Teaching clinicians and nurses to prepare for and present at interdisciplinary meetings through behavioral skills training.

Behavior analysts frequently collaborate with interdisciplinary colleagues to share information and make decisions about client services. This study evaluated the effects of behavioral skills training on preparation for and presentation during interdisciplinary review team meetings by clinicians (n = 4) and nurses (n = 4) at a residential school for students with intellectual and neurodevelopmental disabilities. The primary dependent measure was the percentage of preparation and presentation steps from task-analyzed behavior checklists that the participants implemented correctly. As evaluated by multiple-baseline designs, the participants improved their preparation and presentation skills to nearly 100% following behavioral skills training, maintained performance 1 month after the study, and rated training positively. We discuss elements of the training program, practice implications, and research directions.

Behavioral assessment and faded bedtime intervention for delayed sleep-onset in an adult with autism spectrum disorder.

Faded bedtime has been evaluated as a behavioral intervention for delayed sleep-onset principally with children and youth who have intellectual and developmental disabilities in hospital and home settings. The present case report describes behavioral assessment and faded bedtime intervention in a 21-year old adult man with autism spectrum disorder at a community-based group home. The study also documented the effects of family home visits on the man's sleep when he returned to the group home. Compared to a pre-intervention (baseline) phase, faded bedtime was associated with increased intervals of recorded sleep and a decrease in sleep-onset latency over several months of implementation. We discuss clinical implications of the case and generality of findings across populations and settings.

Psychotropic Medication Monitoring in a Human Services Organization for Children with Autism Spectrum Disorder: Description and Evaluation of Interdisciplinary Team Review.

Children with autism spectrum disorder (ASD) are often prescribed psychotropic medications but pharmacotherapy is typically conducted and evaluated based on clinical judgement without reference to objective measurement of treatment effectiveness and combined efficacy of pharmacological-behavioral interventions. We describe an interdisciplinary review team (IRT) model at a human services organization for children with ASD that was designed to standardize a process of psychotropic medication monitoring through (1) coordinated involvement of medical, nursing, behavior analyst, and special education professionals, (2) parent-guardian participation, (3) data-driven decision making, and (4) high-level administrative support. Our description includes case illustrations of medication reduction-elimination trials with five students and social validity assessment of IRT clinicians, nurses, and parent-guardians. Key components of the IRT model are emphasized with associated practice and research recommendations.

Behavioral Training and Performance Management of Human Services Organization Care Providers During the COVID-19 Pandemic.

Objectives: This report describes a model of training and performance management that was designed for and implemented with care providers at a residential school for children with neurodevelopmental and intellectual disabilities in response to the COVID-19 pandemic. The model focused on health and safety concerns, risk mitigation, and intervention integrity. Methods: Procedures followed an applied behavior analysis (ABA) and organizational behavior management (OBM) framework. Action plans addressed (a) critical COVID-19 protocols, (b) behavior-specific implementation guidelines, (c) remote and in-person training formats, (d) in vivo supervision, and (e) knowledge and performance assessments. Results: A competency evaluation (field study) revealed that participant care providers (N = 25) acquired and maintained COVID-19 protocols at near 100% proficiency immediately following and 1-month post-training. Supervisors had uniformly positive approval and acceptance ratings of school responsiveness to the COVID-19 pandemic. Conclusions: Integrated and evidence-based care provider training and supervisory practices can promote risk mitigation and performance effectiveness during health crises such as the COVID-19 pandemic. More controlled research that includes multiple dependent measures is needed to replicate and extend our findings to similar human services settings.

Teaching students with autism spectrum disorder to tolerate haircutting.

We describe intervention with 2 adolescent male students who had autism spectrum disorder (ASD) and resisted haircutting performed by care providers at a residential school. The students were exposed to a graduated hierarchy of steps including the presence of hair clippers, and increased duration of hair clippers against their scalp and hair. Edible reinforcement was presented contingent on completion of a step without interfering behavior. Both students learned to tolerate all of the steps in the graduated hierarchy and a full haircut with maintenance at 2-, 4-, and 6-month follow-up. The study supports previous tolerance-training research with children and youth who have intellectual and developmental disabilities and resist personal care and hygiene routines.

