157:H7 isolates were compared using (i) PFGE XbaI patterns, (ii) PCR profiles of virulence genes and (iii) the DNA sequences of genes reported to play a role in pathogenicity. The 77 E. coli O157:H7 isolates demonstrated 49 different PFGE patterns of which, eight were common to multiple isolates, and the remaining 41 were distinct. Isolates of different origin did not correlate, except for one cluster consisting of two human and two beef isolates. The majority of animal isolates had the same PCR profiles of virulence genes as those isolated from clinical patients. Single nucleotide polymorphisms (SNPs) were identified in the sequence of a 255-bp region of the vtx2 subunit A gene. CONCLUSIONS: Six SNPs were detected in the vtx2A gene, defining four different haplotypes. One nonsynonymous substitution encoded for an amino acid change from glutamic to aspartic acid. SIGNIFICANCE AND IMPACT OF THE STUDY: Results indicate that although E. coli O157:H7 isolates of differing origin were distinct by PFGE, the DNA sequences of the main virulence genes associated with human clinical illness were conserved.

Multi-drug resistant Escherichia coli in diarrhoeagenic foals: Pulsotyping, phylotyping, serotyping, antibiotic resistance and virulence profiling.

Extraintestinal pathogenic E. coli (ExPEC) possess the ability to cause extraintestinal infections such as urinary tract infections, neonatal meningitis and sepsis. While information is readily available describing pathogenic E. coli populations in food-producing animals, studies in companion/sports animals such as horses are limited. In addition, many antimicrobial agents used in the treatment of equine infections are also utilised in human medicine, potentially contributing to the spread of antibiotic resistance determinants among pathogenic strains. The aim of this study was to phenotypically and genotypically characterise the multidrug resistance and virulence associated with 83 equine E. coli isolates recovered from foals with diarrhoeal disease. Serotyping was performed by both PCR and sequencing. Antibiotic resistance was assessed by disc diffusion. Phylogenetic groups, virulence genes, antibiotic resistance genes and integrons were determined by PCR. Thirty-nine (46%) of the isolates were classified as ExPEC and hence considered to be potentially pathogenic to humans and animals. Identified serogroups O1, O19a, O40, O101 and O153 are among previously reported human clinical ExPEC isolates. Over a quarter of the E. coli were assigned to pathogenic phylogroups B2 (6%) and D (23%). Class 1 and class 2 integrons were detected in 85% of E. coli, revealing their potential to transfer MDR to other pathogenic and non-pathogenic bacteria. With 65% of potentially pathogenic isolates harbouring one or more TEM, SHV and CTX-M-2 group ß-lactamases, in addition to the high levels of resistance to fluoroquinolones observed, our findings signal the need for increased attention to companion/sport animal reservoirs as public health threats.

Binding of the T cell activation monoclonal antibody Ta1 to dipeptidyl peptidase IV.

The monoclonal antibodies, Ta1 and IOT15, define T cell activation cell surface markers and have been assigned to the CD26 leukocyte differentiation antigen cluster. Dipeptidyl peptidase IV (DPP IV, EC 3.4.14.5) is an exoaminopeptidase that, among leukocytes, is expressed almost exclusively on activated T cells. Comparative binding studies showed that the Ta1 mAb binds to DPP IV purified from human placenta as well as in extracts of the human YT lymphoid cell line and of CD3 stimulated normal human peripheral blood mononuclear cells. The mAb IOT15 did not bind to DPP IV from any source even upon repeated incubations. Western blot analysis of YT cell extracts revealed that Ta1 and IOT15 bound to distinctly different molecular weight molecules. Immunofluorescent cell surface capping experiments showed that capping of the IOT15 did not alter the surface distribution of the Ta1 fluorescence. The capping results combined with the DPP IV binding results indicate that IOT15 and Ta1 mAb's bind to different, apparently unassociated, molecules on the surface of T cells and that only Ta1 binds the T cell surface enzyme DPP IV.

Atypical roentgenographic manifestations of Pneumocystis carinii pneumonia.

