The stacking concept: cannulated screws for extra-articular metacarpal base fracture of the thumb

An alternative technique to treat extra-articular fractures of the base of the first metacarpal with intramedullary canulated headless screws is presented. The principle is creating an internal fixator within the medullary canal by introducing multiple retrograde screws until they have jammed.

Genome sequence and annotation of the B3 mycobacteriophage Phayeta

Mycobacteriophage Phayeta was extracted from soil near Myrtle Beach, South Carolina using Mycobacterium smegmatis as a host. Annotation of the 68,700 base-pair circularly permuted genome identified 104 predicted protein-encoding genes, 34 of which have functional assignments.

Genome sequences of six cluster CT and two cluster DJ bacteriophages that infect Gordonia rubripertincta

We report the genome sequences of eight bacteriophages isolated using Gordonia rubripertincta NRRL B-16540-SEA. Based on gene content similarity to phages in the Actinobacteriophage database, six of the phages are assigned to phage cluster CT while two are assigned to cluster DJ.

Collapse after Carpal Bone Tunneling. An Underreported Complication?

PURPOSE

To report the complication of carpal bone tunnel collapse in scapholunate reconstruction.

METHODS

The authors present six cases of carpal collapse or bone necrosis after bone tunneling for ligamentous reconstruction, three in the scaphoid bone and three in the lunate.

RESULTS

All six cases were secondary to ligament reconstruction for chronic scapholunate dissociations, none of which had preoperative structural scaphoid or lunate deformities.

CONCLUSIONS

Although the incidence of this occurrence is unknown, the consequences could be substantial; therefore, patients should be warned of this possibility when discussing complications of ligament reconstruction for chronic scapholunate instability requiring the creation of a bone tunnel.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Arthroscopic Management of Distal Radius Fractures and Malunions

Articular congruity is the most important prognostic factor when dealing with a distal intra-articular radius fracture or the correction of intra-articular malunion. This article details our approach with tips and tricks for effectively managing these complex injuries with the aid of dry arthroscopy.

Multidimensional Evaluation of Screening Brief Intervention and Referral to Treatment Training for Medical Students

OBJECTIVE

Screening, Brief Intervention, and Referral to Treatment (SBIRT) is an evidence-based approach to identifying and addressing alcohol use in non-specialty settings. Many medical schools teach SBIRT, but most published evaluations of these efforts exclude rigorous skill assessments and teaching methods.

METHODS

During the 2017-2018 academic year, 146 third-year medical students received classroom-based learning on SBIRT and motivational interviewing (MI) and at least two SBIRT practices with feedback as part of a 4-week psychiatry clerkship. The objective of this curriculum was to improve SBIRT knowledge, attitudes, and confidence and enable learners to skillfully deliver SBIRT. Outcomes evaluated included satisfaction, knowledge, attitudes and confidence, and clinical skill in delivering SBIRT to a standardized patient (rated by the actor, as well as an expert).

RESULTS

Results indicated acceptable satisfaction at post-curriculum and significant improvements in attitudes and knowledge from pre- to post-curriculum. On the clinical skills exam, all students were rated as having mastered at least 80% of SBIRT elements by standardized patients and 91.8% were rated at this level by a faculty expert. Student attitudes and knowledge were unrelated to expert ratings, and standardized patient ratings had limited associations with expert ratings.

CONCLUSIONS

These results suggest curriculum objectives were achieved and provide unique contributions to the SBIRT curricular outcome research for healthcare trainees. Other findings included that trainee knowledge and confidence may not relate to skill, and standardized patient feedback provides different information on SBIRT and MI skill than expert ratings.

The Status of SBIRT Training in Health Professions Education: A Cross-Discipline Review and Evaluation of SBIRT Curricula and Educational Research

PURPOSE

To assess the quality of curricular research on the Screening Brief Intervention and Referral to Treatment (SBIRT) approach and determine the presence of useful training modalities, particularly motivational interviewing (MI) training, across health care training curricula.

METHOD

The authors conducted a systematic review of published, peer-reviewed studies in PubMed, ERIC, CINAHL, Ovid HealthSTAR, and PsycINFO databases through March 2021 for English-language studies describing SBIRT, a curriculum for health care trainees, and curricular intervention outcomes. After the records were independently assessed, data were extracted and 20% of the studies were double-coded for interrater reliability.

RESULTS

Of 1,856 studies, 95 were included in the review; 22 had overlapping samples and were consolidated into 10 nested studies, leaving 83 total. Interrater reliability ranged from moderate (κ = .74, P < .001) to strong (κ = .91, P < .001) agreement. SBIRT training was delivered to trainees across many professions, including nursing (n = 34, 41%), medical residency (n = 28, 34%), and social work (n = 24, 29%). Nearly every study described SBIRT training methods (n = 80, 96%), and most reported training in MI (n = 54, 65%). On average, studies reported 4.06 (SD = 1.64) different SBIRT training methods and 3.31 (SD = 1.59) MI training methods. Their mean design score was 1.92 (SD = 0.84) and mean measurement score was 1.89 (SD = 1.05). A minority of studies measured SBIRT/MI skill (n = 23, 28%), and 4 studies (5%) set a priori benchmarks for their curricula.

CONCLUSIONS

SBIRT training has been delivered to a wide range of health care trainees and often includes MI. Rigor scores for the studies were generally low due to limited research designs and infrequent use of objective skill measurement. Future work should include predefined training benchmarks and validated skills measurement.

Impact of COVID-19 on Admissions and Outcomes for Children With Complex Chronic Conditions

BACKGROUND

Although pediatric health care use declined during the coronavirus disease 2019 (COVID-19) pandemic, the impact on children with complex chronic conditions (CCCs) has not been well reported.

OBJECTIVE

To describe the impact of the pandemic on inpatient use and outcomes for children with CCCs.

METHODS

This multicenter cross-sectional study used data from the Pediatric Health Information System. We examined trends in admissions between January 2020 through March 2021, comparing them to the same timeframe in the previous 3 years (pre-COVID-19). We used generalized linear mixed models to examine the association of the COVID-19 period and outcomes for children with CCCs presenting between March 16, 2020 to March 15, 2021 (COVID-19 period) to the same timeframe in the previous 3 years (pre-COVID-19).

RESULTS

Children with CCCs experienced a 19.5% overall decline in admissions during the COVID-19 pandemic. Declines began in the second week of March of 2020, reaching a nadir in early April 2020. Changes in admissions varied over time and by admission indication. Children with CCCs hospitalized for pneumonia and bronchiolitis experienced overall declines in admissions of 49.7% to 57.7%, whereas children with CCCs hospitalized for diabetes experienced overall increases in admissions of 21.2%. Total and index length of stay, costs, and ICU use, although statistically higher during the COVID-19 period, were similar overall to the pre-COVID-19 period.