Improving Classroom Appearance and Organization Through a Supervisory Performance Improvement Intervention.

This study evaluated the effects of a supervisory intervention on maintenance of appearance and organization in classrooms at a human services program for children and youths. The intervention combined performance feedback to classroom staff, public posting of performance outcomes, and eligibility for a performance-based incentive. Conducted in a multiple-baseline design, intervention was immediately and consistently effective in all classrooms. These findings support organizational behavior management applications within human services programs to improve performance that is related to environmental care.

The synthesis of OspD3 (ShET2) in Shigella flexneri is independent of OspC1.

Shigella flexneri is a Gram-negative pathogen that invades the colonic epithelium and causes millions of cases of watery diarrhea or bacillary dysentery predominately in children under the age of 5 years in developing countries. The effector Shigella enterotoxin 2 (ShET2), or OspD3, is encoded by the sen or ospD3 gene on the virulence plasmid. Previous literature has suggested that ospD3 is in an operon downstream of the ospC1 gene, and expression of both genes is controlled by a promoter upstream of ospC1. Since the intergenic region is 328 bases in length and contains several putative promoter regions, we hypothesized the genes are independently expressed. Here we provide data that ospD3 and ospC1 are not co-transcribed and that OspC1 is not required for OspD3/ShET2 function. Most importantly, we identified strong promoter activity in the intergenic region and demonstrate that OspD3/ShET2 can be expressed and secreted independently of OspC1. This work increases our understanding of the synthesis of a unique virulence factor and provides further insights into Shigella pathogenesis.

Test-specific control conditions for functional analyses.

Most functional analyses of problem behavior include a common condition (play or noncontingent reinforcement) as a control for both positive and negative reinforcement. However, test-specific conditions that control for each potential source of reinforcement may be beneficial occasionally. We compared responding during alone, ignore, play, and differential reinforcement of other behavior (DRO) control conditions for individuals whose problem behavior was maintained by positive or negative reinforcement. Results showed that all of the conditions were effective controls for problem behavior maintained by positive reinforcement; however, the DRO condition was consistently ineffective as a control for problem behavior maintained by negative reinforcement. Implications for the design of functional analyses and future research are discussed.

Evaluation of the divided attention condition during functional analyses.

A common condition included in most functional analyses (FAs) is the attention condition, in which the therapist ignores the client by engaging in a solitary activity (antecedent event) but delivers attention to the client contingent on problem behavior (consequent event). The divided attention condition is similar, except that the antecedent event consists of the therapist conversing with an adult confederate. We compared the typical and divided attention conditions to determine whether behavior in general (Study 1) and problem behavior in particular (Study 2) were more sensitive to one of the test conditions. Results showed that the divided attention condition resulted in faster acquisition or more efficient FA results for 2 of 9 subjects, suggesting that the divided attention condition could be considered a preferred condition when resources are available.

Assessment and treatment of social avoidance.

Problem behavior maintained by social-negative reinforcement often is evoked by a specific type of social interaction--the presentation of task demands. This study involved assessment and treatment of a more general form of social avoidance in which the establishing operation (EO) for problem behavior consisted of social interaction per se. Four subjects exhibited high rates of problem behavior during the play or demand conditions of a functional analysis (FA). A subsequent FA in which problem behavior produced escape from social interaction confirmed social avoidance for all subjects. A series of interventions aimed at attenuating aversive characteristics of social interaction then was implemented with 3 of the subjects. These interventions included vicarious reinforcement, conditioning of social interaction as a reinforcer, stimulus fading, and differential reinforcement (DRA) plus extinction (EXT). DRA plus EXT was the only condition in which decreases in problem behavior and increases in social interactions were observed reliably.

Effects of alternative responses on behavior exposed to noncontingent reinforcement.

