Connectome-driven neural inventory of a complete visual system

Vision provides animals with detailed information about their surroundings, conveying diverse features such as color, form, and movement across the visual scene. Computing these parallel spatial features requires a large and diverse network of neurons, such that in animals as distant as flies and humans, visual regions comprise half the brain's volume. These visual brain regions often reveal remarkable structure-function relationships, with neurons organized along spatial maps with shapes that directly relate to their roles in visual processing. To unravel the stunning diversity of a complex visual system, a careful mapping of the neural architecture matched to tools for targeted exploration of that circuitry is essential. Here, we report a new connectome of the right optic lobe from a male Drosophila central nervous system FIB-SEM volume and a comprehensive inventory of the fly's visual neurons. We developed a computational framework to quantify the anatomy of visual neurons, establishing a basis for interpreting how their shapes relate to spatial vision. By integrating this analysis with connectivity information, neurotransmitter identity, and expert curation, we classified the ~53,000 neurons into 727 types, about half of which are systematically described and named for the first time. Finally, we share an extensive collection of split-GAL4 lines matched to our neuron type catalog. Together, this comprehensive set of tools and data unlock new possibilities for systematic investigations of vision in Drosophila, a foundation for a deeper understanding of sensory processing.

Homeodomain proteins hierarchically specify neuronal diversity and synaptic connectivity

How our brain generates diverse neuron types that assemble into precise neural circuits remains unclear. Using Drosophila lamina neuron types (L1-L5), we show that the primary homeodomain transcription factor (HDTF) brain-specific homeobox (Bsh) is initiated in progenitors and maintained in L4/L5 neurons to adulthood. Bsh activates secondary HDTFs Ap (L4) and Pdm3 (L5) and specifies L4/L5 neuronal fates while repressing the HDTF Zfh1 to prevent ectopic L1/L3 fates (control: L1-L5; Bsh-knockdown: L1-L3), thereby generating lamina neuronal diversity for normal visual sensitivity. Subsequently, in L4 neurons, Bsh and Ap function in a feed-forward loop to activate the synapse recognition molecule DIP-β, thereby bridging neuronal fate decision to synaptic connectivity. Expression of a Bsh:Dam, specifically in L4, reveals Bsh binding to the DIP-β locus and additional candidate L4 functional identity genes. We propose that HDTFs function hierarchically to coordinate neuronal molecular identity, circuit formation, and function. Hierarchical HDTFs may represent a conserved mechanism for linking neuronal diversity to circuit assembly and function.

Different spectral sensitivities of ON- and OFF-motion pathways enhance the detection of approaching color objects in Drosophila

Color and motion are used by many species to identify salient objects. They are processed largely independently, but color contributes to motion processing in humans, for example, enabling moving colored objects to be detected when their luminance matches the background. Here, we demonstrate an unexpected, additional contribution of color to motion vision in Drosophila. We show that behavioral ON-motion responses are more sensitive to UV than for OFF-motion, and we identify cellular pathways connecting UV-sensitive R7 photoreceptors to ON and OFF-motion-sensitive T4 and T5 cells, using neurogenetics and calcium imaging. Remarkably, this contribution of color circuitry to motion vision enhances the detection of approaching UV discs, but not green discs with the same chromatic contrast, and we show how this could generalize for systems with ON- and OFF-motion pathways. Our results provide a computational and circuit basis for how color enhances motion vision to favor the detection of saliently colored objects.

Abelson kinase's intrinsically disordered region plays essential roles in protein function and protein stability

Background

The non-receptor tyrosine kinase Abelson (Abl) is a key player in oncogenesis, with kinase inhibitors serving as paradigms of targeted therapy. Abl also is a critical regulator of normal development, playing conserved roles in regulating cell behavior, brain development and morphogenesis. Drosophila offers a superb model for studying Abl’s normal function, because, unlike mammals, there is only a single fly Abl family member. In exploring the mechanism of action of multi-domain scaffolding proteins like Abl, one route is to define the roles of their individual domains. Research into Abl’s diverse roles in embryonic morphogenesis revealed many surprises. For instance, kinase activity, while important, is not crucial for all Abl activities, and the C-terminal F-actin binding domain plays a very modest role. This turned our attention to one of Abl’s least understood features—the long intrinsically-disordered region (IDR) linking Abl’s kinase and F-actin binding domains. The past decade revealed unexpected, important roles for IDRs in diverse cell functions, as sites of posttranslational modifications, mediating multivalent interactions and enabling assembly of biomolecular condensates via phase separation. Previous work deleting conserved regions in Abl’s IDR revealed an important role for a PXXP motif, but did not identify any other essential regions.