CONCLUSIONS

Total admissions for children with CCCs declined nearly 20% during the pandemic. Among prevalent conditions, the greatest declines were observed for children with CCCs hospitalized with respiratory illnesses. Despite declines in admissions, overall hospital-level outcomes remained similar.

Instructional Models for Course-Based Research Experience (CRE) Teaching

The course-based research experience (CRE) with its documented educational benefits is increasingly being implemented in science, technology, engineering, and mathematics education. This article reports on a study that was done over a period of 3 years to explicate the instructional processes involved in teaching an undergraduate CRE. One hundred and two instructors from the established and large multi-institutional SEA-PHAGES program were surveyed for their understanding of the aims and practices of CRE teaching. This was followed by large-scale feedback sessions with the cohort of instructors at the annual SEA Faculty Meeting and subsequently with a small focus group of expert CRE instructors. Using a qualitative content analysis approach, the survey data were analyzed for the aims of inquiry instruction and pedagogical practices used to achieve these goals. The results characterize CRE inquiry teaching as involving three instructional models: 1) being a scientist and generating data; 2) teaching procedural knowledge; and 3) fostering project ownership. Each of these models is explicated and visualized in terms of the specific pedagogical practices and their relationships. The models present a complex picture of the ways in which CRE instruction is conducted on a daily basis and can inform instructors and institutions new to CRE teaching.

Inpatient Use and Outcomes at Children's Hospitals During the Early COVID-19 Pandemic

BACKGROUND AND OBJECTIVES

The coronavirus disease 2019 (COVID-19) pandemic has led to changes in health care use, including decreased emergency department visits for children. In this study, we sought to describe the impact of the COVID-19 pandemic on inpatient use within children's hospitals.

METHODS

We performed a retrospective study using the Pediatric Health Information System. We compared inpatient use and clinical outcomes for children 0 to 18 years of age during the COVID-19 period (March 15 to August 29, 2020) to the same time frame in the previous 3 years (pre-COVID-19 period). Adjusted generalized linear mixed models were used to examine the association of the pandemic period with inpatient use. We assessed trends overall and for a subgroup of 15 medical All Patient Refined Diagnosis Related Groups (APR-DRGs).

RESULTS

We identified 424 856 hospitalizations (mean: 141 619 hospitalizations per year) in the pre-COVID-19 period and 91 532 in the COVID-19 period. Compared with the median number of hospitalizations in the pre-COVID-19 period, we observed declines in hospitalizations overall (35.1%), and by APR-DRG (range: 8.5%-81.3%) with asthma (81.3%), bronchiolitis (80.1%), and pneumonia (71.4%) experiencing the greatest declines. Overall readmission rates were lower during the COVID-19 period; however, other outcomes, including length of stay, cost, ICU use, and mortality remained similar to the pre-COVID-19 period with some variability by APR-DRGs.

CONCLUSIONS

US children's hospitals observed substantial reductions in inpatient admissions with largely unchanged hospital-level outcomes during the COVID-19 pandemic. Although the impact on use varied by condition, the most notable declines were related to inpatient admissions for respiratory conditions, including asthma, bronchiolitis, and pneumonia.

Practice and Dissemination of Motivational Interviewing: A Psychology Internship Curriculum

Sufficient training in substance use issues has been identified as a common gap in professional psychology graduate training. Satisfactory training in evidence-based practices has also been identified as a common gap for providers who care for individuals with substance use problems. The "practice and dissemination" curriculum we developed seeks to address both of these gaps during the predoctoral internship training year by first training psychology interns to competently deliver motivational interviewing (MI) to individuals with substance use problems and then train community providers and volunteers to do so. From 2012-2013, a total of 55 community providers and volunteers from a homeless shelter, a substance use treatment facility, and a community mental health facility received training in MI through this curriculum by attending continuing education events delivered by 17 psychology interns. Evaluation of the dissemination portion of the curriculum as part of an exempt educational research project revealed that community providers were able to achieve significant increases in MI knowledge, readiness to implement MI, and MI skill as assessed with a video analogue measure by the end of the workshop. They also reported satisfaction with the workshop. These evaluation findings provide preliminary support for the curriculum as a novel and efficacious way to disseminate MI to community providers. Research is necessary to determine long-term outcomes of such training and to identify strategies to overcome potential barriers such as the substantial faculty effort necessary to implement the intensive curriculum.

Genomic diversity of bacteriophages infecting Microbacterium spp

The bacteriophage population is vast, dynamic, old, and genetically diverse. The genomics of phages that infect bacterial hosts in the phylum Actinobacteria show them to not only be diverse but also pervasively mosaic, and replete with genes of unknown function. To further explore this broad group of bacteriophages, we describe here the isolation and genomic characterization of 116 phages that infect Microbacterium spp. Most of the phages are lytic, and can be grouped into twelve clusters according to their overall relatedness; seven of the phages are singletons with no close relatives. Genome sizes vary from 17.3 kbp to 97.7 kbp, and their G+C% content ranges from 51.4% to 71.4%, compared to ~67% for their Microbacterium hosts. The phages were isolated on five different Microbacterium species, but typically do not efficiently infect strains beyond the one on which they were isolated. These Microbacterium phages contain many novel features, including very large viral genes (13.5 kbp) and unusual fusions of structural proteins, including a fusion of VIP2 toxin and a MuF-like protein into a single gene. These phages and their genetic components such as integration systems, recombineering tools, and phage-mediated delivery systems, will be useful resources for advancing Microbacterium genetics.

Patient related outcome measures for breast augmentation mammoplasty: a systematic review

We review the current literature for validated patient related outcome measures (PROM) in breast augmentation mammoplasty (BAM). Using Medline search between 1966 to 2018, using the search strategy ("patient reported outcome measure" OR "surveys or questionnaires") AND "breast" AND ("augment" OR "implant") was performed. A manual search with Google Scholar using the search term "Patient Reported Outcome Measures in Bilateral Augmentation Mammaplasty" was also performed. Once the search yielded its results, a further search of bibliographic references within the articles was also performed. The Medline computer search produced 72 results, with a Google Scholar search yielding two results and a bibliographic search of all articles revealing a further single result. Ten studies were included as they used validated PROM. Three articles used the same PROM (Breast-Q) and seven used different PROM, therefore 8 validated PROM were discovered. Bilateral augmentation mammoplasty has been demonstrated to confer an increase in patient reported outcomes in domains of satisfaction with breasts and psychological well-being. There is some decrease in physical well-being following this procedure. Validated PROMs provide objective data relating to different aspects of BAM. Combined with traditional surgeon-based outcome measures and implant registry data, they may provide a more comprehensive insight into the patient journey.