Although Pneumocystis carinii pneumonia (PCP) usually presents with bilateral interstitial pulmonary infiltrates, many other roentgenographic presentations occur in human immunodeficiency virus-infected patients. To clarify the determinants of atypical presentations of PCP, we evaluated 65 English-language reports that related the roentgenographic manifestations of consecutive cases of PCP. The incidence of PCP-associated upper lobe disease, cysts, and spontaneous pneumothoraxes was increased in human immunodeficiency virus-infected patients receiving aerosolized pentamidine prophylaxis. Normal chest roentgenograms were more common and nodular lesions were less common in human immunodeficiency virus-infected patients than in uninfected patients. However, the roentgenographic manifestations of PCP could not be specifically predicted by a patient's underlying disease. Neither zidovudine therapy nor intravenous drug use apparently affected the roentgenographic presentation of PCP. Unusual pathologic responses to PCP, including granuloma formation, vascular invasion, and microscopic foci of calcification, were present in all patient groups.

Family support for heterosexual partners in HIV-serodiscordant couples.

OBJECTIVE: To ascertain the extent of family member support to heterosexual HIV-serodiscordant couples, and to identify associated sociodemographic and clinical characteristics. DESIGN: Discordant couples enrolled in a cohort study of heterosexual HIV transmission were interviewed with structured questionnaires to obtain sociodemographic data, family member awareness of HIV and perceived support from family members. Clinical characteristics were established by medical history, physical examination and laboratory tests. RESULTS: Awareness and support of family members were associated with sex of family member and HIV seropositivity, sex, education, and race of the partner. HIV-seropositive partners were more likely to have a sister aware than were HIV-negative partners (P = 0.01). More educated HIV-positive partners had fewer aware family members than less educated HIV-positive individuals (P = 0.02). Mothers of HIV-positive women were more often aware than mothers of all other partners (P = 0.04). Black HIV-negative partners had fewer aware family members than whites or Hispanics (P = 0.02). CONCLUSION: This research shows both encouraging and disturbing patterns of family awareness of HIV and support to serodiscordant partners.

Psychological distress, drug and alcohol use as correlates of condom use in HIV-serodiscordant heterosexual couples.

OBJECTIVE: To investigate the relationship between psychological distress, alcohol, drug and condom use in HIV-serodiscordant heterosexual couples. METHODS: Structured interviews were conducted to collect demographic information, detailed data on psychological distress, drug and alcohol use and sexual behavior. RESULTS: Analyses were based on 106 pairs of sexually active discordant couples. Significant differences among heterosexual condom users and non-users varied according to gender and HIV serostatus. Affect domains of interpersonal sensitivity and hostility were significant, as were the variables of regular drug or alcohol use and combining sex with drugs or alcohol. Employment was strongly associated with condom use in HIV-negative women whose regular sexual partners were HIV-positive men. CONCLUSION: The risk of vaginal sex without condoms in HIV-serodiscordant heterosexual couples may be reduced by specific psychological counseling and attention to drug and alcohol use as risk factors. Further research on the effect of employment of HIV-negative women is required.

PIP: The authors investigated the relationship of psychological distress and drug and alcohol use to reported condom use in 106 sexually active HIV-serodiscordant heterosexual couples. Significant differences were found among heterosexual condom users and non-users which varied according to gender and HIV serostatus. Affect domains of interpersonal sensitivity and hostility were significant, as were the variables of regular drug or alcohol use and combining sex with drugs or alcohol. Further, employment was strongly associated with condom use HIV-negative women whose regular sex partners were HIV-positive men. The authors therefore conclude that the risk of vaginal sex without condoms in HIV-serodiscordant heterosexual couples may be reduced by specific psychological counseling and attention to drug and alcohol use as risk factors. Further research is, however, called for on the effect of employment on HIV-negative women.

Rapid purification of the human C3b/C4b receptor (CR1) by monoclonal antibody affinity chromatography.

The human C3b/C4b receptor (CR1) is a polymorphic glycoprotein that is expressed on erythrocytes, leukocytes and glomerular podocytes. Further structural analysis and molecular genetic studies would be facilitated by the availability of relatively larger amounts of purified CR1. Milligram quantities of CR1 were purified from erythrocyte membranes 10,000-fold with an average yield of 30-40% by a rapid procedure which utilized sequential chromatography on Matrex Red A and a monoclonal anti-CR1 antibody affinity column. The purified receptor was homogeneous by SDS-PAGE and consisted of the 2 most common alleles of CR1. Purified CR1 also retained its function of serving as a cofactor for the cleavage of C3b to iC3b, C3dg and C3c. The amino acid composition was typical of that of a globular protein and sequence analysis of the N-terminus of the purified CR1 revealed that it was blocked.