Methods

Here we extend this analysis by deleting the entire IDR, and asking whether Abl∆IDR rescues the diverse roles of Abl in viability and embryonic morphogenesis in Drosophila.

Results

This revealed that the IDR is essential for embryonic and adult viability, and for cell shape changes and cytoskeletal regulation during embryonic morphogenesis, and, most surprisingly, revealed a role in modulating protein stability.

Conclusion

Our data provide new insights into the role of the IDR in an important signaling protein, the non-receptor kinase Abl, suggesting that it is essential for all aspects of protein function during embryogenesis, and revealing a role in protein stability. These data will stimulate new explorations of the mechanisms by which the IDR regulates Abl stability and function, both in Drosophila and also in mammals. They also will stimulate further interest in the broader roles IDRs play in diverse signaling proteins.

Spatial readout of visual looming in the central brain of Drosophila

Visual systems can exploit spatial correlations in the visual scene by using retinotopy, the organizing principle by which neighboring cells encode neighboring spatial locations. However, retinotopy is often lost, such as when visual pathways are integrated with other sensory modalities. How is spatial information processed outside of strictly visual brain areas? Here, we focused on visual looming responsive LC6 cells in Drosophila, a population whose dendrites collectively cover the visual field, but whose axons form a single glomerulus-a structure without obvious retinotopic organization-in the central brain. We identified multiple cell types downstream of LC6 in the glomerulus and found that they more strongly respond to looming in different portions of the visual field, unexpectedly preserving spatial information. Through EM reconstruction of all LC6 synaptic inputs to the glomerulus, we found that LC6 and downstream cell types form circuits within the glomerulus that enable spatial readout of visual features and contralateral suppression-mechanisms that transform visual information for behavioral control.

The Emergence of Directional Selectivity in the Visual Motion Pathway of Drosophila

The perception of visual motion is critical for animal navigation, and flies are a prominent model system for exploring this neural computation. In Drosophila, the T4 cells of the medulla are directionally selective and necessary for ON motion behavioral responses. To examine the emergence of directional selectivity, we developed genetic driver lines for the neuron types with the most synapses onto T4 cells. Using calcium imaging, we found that these neuron types are not directionally selective and that selectivity arises in the T4 dendrites. By silencing each input neuron type, we identified which neurons are necessary for T4 directional selectivity and ON motion behavioral responses. We then determined the sign of the connections between these neurons and T4 cells using neuronal photoactivation. Our results indicate a computational architecture for motion detection that is a hybrid of classic theoretical models.

Abelson kinase acts as a robust, multifunctional scaffold in regulating embryonic morphogenesis

The importance of Abl kinase activity, the F-actin–binding site, and scaffolding ability in Abl’s many cell biological roles during Drosophila morphogenesis is examined. Abl is a robust multidomain scaffold with different protein motifs and activities contributing differentially to diverse cellular behaviors.

Abelson family kinases (Abls) are key regulators of cell behavior and the cytoskeleton during development and in leukemia. Abl’s SH3, SH2, and tyrosine kinase domains are joined via a linker to an F-actin–binding domain (FABD). Research on Abl’s roles in cell culture led to several hypotheses for its mechanism of action: 1) Abl phosphorylates other proteins, modulating their activity, 2) Abl directly regulates the cytoskeleton via its cytoskeletal interaction domains, and/or 3) Abl is a scaffold for a signaling complex. The importance of these roles during normal development remains untested. We tested these mechanistic hypotheses during Drosophila morphogenesis using a series of mutants to examine Abl’s many cell biological roles. Strikingly, Abl lacking the FABD fully rescued morphogenesis, cell shape change, actin regulation, and viability, whereas kinase-dead Abl, although reduced in function, retained substantial rescuing ability in some but not all Abl functions. We also tested the function of four conserved motifs in the linker region, revealing a key role for a conserved PXXP motif known to bind Crk and Abi. We propose that Abl acts as a robust multidomain scaffold with different protein motifs and activities contributing differentially to diverse cellular behaviors.