Selected nitrostyrene compounds demonstrate potent activity in chronic lymphocytic leukaemia cells, including those with poor prognostic markers

The nitrostyrene scaffold was previously identified as a lead target structure for the development of effective compounds targeting Burkitt's lymphoma. The present study aimed to develop these compounds further in haematological malignancies, including chronic lymphocytic leukaemia (CLL). Cellular viability, flow cytometry and lactate dehydrogenase assays, amongst others, were used to examine the effects of nitrostyrene compounds on CLL cells, including a cell line representing disease with poor prognosis (HG‑3) and in ex vivo CLL patient samples (n=14). The results demonstrated that two representative nitrostyrene compounds potently induced apoptosis in CLL cells. The pro‑apoptotic effects of the compounds were found to be reactive oxygen species and caspase‑dependent, and had minimal effects on the viability of normal donor peripheral blood mononuclear cells. Nitrostyrene compounds exhibited synergistic augmentation of apoptosis when combined with the phosphatidylinositol 3‑kinase inhibitor idelalisib and demonstrated potent toxicity in ex vivo CLL cells, including those co‑cultured with bone marrow stromal cells, making them more resistant to apoptosis (n=8). These compounds also demonstrated activity in samples from patients with poor prognostic indicators; unmutated immunoglobulin heavy chain genes, expression of CD38 and deletions in chromosomes 17p and 11q. These results suggest that this class of pharmaceutically active compounds offer potential in the treatment of CLL.

Genetic analysis of KillerRed in C. elegans identifies a shared role of calcium genes in ROS-mediated neurodegeneration

In C. elegans, neurodegeneration induced by excitotoxicity or aggregation of misfolded proteins is dependent on genes involved in calcium release from the endoplasmic reticulum. Reactive oxygen species (ROS) can also induce neurodegeneration, but the relationship between ROS-mediated neurodegeneration and calcium has not been established. We activated KillerRed in the GABA neurons of C. elegans to produce ROS that leads to functional loss and structural degeneration of these neurons and demonstrated that the severity of neurodegeneration was dependent on extent of KillerRed activation. To genetically examine the role of calcium in ROS-mediated neurodegeneration, we measured functional neurodegeneration in itr-1 (inositol trisphosphate receptor), crt-1 (caltreticulin), and unc-68 (ryanodine receptor) mutants. Similar to other neurotoxic conditions, neurodegeneration triggered by KillerRed was reduced in itr-1 and crt-1 mutants. Somewhat unexpectedly, genetic or pharmacological disruption of unc-68 had a minimal effect on neurodegeneration. Our results indicate ROS-mediated neurodegeneration occurs through a conserved calcium regulated mechanism and suggest that components of the degeneration process have different sensitivities to ROS.

Motivational interviewing training of substance use treatment professionals: A systematic review

Background: Through evaluations of training programs, systematic reviews, and meta-analyses, advances in identifying best practices for disseminating motivational interviewing (MI) have emerged. To advance this work further, inclusion of thorough descriptions of the following is needed in research publications: study (design, trainee characteristics, setting characteristics), training and coaching methods (if applicable), trainer qualifications, and evaluation of MI skills. Methods: The purpose of this study was to systematically evaluate the research on MI training of substance use treatment professionals for the inclusion of such descriptions. Twenty-five studies were reviewed using a scoring rubric developed by the authors. Results: Just over two thirds of the studies (68%) were randomized controlled trials of MI training. The majority of studies provided information about (a) trainee characteristics (professional background = 76%, education = 60%, experience = 56%); (b) setting characteristics (80%); (c) training methods (format = 96%, length = 92%); (d) coaching (76%); and (e) evaluation of MI skills (92%). Conclusion: Findings suggest advancements in MI training studies since previous reviews, especially in regards to the inclusion of feedback and coaching. However, this review also found that inconsistencies in methods and reporting of training characteristics, as well as limited follow-up assessment of trainees' skill, continue to limit knowledge of effective training methods.

Brief Report: Competency-Based Supervision in Motivational Interviewing for Advanced Psychology Trainees: Targeting an A Priori Benchmark

Motivational interviewing (MI) is an evidence based intervention with considerable support for promoting behavior change across a broad range of health and mental health issues. Despite its effectiveness, challenges associated with learning the approach may limit its full implementation in many clinical settings. The aim of the present study was to evaluate a supervised MI training practicum implemented within a doctoral internship/postdoctoral fellowship training Program. The goal of the practicum was to enable each trainee to achieve expert competence in MI. Participants were 29 psychology doctoral interns and 1 postdoctoral fellow who participated in the training as part of their internship or fellowship program. Training included an initial workshop followed by a supervised practicum during which progress towards an a priori established expert competence benchmark was tracked through the use of an established coding system. Results indicated that trainees were satisfied with the supervision received. Three trainees did not achieve the a priori benchmark due to schedule conflicts. The 27 trainees who achieved the benchmark required between 4 and 20 supervision sessions to do so (mean = 9.22, SD = 3.77). With the exception of reflective listening skill, prior training, baseline skill, and self-reported motivation were not associated with number of supervision sessions required to achieve the benchmark. Implications for training and dissemination of MI in clinical settings are discussed.

Management of Pediatric Isolated Skull Fractures: A Decision Tree and Cost Analysis on Emergency Department Disposition Strategies

OBJECTIVE

Pediatric isolated skull fractures (ISFs) are common injuries that represent challenging disposition decisions for clinicians. The purpose of this study is to use a decision analysis to compare the clinical and cost-effectiveness of 3 emergency department (ED)-based disposition scenarios for a pediatric patient presenting with ISF.

METHODS

We conducted a cost-effectiveness analysis comparing ED disposition scenarios that included current practice, increased at-home surveillance, and observation unit utilization. Current rates of admission, deterioration after initial diagnosis, and ED return after discharge, as well as cost of observation-only status, were obtained through literature review. Cost calculations using Healthcare Cost and Utilization Project data included total ED cost, admission without complication, and admission with deterioration.

RESULTS

In current practice, 76% of subjects with ISF are admitted and 2.5% of those develop persistent or new symptoms. No patient diagnosed with ISF required neurosurgical intervention. Of those discharged home from the ED, 2.8% return with a new concern with 7.4% having new findings on imaging leading to admission. Total cost per 100 patients by current practice was US $583,587. Increasing at-home surveillance by 20% resulted in a total cost saving of US $113,176 per 100 patients while increasing returns to the ED from less than 1% to 1.1%. Admitting at the current rate to an observation unit resulted in a US $205,395 cost saving per 100 patients.

