Cruising on the Internet highway

This study evaluated differences in sexual behavior and risk for sexually transmitted diseases (STDs) among men who have sex with men (MSM) who met their partners on-line and those who did not. A self-administered questionnaire on sexual behavior was offered to a convenience sample of patients seeking public STD services. Thirty-two percent of MSM patients reported meeting a sexual partner over the Internet in the past year. MSM with on-line partners were younger, more likely to report sex with an HIV-positive person in the last year, and more likely to report casual partners in the last year compared with MSM with only off-line partners. HIV-negative MSM with on-line partners were more likely than HIV-negative MSM with only off-line partners to have received money or drugs for sex in the past year and to report sex with an HIV-positive partner in the past year. Although meeting partners on the Internet was common and associated with increased risk for STDs in MSM, it also presents new untapped opportunities for on-line health promotion and disease prevention.     

The recording of odorant-induced mucosal activity patterns with a voltage-sensitive dye.

1. Fluorescence changes in the dye (WW 781) were monitored at 100 contiguous sites in a 10 x 10-pixel array on the bullfrog and salamander olfactory mucosas every 10 ms in response to odorous stimuli. The odorants were d-limonene, butanol, and amyl acetate, each presented at two concentrations with a 3:1 ratio. 2. The fluorescence signals elicited by these odorous stimuli were nearly identical in shape and time course to the electro-olfactograms (EOGs) recorded from the same animal under identical conditions. Like the EOGs, the fluorescence signals exhibited adaptation and were abolished by both Triton X-100 and ether. There was no measurable fluorescence when the tissue was not stained with the dye, and there was no change in fluorescence when, for stained tissue, nonodorized, humidified air was presented as the stimulus. 3. This technique presumably monitors the same events as the EOG, but has the advantage of simultaneously recording the odorant-induced activity from multiple sites across most of the mucosa. Thus this technique preserves subtle differences heretofore lost by other techniques both in the coarseness of their matrices and in the variability generated by trying to piece together, into one collage, results from numerous presentations given at different times. 4. In all preparations, there was a larger difference in the inherent activity patterns (derived from response magnitudes) between different odorants than between different concentrations of the same odorant. These differences were largest on the mucosa lining the floor of salamander's olfactory sac. d-limonene and butanol gave their largest responses near the internal and external nares, respectively, whereas the responses for amyl acetate were more uniform across the mucosal sheet. In contrast to the salamander, smaller differences were observed for both the roof and the floor of the bullfrog's olfactory sac. For the floor, both amyl acetate and d-limonene elicited similar patterns of response magnitude, whereas butanol differed from each of these odorants by eliciting a larger response on the anteriolateral aspect of the mucosa and a lesser response on the remainder. For the roof, different odorants produced different activity patterns, which had profiles not simply described as regions of maximal and minimal responsiveness. 5. Different inherent activity patterns based on temporal characteristics of the fluorescence responses were also observed for different odorants. Each odorant produced a different pixel-by-pixel pattern for the times at which the responses started and ended. For any given odorant, these temporal patterns paralleled the patterns given by response magnitudes.(ABSTRACT TRUNCATED AT 400 WORDS)     

Immunological Relationship between the Class I Epitope of Streptococcal M Protein and Myosin

