Manipulating leukocyte populations to mimic immune disease states: a novel active approach to teaching flow cytometry to undergraduate immunology students.

Flow cytometry detects and measures the physical and chemical characteristics of cells or particles. In medical laboratories, flow cytometers are used to quantify changes in cell populations associated with disease states, such as AIDS. While a powerful technique, it is challenging to teach the principles of flow cytometry to undergraduate students. One approach is to have students process and analyze a patient sample. However, this is not possible when the patient has an infectious disease. Here we report a two-stage approach to address this challenge. Magnetic beads were used to manipulate leukocytes cell populations in healthy blood to mimic the phenotype of eight immune disease conditions. The cells were then stained against cell surface markers for cell populations and analyzed by flow cytometry. The second stage focused on teaching flow cytometry over 2 wk. Week 1 involved a lecture, followed by a laboratory session where students learned how to stain a blood sample. In week 2, students worked in a computer pool to analyze the previously generated data and determine the immunological status of a control and patient sample. Using this approach, all students achieved 100% correct diagnosis of both control and patient samples. Student feedback via a questionnaire was overwhelmingly positive, and student perceived knowledge of flow cytometry increased after the session significantly. We effectively mimicked several disease states, eliminating the need to source patient samples, yet still teaching undergraduate students the principles of flow cytometry.

The reliability and validity of a research-grade pedometer for children and adolescents with cerebral palsy.

AIM: The aim of this study was to determine the reliability, validity, and optimal placement of pedometers in children with cerebral palsy (CP) who ambulate without aids. METHOD: Seventeen participants aged 7 to 17 years with CP (eight males, nine females; mean age 12y 4mo; SD 3y 2mo), who could ambulate without aids, wore four New Lifestyles pedometers (NL-1000) on an elasticized waist belt. Fourteen participants had hemiplegia, two diplegia, and one triplegia; all were classified in Gross Motor Function Classification System (GMFCS) level I (n=8) or II (n=9). Participants completed 3-minute walking and running trials around an indoor course and were videotaped to verify the actual number of steps taken during each trial. Inter-pedometer reliability was determined by comparing pedometer readings using intraclass correlation coefficients (ICCs). Validity was determined by comparing pedometer step counts with video step counts using ICC, t-tests, and Bland-Altman plots. Optimal pedometer placement was determined using Wilcoxon signed-rank tests to compare the percentage error for pedometers positioned on the dominant and non-dominant hips. RESULTS: Excellent reliability (ICC 0.88-0.99) and validity (ICC 0.78-0.95) were demonstrated with no significant difference between the video step counts and pedometer step counts. There was no significant difference between the step counts recorded by pedometers on the dominant and non-dominant hips. INTERPRETATION: This study showed that NL-1000 pedometers have a high degree of reliability and validity in ambulant children with CP in controlled conditions.

Validity of pedometers in people with physical disabilities: a systematic review.

OBJECTIVE: To review the literature for the criterion validity of pedometers for use in child and adult populations with physical disabilities. DATA SOURCES: Academic Search Premier, ERIC, SPORTDiscus, MEDLINE, AMED, Scopus, CINAHL, Web of Science, and EMBASE databases, searched from inception to September 7, 2011. STUDY SELECTION: Studies were included if they were peer-reviewed articles, included populations with physical disabilities, and reported primary data for pedometer validity in comparison with direct observation. A consensus approach was used to apply the inclusion and exclusion criteria. Of the 163 articles identified in the database searches (excluding duplicates), 7 studies met the inclusion criteria. DATA EXTRACTION: The quality of the studies was assessed independently by 2 reviewers, using a purpose-designed appraisal tool, with a consensus approach used to settle disagreement. A single reviewer extracted data relating to sample size, participant characteristics, pedometer model, main variables tested, duration of tests, and method of direct observation. DATA SYNTHESIS: The methodologic quality of the studies was generally high; however, there was a wide variation of population and methodology between studies. The correlation between pedometer step counts and directly observed step counts was moderate to excellent (intraclass correlation coefficient, .52-.87), and percent errors ranged from 0.5% to 24.7%. Secondary variables reported included the effect of speed of movement, pedometer placement, comparison of pedometer makes/models, and test-retest reliability. CONCLUSIONS: Available evidence suggests that pedometers are valid for use in clinical and research settings in people with physical disabilities. Further research examining the validity of pedometers in less heterogeneous populations of people with disabilities is warranted to determine validity for specific disability populations and to determine optimal pedometer placement.

Development of a device to measure adherence and pressure characteristics of positive expiratory pressure therapies used by adults with cystic fibrosis.