CONCLUSIONS

Decreased inpatient utilization through home surveillance or observation unit use reduced cost associated with pediatric ISF management without increasing clinical risk owing to the low probability of clinical deterioration after initial diagnosis.

Clinical Implications and Hospital Outcome of Immune-Mediated Myositis in Horses

BACKGROUND

Immune-mediated myositis (IMM) is a cause of rhabdomyolysis, stiffness, and muscle atrophy predominantly affecting Quarter horses. Limited information is available with regard to outcome, prognostic indicators, and associations with concurrent diseases.

HYPOTHESIS/OBJECTIVES

To report outcomes and associations between outcome and clinical and laboratory parameters, and presence of concurrent illness.

ANIMALS

Sixty-eight horses; 52 Quarter horses and related breeds and 16 other breeds.

METHODS

Retrospective cohort study (1991-2014). Medical records of horses with histological diagnosis of IMM were reviewed. Data recovery included signalment, laboratory variables, therapy, and outcome. Logistic regression was used to quantify the association between potential prognostic factors and survival to discharge.

RESULTS

Quarter horses were younger (mean < 4 years, range 3 months-21 years) than other breeds (mean < 10 years, range 1-23 years). Pathogens causing concurrent or recent infection included S. equi equi, S. equi zooepidemicus, C. pseudotuberculosis, Anaplasma phagocytophilum, herpes virus-1, and influenza. The most common clinical signs consisted of rapidly progressive diffuse symmetrical muscle atrophy (80%), stiff gait (74%), and fever (44%). All horses that received medical therapy immediately upon admission survived to discharge (survival proportion = 87%). Leucocytosis was a common finding (60%). Horses with concurrent fever and other illness had a poor prognosis for hospital discharge.

CONCLUSIONS AND CLINICAL IMPORTANCE

Horses with IMM can have a favorable outcome. Horses with concurrent fever and another illness had decreased probability of survival to discharge.

Pre-clinical evaluation of a novel class of anti-cancer agents, the Pyrrolo-1, 5-benzoxazepines

Microtubules are currently ranked one of the most validated targets for chemotherapy; with clinical use of microtubule targeting agents (MTAs) extending beyond half a century. Recent research has focused on the development of novel MTAs to combat drug resistance and drug associated toxicities. Of particular interest are compounds structurally different to those currently used within the clinic. The pyrrolo-1, 5-benzoxazepines (PBOXs) are a structurally distinct novel group of anti-cancer agents, some of which target tubulin. Herein, we review the chemistry, mechanism of action, preclinical development of the PBOXs and comparisons with clinically relevant chemotherapeutics. The PBOXs induce a range of cellular responses including; cell cycle arrest, apoptosis, autophagy, anti-vascular and anti-angiogenic effects. The apoptotic potential of the PBOXs extends across a wide spectrum of cancer-derived cell lines, by targeting tubulin and multiple molecular pathways frequently deregulated in human cancers. Extensive experimental data suggest that combining the PBOXs with established chemotherapeutics or radiation is therapeutically advantageous. Pre-clinical highlights of the PBOXs include; cancer specificity and improved therapeutic efficacy as compared to some current first line therapeutics.

Diagnostic Concordance between DSM-5 and ICD-10 Cannabis Use Disorders

OBJECTIVES

With the recent federal mandate that all U.S. health care settings transition to ICD-10 billing codes, empirical evidence is necessary to determine if the DSM-5 designations map to their respective ICD-10 diagnostic categories/billing codes. The present study examined the concordance between DSM-5 and ICD-10 cannabis use disorder diagnoses.

METHOD

Data were derived from routine clinical assessments of 6871 male and 801 female inmates recently admitted to a state prison system from 2000 to 2003. DSM-5 and ICD-10 diagnostic determinations were made from algorithms corresponding to the respective diagnostic formulations.

RESULTS

Past 12-month prevalence rates of cannabis use disorders were comparable across classification systems. The vast majority of inmates with no DSM-5 diagnosis continued to have no diagnosis per the ICD-10, and a similar proportion with a DSM-5 severe diagnosis received an ICD-10 dependence diagnosis. Most of the variation in diagnostic classifications was accounted for by those with a DSM-5 moderate diagnosis in that approximately half of these cases received an ICD-10 dependence diagnosis while the remaining cases received a harmful use diagnosis.

CONCLUSIONS

Although there appears to be a generally high level of agreement between diagnostic classification systems for those with no diagnosis or those evincing symptoms of a more severe condition, concordance between DSM-5 moderate and ICD-10 dependence diagnoses was poor. Additional research is warranted to determine the appropriateness and implications of the current DSM-5 coding guidelines regarding the assignment of an ICD-10 dependence code for those with a DSM-5 moderate diagnosis.

Qualitative and Quantitative Characteristics of the Electroencephalogram in Normal Horses during Administration of Inhaled Anesthesia

BACKGROUND

The effects of anesthesia on the equine electroencephalogram (EEG) after administration of various drugs for sedation, induction, and maintenance are known, but not that the effect of inhaled anesthetics alone for EEG recording.

OBJECTIVE

To determine the effects of isoflurane and halothane, administered as single agents at multiple levels, on the EEG and quantitative EEG (qEEG) of normal horses.

ANIMALS

Six healthy horses.

METHODS

Prospective study. Digital EEG with video and quantitative EEG (qEEG) were recorded after the administration of one of the 2 anesthetics, isoflurane or halothane, at 3 alveolar doses (1.2, 1.4 and 1.6 MAC). Segments of EEG during controlled ventilation (CV), spontaneous ventilation (SV), and with peroneal nerve stimulation (ST) at each MAC multiple for each anesthetic were selected, analyzed, and compared. Multiple non-EEG measurements were also recorded.

RESULTS

Specific raw EEG findings were indicative of changes in the depth of anesthesia. However, there was considerable variability in EEG between horses at identical MAC multiples/conditions and within individual horses over segments of a given epoch. Statistical significance for qEEG variables differed between anesthetics with bispectral index (BIS) CV MAC and 95% spectral edge frequency (SEF95) SV MAC differences in isoflurane only and median frequency (MED) differences in SV MAC with halothane only.

CONCLUSIONS AND CLINICAL IMPORTANCE

Unprocessed EEG features (background and transients) appear to be beneficial for monitoring the depth of a particular anesthetic, but offer little advantage over the use of changes in mean arterial pressure for this purpose.

