Homonegativity Scores in Response to Static Same-Sex Imagery versus Observable Behavioral Change in Response to an Interactive Gay Male Target.

Homonegativity research tends to focus on the identities of gay men and lesbian women through inauthentic means such as vignettes and signifiers like t-shirts with pro-gay slogans. Such research also tends to neglect sexual behavior. These issues were addressed in the present mixed-methods study. Heterosexual male (n = 196) and female (n = 219) participants were asked to complete measures of old-fashioned and modern homonegativity toward gay men and lesbian women after viewing a set of stimuli depicting gay male, lesbian female, or heterosexual couples. Participants also completed an interview with the researcher where he self-identified as a gay male and observed any changes in behavior following his disclosure. Findings indicated that male participants showed higher levels of modern homonegativity than female participants, regardless of the images viewed, and had higher odds of exhibiting negative behavioral change in response to the researcher's self-disclosure. Also, participants who viewed images of lesbian couples kissing or embracing had lower odds of showing negative behavioral change.

Affective responses to non-sexual imagery depicting gay men and lesbian women.

When examining negative attitudes and behaviors directed toward gay men and lesbian women (i.e., homonegativity), researchers tend to use measures that require participants to respond to belief statements. This methodology is problematic for two reasons: 1) it focuses on the social categories "gay men" and "lesbian women" and ignores the practices of relational intimacy engaged in by gay and lesbian persons (practices that, arguably, are at the crux of homonegativity); and 2) it overlooks the affective responses that sexual minorities evoke in heterosexual people. These issues were tackled in the current study. Specifically, heterosexual participants (N = 241) were asked to report their affective state using six basic emotions while viewing photos depicting male-male, female-female, and heterosexual couples. Findings demonstrated that participants, regardless of gender, reacted most negatively to images of female-female couples engaging in everyday intimacies. Theoretical explanations for these findings are explored.

A Systematic Review of the Psychometric Properties of Composite LGBT Prejudice and Discrimination Scales.

Prejudice and discrimination against LGBT individuals is widespread and has been shown to have negative consequences for sexual and gender minority persons' physical and psychological wellbeing. A recent and problematic trend in the literature is to compositely measure prejudice toward and discrimination against LGBT persons. As such, a review of the psychometric properties of scales assessing, in a combinatory fashion, negative attitudes and/or behaviors toward LGBT persons is warranted. In the current study, 32 scales were identified, and their psychometric properties were evaluated. Most of the scales reviewed did not provide sufficient information regarding item development and refinement, scale dimensionality, scale score reliability, or validity. Properties of the reviewed scales are summarized, and recommendations for better measurement practice are articulated.

"We're Disgusted With Queers, not Fearful of Them": The Interrelationships Among Disgust, Gay Men's Sexual Behavior, and Homonegativity.

Using a combination of personal reflections, published literature, and original empirical research, we argue that the disgust triggered by gay men's sexual practices (specifically, anal intercourse) is a critical, though overlooked, contributor to heterosexual men and women's homonegativity (i.e., negative attitudes and behaviors directed toward men who are or are perceived to be gay). We conclude our article by articulating several directions for future inquiry that we believe will advance current understanding of prejudice and discrimination directed toward gay men.

A Psychometric Review of Measures Assessing Discrimination Against Sexual Minorities.

Discrimination against sexual minorities is widespread and has deleterious consequences on victims' psychological and physical wellbeing. However, a review of the psychometric properties of instruments measuring lesbian, gay, and bisexual (LGB) discrimination has not been conducted. The results of this review, which involved evaluating 162 articles, reveal that most have suboptimal psychometric properties. Specifically, myriad scales possess questionable content validity as (1) items are not created in collaboration with sexual minorities; (2) measures possess a small number of items and, thus, may not sufficiently represent the domain of interest; and (3) scales are "adapted" from measures designed to examine race- and gender-based discrimination. Additional limitations include (1) summed scores are computed, often in the absence of scale score reliability metrics; (2) summed scores operate from the questionable assumption that diverse forms of discrimination are necessarily interrelated; (3) the dimensionality of instruments presumed to consist of subscales is seldom tested; (4) tests of criterion-related validity are routinely omitted; and (5) formal tests of measures' construct validity are seldom provided, necessitating that one infer validity based on the results obtained. The absence of "gold standard" measures, the attendant difficulty in formulating a coherent picture of this body of research, and suggestions for psychometric improvements are noted.

Gene delivery polymer structure-function relationships elucidated via principal component analysis.