Enabled plays key roles in embryonic epithelial morphogenesis in Drosophila

Studies in cultured cells and in vitro have identified many actin regulators and begun to define their mechanisms of action. Among these are Enabled (Ena)/VASP proteins, anti-Capping proteins that influence fibroblast migration, growth cone motility, and keratinocyte cell adhesion in vitro. However, partially redundant family members in mammals and maternal Ena contribution in Drosophila previously prevented assessment of the roles of Ena/VASP proteins in embryonic morphogenesis in flies or mammals. We used several approaches to remove maternal and zygotic Ena function, allowing us to address this question. We found that inactivating Ena does not disrupt cell adhesion or epithelial organization, suggesting its role in these processes is cell type-specific. However, Ena plays an important role in many morphogenetic events, including germband retraction, segmental groove retraction and head involution, whereas it is dispensable for other morphogenetic movements. We focused on dorsal closure, analyzing mechanisms by which Ena acts. Ena modulates filopodial number and length, thus influencing the speed of epithelial zippering and the ability of cells to match with correct neighbors. We also explored filopodial regulation in cultured Drosophila cells and embryos. These data provide new insights into developmental and mechanistic roles of this important actin regulator.

Using Bcr-Abl to examine mechanisms by which abl kinase regulates morphogenesis in Drosophila

Signaling by the nonreceptor tyrosine kinase Abelson (Abl) plays key roles in normal development, whereas its inappropriate activation helps trigger the development of several forms of leukemia. Abl is best known for its roles in axon guidance, but Abl and its relatives also help regulate embryonic morphogenesis in epithelial tissues. Here, we explore the role of regulation of Abl kinase activity during development. We first compare the subcellular localization of Abl protein and of active Abl, by using a phosphospecific antibody, providing a catalog of places where Abl is activated. Next, we explore the consequences for morphogenesis of overexpressing wild-type Abl or expressing the activated form found in leukemia, Bcr-Abl. We find dose-dependent effects of elevating Abl activity on morphogenetic movements such as head involution and dorsal closure, on cell shape changes, on cell protrusive behavior, and on the organization of the actin cytoskeleton. Most of the effects of Abl activation parallel those caused by reduction in function of its target Enabled. Abl activation leads to changes in Enabled phosphorylation and localization, suggesting a mechanism of action. These data provide new insight into how regulated Abl activity helps direct normal development and into possible biological functions of Bcr-Abl.

CREB and phospho-CREB interact with RFX5 and CIITA to regulate MHC class II genes

Major histocompatibility class II (MHC-II) genes are coordinately regulated by conserved, upstream promoter elements that are bound cooperatively by cyclic AMP response element binding protein (CREB), regulatory factor X (RFX), and nuclear factor Y (NF-Y). These DNA-binding proteins serve as a scaffold for the transcriptional coactivator class II transactivator (CIITA). To determine how CREB interacts with RFX and CIITA, co-immunoprecipitations and reporter assays were performed using a variety of CREB mutants. These assays demonstrated that CREB interacted with CIITA and the RFX5 subunit of RFX through the C-terminal portion of CREB. This C-terminal portion of CREB was fully functional in MHC-II promoter reporter assays. Phosphorylation of CREB enhanced transcription from the reporter, but was not required for transcription. Phospho-CREB was found at the HLA-DRA promoter by chromatin immunoprecipitation, providing evidence for its role. Together, these data provide genetic and biochemical evidence of the specific associations between CREB and two elements of the MHC-II regulatory complex and of the role played by phosphorylated CREB at MHC-II promoters.