Staphylococcal pyomyositis in patients infected by the human immunodeficiency virus.

PURPOSE: We describe the manifestations of spontaneous staphylococcal pyomyositis in patients infected by the human immunodeficiency virus (HIV). PATIENTS AND METHODS: We present the courses of five previously unreported patients infected by HIV who presented to our medical centers with spontaneous staphylococcal pyomyositis. Additionally, we review all previously reported cases of this entity in HIV-infected patients and discuss its possible pathogenesis and importance in the context of HIV infection. RESULTS: All patients presented with gradually developing fever and localized pain and swelling without accompanying leukocytosis. Often only scant evidence of local inflammation was found. None of our patients used intravenous drugs, had a history of trauma, had HIV- or zidovudine-related myositis, or had other conditions known to be associated with serious staphylococcal infections. Two patients studied had normal serum levels of all IgG subclasses. Elevated serum IgE, eosinophilic inflammatory infiltrates, or marked peripheral eosinophilia was observed in two patients. CONCLUSIONS: Staphylococcal pyomyositis in HIV-infected patients presents in an indolent fashion, which may delay appropriate diagnosis and treatment. Since staphylococcal pyomyositis is infrequently reported in the United States, the development of 14 such cases (five in this series and nine previously reported) among the first 140,000 cases of acquired immunodeficiency syndrome in this country implies that this patient population is predisposed to this infectious complication. The pathogenesis of this entity is uncertain, but it is notable that HIV-infected patients are commonly colonized by Staphylococcus aureus and that neutrophils from HIV-infected patients frequently manifest phagocytic, chemotactic, and oxidative defects, diminished expression of Fc tau RIII (CD16) and CR1, and impaired bactericidal activity against S. aureus.

Structure-activity relationships of boronic acid inhibitors of dipeptidyl peptidase IV. 1. Variation of the P2 position of Xaa-boroPro dipeptides.

A series of prolineboronic acid (boroPro) containing dipeptides were synthesized and assayed for their ability to inhibit the serine protease dipeptidyl peptidase IV (DPPIV). Inhibitory activity, which requires the (R)-stereoisomer of boroPro in the P1 position, appears to tolerate a variety of L-amino acids in the P2 position. Substitution at the P2 position which is not tolerated include the D-amino acids, alpha,alpha-disubstituted amino acids, and glycine. Specificity against DPPII and proline specific endopeptidase is reported. A correlation between the ability to inhibit DPPIV in cell culture and in the human mixed lymphocyte reaction is demonstrated. A synthesis of prolineboronic acid is reported as well as conditions for generating the fully unprotected boronic acid dipeptides in either their cyclic or acyclic forms.

Effect of deoxycoformycin and Val-boroPro on the associated catalytic activities of lymphocyte CD26 and ecto-adenosine deaminase.

CD26 and ecto-adenosine deaminase (ADA) are found associated on the plasma membrane of T lymphocytes and each possess distinct catalytic activities. CD26 has a proteolytic activity identical to dipeptidylpeptidase IV (DPPIV; E.C. 3.4.14.5), and ecto-ADA (E.C. 3.5.4.4) degrades extracellular adenosine. The cell surface expression of CD26 and ecto-adenosine deaminase (ecto-ADA) is regulated on stimulated T lymphocytes, and ADA binding to CD26 produces a synergistic costimulatory response with T cell receptor activation. This study addresses the potential regulation by allosteric interactions of the catalytic activities of CD26 associated with ecto-ADA, which could define the mechanism of the synergism observed in T cell signaling. Cell lines genetically deficient in ADA, ligands for ADA such as adenosine, and a specific inhibitor of ADA, deoxycoformycin, were used to define the effect of ADA activity on CD26 DPPIV activity and affinity for dipeptide substrate. Conversely, a recombinant Chinese hamster ovary cell line expressing human CD26 with or without a mutation in the DPPIV catalytic domain, and the boronic acid inhibitor Val-boroPro, were used to determine the effect of DPPIV activity on ecto-ADA activity and association with CD26. These studies found no significant allosteric interaction between the catalytic activities of CD26 and ecto-ADA when associated. Therefore, signaling events in T cells involving costimulation with CD26 and ecto-ADA and the synergism observed upon ADA binding to CD26 occur independently of the catalytic activities of these cell surface molecules.

Medication costs associated with the care of HIV-infected patients.

