Images of gays and lesbians in sexuality and health textbooks.

Photographs have become a major form of illustration in college level health and sexuality textbooks and may be more memorable than the text itself. Unlike other forms of illustration, photographs are often viewed as objective and unable to "lie." Photographs of individuals from nondominant groups, in addition to being seen as objective representations of reality, are often seen as representing the group to which they belong. To study the representation of nondominant groups in textbooks, it is, therefore, as important to analyze the photographs as the text itself. This paper examines photographs of gay men and lesbians in 14 health and 16 human sexuality college level textbooks. The photographs of individuals present an inaccurate portrait of lesbians and gay men as white, young, and physically-abled. Individual and large group photographs of activism (31% of the total photographs of gay men and lesbians) were positive images that emphasized issues of civil rights. The paper discusses various interpretations of the photographs of gay men and lesbians, subtle homophobia or heterosexism in the texts, and progress that has been made.

An instrument for measuring cancer patients' preferences for support groups.

The purpose of this study was to develop a valid and reliable instrument to assess cancer patients' preferences for all types of social support and organizational features of cancer support groups. The content of the instrument was the result of a detailed analysis of four resources: (1) literature relating to cancer support group interventions, (2) program materials from existing groups, (3) interviews with individuals who developed or directed groups, and (4) interviews with patients who have participated in cancer support groups. A jury of six experts was used to establish content validity of the instrument. The reliability of the instrument was examined by measuring a sample of 258 cancer patients. The reliability coefficients of the instrument were all above .80, except for two types of social support (instrumental and informational-educational), which were .72 and .78, respectively. It was concluded that the instrument produces valid and reliable measurements of cancer patients' preferences for cancer support groups.

School sexual abuse prevention: unintended consequences and dilemmas.

In view of the recent proliferation of school sexual abuse prevention programs and materials, this article critically examines current assumptions about the role of elementary school personnel in prevention and possible unintended consequences of such assumptions. These unintended consequences include emphasizing a simple solution to a complex social problem and contributing to victim blaming. Some dilemmas that arise for classroom teachers around predeveloped curricular materials and mandatory reporting are also explored. Teacher use of predeveloped materials may mean a diminishing of wider teaching skills and reduction of complex concepts to brief, noncontroversial interventions that may serve to mystify sexuality and unduly frighten students. Mandatory reporting, as it is frequently presented to teachers, can create further dilemmas by obscuring the ethical decisions inherent in the process, assuming consistently positive outcomes after reporting, and neglecting the context in which teachers work. The authors suggest that educators should be aware of these possible unintended consequences and dilemmas in order to maintain a broad perspective on child sexual abuse and to focus their efforts more effectively within a larger network addressing the problem.

Agglutination of Erwinia stewartii Strains with a Corn Agglutinin: Correlation with Extracellular Polysaccharide Production and Pathogenicity.

A bacterial agglutinin was extracted from ground corn (WI hybrid 64A x W117) seed with phosphate-buffered saline (pH 6.0) and precipitated with (NH(4))(2)SO(4) at 70% saturation. The activities of this agglutinin against 22 strains of Erwinia stewartii (agent of bacterial wilt of corn) that varied in virulence were determined. Specific agglutination (agglutination titer per milligram of protein per milliliter) values were correlated negatively with virulence ratings. Strains with high specific agglutination values (15 or higher) were avirulent or weakly virulent; strains with low specific agglutination values (10 or lower) were highly virulent, with two exceptions. Avirulent strains produced butyrous colonies and released only small amounts of extracellular polysaccharide (EPS) into the medium, and the cells lacked capsules; virulent strains produced fluidal colonies and released large amounts of EPS, and the cells were capsulated. There was a strong correlation between the amount of EPS produced by each strain (as determined by increase in viscosity of the medium) and the specific agglutination value; in contrast, lipopolysaccharide compositions were similar in all strains. When cells of six fluidal strains were washed by repeatedly centrifuging and resuspending them in buffer, they were agglutinated more strongly by corn agglutinin than were unwashed cells. When avirulent cells were washed, their specific agglutination values did not increase significantly. Eight EPS-deficient mutants of E. stewartii, selected for resistance to the capsule-dependent bacteriophage K9, had lower virulence but higher specific agglutination than did their corresponding wild-type parents. Production of EPS appears to be essential for virulence; EPS may prevent agglutination of bacteria in the host, thus allowing their multiplication.