Pointed regulates an eye-specific transcriptional enhancer in the Drosophila hedgehog gene, which is required for the movement of the morphogenetic furrow

Drosophila development depends on stable boundaries between cellular territories, such as the embryonic parasegment boundaries and the compartment boundaries in the imaginal discs. Patterning in the compound eye is fundamentally different: the boundary is not stable, but moves (the morphogenetic furrow). Paradoxically, Hedgehog signaling is essential to both: Hedgehog is expressed in the posterior compartments in the embryo and in imaginal discs, and posterior to the morphogenetic furrow in the eye. Therefore, uniquely in the eye, cells receiving a Hedgehog signal will eventually produce the same protein. We report that the mechanism that underlies this difference is the special regulation of hedgehog (hh) transcription through the dual regulation of an eye specific enhancer. We show that this enhancer requires the Egfr/Ras pathway transcription factor Pointed. Recently, others have shown that this same enhancer also requires the eye determining transcription factor Sine oculis (So). We discuss these data in terms of a model for a combinatorial code of furrow movement.

Slingshot cofilin phosphatase localization is regulated by receptor tyrosine kinases and regulates cytoskeletal structure in the developing Drosophila eye

Animal development requires that positional information act on the genome to control cell fate and cell shape. The primary determinant of animal cell shape is the cytoskeleton and thus the mechanisms by which extracellular signals influence the cytoskeleton are crucial for morphogenesis. In the developing Drosophila compound eye, localized polymerization of actin functions to constrict the apical surface of epithelial cells, both at the morphogenetic furrow and later to maintain the coherence of the nascent ommatidia. As elsewhere, actin polymerization in the developing eye is regulated by ADF/cofilin ('Twinstar', or 'Tsr' in Drosophila), which is activated by Slingshot (Ssh), a cofilin phosphatase. Here we show that Ssh does act in the developing eye to limit actin polymerization in the assembling ommatidia, but not in the morphogenetic furrow. While Ssh does control cell shape, surprisingly there are no direct or immediate consequences for cell type. Ssh protein becomes apically concentrated in cells that express elevated levels of the Sevenless (Sev) receptor-tyrosine kinase (RTK), even those which receive no ligand. We interpret this as a non-signal driven, RTK-dependent localization of Ssh to allow for locally increased actin filament turnover. We suggest that there are two modes of actin remodeling in the developing eye: a non-RTK, non-Ssh mediated mechanism in the morphogenetic furrow, and an RTK and Ssh-dependent mode during ommatidial assembly.

Formative research activities to provide Web-based nutrition education to adults in the Upper Rio Grande Valley

The Internet is a promising new tool for disseminating cancer prevention information. Barriers to full implementation include disparities in access and skill and availability of information relevant at the local level. A nutrition education Web site to promote fruit and vegetable intake is being produced for a tri-ethnic adult population in Colorado and New Mexico. Development is guided by findings from formative research including focus groups with local residents, a survey on computer and Internet use with 200 adults in 1998, an assessment of public access computer sites, and in-depth discussion with local community computer skills trainers.

MADD victim impact panels and stages-of-change in drunk-driving prevention

OBJECTIVE

To assess the additional effects of Mothers Against Drunk Driving (MADD) Victim Impact Panels (VIPs) over the effects of a DWI (driving while intoxicated) school, on (1) moving individuals through the stages-of-change toward not drinking while driving and (2) drunk-driving recidivism.

METHOD

A randomized experiment with 813 (75% male) DWI offenders in New Mexico measured progress through the stages-of-change at pretest, posttest, 1-year follow-up and 2-year follow-up. In addition, drunk-driving recidivism over 2 years was measured from state driving records. Individuals were randomly assigned to a DWI school or a DWI school plus a MADD VIP.

RESULTS

No significant difference in movement through the stages-of-change, or in recidivism, occurred between respondents in the DWI-school-only treatment, and those in the DWI school plus VIP treatment.

CONCLUSIONS

There was no additional effect of the MADD VIP, a relatively emotional intervention, over that of the DWI school, a relatively informational approach, on DWI behavior (whether measured by stages-of-change or by DWI rearrest data) over the 2-year period following the two interventions.