The class I epitope of streptococcal M protein is an epidemiological marker for acute rheumatic fever (ARF)-associated serotypes of group A streptococci and is recognized by anti-M protein monoclonal antibody (MAb) 10B6. Using MAb 10B6, we determined the relationship between the class I epitope of M protein and the α-helical coiled-coil protein myosin. MAb 10B6 reacted by enzyme-linked immunosorbent assay and Western blotting with human cardiac myosin and rabbit skeletal myosin and its heavy meromyosin (HMM) subfragment. Overlapping synthetic peptides of M5 protein were used to identify the region of M5 protein recognized by MAb 10B6. Two C repeat peptides (C2A and C3) containing the amino acid sequence KGLRRDLDASREAK reacted with MAb 10B6. Partial sequence identity, RRDL, was found in the HMM fragment of myosin, which reacted with MAb 10B6. However, not all peptides of M5 protein and myosin containing the RRDL sequence reacted with MAb 10B6. ARF sera and sera from uncomplicated pharyngitis (UNC) reacted with C repeat region peptides of M protein, while acute glomerulonephritis sera were not as reactive. Affinity-purified human antibody to peptide C3 reacted with myosin. The data demonstrate that the class I epitope of M protein is immunologically cross-reactive with myosin and the HMM subfragment, and antibodies to peptide C3 and myosin were present in ARF and UNC sera.Acute rheumatic fever (ARF) is an inflammatory disease that can follow group A streptococcal pharyngitis. The most serious clinical manifestation is rheumatic carditis; however, arthritis, chorea, erythema marginatum, or subcutaneous nodules may be present (40, 41). The pathogenesis of ARF is thought to be mediated by autoimmune mechanisms activated during a streptococcal infection (40). The autoimmune hypothesis is supported by a number of previous observations, including a time interval of at least 3 weeks between the initial streptococcal throat infection and the onset of ARF (40, 41), the identification of heart-reactive immunoglobulin (Ig) and complement deposits in the myocardium of patients with fatal rheumatic carditis (25–27, 30), and the elevation of heart-reactive antibodies in the sera of patients with ARF (46). Cardiac myosin has been identified as one of the cardiac antigens recognized by these heart-reactive antistreptococcal autoantibodies (13, 29).Streptococcal M protein, an α-helical coiled-coil protein, structurally and immunologically mimics host tissue antigens, particularly the rod region of myosin (12, 14, 15, 17, 34, 35). Sequence analysis has revealed that streptococcal M proteins contain blocks of internally repeated amino acid sequences referred to as A, B, and C repeat regions (19). The NH2-terminal nonrepeat and A repeat regions contain determinants of type specificity, while epitopes found in the B and more highly conserved C repeat regions may be common to different M serotypes (19). While there are nearly 100 different serological types of group A streptococcal M protein, epidemiological studies indicate that only a limited number of M protein serotypes are associated with ARF outbreaks (6). This finding suggests that certain M protein serotypes may be more rheumatogenic than others. In a previous attempt to classify streptococcal serotypes according to their rheumatogenic capacity, Widdowson identified human antisera directed to a non-type-specific protein moiety of M protein known as M-associated protein (44, 45). However, a more recent classification scheme has been proposed by Bessen and colleagues, in which streptococcal serotypes were grouped based on the expression of a conserved surface-exposed M protein epitope (4). It was demonstrated that the M serotypes associated with the majority of ARF outbreaks possessed an epitope (class I) defined by monoclonal antibody (MAb) probes 10B6 and 10F5. The sequence of the 10B6 and 10F5 epitope was localized to a 15-amino-acid fragment within the C repeat region of the type 6 M protein (23). The remaining serotypes (class II) lack this epitope or the determinant is structurally inaccessible in those strains. There was a close parallel between serotypes designated class I and those serotypes previously classified as M-associated protein I by Widdowson (44, 45). The fact that only certain serotypes within class I streptococci are rheumatogenic implies that these organisms are of a phenotype that is capable of inducing ARF (4). This implication is supported in part by a recent publication in which it was shown that sera of ARF patients contained high levels of antibodies to the class I epitope, suggesting that their disease was the result of an infection by a class I streptococcus (5).Elevated titers of antibodies to many streptococcal antigens (2), including M protein and the self-antigen myosin (12–15, 17, 29), are associated with ARF. While antibodies to M protein are crucial for the opsonization of streptococci, they have also been implicated in the immunological cross-reactions between streptococci and host tissue antigens such as cardiac myosin (12–15, 17, 29). In earlier studies, many of these cross-reactive epitopes have been localized to the N-terminal, hypervariable A and B repeat regions of the M molecule (12, 15, 17). Myosin-reactive antibodies, found to be elevated in almost all cases of ARF (13), have been shown to bind to human heart tissue and to cross-react with streptococcal M protein (12). Previous studies have demonstrated that immunization of animals with the cell walls of certain strains of group A streptococci resulted in the production of heart-reactive antibodies which could be adsorbed with streptococcal extracts containing streptococcal M protein (16, 24, 28). Human MAbs or myosin affinity-purified antibodies produced from patients with ARF cross-reacted with streptococcal M protein and human cardiac myosin and contributed to the presence of heart-cross-reactive antistreptococcal antibodies in ARF (12, 13, 39). More recent studies have identified cytotoxic antistreptococcal/antimyosin MAbs from rheumatic carditis patients (1). Antimyosin antibody has been shown to deposit in the heart tissues of susceptible mice (31), and a cytotoxic mouse antistreptococcal/antimyosin antibody which binds to the surface of heart cells and to the α-helical coiled coil molecule laminin has been described (10).Identification of myosin cross-reactive epitopes of M protein recognized in ARF has been reported for the amino-terminal half of the molecule (12, 15, 17), and a study by Vashishtha and Fischetti demonstrated antimyosin antibody responses to the C repeat region. However, the reactivity was directed only to denatured myosin (43). More recently, studies of the C repeat or carboxy-terminal region of M protein have shown T-cell cross-reactions with myosin (38). The goal of the present study was to investigate the possibility that the class I epitope in the C repeat region of M protein cross-reacts immunologically with myosin. In this study we show that MAb 10B6, which recognizes the class I epitope of M protein, reacts with cardiac and skeletal myosin. This study also demonstrates that ARF and UNC sera react with a site in the conserved C repeat region of M protein within the class I epitope of rheumatogenic M protein serotypes. The new data show that in addition to previously described N-terminal epitopes, the class I epitope of streptococcal M protein is immunologically cross-reactive with myosin.(Portions of this work were presented at the XIII International Lancefield Society Meeting on Streptococci and Streptococcal Diseases at the Pasteur Institute in Paris, France, in September 1996.)     