Lipopolysaccharide Composition of the Wilt Pathogen, Pseudomonas solanacearum: CORRELATION WITH THE HYPERSENSITIVE RESPONSE IN TOBACCO.

In the induction of the hypersensitive response (HR) in tobacco by Pseudomonas solanacearum, the recognition between host and pathogen is thought to involve an interaction between plant lectins and bacterial lipopolysaccharide (LPS). The LPS of a series of strains of P. solanacearum were examined to determine if there are structural differences that might account for the ability or inability of these strains to induce the hypersensitive response. Analysis of the components of LPS by gas chromatography indicates a clear difference in sugar composition between the HR-inducing and non-HR-inducing strains, especially in terms of the percentage of glucose, xylose and rhamnose. Sodium dodecyl sulfate polyacrylamide gel electrophoresis shows there are two distinct kinds of LPS, differing greatly in size, which correspond to rough and smooth LPS in other systems. In addition, a phage, CH154, was isolated which lyses non-HR-inducing bacteria and which is inactivated by LPS from these bacterial strains. Therefore, differences in LPS structure correlate strongly with host recognition of Pseudomonas solanacearum.

Role of bacterial lipopolysaccharide in attachment of agrobacterium to moss.

Gametophore induction in moss by Agrobacterium tumefaciens was inhibited by addition of lipopolysaccharide (LPS) from A. tumefaciens. The LPS did not affect bacterial viability or appear to bind to bacterial cells. LPS from nonbinding Agrobacterium radiobacter was not effective in reducing gametophore formation. A. tumefaciens LPS, if added 24 hours after addition of viable bacterial cells, had no effect in reducing gametophore formation. The polysaccharide portion of the LPS was identified as the binding component necessary for attachment of agrobacteria for induction of gametophores in moss and tumors in higher plants.

Tumor induction by agrobacterium involves attachment of the bacterium to a site on the host plant cell wall.

Cell wall preparations from primary bean leaves were found to inhibit tumor initiation by Agrobacterium tumefaciens strain B6 when inoculated with the bacteria on bean leaves. Membrane fractions from these same leaves were noninhibitory. The cell walls were effective when applied prior to or with bacteria, but application of cell walls about 15 minutes after bacteria did not affect the number of tumors initiated. Much of the inhibitory activity of the plant cell walls was eliminated by pretreatment with dead site-attaching bacteria or with lipopolysaccharide from these bacteria. Cells and lipopolysaccharide from non-site-attaching agrobacteria had no effect on the activity of the plant cell walls. About 30% inhibition of tumor initiation was obtained with plant cell walls at 50 mug/ml dry weight, and at 10 mg/ml dry weight about 70% inhibition was typical. Both early and late appearing tumors were affected by the cell walls, indicating that they do not exclusively affect tumors arising from either small or large wounds. These data show that plant cell walls but not membranes contain surfaces to which A. tumefaciens adheres and these exhibit the specificity typical of the host site to which virulent agrobacteria must attach to induce tumors. It is concluded that some portion of wound-exposed plant cell wall constitutes the host adherence site in Agrobacterium infections.

Role of Agrobacterium cell envelope lipopolysaccharide in infection site attachment.

Lipopolysaccharide (LPS) isolated from Agrobacterium tumefaciens inhibited tumor induction by virulent bacteria. LPS from site-binding strains was not effective if added to the plant wound shortly after the bacteria, and LPS from avirulent, non-site-binding strains of Agrobacterium was not inhibitory regardless of the order of addition. However, LPS and whole cells of avirulent strains NT1 and IIBNV6, which lack of Agrobacterim virulence plasmid, were inhibitory. Chromosomal deoxyribonucleic acid thus determines specificity of this essential component of the Agrobacterium infection process.