A staged model of communication effects: evidence from an entertainment-education radio soap opera in Tanzania

The authors draw on (1) the hierarchy-of-effects (HOE) model, (2) the stages-of-change (SOC) model, (3) social learning theory (SLT), and (4) the diffusion of innovations (DOI) to synthesize a staged model through which communication messages have effects on individual behavior change by stimulating (1) involvement with media characters and role modeling of their actions, and (2) interpersonal communication. Data from a field experiment in Tanzania on the effects of an entertainment-education radio soap opera, Twende na Wakati (Let's Go With the Times), on the adoption of family planning, are analyzed in light of a six-staged model of communication effects. It is found that (1) the model provides a useful framework for understanding the effects of an entertainment-education program, and (2) the radio soap opera promoted progress through the stages for family planning adoption in the treatment area in three of the four years of broadcast, and in the comparison area after broadcasts of the radio program began there.

Entertainment-education and HIV/AIDS prevention: a field experiment in Tanzania

Entertainment-education is the process of designing and implementing an entertainment program to increase audience members' knowledge about a social issue, create more favorable attitudes, and change their overt behaviors regarding the social issue. The results of a field experiment in Tanzania to measure the effects of a long-running entertainment-education radio soap opera, Twende na Wakati (Let's Go with the Times), on knowledge, attitudes, and adoption of human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) prevention behaviors are presented. Multiple independent measures of effects and the experimental design of this study confer strong internal and external validity regarding the results of this investigation. The effects of the radio program in Tanzania include (1) a reduction in the number of sexual partners by both men and women, and (2) increased condom adoption. The radio soap opera influenced these behavioral variables through certain intervening variables, including (1) self-perception of risk of contracting HIV/AIDS, (2) self-efficacy with respect to preventing HIV/AIDS, (3) interpersonal communication about HIV/AIDS, and (4) identification with, and role modeling of, the primary characters in the radio soap opera.

Effects of an entertainment-education radio soap opera on family planning behavior in Tanzania

An entertainment-education radio soap opera introduced in Tanzania in 1993 was evaluated by means of a field experimental design in which the radio program was broadcast by seven mainland stations of Radio Tanzania. An eighth station broadcast alternative programming from 1993 to 1995, its listenership serving as a comparison area in which contemporaneous changes in family planning adoption were measured. The soap opera was subsequently broadcast nationwide from 1995 to 1997. Data about the effects of the radio soap opera were gathered in five annual surveys of about 2,750 households in the comparison and the treatment areas and from a sample of new family planning adopters in 79 health clinics. The soap opera had strong behavioral effects on family planning adoption; it increased listeners' self-efficacy regarding family planning adoption and influenced listeners to talk with their spouses and peers about contraception.

Nuclear factor-kappa B p65 mediates the assembly and activation of the TNF-responsive element of the murine monocyte chemoattractant-1 gene

TNF-alpha transcriptionally regulates murine monocyte chemoattractant protein-1 (MCP-1) expression. Three approaches were used to determine the mechanism by which TNF regulates MCP-1. Mutation analysis showed that two distal kappa B sites, a novel dimethylsulfate-hypersensitive sequence, and a promoter proximal SP-1 site were required for TNF induction. Although the kappa B sites and the hypersensitive sequence function as a NF-kappa B-mediated enhancer, regulating induction by TNF, stereospecific alignment of the kappa B sites was not critical. Trans-activation studies conducted by cotransfection of p50 and/or p65 expression vectors with MCP-1 constructions showed that TNF regulates MCP-1 through NF-kappa B. Examination of MCP-1 induction in NF-kappa B-disrupted embryonic fibroblasts showed that p65 was necessary for both the induction and the TNF-induced protein occupancy of the enhancer in vivo. The action of the antioxidant inhibitor of NF-kappa B activation, pyrrolidine dithiocarbamate, in wild-type and NF-kappa B mutant cells was examined. The results suggested that TNF activates NF-kappa B through both pyrrolidine dithiocarbamate-sensitive and -insensitive mechanisms. This study illustrates the crucial role for NF-kappa B p65 in the induction of the MCP-1 gene by TNF and in the assembly of a NF-kappa B dependent enhancer in vivo.