Prostate specific antigen and acid phosphatase-reactive cells in cystitis cystica and glandularis

Cystitis cystica (CC) and cystitis glandularis (CG) are common in the urothelium lining the bladder neck and trigone. Because some cases of CG show histologic features strikingly similar to prostatic acini, we hypothesized that some such foci may represent prostatelike metaplasia in the urinary bladder. Forty surgical and autopsy bladder specimens (23 males, 17 females) showing CC or CG were studied using anti-prostate specific antigen and anti-prostate specific acid phosphatase antibodies. Fourteen (35%) of these 40 cases showed positive staining for prostate specific antigen or prostate specific acid phosphatase or both in CC or CG foci. Among these were five female patients. The findings indicate that bladder epithelium is capable of undergoing prostatelike metaplasia and lend support to the hypothesis that the adult bladder stroma closest to the prostate may exert inductive influences on the overlying epithelium to show prostatelike metaplasia.     

The human genome browser at UCSC

As vertebrate genome sequences near completion and research refocuses to their analysis, the issue of effective genome annotation display becomes critical. A mature web tool for rapid and reliable display of any requested portion of the genome at any scale, together with several dozen aligned annotation tracks, is provided at http://genome.ucsc.edu. This browser displays assembly contigs and gaps, mRNA and expressed sequence tag alignments, multiple gene predictions, cross-species homologies, single nucleotide polymorphisms, sequence-tagged sites, radiation hybrid data, transposon repeats, and more as a stack of coregistered tracks. Text and sequence-based searches provide quick and precise access to any region of specific interest. Secondary links from individual features lead to sequence details and supplementary off-site databases. One-half of the annotation tracks are computed at the University of California, Santa Cruz from publicly available sequence data; collaborators worldwide provide the rest. Users can stably add their own custom tracks to the browser for educational or research purposes. The conceptual and technical framework of the browser, its underlying MYSQL database, and overall use are described. The web site currently serves over 50,000 pages per day to over 3000 different users.     

Comparative study of marginal zone lymphoma involving bone marrow

Few studies have characterized or compared the pathologic features of bone marrow involvement by extranodal (EMZL), splenic (SMZL), and nodal marginal zone lymphoma (NMZL). We evaluated 45 bone marrow biopsy specimens from 39 patients with marginal zone lymphomas. As previously reported, bone marrow involvement was frequent (100%) in patients with SMZL. We also identified lymphoma involving bone marrow in 11 (44%) of 25 patients with EMZL and 1 of 2 patients with NMZL. The patterns of infiltration were mixed in all groups; however, the extent of involvement was greater in SMZL than in EMZL. In addition, germinal centers were present in bone marrow biopsy specimens involved by lymphoma in 4 patients with SMZL. Intrasinusoidal infiltration was common (10/12 [83%]) and prominent in patients with bone marrow involvement by SMZL, but was not invariably present. Intrasinusoidal infiltration of the bone marrow also was not specific for SMZL since similar infiltrates, although subtle, also were found in patients with other small B-cell lymphoproliferative disorders, including 6 (55%) of 11 patients whose bone marrow samples were infiltrated by EMZL.     

Galaxy: a platform for interactive large-scale genome analysis

Accessing and analyzing the exponentially expanding genomic sequence and functional data pose a challenge for biomedical researchers. Here we describe an interactive system, Galaxy, that combines the power of existing genome annotation databases with a simple Web portal to enable users to search remote resources, combine data from independent queries, and visualize the results. The heart of Galaxy is a flexible history system that stores the queries from each user; performs operations such as intersections, unions, and subtractions; and links to other computational tools. Galaxy can be accessed at http://g2.bx.psu.edu.     

Disease prevention and health promotion in medical education: reflections from an academic health center.

PURPOSE: It is unclear whether academic health centers are successfully addressing societal needs and expectations by preparing students with knowledge and skills in disease prevention and health promotion. The authors assessed whether students were exposed to key content in these areas and whether they felt this exposure was adequate. METHOD: All components of the first three years of the Case Western Reserve University (Case) curriculum were examined in 2001 to create a curricular map, using competencies in disease prevention and health promotion identified by the Association of Teachers of Preventive Medicine (ATPM) as a template to assess the scope of instruction. Case students' United States Medical Licensing Examination (USMLE) Step 2 subscores in preventive medicine and health maintenance from 1994 to 2000 and graduating seniors' assessment of the adequacy of their training were compared to national data from the Association of American Medical Colleges' 2000 Graduation Questionnaire (GQ). RESULTS: Most content areas identified by ATPM were present in the Case curriculum and were offered frequently in a variety of educational venues over the first three years. USMLE scores increased nationally and at Case from 1994 to 2000 and Case students' perception of training adequacy in preventive medicine and health promotion was comparable to national ratings from the 2000 GQ. CONCLUSIONS: Broad and frequent exposure to disease prevention and health promotion core competencies has value, but may not sufficiently prepare students to deliver health-promoting services confidently. Creative curricula highlighting prevention's relevance throughout clinical practice and incorporating formal opportunities to apply knowledge and build experience may result in greater success.