Neurologic Deficits Including Auditory Loss and Recovery of Function in Horses with Temporohyoid Osteoarthropathy

BACKGROUND

Auditory loss is a common deficit in horses with temporohyoid osteoarthropathy (THO), however, recovery of function is unknown.

HYPOTHESIS/OBJECTIVES

To investigate neurologic function with emphasis in audition in horses with THO after treatment. To describe anatomical alterations of the petrous temporal bone that might result in auditory loss.

ANIMALS

Twenty-four horses with a clinical diagnosis of THO.

METHODS

Prospective study. A brainstem auditory evoked response (BAER) study was done as part of the criteria for inclusion in horses with a clinical diagnosis of THO from the years of 2005 to 2014. Physical and neurologic status and BAER findings were recorded. Brainstem auditory evoked response variables were compared by using Wilcoxon sign test. Fisher's exact test was also used. Significance was set at P < 0.05.

RESULTS

The most common signs included auditory loss (100% of horses), vestibular and facial nerve dysfunction (83%), and exposure ulcerative keratitis (71%). Concurrent left laryngeal hemiparesis was observed in 61% of horses through endoscopy. Auditory dysfunction was bilateral in 50% of the cases (complete and partial), and unilateral affecting more commonly the right ear (R = 8, L = 4). Short- and long-term follow-up revealed persistent auditory loss in all horses based on abnormal response to sound, and further confirmed through a BAER in 8 horses.

CONCLUSIONS AND CLINICAL IMPORTANCE

Auditory dysfunction appears to be a permanent neurologic deficit in horses diagnosed with THO despite overall neurologic improvement.

Electroencephalogram of Healthy Horses During Inhaled Anesthesia

Background

Previous study of the diagnostic validity of electroencephalography (EEG) to detect abnormalities in equine cerebral cortical function relied on the administration of various drugs for sedation, induction, and maintenance of general anesthesia but used identical criteria to interpret recordings.

Objectives

To determine the effects of 2 inhalation anesthetics on the EEG of healthy horses.

Animals

Six healthy horses.

Methods

Prospective study. After the sole administration of one of either isoflurane or halothane at 1.2, 1.4, and 1.6 times the minimum alveolar concentration, EEG was recorded during controlled ventilation, spontaneous ventilation, and nerve stimulation.

Results

Burst suppression was observed with isoflurane, along with EEG events that resembled epileptiform discharges. Halothane results were variable between horses, with epileptiform‐like discharges and bursts of theta, alpha, and beta recorded intermittently. One horse died and 2 were euthanized as the result of anesthesia‐related complications.

Conclusions and Clinical Importance

The results of this study indicate that the effects of halothane and isoflurane on EEG activity in the normal horse can be quite variable, even when used in the absence of other drugs. It is recommended that equine EEG be performed without the use of these inhalation anesthetics and that general anesthesia be induced and maintained by other contemporary means.

Electrophysiologic Study of a Method of Euthanasia Using Intrathecal Lidocaine Hydrochloride Administered during Intravenous Anesthesia in Horses

Background

An intravenous (IV) overdose of pentobarbital sodium is the most commonly used method of euthanasia in veterinary medicine. However, this compound is not available in many countries or rural areas resulting in usage of alternative methods such as intrathecal lidocaine administration after IV anesthesia. Its safety and efficacy as a method of euthanasia have not been investigated in the horse.

Hypothesis/Objectives

To investigate changes in mean arterial blood pressure and electrical activity of the cerebral cortex, brainstem, and heart during intrathecal administration of lidocaine. Our hypothesis was that intrathecal lidocaine affects the cerebral cortex and brainstem before affecting cardiovascular function.

Animals

Eleven horses requiring euthanasia for medical reasons.

Methods

Prospective observational study. Horses were anesthetized with xylazine, midazolam, and ketamine; and instrumented for recording of electroencephalogram (EEG), electrooculogram (EOG), brainstem auditory evoked response (BAER), and electrocardiogram (ECG). Physical and neurological (brainstem reflexes) variables were monitored. Mean arterial blood pressure was recorded throughout the study.

Results

Loss of cerebro‐cortical electrical activity occurred up to 226 seconds after the end of the infusion of lidocaine solution. Cessation of brainstem function as evidenced by a lack of brainstem reflexes and disappearance of BAER occurred subsequently. Undetectable heart sounds, nonpalpable arterial pulse, and extremely low mean arterial blood pressure supported cardiac death; a recordable ECG was the last variable to disappear after the infusion (300–1,279 seconds).

Conclusions and Clinical Importance

Intrathecal administration of lidocaine is an effective alternative method of euthanasia in anesthetized horses, during which brain death occurs before cardiac death.

A Preliminary Examination of Negative Affect, Emotion Dysregulation, and Risky Behaviors among Military Veterans in Residential Substance Abuse Treatment

Substance use disorder (SUD) is highly prevalent among military populations and associated with a wide range of negative outcomes. The goal of the present study was to explicate the relations among negative affect, emotion dysregulation, and urges to engage in risky behaviors among military veterans in residential SUD treatment. Emotion dysregulation (overall and three dimensions: access to emotion regulation strategies, impulse control, and emotional awareness) mediated the relation between negative affect and urges to engage in risky behaviors. Findings highlight the potential utility of treatments targeting emotion dysregulation in reducing risky behaviors among military veterans with SUD.

Cerebral and brainstem electrophysiologic activity during euthanasia with pentobarbital sodium in horses

Background

An overdose of pentobarbital sodium administered IV is the most commonly used method of euthanasia in veterinary medicine. Determining death after the infusion relies on the observation of physical variables. However, it is unknown when cortical electrical activity and brainstem function are lost in a sequence of events before death.

Hypothesis/Objectives

To examine changes in the electrical activity of the cerebral cortex and brainstem during an overdose of pentobarbital sodium solution for euthanasia. Our testing hypothesis is that isoelectric pattern of the brain in support of brain death occurs before absence of electrocardiogram (ECG) activity.

Animals

Fifteen horses requiring euthanasia.

Methods

Prospective observational study. Horses with neurologic, orthopedic, and cardiac illnesses were selected and instrumented for recording of electroencephalogram, electrooculogram, brainstem auditory evoked response (BAER), and ECG. Physical and neurologic (brainstem reflexes) variables were monitored.

Results

Loss of cortical electrical activity occurred during or within 52 seconds after the infusion of euthanasia solution. Cessation of brainstem function as evidenced by a lack of brainstem reflexes and disappearance of the BAER happened subsequently. Despite undetectable heart sounds, palpable arterial pulse, and mean arterial pressure, recordable ECG was the last variable to be lost after the infusion (5.5–16 minutes after end of the infusion).