Noncontingent reinforcement (NCR) may decrease the frequency of behavior by either inducing satiation or terminating the response-reinforcer contingency (extinction). Another possibility is that the target behavior is replaced by other behaviors maintained by preexisting contingencies. We conducted 2 experiments in which we allowed access to a target response and several alternatives. In Experiment 1, NCR, preceded by contingent reinforcement (CR) for the target, produced a reduction in the target and an increase in the alternatives in 2 subjects with intellectual disabilities. To separate the effects of NCR from the availability of alternative responses, we presented CR conditions to 4 subjects in Experiment 2 with and without the availability of alternatives. The availability of alternatives decreased the target in only 1 subject. Subsequent manipulations showed that reductions in the target were solely a function of NCR for the other 3 subjects. Thus, response competition may have marginal effects on response suppression during NCR.

Chromosomal and plasmid-encoded factors of Shigella flexneri induce secretogenic activity ex vivo.

Shigella flexneri is a Gram-negative, facultative intracellular pathogen that causes millions of cases of watery or bloody diarrhea annually, resulting in significant global mortality. Watery diarrhea is thought to arise in the jejunum, and subsequent bloody diarrhea occurs as a result of invasion of the colonic epithelium. Previous literature has demonstrated that Shigella encodes enterotoxins, both chromosomally and on the 220 kilobase virulence plasmid. The ShigellaEnterotoxins 1 and 2 (ShET1 and ShET2) have been shown to increase water accumulation in the rabbit ileal loop model. In addition, these toxins increase the short circuit current in rabbit tissue mounted in Ussing chambers, which is a model for the ion exchange that occurs during watery diarrhea. In this study, we sought to validate the use of mouse jejunum in Ussing chamber as an alternative, more versatile model to study bacterial pathogenesis. In the process, we also identified enterotoxins in addition to ShET1 and ShET2 encoded by S. flexneri. Through analysis of proteins secreted from wildtype bacteria and various deletion mutants, we have identified four factors responsible for enterotoxin activity: ShET1 and Pic, which are encoded on the chromosome; ShET2 (encoded by sen or ospD3), which requires the type-III secretion system for secretion; and SepA, an additional factor encoded on the virulence plasmid. The use of mouse jejunum serves as a reliable and reproducible model to identify the enterotoxins elaborated by enteric bacteria. Moreover, the identification of all Shigella proteins responsible for enterotoxin activity is vital to our understanding of Shigella pathogenicity and to our success in developing safe and effective vaccine candidates.

Elimination of position-biased responding in individuals with autism and intellectual disabilities.

Five individuals with autism or other developmental disabilities participated in paired-stimulus preference assessments during repeated baseline probes. All subjects initially showed a pronounced bias by typically selecting the stimulus placed in either the left or right position. Biased responding for 3 subjects was eliminated when training trials were conducted in which a stimulus of known lesser quality was presented as one of the choices. Reinforcer-quality training was unsuccessful for 2 subjects, as was a condition in which reinforcer magnitude was modified to favor unbiased responding. These subjects' biased responding was eliminated only when a correction procedure (repetition of error trials) was implemented.

False-positive tangible outcomes of functional analyses.

Functional analysis (FA) methodology is the most precise method for identifying variables that maintain problem behavior. Occasionally, however, results of an FA may be influenced by idiosyncratic sensitivity to aspects of the assessment conditions. For example, data from several studies suggest that inclusion of a tangible condition during an FA may be prone to a false-positive outcome, although the extent to which tangible reinforcement routinely produces such outcomes is unknown. We examined susceptibility to tangible reinforcement by determining whether a new response was acquired more readily when exposed to a tangible contingency relative to others commonly used in an FA (Study 1), and whether problem behavior known not to have a social function nevertheless emerged when exposed to tangible reinforcement (Study 2). Results indicated that inclusion of items in the tangible condition should be done with care and that selection should be based on those items typically found in the individual's environment.

Enteroaggregative Escherichia coli disrupts epithelial cell tight junctions.