Nuclear Factor-κB p65 Mediates the Assembly and Activation of the TNF-Responsive Element of the Murine Monocyte Chemoattractant-1 Gene

TNF-α transcriptionally regulates murine monocyte chemoattractant protein-1 (MCP-1) expression. Three approaches were used to determine the mechanism by which TNF regulates MCP-1. Mutation analysis showed that two distal κB sites, a novel dimethylsulfate-hypersensitive sequence, and a promoter proximal SP-1 site were required for TNF induction. Although the κB sites and the hypersensitive sequence function as a NF-κB-mediated enhancer, regulating induction by TNF, stereospecific alignment of the κB sites was not critical. Trans-activation studies conducted by cotransfection of p50 and/or p65 expression vectors with MCP-1 constructions showed that TNF regulates MCP-1 through NF-κB. Examination of MCP-1 induction in NF-κB-disrupted embryonic fibroblasts showed that p65 was necessary for both the induction and the TNF-induced protein occupancy of the enhancer in vivo. The action of the antioxidant inhibitor of NF-κB activation, pyrrolidine dithiocarbamate, in wild-type and NF-κB mutant cells was examined. The results suggested that TNF activates NF-κB through both pyrrolidine dithiocarbamate-sensitive and -insensitive mechanisms. This study illustrates the crucial role for NF-κB p65 in the induction of the MCP-1 gene by TNF and in the assembly of a NF-κB dependent enhancer in vivo.

The MHC class II transactivator (CIITA) requires conserved leucine charged domains for interactions with the conserved W box promoter element

The class II transactivator CIITA is required for transcriptional activation of the major histocompatibility complex (MHC) class II genes. Aside from an N-terminal acidic transcriptional activation domain, little is known about how this factor functions. Extensive mutagenesis of CIITA was undertaken to identify structural motifs required for function. The ability of mutants to activate a reporter gene under the control of MHC class II conserved W-X-Y or X-Y regulatory elements was determined. Two mutants displayed differential activity between the two promoters, activating transcription with the W-X-Y but not the X-Y elements. All mutants were tested for their ability to interfere with wild-type CIITA activity. Five CIITA mutant constructions were able to down-regulate wild-type CIITA activity. Three of these mutants contained targeted disruptions of potential functional motifs: the acidic activation domain, a putative GTP-binding motif and two leucine charged domains (LCD motifs). The other two contained mutations in regions that do not have homology to described proteins. The characterization of CIITA mutants that are able to discriminate between promoters with or without the W box strongly suggests that CIITA requires such interactions for function. The identification of LCD motifs required for CIITA function brings to light a previously undefined role of these motifs in CIITA function.

Diffusion of innovations theory and work-site AIDS programs

Four case studies of the adoption of work-site AIDS programs are investigated, two of which were modifications of the Centers for Disease Control and Prevention's Business Responds to AIDS (BRTA) program. AIDS work-site programs were mainly initiated by the four study companies as a result of the efforts of a champion (defined as an individual who gains attention and resources for an issue in a system) or the occurrence of a tragic event, such as a company employee contracting AIDS. The BRTA program is an innovation that has not yet reached critical mass, which is the point after which further rates of adoption occur rapidly in a self-sustaining process.

Regulatory factor X, a bare lymphocyte syndrome transcription factor, is a multimeric phosphoprotein complex

Regulatory factor X (RFX) is a transcription factor that binds the conserved X1 box of MHC class II promoters and is essential for transcription of class II genes. The subunit structure of the native RFX complex was examined by coimmunoprecipitation using polyclonal antisera to the 75-kDa subunit of RFX, RFX5. Two polypeptides with apparent masses of 41 and 36 kDa coimmunoprecipitated with RFX5 and appear to be subunits of the native RFX complex. Metabolic labeling of wild-type and mutant B cells with [32P]orthophosphate demonstrated that each of the RFX subunits was phosphorylated in vivo and that the phosphorylation of the RFX subunits was independent of the essential MHC class II regulatory factor, CIITA. The trimeric RFX complex was also present in fibroblast cells with or without IFN-gamma treatment. Both the p41 and p36 subunits were absent in immunoprecipitations of RFX5 from lysates of independently established B cell lines from bare lymphocyte syndrome complementation groups B and D. Together, these results suggest that RFX complex assembly is required for class II expression and that the mutations in bare lymphocyte syndrome complementation groups B and D result in an inability to assemble the RFX complex.