Principal component analysis was applied to a biomaterial library of poly(beta-amino ester)s, useful for non-viral gene delivery, to elucidate chemical parameters that drive biological function. Correlative relationships and principal components were analyzed between 24 physico-chemical polymer properties and 3 cell-based functional variables in human glioblastoma cells (transfection, uptake, and viability).

A systematic review of sexual dysfunction measures for gay men: how do current measures measure up?

The measurement of subjective components of sexual functioning is of increasing importance in clinical research and practice. Differences have been reported in prevalence rates and experiences of sexual difficulties between heterosexual and gay men. The aim of this article is to identify reliable and valid measures of sexual dysfunction suitable for use with gay men. Seven measures were reviewed; details about item development, dimensionality, reliability, and validity are provided. Heteronormative and heterosexist wording were evident throughout. Several areas of concern emerged in relation to psychometric properties (e.g., questionable validity). No psychometrically robust sexual function measure was identified for use with gay populations.

The association between gay men's stereotypic beliefs about drag queens and their endorsement of hypermasculinity.

To date, few researchers have investigated gay men's stereotypic beliefs about drag queens and the association between these beliefs and individual difference variables such as hypermasculinity. To address this omission, 118 men self-identifying as non-heterosexual completed an online survey consisting of an adjective checklist about drag queens and a psychometrically sound indicant of hypermasculinity. As predicted, participants who were more likely to endorse hypermasculine belief statements tended to perceive negatively valenced attributes as more characteristic of drag queens. Possible explanations for this relationship, limitations associated with the current study, and directions for future research are delineated.

Clonal replacement among 19A Streptococcus pneumoniae in Massachusetts, prior to 13 valent conjugate vaccination.

As part of an ongoing study of the response of the Streptococcus pneumoniae population to conjugate vaccination, we applied multi-locus sequence typing (MLST) to 291 isolates sampled from nasopharyngeal carriage in Massachusetts children. We found 94 distinct sequence types (STs), including 19 that had not been previously recorded, and a xpt allele containing a large insertion. Comparison with a similar sample collected in 2007 revealed no significant overall difference in the ST composition (p=0.51) suggesting that the population has reached a new equilibrium following the introduction of 7 valent vaccination in 2000. Within serotypes, a large and statistically significant increase (p=0.014 Fisher's Exact test) was noted in the prevalence of the major multiresistant clone ST 320, which is apparently outcompeting ST 199 among serotype 19A strains. This sample will be used as a baseline to study the future evolution of the pneumococcal population in Massachusetts following introduction of vaccines with higher valency.

High levels of recombination among Streptococcus pneumoniae isolates from the Gambia.

We carried out multilocus sequence typing (MLST) on 148 pneumococcal carriage isolates collected from children <24 months old in the Upper River Division, the Gambia. MLST revealed a diverse population. Seventy-six different sequence types (STs) were found, the most common of which were 802 and 919, associated with 23F and 6A serotypes, respectively. Comparison with the MLST database showed that only 11 of the STs found in the present sample had been reported outside Africa. Six STs showed evidence of capsular switching (172, 802, 847, 1730, 1736, and 1737). Serotype switches were confirmed by microarrays that detected capsule genes. Of isolates analyzed by using microarrays, 40/69 (58%) harbored the tetM resistance determinant. A statistical genetic analysis to detect recombination found that 49/144 (34%) isolates showed significant (P<0.05) evidence of admixture, which is greater than that observed in similar samples from the United Kingdom (5%) and Finland (2%). We hypothesize that large amounts of admixture could reflect the high prevalence of multiple carriage in this region, leading to more opportunities for homologous recombination between strains. This could have consequences for the population response to conjugate vaccination.

The capsule drug device: novel approach for drug delivery to the eye.

Treatment of age-macular degeneration requires monthly intravitreal injections, which are costly and have serious risks. The objective of this study was to develop a novel intraocular implant for drug delivery. The capsule drug ring is a reservoir inserted in the lens capsule during cataract surgery, refillable and capable of delivering multiple drugs. Avastin was the drug of interest in this study. Prototypes were manufactured using polymethylmethacrylate sheets as the reservoir material, a semi-permeable membrane for controlled delivery and silicone check valves for refilling. The device showed near zero-order release kinetics and Avastin stability was investigated with accelerated temperature studies.

Emergence of 19A as virulent and multidrug resistant Pneumococcus in Massachusetts following universal immunization of infants with pneumococcal conjugate vaccine.