The treatment costs for human immunodeficiency virus (HIV)-infected patients continue to rise as patients survive longer because of advances in antiretroviral therapy and effective chemoprophylaxis. Medication costs per patient increase in proportion to progressive immunodeficiency. We retrospectively studied medication costs for 196 HIV-infected patients with stratification by CD4-lymphocyte count. Medication costs per patient-month were correlated with CD4-lymphocyte count (linear regression, r = -.53, P < 0.01), with higher costs associated with lower CD4 counts. The medication cost for patients with CD4 counts < 100 cells/mm3 averaged $1043 per month. Medication costs per patient increase with the development of each new opportunistic infection or other AIDS-associated condition. Costs can be expected to increase as new therapeutic agents are introduced, as treatment is initiated at earlier stages of HIV infection, and as more patients survive to the point of severe CD4-lymphocyte depletion.

Environmental regulation of biofilm formation in intensive care unit isolates of Staphylococcus epidermidis.

Staphylococcus epidermidis is a common cause of prosthetic device-related infection in the intensive care unit (ICU). The environmentally regulated ica operon encodes a polysaccharide adhesin which is a key virulence determinant in the development of S. epidermidis biofilms. To evaluate the capacity of ICU S. epidermidis isolates to form biofilm, we measured biofilm production by 18 isolates associated with device-related infection and 20 contaminating isolates that were not associated with clinically diagnosed infection. Biofilm assays were performed in brain-heart infusion (BHI) medium and in BHI supplemented with salt, ethanol or subinhibitory tetracycline, all of which have the potential to promote biofilm formation. Polymerase chain reaction (PCR) was used to screen for the presence of the ica genes. A significant proportion of S. epidermidis strains associated with device-related infections (89%) were found to contain the ica locus compared with 50% of contaminating isolates (P = 0.01). However only four of 26 (15.3%) of all ica-positive isolates were biofilm-positive when grown in BHI medium, indicating that no significant association existed between the presence of the ica locus and biofilm-forming capacity, under standard growth conditions. In contrast the number of ica-positive isolates that were biofilm-positive under stress-inducing growth conditions or in the presence of subinhibitory tetracycline increased significantly to 73% (P = 0.02). These findings suggest that the presence of the ica locus alone is not sufficient for biofilm formation and that regulation of biofilm formation under altered growth conditions, which may exist in the in vivo environment, also plays a possible role in the pathogenesis of biomaterial-related S. epidermidis infections.

Maintenance of safe sex behavior by HIV-serodiscordant heterosexual couples.

We present findings from a prospective study of heterosexual HIV transmission in stable New Jersey couples who are serodiscordant for HIV and in which the uninfected partner is at risk solely from heterosexual contact. One hundred thirty-one couples were interviewed at enrollment and 6-month follow-up. This report describes couples' sexual behavior before and after knowledge of infective risk and examines associations of behavior with clinical and demographic characteristics. We observed that HIV serodiscordant couples' habitual sexual practices, drug and alcohol use, and measure of psychological distress may predict difficulty in adopting and maintaining safe sex. An understanding of common risk sexual behavior patterns and characteristic correlates of risk taking may prove useful for counseling individuals at risk and their infected partners and may contribute to the development of effective public health messages targeted to eliminate unsafe sexual contact.

PIP: Findings are presented from a prospective study of heterosexual HIV transmission in stable New Jersey couples serodiscordant for HIV infection and in which the uninfected partner is at risk solely from heterosexual contact. Between August 1990 and February 1992, 131 couples were interviewed at enrollment and 6-month follow-up, reporting their frequencies of vaginal, oral, and anal sex, with and without condoms, during the year before the negative partner learned of the positive partner's HIV infection, the month before baseline interview, and the interval between baseline and follow-up. A marked and significant decline was observed in couples' reported sexual activity and an increase in condom use after they first learned of their HIV serodiscordance. However, at the 6-month follow-up, the proportion who abstained from having sex declined from 33% to 21%, the proportion who practiced unsafe sex increased from 15% to 26%, and the proportion of couples who used condoms reliably was 53% at follow-up compared to 51% in the month before enrollment. Demographic characteristics, stage of disease in the HIV-infected partner, use of alcohol or drugs, and psychological state were correlates of unsafe sexual behavior after learning of HIV serodiscordance. The most important socioeconomic correlate of safe sex at baseline was employment of the female partner. People in stable partnerships may have greater difficulty changing well-established patterns of sexual behavior after one partner is found to be infected with HIV.