Enteroaggregative Escherichia coli (EAEC) is responsible for inflammatory diarrhea in diverse populations, but its mechanisms of pathogenesis have not been fully elucidated. We have used a previously characterized polarized intestinal T84 cell model to investigate the effects of infection with EAEC strain 042 on tight junction integrity. We find that infection with strain 042 induces a decrease in transepithelial electrical resistance (TER) compared to uninfected controls and to cells infected with commensal E. coli strain HS. When the infection was limited after 3 h by washing and application of gentamicin, we observed that the TER of EAEC-infected monolayers continued to decline, and they remained low even as long as 48 h after the infection. Cells infected with the afimbrial mutant strain 042aafA exhibited TER measurements similar to those seen in uninfected monolayers, implicating the aggregative adherence fimbriae II (AAF/II) as necessary for barrier dysfunction. Infection with wild-type strain 042 induced aberrant localization of the tight junction proteins claudin-1 and, to a lesser degree, occludin. EAEC-infected T84 cells exhibited irregular shapes, and some cells became elongated and/or enlarged; these effects were not observed after infection with commensal E. coli strain HS or 042aafA. The effects on tight junctions were also observed with AAF/I-producing strain JM221, and an afimbrial mutant was similarly deficient in inducing barrier dysfunction. Our results show that EAEC induces epithelial barrier dysfunction in vitro and implicates the AAF adhesins in this phenotype.

An in vitro system to model the establishment and reactivation of HIV-1 latency.

HIV-1 establishes latency primarily by infecting activated CD4(+) T cells that later return to quiescence as memory cells. Latency allows HIV-1 to evade immune responses and to persist during antiretroviral therapy, which represents an important problem in clinical practice. The lack of a valid cellular model to study HIV-1 latency has hindered advances in the understanding of its biology. In this study, we attempted to model HIV-1 latency using human primary CD4(+) T cells infected in vitro with HIV-1 after activation with Ag-loaded dendritic cells and then brought back to quiescence through a resting phase in the presence of IL-7. During the resting phase, expression of cellular activation markers disappeared and cell proliferation and viral replication ceased, but resumed following restimulation of rested cells with Ag or mAbs directed to CD3/CD28. In addition, higher cell death rates were observed in HIV-1-infected than uninfected cultures during secondary but not primary stimulation. Thus, this system may allow us to study the biology of HIV-1 latency, as well as the mechanisms of CD4(+) T cell death following HIV-1 reactivation.

Increased interferon alpha expression in circulating plasmacytoid dendritic cells of HIV-1-infected patients.

BACKGROUND: The role of plasmacytoid dendritic cells (pDC) and interferon alpha (IFN alpha) in HIV-1 infection is still unclear. On one hand, HIV-1 disease is associated with a progressive decline of pDC, which displays reduced ability to produce IFN alpha after in vitro challenge. On the other hand, high IFN alpha serum levels in HIV-1-infected individuals have been proposed to promote immune hyper-activation and disease progression. METHODS: We sought to determine whether disappearance of pDC in HIV-1 disease is due to homing in lymphoid tissues. We also studied IFN alpha and myxovirus resistance protein A (MxA) expression in unstimulated pDC and correlated these results with selected clinical and laboratory parameters. RESULTS: We found that pDC decline markedly in peripheral blood of patients progressing to disease but at the same time express much higher levels of IFN alpha and MxA compared to control individuals. On the other hand, we observed steady pDC counts in lymph nodes of HIV-1 patients. The frequency of circulating pDC correlated directly with CD4 cell counts and inversely with viral load. However, we found no correlation between IFN alpha and MxA expression levels, CD4 counts, and viral load. CONCLUSIONS: Circulating pDC decline sharply in the course of HIV-1 disease, but express high levels of IFN alpha, which may represent a hallmark of systemic immune dysfunction.

A transient forward-targeting element for microneme-regulated secretion in Toxoplasma gondii.