BACKGROUND: The long-term effects of selective pressure from conjugate pneumococcal vaccine on the serotype distribution and antimicrobial resistance of carriage and invasive isolates of Streptococcus pneumoniae are unknown. Early changes demonstrate a reduction in vaccine serotypes and an increase in nonvaccine serotypes (NVT) among both carriage and invasive isolates. Ongoing surveillance is necessary to identify emerging invasive serotypes and antimicrobial susceptibilities. METHODS: Enhanced surveillance of invasive pneumococcal disease in Massachusetts began in October 2001 and remains ongoing. Isolates from children less than 5 are sent to the Massachusetts Department of Public Health and subsequently to the Maxwell Finland laboratory for serotyping and determination of antimicrobial susceptibility. Annual incidence rates for vaccine serotype and NVT disease are calculated using 2000 census data. RESULTS: NVT caused 72%-91% of invasive pneumococcal disease annually in children less than 5 years of age between 2002 and 2005. Serotype 19A has emerged as the most frequent cause of IPD in Massachusetts. A multidrug-resistant clone (ceftriaxone, amoxicillin, azithromycin and trimethoprim-sulfamethoxazole) (MLST 320) was first identified in Massachusetts in 2005. CONCLUSIONS: Three years after the introduction of pneumococcal conjugate vaccine for universal administration to children less than 2 in Massachusetts, a significant increase in invasive disease due to serotype 19A was observed. Although MLST 199 remains the most frequent sequence type among invasive isolates (of 19A), a multidrug-resistant sequence type, not previously identified in Massachusetts, has become an important cause of invasive disease. Further surveillance of the changing ecology of S. pneumoniae is necessary as a 4-year time period is not sufficient to fully evaluate the impact of PCV of pneumococcal infections.

Aspiration of oocytes for in-vitro fertilization.

An aspiration system, incorporating a regulated vacuum pump, was used to examine, in vitro, some factors that may affect oocyte collection. In an open aspiration system, as the length of the needle was increased, or the internal diameter decreased, the velocity (and flow rate) of aspirated fluid decreased. There was a difference, however, between experimental flows and those predicted by Hagen-Poiseuille's Law. Upon application of vacuum to a closed aspiration system, employing isolated bovine ovaries, there was an initial rapid increase in the collection tube vacuum to 85% of the selected pump vacuum followed by a more gradual rise to 100%. The vacuum within the needle similarly rose rapidly to approximately half the selected vacuum, while the vacuum at the needle tip was approximately 5% of selected vacuum. The vacuums throughout the system briefly equilibrated as maximum flow/velocity was reached. Flow/velocity slowed dramatically as the follicle collapsed, and stopped as the needle tip was blocked. If vacuum was maintained during the withdrawal of the needle from the follicle, there was a dramatic forward flow of fluid toward the collection tube. The morphological appearance of bovine cumulus after in-vitro aspiration was generally unaltered by vacuums commonly utilized in oocyte collection, providing the cumulus was regular, compact and refractile. The cumulus was less resistant to aspiration if it was damaged or had degenerated. These results suggest that an intact cumulus may offer protection during oocyte collection.

T lymphocytes in infectious mononucleosis; effect of IL-2 on the outgrowth of Epstein-Barr virus-infected cells.

The addition of interleukin-2 (IL-2) to lymphocyte cultures from acute infectious mononucleosis (IM) donors dramatically increased the incidence of regression in such cultures and resulted in the emergence of an IL-2 dependent, CD3 Epstein-Barr virus nuclear antigen (EBNA)-negative cell population. Corresponding cultures seeded in the absence of IL-2 rarely regressed and were quickly dominated by IL-2 independent, CD3-negative, EBNA-positive cells. Lymphocyte cultures from Epstein-Barr virus (EBV) seropositive donors showed enhanced regression in the presence of IL-2 but failed to regress after the removal of the E-rosetting population. Cultures from EBV-seronegative donors showed no evidence of regression in the presence or absence of IL-2. E-rosetting cells isolated from cultures from acute IM donors that had been cultured in the presence of IL-2 lysed autologous and allogeneic lymphoblastoid cell lines.

Monoclonal antibody against a melanosomal protein in melanotic and amelanotic human melanoma cells.