HIV heterosexual transmission: a hypothesis about an additional potential determinant.

Transmission rates of human immunodeficiency virus (HIV) during heterosexual intercourse vary dramatically around the world. In Asia and South America, they are extraordinarily high, whereas in the United States and Europe, rates are much lower even after a large number of unprotected contacts. The transmission rates in Africa also probably are high, but the available studies unfortunately are weak. In Thailand, female-to-male transmission rates per contact were estimated at.056 (l in 18) compared to.0002 to.0015 (1/5000-1. 5/1000) for male-to-female transmission in the United States and Europe. Male-to-female transmission in Thailand appears to show, as expected, even greater transmission likelihood compared to female-to-male rates. In general, in the United States and Europe, transmission rates within heterosexual couples range from less than 10% to 22%, whereas in Thailand and Brazil, the rates exceed 40%. The much lower transmission rate per contact in the United States and Europe is based on an assumption that HIV transmitters are a homogeneous group. Wiley and colleagues argue that transmitters are likely to be a heterogeneous group with a large percentage of very low frequency transmitters and a small percentage of high frequency transmitters. That hypothesis is given some support by a cluster of cases in rural New York State in which one man appeared to infect 31% of his many contacts.

CD3+CD8+ cell levels as predictors of transmission in human immunodeficiency virus-infected couples: a report from the heterosexual HIV transmission study.

OBJECTIVE: The goal of this study was to identify in human immunodeficiency virus (HIV)-infected individuals immunologic markers that correlated with transmission of HIV by heterosexual contact. METHODS: In a case-control comparison of couples, immunologic and viral parameters were evaluated in 343 HIV-positive individuals who were members of 67 HIV-seroconcordant couples (both partners HIV positive) and 211 HIV serodiscordant couples (one positive, one negative). RESULTS: The most striking immunologic finding was the increased numbers of CD3+CD8+ cells found in the index member of discordant couples as compared to the index member of the concordant couples. Differences in CD3+CD8+ levels persisted after adjustment for stage of disease and CD3+CD4+ count. This increase in the number of CD3+CD8+ cells was accompanied by a concomitant decrease in the amount of viral replication measured by both HIV culture endpoint and quantitative RNA polymerase chain reaction (PCR). CONCLUSION: Data presented here further support the role of CD3+CD8+ cells in suppressing or controlling viral activity, although a causal role based on case-control data must be advanced cautiously. This in vivo biologic function may help prevent or lower the risk of HIV transmission.

Herpes simplex type II and Mycoplasma genitalium as risk factors for heterosexual HIV transmission: report from the heterosexual HIV transmission study.

OBJECTIVES: Two hundred twenty-four human immunodeficiency virus (HIV) discordant couples (one HIV negative, one HIV positive) were compared with 78 seroconcordant heterosexually infected couples with HIV with regard to sexually transmitted diseases. METHODS: Serologic testing and cultures were used to determine exposure of participants to sexually transmitted pathogens. These data were compared with HIV concordance of partners to investigate possible risk factors for HIV transmission. RESULTS: Syphilis, chlamydia, and hepatitis B virus (HBV) serologies did not distinguish between concordant and discordant couples nor did cultures for Neisseria gonorrhoeae and Trichomonas or Chlamydia enzyme immunoassay (EIA). Risk of transmission increased with positive serologies for herpes simplex virus (HSV)-2 (P = 0.002), cytomegalovirus (CMV) (P = 0.04), and Mycoplasma genitalium (P = 0.01), but not with Mycoplasma fermentans or Mycoplasma penetrans. Cytomegalovirus was not a significant risk factor when controlled for HSV-2 status. Examination by partner status showed increased risk of concordance with: HSV-2 positive serology in both partners (odds ratio [OR] = 3.14; confidence interval [CI] = 1.62-6.09; P = 0.007); HSV-2 in female secondary partner (OR = 2.10; CI = 1.12-3.93; P = 0.02) or the male primary partner (OR = 2.15; CI = 1.15-4.02; P = 0.017); M. genitalium antibody in both partners (OR = 3.44; CI = 1.68-7.04; P < 0.001); M. genitalium antibody in the primary male partner (OR = 2.51, CI = 1. 27-4.91; P = 0.008) and M. genitalium antibody in the secondary female partner (OR = 2.52; CI = 1.21-5.23; P = 0.01). CONCLUSIONS: These data support the role of HSV-2 in transmission of HIV and, for the first time, suggest a role for M. genitalium as an independent risk factor.