Regulatory factor X, a bare lymphocyte syndrome transcription factor, is a multimeric phosphoprotein complex

Regulatory factor X (RFX) is a transcription factor that binds the conserved X1 box of MHC class II promoters and is essential for transcription of class II genes. The subunit structure of the native RFX complex was examined by coimmunoprecipitation using polyclonal antisera to the 75-kDa subunit of RFX, RFX5. Two polypeptides with apparent masses of 41 and 36 kDa coimmunoprecipitated with RFX5 and appear to be subunits of the native RFX complex. Metabolic labeling of wild-type and mutant B cells with [32P]orthophosphate demonstrated that each of the RFX subunits was phosphorylated in vivo and that the phosphorylation of the RFX subunits was independent of the essential MHC class II regulatory factor, CIITA. The trimeric RFX complex was also present in fibroblast cells with or without IFN-gamma treatment. Both the p41 and p36 subunits were absent in immunoprecipitations of RFX5 from lysates of independently established B cell lines from bare lymphocyte syndrome complementation groups B and D. Together, these results suggest that RFX complex assembly is required for class II expression and that the mutations in bare lymphocyte syndrome complementation groups B and D result in an inability to assemble the RFX complex.

Social marketing and diffusion-based strategies for communicating with unique populations: HIV prevention in San Francisco

We conducted a 2-year investigation of the extent to which strategies based on social marketing and diffusion of innovations concepts are used in preventive health communication with unique (highly ostracized) populations. Of the 49 organizations in San Francisco that operate HIV prevention programs (N = 100), programs that most highly targeted unique populations were surveyed. Personal interviews were then conducted with 38 staff leaders who operated the most and least effective programs. Audiotapes and transcripts were content analyzed to identify the strategies used by program staff. Strategies based on social marketing concepts were more prevalent than strategies based on the diffusion of innovations: More effective programs were characterized by emphasis on homophily, audience segmentation, compatibility-based strategies, and interorganizational collaboration.

The field of health communication today: an up-to-date report

One important starting point for the field of health communication was the Stanford Heart Disease Prevention Program, a multiyear community intervention that began 25 years ago. Health communication is a specialty field of communication study that includes the media agenda-setting process for health issues; media advocacy for health; scientific communication among biomedical scientists; doctor-patient communication; and, particularly, the design and evaluation of preventive health communication campaigns, the focus of this article. Health communication study today is a well-established, expanding specialty in the United States and abroad.

The origins and development of the diffusion of innovations paradigm as an example of scientific growth

This article traces the emergence of the basic paradigm for early diffusion research created by two rural sociologists at Iowa State University, Bryce Ryan and Neal C. Gross. The diffusion paradigm spread to an invisible college of midwestern rural sociological researchers in the 1950s and 1960s, and then to a larger, interdisciplinary field of diffusion scholars. By the late 1960s, rural sociologists lost interest in diffusion studies, not because it was ineffective scientifically, but because of lack of support for such study as a consequence of farm overproduction and because most of the interesting research questions were thought to be answered.

Lowering the cost of lowering the cholesterol: a formulary policy for lovastatin

OBJECTIVES

To describe a medical center policy designed to contain the cost of using the lipid-lowering drug lovastatin in a primary care setting, to examine the effect of the policy on cost containment, and to examine physician acceptance of the policy.

SETTING

A Veterans Affairs medical center.

INTERVENTIONS

The policy made lovastatin available to physicians when failure of therapy with diet and two first-line drugs was documented on an order form. The form also contained educational information including prices and recommended niacin as the drug treatment of first choice for most patients.