BACKGROUND INFORMATION: Accurate sorting of proteins to the three types of secretory granules in Toxoplasma gondii is crucial for successful cell invasion by this obligate intracellular parasite. As in other eukaryotic systems, propeptide sequences are a common yet poorly understood feature of proteins destined for regulated secretion, which for Toxoplasma occurs through two distinct invasion organelles, rhoptries and micronemes. Microneme discharge during parasite apical attachment plays a pivotal role in cell invasion by delivering adhesive proteins for host receptor engagement. RESULTS: We show here that the small micronemal proprotein MIC5 (microneme protein-5) undergoes proteolytic maturation at a site beyond the Golgi, and only the processed form of MIC5 is secreted via the micronemes. Proper cleavage of the MIC5 propeptide relies on an arginine residue in the P1' position, although P1' mutants are still cleaved to a lesser extent at an alternative site downstream of the primary site. Nonetheless, this aberrantly cleaved species still correctly traffics to the micronemes, indicating that correct cleavage is not necessary for micronemal targeting. In contrast, a deletion mutant lacking the propeptide was retained within the secretory system, principally in the ER (endoplasmic reticulum). The MIC5 propeptide also supported correct trafficking when exchanged for the M2AP propeptide, which was recently shown to also be required for micronemal trafficking of the TgMIC2 (T. gondii MIC2)-M2AP complex [Harper, Huynh, Coppens, Parussini, Moreno and Carruthers (2006) Mol. Biol. Cell 17, 4551-4563]. CONCLUSION: Our results illuminate common and unique features of micronemal propeptides in their role as trafficking facilitators.

Targeted deletion of MIC5 enhances trimming proteolysis of Toxoplasma invasion proteins.

Limited proteolysis of proteins transiently expressed on the surface of the opportunistic pathogen Toxoplasma gondii accompanies cell invasion and facilitates parasite migration across cell barriers during infection. However, little is known about what factors influence this specialized proteolysis or how these proteolytic events are regulated. Here we show that genetic ablation of the micronemal protein MIC5 enhances the normal proteolytic processing of several micronemal proteins secreted by Toxoplasma tachyzoites. Restoring MIC5 expression by genetic complementation reversed this phenotype, as did treatment with the protease inhibitor ALLN, which was previously shown to block the activity of a hypothetical parasite surface protease called MPP2. We show that, despite its lack of obvious membrane association signals, MIC5 occupies the parasite surface during invasion in the vicinity of the proteins affected by enhanced processing. Proteolysis of other secretory proteins, including GRA1, was also enhanced in MIC5 knockout parasites, indicating that the phenotype is not strictly limited to proteins derived from micronemes. Together, our findings suggest that MIC5 either directly regulates MPP2 activity or it influences MPP2's ability to access substrate cleavage sites on the parasite surface.

A cleavable propeptide influences Toxoplasma infection by facilitating the trafficking and secretion of the TgMIC2-M2AP invasion complex.

Propeptides regulate protein function and trafficking in many eukaryotic systems and have emerged as important features of regulated secretory proteins in parasites of the phylum Apicomplexa. Regulated protein secretion from micronemes and host cell invasion are inextricably linked and essential processes for the apicomplexan parasite Toxoplasma gondii. TgM2AP is a propeptide-containing microneme protein found in a heterohexameric complex with the microneme protein TgMIC2, a protein that has a demonstrated fundamental role in gliding motility and invasion. TgM2AP function is also central to these processes, because disruption of TgM2AP (m2apKO) results in secretory retention of TgMIC2, leading to reduced TgMIC2 secretion from the micronemes and impaired invasion. Because the TgM2AP propeptide is predicted to be processed in an intracellular site near where TgMIC2 is retained in m2apKO parasites, we hypothesized that the propeptide and its proteolytic removal influence trafficking and secretion of the complex. We found that proTgM2AP traffics through endosomal compartments and that deletion of the propeptide leads to defective trafficking of the complex within or near this site, resulting in aberrant processing and decreased secretion of TgMIC2, impaired invasion, and reduced virulence in vivo, mirroring the phenotypes observed in m2apKO parasites. In contrast, mutation of several cleavage site residues resulted in normal localization, but it affected the stability and secretion of the complex from the micronemes. Therefore, the propeptide and its cleavage site influence distinct aspects of TgMIC2-M2AP function, with both impacting the outcome of infection.