Middle ear pathologic changes associated with chronic anaerobic sinusitis in rabbits.

OBJECTIVE/HYPOTHESIS: To study the histopathologic changes in association with the inflammatory/immune response present in the middle ears of a rabbit model of unilateral chronic anaerobic sinusitis. STUDY DESIGN: New Zealand white rabbits, two at each experimental time point. Normal rabbits and sham-operated animals served as controls. METHODS: Left maxillary sinusitis was induced by inoculating Bacteroides fragilis surgically after closure of the ostium. Cultures, lavages, and mucosa were harvested from bilateral middle ear and sinus cavities at 1, 2, 3, and 4 weeks following inoculation. Parameters analyzed include tissue for histopathologic study, immunoglobulin G antibody (IgG Ab) against B fragilis, and lactate dehydrogenase (LDH) levels in lavage samples, interferon gamma (IFN gamma) messenger RNA (mRNA) expression in mucosal tissue, and bacterial culture. RESULTS: Despite closure of the ostium of the left sinus, mild to moderate dissemination of B fragilis into the right sinus and left and right ears were observed in some but not all rabbits (2/8, 5/7, and 2/8, respectively). Histopathologic changes in the right sinus and middle ears were much less severe in contrast to the severe inflammatory changes in the left sinus. An immune response against B fragilis appeared to occur in the sinuses and ears bilaterally independent of bacterial dissemination, as evidenced by a rise of IgG Ab in lavage fluid and detection of IFNg mRNA. Neither control nor sham-operated animals had detectable levels of IFNg mRNA or IgG Ab. In B fragilis-inoculated rabbits, the magnitude of IgG Ab responses was equivalent in the right and left ear, independent of B fragilis dissemination; IgG Ab levels in the middle ear positively correlated to each other (P < .01) and to the levels in the sinuses (P < .01 and P < .01). LDH levels were closely associated with bacterial growth and degree of tissue inflammation. CONCLUSION: This reproducible model of chronic sinusitis provides an opportunity to study the middle ear infection and inflammatory/immune responses occurring with sinusitis. Our results indicate bilateral middle ear mucosal immune responses to an elicited sinus infection, independent of B fragilis dissemination.

Interferon gamma levels in the sinus, ear, and airway in a rabbit sinusitis model induced by Bacteroides inoculation.

BACKGROUND: Previously, we found minimal bacterial dissemination and no evidence of systemic inflammation in a rabbit sinusitis model in which the left maxillary sinus was inflamed by Bacteroides inoculation with the ostium closed. However, we observed an increase in anti-Bacteroides IgG antibodies in the contralateral sinus, lower airway, and middle ear, with an apparent increase in interferon gamma (IFN-gamma) messenger RNA expression in the ear and sinus mucosa. OBJECTIVE: To evaluate how IFN-gamma production in the upper and lower airway is associated with localized bacterial sinusitis. DESIGN: Interferon gamma levels were measured in lavage solutions from the sinus, airway, and middle ear and in serum at 1, 2, 3, and 4 weeks following bacterial inoculation. SUBJECTS: The subjects were 6 rabbits at each time point. The controls were untreated (n = 5) and sham-operated (n = 4-5) rabbits at 2 and 4 weeks. INTERVENTION: Bacteroides fragilis (10(8) plaque-forming units) was inoculated into the left maxillary sinus. RESULTS: Interferon gamma levels in the ear and sinus were less than 0.2 microg/g protein in controls. Following bacterial inoculation into the left sinus, IFN-gamma levels increased up to 10-fold in both sinuses and even more in the middle ear at 3 weeks, independent of bacterial dissemination. Mean +/- SD IFN-gamma levels in the airway (0.3+/-0.28 microg/g protein in controls) were not altered by bacterial inoculation into the sinus. Serum IFN-gamma levels were very low (<0.05 microg/g protein) in most rabbits and were unchanged by bacterial inoculation. CONCLUSIONS: Interferon gamma levels increase in the ear and contralateral sinus in response to localized sinus inflammation, indicating concerted mucosal proinflammatory immune responses in the upper airway. Such responses may lead to the aseptic middle ear inflammation often observed in patients with chronic sinusitis.