Conclusions and Clinical Importance

Overdose of pentobarbital sodium solution administered IV is an effective, fast, and humane method of euthanasia. Brain death occurs within 73–261 seconds of the infusion. Although absence of ECG activity takes longer to occur, brain death has already occurred.

Rapid and permanent neuronal inactivation in vivo via subcellular generation of reactive oxygen with the use of KillerRed

Inactivation of selected neurons in vivo can define their contribution to specific developmental outcomes, circuit functions, and behaviors. Here, we show that the optogenetic tool KillerRed selectively, rapidly, and permanently inactivates different classes of neurons in C. elegans in response to a single light stimulus, through the generation of reactive oxygen species (ROS). Ablation scales from individual neurons in single animals to multiple neurons in populations and can be applied to freely behaving animals. Using spatially restricted illumination, we demonstrate that localized KillerRed activation in either the cell body or the axon triggers neuronal degeneration and death of the targeted cell. Finally, targeting KillerRed to mitochondria results in organelle fragmentation without killing the cell, in contrast to the cell death observed when KillerRed is targeted to the plasma membrane. We expect this genetic tool to have wide-ranging applications in studies of circuit function and subcellular responses to ROS.

Reactive oxygen species-mediated neurodegeneration is independent of the ryanodine receptor in Caernorhabditis elegans

Despite the significant impacts on human health caused by neurodegeneration, our understanding of the degeneration process is incomplete. The nematode Caenorhabditis elegans is emerging as a genetic model organism well suited for identification of conserved cellular mechanisms and molecular pathways of neurodegeneration. Studies in the worm have identified factors that contribute to neurodegeneration, including excitotoxicity and stress due to reactive oxygen species (ROS). Disruption of the gene unc-68, which encodes the ryanodine receptor, abolishes excitotoxic cell death, indicating a role for calcium (Ca²⁺) signaling in neurodegeneration. We tested the requirement for unc-68 in ROS-mediated neurodegeneration using the genetically encoded photosensitizer KillerRed. Upon illumination of KillerRed expressing animals to produce ROS, we observed similar levels of degeneration in wild-type and unc-68 mutant strains. Our results indicate that ROS-mediated cell death is independent of unc-68 and suggest multiple molecular pathways of neurodegeneration.

Electrophysiologic confirmation of heterogenous motor polyneuropathy in young cats

Background

Reports of motor polyneuropathies in young cats are scarce. Further, in‐depth electrophysiologic evaluation to confirm a motor polyneuropathy in young cats of various breeds other than 2 Bengal cats is lacking.

Hypothesis/Objectives

To confirm a motor polyneuropathy in young cats of various breeds.

Animals

Five young cats with heterogenous chronic or relapsing episodes of weakness.

Methods

Retrospective case series. Cats were presented for evaluation of generalized neuromuscular disease and underwent electrophysiologic examination including electromyography, nerve conduction, and repetitive nerve stimulation. Minimum database and muscle and nerve biopsy analyses were carried out. Descriptive statistics were performed.

Results

Disease onset was at 3 months to 1 year of age and in 5 breeds. The most common clinical sign (5 of 5 cats) was weakness. Additional neurologic deficits consisted of palmigrade and plantigrade posture (4/4), low carriage of the head and tail (4/4), and variable segmental reflex deficits (5/5). Motor nerve conduction studies were abnormal for the ulnar (4/4), peroneal (5/5), and tibial (2/2) nerves (increased latencies, reduced amplitudes, slow velocities). A marked decrement was observed on repetitive nerve stimulation of the peroneal nerve in 3 cats for which autoimmune myasthenia gravis was ruled out. All sensory nerve conduction studies were normal. Histologic evaluation of muscle and nerve biopsies supported heterogenous alterations consistent with motor polyneuropathy with distal nerve fiber loss.

Conclusions and Clinical Importance

Heterogenous motor polyneuropathies should be considered in young cats of any breed and sex that are presented with relapsing or progressive generalized neuromuscular disease.

Brainstem auditory evoked responses in an equine patient population: part I--adult horses

Background

Brainstem auditory evoked response has been an underused diagnostic modality in horses as evidenced by few reports on the subject.

Hypothesis/Objectives

To describe BAER findings, common clinical signs, and causes of hearing loss in adult horses.

Animals

Study group, 76 horses; control group, 8 horses.

Methods

Retrospective. BAER records from the Clinical Neurophysiology Laboratory were reviewed from the years of 1982 to 2013. Peak latencies, amplitudes, and interpeak intervals were measured when visible. Horses were grouped under disease categories. Descriptive statistics and a posthoc Bonferroni test were performed.

Results

Fifty‐seven of 76 horses had BAER deficits. There was no breed or sex predisposition, with the exception of American Paint horses diagnosed with congenital sensorineural deafness. Eighty‐six percent (n = 49/57) of the horses were younger than 16 years of age. The most common causes of BAER abnormalities were temporohyoid osteoarthropathy (THO, n = 20/20; abnormalities/total), congenital sensorineural deafness in Paint horses (17/17), multifocal brain disease (13/16), and otitis media/interna (4/4). Auditory loss was bilateral and unilateral in 74% (n = 42/57) and 26% (n = 15/57) of the horses, respectively. The most common causes of bilateral auditory loss were sensorineural deafness, THO, and multifocal brain disease whereas THO and otitis were the most common causes of unilateral deficits.

Conclusions and Clinical Importance

Auditory deficits should be investigated in horses with altered behavior, THO, multifocal brain disease, otitis, and in horses with certain coat and eye color patterns. BAER testing is an objective and noninvasive diagnostic modality to assess auditory function in horses.

Brainstem auditory evoked responses in an equine patient population. Part II: foals

Background

Reports of the use of brainstem auditory evoked response (BAER) as a diagnostic modality in foals have been limited.

Hypothesis/Objectives

To describe BAER findings and associated causes of hearing loss in foals.

Animals

Study group 18 foals (15 neonatal, 3 nonneonatal), control group (5 neonatal foals).

Methods

Retrospective. BAER records from the Clinical Neurophysiology Laboratory were reviewed from the years of 1982 to 2013. Peak latencies, amplitudes, and interpeak intervals were measured when visible. Clinical data were extracted from the medical records. Foals were grouped under disease categories. Descriptive statistics were performed.

Results

Ten neonatal foals had complete absence of BAER bilaterally and 5 had findings within reference range. Abnormalities were associated with common neonatal disorders such as sepsis, neonatal encephalopathy, neonatal isoerythrolysis, and prematurity. BAER loss also was observed in foals with specific coat color patterns such as completely or mostly white with blue irides or lavender with pale yellow irides. An American Miniature foal with marked facial deformation also lacked BAER bilaterally. One nonneonatal foal with an intracranial abscess had no detectable BAER peaks bilaterally, and 2 older foals, 1 with presumed equine protozoal myeloencephalitis and the other with progressive scoliosis and ataxia, had BAER within normal limits.