BALB/c mice were immunized with tyrosinase, partially purified in two stages from a human melanoma cell line. A hybridoma was obtained which produced monoclonal antibody (MoAb 1C11) reactive with 8/10 melanoma cell lines and 10/10 primary cultures of human melanocytes, neval cells, and melanomas. Immunoreactivity correlated to a certain extent with tyrosinase activity but not with melanin content. No crossreactivity was obtained with neuroblastoma, medulloblastoma, fibroblasts, keratinocytes, lymphoid cells, or murine melanomas. Purification of the antigen directly from cell lysates with a MoAb 1C11 CNBr-Sepharose affinity column gave a green-brown protein of 56 kDa with no detectable tyrosinase activity. This protein was therefore different from 60 kDa active tyrosinase, identified by enzyme activity and Western blotting with a MoAb derived previously (MoAb 5C12). Unlike 5C12, 1C11 reactivity was not destroyed by pretreatment of the antigen with periodate. Immunogold labelling showed that the 1C11-reactive antigen was associated with melanosomes, and there was close correlation between 5C12 and 1C11 reactivity in resistance to trypsin and in staining various melanocytic cell populations. MoAb 1C11 may therefore recognise a polypeptide epitope in a molecule closely linked to melanin biosynthesis.

The role of reactive oxygen metabolites in lymphocyte-mediated cytolysis.

To examine the possible role of reactive oxygen metabolites in lymphocyte-mediated cytolysis, the morphology of cell death following the exposure of cells to reactive oxygen metabolites in vitro was compared with the morphology of cell-mediated killing in vitro of tumour cells by natural killer (NK) cells. Ultrastructural examination of human tumour cells that were dying following incubation for 60 min with the oxygen metabolite generating systems, xanthine-xanthine oxidase or t-butylhydroperoxide, showed that cell death in both instances was exclusively by necrosis. It was unclear which oxygen metabolites were involved in killing. Cell death was not decreased by the addition of superoxide dismutase, a scavenger of the superoxide anion, to the xanthine-xanthine oxidase mixture. Although the cells were not killed by incubation with 1 mM-hydrogen peroxide, the addition of catalase, a scavenger of hydrogen peroxide, to the xanthine-xanthine oxidase mixture significantly reduced cell death. The addition of scavengers for the hydroxyl radical to either the xanthine-xanthine oxidase mixture or t-butylhydroperoxide gave inconsistent protection. In contrast, tumour cell killing mediated by natural killer cells was by apoptosis, a morphologically distinct mode of cell death with a different basic mechanism, indicating that reactive oxygen metabolites are not directly involved in lymphocyte-mediated cytolysis.

T lymphocyte lines from arthritic synovial fluid: establishment and function.

T lymphocyte lines have been established, with the addition of interleukin-2 (IL-2), from the synovial fluid (SF) of patients with arthritis. Characterisation of seven of these SF-derived T cell lines showed them to be T3+, T11+, and to contain a significant proportion of T8+ cells (mean 41%). The proportion of T4+ cells varied among the lines, with a mean T4+/T8+ ratio of 0.6. A significant autologous mixed lymphocyte reaction (AMLR) was observed only in one of four T cell lines assayed. Two of four lines assayed showed natural killer (NK) cell-like activity, while one line displayed a significant suppressor activity, suggesting that the T cell population in SF contained NK-like cells or suppressor cells, or both, either of which may be selected in the establishment of SF-derived T cell lines.

Stimulation of neutrophil respiratory burst and iodination reaction by opsonized microfilariae of Dirofilaria immitis.

It has been shown that the interaction of Dirofilaria immitis microfilariae (Mf) opsonized with sera from infected but amicrofilaraemic dogs (occult dogs) stimulated the respiratory burst and degranulation of neutrophils as measured by chemiluminescence and iodination. Sera from normal and microfilaraemic dogs gave either low level or non-significant reactions. Since the sera required were also those required for neutrophil-mediated cytotoxicity to D. immitis Mf in vitro, the results suggested that the products of oxygen reduction as well as the myeloperoxidase system could be involved in the killing of Mf by neutrophils. However, whether these pathways have a major role to play in neutrophil-mediated cytotoxicity to Mf is uncertain, as various chemical and enzymatic inhibitors of the products of the respiratory burst were unable to prevent or reduce cytotoxicity. Azide, which is a known inhibitor of the iodination reaction, also failed to reduce cytotoxicity.

The ability of microfilariae to evade in vitro cell-mediated cytotoxicity.

When microfilariae (Mf) of Dirofilaria immitis, both uterine and systemic, were incubated in an in vitro cytotoxicity assay with neutrophils and sera from dogs with occult infections, some Mf remained free of adherent cells and consequently evaded cytotoxicity. The ability to evade cytotoxicity could not be related to the age of the Mf, and host albumin was not detected on any Mf, either uterine or systemic. However, it was shown that some Mf failed to bind IgM, IgG and C3 when incubated with occult sera. It is suggested that the ability of some Mf to evade serum-dependent, neutrophil-mediated cytotoxicity in vitro was related to differences in their antigenicity.