DESIGN

To evaluate the effect of the policy, lipid-lowering drug use at the medical center was compared with that at a similar center that did not restrict lovastatin use, and with lipid-lowering drug use in the United States as a whole. A written questionnaire was used to survey physician reaction to the policy.

RESULTS

The use of lovastatin as a percentage of total lipid-lowering drug use at the center with the lovastatin policy was one-fourth that at the other center or nationwide, and the use of niacin was four times greater (p less than 0.0001). The estimated savings in drug costs to the center with the lovastatin policy due to these differences was more than $30,000 per year. In the survey of physicians affected by the policy (n = 78, response rate = 100%), less than one-fourth viewed it unfavorably, and 90% favored this policy over restricting the drug to a subspecialty clinic.

CONCLUSION

The authors' experience indicates that a formulary policy that permits limited use of an expensive drug in a primary care setting can contain costs in a way that is acceptable to physicians. A policy of this type could be useful to the increasing number of health care provider organizations that cover the cost of outpatient medications.

Lowering the cost of lowering the cholesterol: a formulary policy for lovastatin

OBJECTIVES

To describe a medical center policy designed to contain the cost of using the lipid-lowering drug lovastatin in a primary care setting, to examine the effect of the policy on cost containment, and to examine physician acceptance of the policy.

SETTING

A Veterans Affairs medical center.

INTERVENTIONS

The policy made lovastatin available to physicians when failure of therapy with diet and two first-line drugs was documented on an order form. The form also contained educational information including prices and recommended niacin as the drug treatment of first choice for most patients.

DESIGN

To evaluate the effect of the policy, lipid-lowering drug use at the medical center was compared with that at a similar center that did not restrict lovastatin use, and with lipid-lowering drug use in the United States as a whole. A written questionnaire was used to survey physician reaction to the policy.

RESULTS

The use of lovastatin as a percentage of total lipid-lowering drug use at the center with the lovastatin policy was one-fourth that at the other center or nationwide, and the use of niacin was four times greater (p less than 0.0001). The estimated savings in drug costs to the center with the lovastatin policy due to these differences was more than $30,000 per year. In the survey of physicians affected by the policy (n = 78, response rate = 100%), less than one-fourth viewed it unfavorably, and 90% favored this policy over restricting the drug to a subspecialty clinic.

CONCLUSION

The authors' experience indicates that a formulary policy that permits limited use of an expensive drug in a primary care setting can contain costs in a way that is acceptable to physicians. A policy of this type could be useful to the increasing number of health care provider organizations that cover the cost of outpatient medications.

Outpatient pharmacy redesign to improve work flow, waiting time, and patient satisfaction

An outpatient pharmacy redesign in which a pharmacist located outside the dispensing area speaks with each patient before the prescription is processed is described, and the effect of patients' waiting time and satisfaction is reported. Adoption of an open pharmacy plan at a Veterans Administration outpatient pharmacy allows patients to present their prescriptions to pharmacists in consultation booths equipped with computer terminals. The pharmacist promptly identifies and resolves any problem associated with a prescription or medication profile. The prescription then enters the dispensing work area, which was also redesigned to improve efficiency; patients now pick up their medications at a window on the opposite end of the dispensing area from where the pharmacist initially receives the prescription. Workload data and waiting times before and after implementation of the open pharmacy showed that prescriptions could be processed more quickly under the new system; average waiting times decreased from more than one hour to 30 minutes. Interviews of randomly selected patients indicated that the reduced waiting times led to increased patient satisfaction. The open pharmacy design appeared to improve work flow and to improve patient satisfaction by decreasing waiting times.

Traditional midwives and family planning in Asia

The objectives of this article are (1) review the contribution of traditional midwives to family planning communication in several Asian countries; (2) organize knowledge gathered from various studies into general guidelines for the most effective use of traditional midwives in family planning programs; and (3) present hypotheses for future research. In certain countries where pilot projects have tested the potential performance of traditional midwives in family planning programs, results have been encouraging. In other nations, more research is needed to determine the contribution traditional midwives can make to the family planning program.