Conclusions and Clinical Importance

In neonatal foals, BAER deficits commonly are complete and bilateral, and associated with common neonatal disorders and certain coat and eye color patterns. Sepsis, hypoxia, bilirubin toxicity, and prematurity should be investigated as potential causes of auditory loss in neonatal foals.

High-fidelity simulation enhances pediatric residents' retention, knowledge, procedural proficiency, group resuscitation performance, and experience in pediatric resuscitation

OBJECTIVE

The goal of this study was to assess the effect of high-fidelity simulation (HFS) pediatric resuscitation training on resident performance and self-reported experience compared with historical controls.

METHODS

In this case-control study, pediatric residents at a tertiary academic children's hospital participated in a 16-hour HFS resuscitation curriculum. Primary outcome measures included cognitive knowledge, procedural proficiency, retention, and self-reported comfort and procedural experience. The intervention group was compared with matched-pair historical controls.

RESULTS

Forty-one residents participated in HFS training with 32 matched controls. The HFS group displayed significant initial and overall improvement in knowledge (P < .01), procedural proficiency (P < .05), and group resuscitation performance (P < .01). Significant skill decay occurred in all performance measures (P < .01) with the exception of endotracheal intubation. Compared with controls, the HFS group reported not only greater comfort with most procedures but also performed more than twice the number of successful real-life pediatric intubations (median: 6 vs 3; P = .03).

CONCLUSIONS

Despite significant skill decay, HFS pediatric resuscitation training improved pediatric resident cognitive knowledge, procedural proficiency, and comfort. Residents who completed the course were not only more proficient than historical controls but also reported increased real-life resuscitation experiences and related procedures.

Sensory nerve conduction and somatosensory evoked potentials of the trigeminal nerve in horses with idiopathic headshaking

BACKGROUND

Idiopathic headshaking (HSK) in horses is a distressing disorder in which the etiology and pathophysiology are unknown.

HYPOTHESIS

Differences in sensory function of the trigeminal nerve exist between healthy and affected horses.

ANIMALS

Six healthy mature geldings and 6 mature geldings with idiopathic HSK.

METHODS

Prospective study. Sensory nerve action and somatosensory evoked potentials studies were performed. The stimulus site comprised the gingival mucosa dorsal to the maxillary canine. A pair of recording electrodes was placed along the sensory pathway of the trigeminal complex at the infraorbital nerve (R1), maxillary nerve (R2), spinal tract of trigeminal (R3), and somatosensory cortex (R4). Sensory nerve action potential latency (ms), amplitude (μV), duration (ms), area under the curve (μVms), and conduction velocity (m/s) were calculated.

RESULTS

Threshold for activation of the infraorbital branch of the trigeminal nerve was significantly different between 5 affected (≤ 5 mA) and 6 control horses (≥ 10 mA). After initiation of an action potential, there were no differences in all parameters measured and no differences between left and right sides. A horse with seasonal HSK tested during a time of no clinical manifestations showed a threshold for activation similar to control horses.

CONCLUSIONS AND CLINICAL IMPORTANCE

This study confirms involvement of the trigeminal nerve hyperexcitability in the pathophysiology of disease. Further, results might support a functional rather than a structural alteration in the sensory pathway of the trigeminal complex that can be seasonal. The horse could serve as a natural animal model for humans with idiopathic trigeminal neuralgia.

Simulation training as a mechanism for procedural and resuscitation education for pediatric residents: a systematic review

BACKGROUND

Pediatric residents often finish their training lacking sufficient procedural proficiency and resuscitation experience in the care of critically ill children. Simulation is gaining favor in pediatric residency programs as a modality for procedural and resuscitation education. We reviewed the literature assessing simulation and its role in pediatric resident training.

METHODS

We conducted a Medline and PubMed search of simulation training in pediatric resident education from January 2007 to July 2012.

RESULTS

Eight studies were included and divided into simulated procedural assessments and simulated resuscitation scenario assessments. The studies varied widely in their approach and analysis, and they yielded mixed results.

CONCLUSIONS

Although some studies show the merits of simulation in the procedural and resuscitation training of pediatric residents, more research is needed to assess the effectiveness of simulation as an educational tool. Goals of future simulation research should include creation of validated assessment tools and applying skills learned to patient care outcomes.

Recognition of allergic conjunctivitis in patients with allergic rhinitis

AIMS

To identify the incidence of allergic conjunctivitis in patients with allergic rhinitis.

METHODS

One hundred and eighty seven consecutive patients with allergic rhinitis (AR) were directly questioned if they have allergic conjunctivitis (AC) and this was clarified using standard screening questions relating to red, itchy and watery eyes recorded through a total ocular symptom score (TOSS). Patients were also asked about further symptoms that may be attributable to AC: eyelid dermatitis, frequent blinking; eye sensitivity and frontal headache from squinting or. blinking. All patients were given a drop of olopatadine hydrochloride 0.1% in each eye to help identify "silent" disease. 20 healthy non-atopic controls were also treated with olopatadine drops and questioned on ocular symptoms.

RESULTS

Fifty five percent of patients with AR were identified as having AC by direct questioning and the use of the TOSS questionaire. A further 41% were identifiable by asking additional questions and performing therapeutic challenge with olopadatine.

CONCLUSIONS

AC is a frequent comorbid condition occurring in 95% of our patients with AR. Only 55% of patients were able to identify that they had AC based on standard screening questions. Additional specific questioning and a therapeutic challenge in suspected patients can help identify patients who may benefit from treatment of AC.

A de novo mutation in KIT causes white spotting in a subpopulation of German Shepherd dogs

Although variation in the KIT gene is a common cause of white spotting among domesticated animals, KIT has not been implicated in the diverse white spotting observed in the dog. Here, we show that a loss-of-function mutation in KIT recapitulates the coat color phenotypes observed in other species. A spontaneous white spotting observed in a pedigree of German Shepherd dogs was mapped by linkage analysis to a single locus on CFA13 containing KIT (pairwise LOD = 15). DNA sequence analysis identified a novel 1-bp insertion in the second exon that co-segregated with the phenotype. The expected frameshift and resulting premature stop codons predicted a severely truncated c-Kit receptor with presumably abolished activity. No dogs homozygous for the mutation were recovered from multiple intercrosses (P = 0.01), suggesting the mutation is recessively embryonic lethal. These observations are consistent with the effects of null alleles of KIT in other species.

Guidance for New Motivational Interviewing Trainers When Training Addiction Professionals: Findings from a Survey of Experienced Trainers

Evidence-based practices, such as motivational interviewing (MI), are not widely used in community alcohol and drug treatment settings. Successfully broadening the dissemination of MI will require numerous trainers and supervisors who are equipped to manage common barriers to technology transfer. The aims of the our survey of 36 MI trainers were: 1) to gather opinions about the optimal format, duration, and content for beginning level addiction-focused MI training conducted by novice trainers and 2) to identify the challenges most likely to be encountered during provision of beginning-level MI training and supervision, as well as the most highly recommended strategies for managing those challenges in addiction treatment sites. It is hoped that the findings of this survey will help beginning trainers equip themselves for successful training experiences.

Chemical characterization of the fine particle emissions from commercial aircraft engines during the Aircraft Particle Emissions eXperiment (APEX) 1 to 3

This paper addresses the need for detailed chemical information on the fine particulate matter (PM) generated by commercial aviation engines. The exhaust plumes of seven turbofan engine models were sampled as part of the three test campaigns of the Aircraft Particle Emissions eXperiment (APEX). In these experiments, continuous measurements of black carbon (BC) and particle surface-bound polycyclic aromatic compounds (PAHs) were conducted. In addition, time-integrated sampling was performed for bulk elemental composition, water-soluble ions, organic and elemental carbon (OC and EC), and trace semivolatile organic compounds (SVOCs). The continuous BC and PAH monitoring showed a characteristic U-shaped curve of the emission index (EI or mass of pollutant/mass of fuel burned) vs fuel flow for the turbofan engines tested. The time-integrated EIs for both elemental composition and water-soluble ions were heavily dominated by sulfur and SO(4)(2-), respectively, with a ∼2.4% median conversion of fuel S(IV) to particle S(VI). The corrected OC and EC emission indices obtained in this study ranged from 37 to 83 mg/kg and 21 to 275 mg/kg, respectively, with the EC/OC ratio ranging from ∼0.3 to 7 depending on engine type and test conditions. Finally, the particle SVOC EIs varied by as much as 2 orders of magnitude with distinct variations in chemical composition observed for different engine types and operating conditions.

Chemical characterization of the fine particle emissions from commercial aircraft engines during the Aircraft Particle Emissions eXperiment (APEX) 1 to 3

This paper addresses the need for detailed chemical information on the fine particulate matter (PM) generated by commercial aviation engines. The exhaust plumes of seven turbofan engine models were sampled as part of the three test campaigns of the Aircraft Particle Emissions eXperiment (APEX). In these experiments, continuous measurements of black carbon (BC) and particle surface-bound polycyclic aromatic compounds (PAHs) were conducted. In addition, time-integrated sampling was performed for bulk elemental composition, water-soluble ions, organic and elemental carbon (OC and EC), and trace semivolatile organic compounds (SVOCs). The continuous BC and PAH monitoring showed a characteristic U-shaped curve of the emission index (EI or mass of pollutant/mass of fuel burned) vs fuel flow for the turbofan engines tested. The time-integrated EIs for both elemental composition and water-soluble ions were heavily dominated by sulfur and SO(4)(2-), respectively, with a ∼2.4% median conversion of fuel S(IV) to particle S(VI). The corrected OC and EC emission indices obtained in this study ranged from 37 to 83 mg/kg and 21 to 275 mg/kg, respectively, with the EC/OC ratio ranging from ∼0.3 to 7 depending on engine type and test conditions. Finally, the particle SVOC EIs varied by as much as 2 orders of magnitude with distinct variations in chemical composition observed for different engine types and operating conditions.

PBOX-15, a novel microtubule targeting agent, induces apoptosis, upregulates death receptors, and potentiates TRAIL-mediated apoptosis in multiple myeloma cells

Background:

In recent years, much progress has been made in the treatment of multiple myeloma. However, a major limitation of existing chemotherapeutic drugs is the eventual emergence of resistance; hence, the development of novel agents with new mechanisms of action is pertinent. Here, we describe the activity and mechanism of action of pyrrolo-1,5-benzoxazepine-15 (PBOX-15), a novel microtubule-targeting agent, in multiple myeloma cells.

Methods:

The anti-myeloma activity of PBOX-15 was assessed using NCI-H929, KMS11, RPMI8226, and U266 cell lines, and primary myeloma cells. Cell cycle distribution, apoptosis, cytochrome c release, and mitochondrial inner membrane depolarisation were analysed by flow cytometry; gene expression analysis was carried out using TaqMan Low Density Arrays; and expression of caspase-8 and Bcl-2 family of proteins was assessed by western blot analysis.

Results:

Pyrrolo-1,5-benzoxazepine-15 induced apoptosis in ex vivo myeloma cells and in myeloma cell lines. Death receptor genes were upregulated in both NCI-H929 and U266 cell lines, which displayed the highest and lowest apoptotic responses, respectively, following treatment with PBOX-15. The largest increase was detected for the death receptor 5 (DR5) gene, and cotreatment of both cell lines with tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), the DR5 ligand, potentiated the apoptotic response. In NCI-H929 cells, PBOX-15-induced apoptosis was shown to be caspase-8 dependent, with independent activation of extrinsic and intrinsic apoptotic pathways. A caspase-8-dependent decrease in expression of Bim_EL preceded downregulation of other Bcl-2 proteins (Bid, Bcl-2, Mcl-1) in PBOX-15-treated NCI-H929 cells.

Conclusion:

PBOX-15 induces apoptosis and potentiates TRAIL-induced cell death in multiple myeloma cells. Thus, PBOX-15 represents a promising agent, with a distinct mechanism of action, for the treatment of this malignancy.

Continuous versus discrete dimensions of reinforcement schedules: An integrative analysis

An approach to reinforcement-schedule contingencies is presented that accommodates continuous as well as discrete effective dimensions of responses and reinforcers. College students' wheel turning was reinforced by projected reading material according to four schedule contingencies that incorporated either a discontinuous (count) or continuous (duration) dimension of the response and the reinforcer. The contingencies arranged a 1:1 correspondence between (a) response count and consequent stimulus count, (b) response duration and stimulus count, (c) response count and stimulus duration, and (d) response duration and stimulus duration. Contingencies incorporating response count produced moderate to high rates of very short-duration responses. Contingencies incorporating response duration produced very low-rate, long-duration responding. The dimension of the reinforcer had minimal or no additional effect. We suggest that incorporating duration and other continuous dimensions into schedule contingencies may improve our understanding of both laboratory and nonlaboratory behavior.