INTRODUCTION: Positive expiratory pressure (PEP) and oscillating positive expiratory pressure (OscPEP) therapies are often used by people with cystic fibrosis (CF) to facilitate airway clearance. However, suboptimal adherence and poor technique may reduce their effectiveness. OBJECTIVE: To develop a device (PEPtrac) to accurately measure and provide preliminary clinical data of adherence and technique characteristics when airway clearance is performed using PEP/OscPEP devices. METHODS: This study comprised two distinct phases: 1) a benchtop validation study; and 2) clinical study. Benchtop study: Accuracy of PEPtrac was measured by comparing it to video analysis for five different PEP/OscPEP devices. Clinical study: Clinical data were then collected for 18 adults with CF using one of three PEP/OscPEP devices (PariPEP S®, Acapella DH® or Aerobika®) unsupervised. RESULTS: There was 100% agreement between PEPtrac and video analysis data. Clinical data revealed significant variability in expiratory duration and pressure properties between the three PEP/OscPEP devices and between participants. For example, expiratory duration with PariPEP S® (mean [SD] = 4.8 [1.2] sec) was longer (p < .001) than Acapella DH® (3.7 [0.8] sec) and Aerobika® (2.9 [1.1] sec) and Aerobika® had a higher oscillation amplitude than Acapella DH® (6.4 [1.7] vs 5.3 [1.5] cmH2O, p < .001). DISCUSSION: Accurate measurement of PEP/OscPEP adherence and technique using a device such as PEPtrac was possible. Further research is required to investigate the clinical importance of the variability in technique seen in our clinical data.

Demographic and clinical characteristics of young people seeking help at youth mental health services: baseline findings of the Transitions Study.

AIM: The Transitions Study was designed to establish a cohort of young people (12-25 years) seeking help for mental health problems, in order to longitudinally explore and refine a clinical staging model of the development and progression of mental disorders. This paper presents the baseline demographic and clinical characteristics of the cohort, particularly the nature and severity of psychopathology. METHOD: All eligible young people attending one of four headspace clinical services were invited to participate, and completed a battery of self-report and interviewer-administered measures of psychopathology and functional impairment at baseline, which will be repeated at the annual follow up. RESULTS: Of 1615 eligible clients, 802 young people (66% women; mean age = 18.3 years) consented to participate and completed baseline assessments (participation rate = 50%). The severity of mental health problems varied, with 51% meeting the criteria for probable caseness related to generalized anxiety, 45% presenting with moderate to severe depressive symptoms and over a third experiencing subthreshold psychotic symptomatology. Disordered eating (32%) and problematic tobacco (56%), cannabis (30%) and alcohol (38%) use also affected a significant proportion. Overall, 39% of the cohort were classed as being functionally impaired at baseline. CONCLUSION: The Transitions Study recruited a heterogeneous cohort at baseline in relation to the nature and severity of mental health problems and levels of functional impairment. The variation in clinical presentations within the cohort, from mild, through moderate to severe levels of psychopathology and impairment, increases the likelihood of the Transitions Study ultimately being able to achieve its aims of empirically testing a clinical staging model for mental disorders.

Arginine Vasopressin selectively enhances recognition of sexual cues in male humans.

Arginine Vasopressin modulates complex social and sexual behavior by enhancing social recognition, pair bonding, and aggression in non-human mammals. The influence of Arginine Vasopressin in human social and sexual behavior is, however, yet to be fully understood. We evaluated whether Arginine Vasopressin nasal spray facilitated recognition of positive and negative social and sexual stimuli over non-social stimuli. We used a recognition task that has already been shown to be sensitive to the influence of Oxytocin nasal spray (Unkelbach et al., 2008). In a double-blind, randomized, placebo-controlled, between-subjects design, 41 healthy male volunteers were administered Arginine Vasopressin (20 IU) or a placebo nasal spray after a 45 min wait period and then completed the recognition task. Results showed that the participants administered Arginine Vasopressin nasal spray were faster to detect sexual words over other types of words. This effect appeared for both positively and negatively valenced words. Results demonstrate for the first time that Arginine Vasopressin selectively enhances human cognition for sexual stimuli, regardless of valence. They further extend animal and human genetic studies linking Arginine Vasopressin to sexual behavior in males. Findings suggest an important cognitive mechanism that could enhance sexual behaviors in humans.

Intranasal arginine vasopressin enhances the encoding of happy and angry faces in humans.

BACKGROUND: Arginine vasopressin (AVP) has a complex but crucial role in social behavior. In nonhuman mammals it facilitates social recognition and bonding while also promoting defensive, aggressive, and territorial behaviors. There has been little research in humans exploring its effect on social cognition, including the encoding of social memories. METHODS: In a double-blind, randomized, placebo-controlled, between-subject design, we administered AVP (20 IU) or a placebo intranasally to 48 healthy human male volunteers and then presented 54 happy, angry, or neutral human faces. Participants returned the following day to make "remember", "know", or "new" judgments for a mix of 108 new and previously seen faces. RESULTS: Participants who were administered AVP were more likely to make know judgments for previously seen happy and angry faces in comparison with neutral human faces. Arginine vasopressin did not influence judgments for faces that had not been presented previously. CONCLUSIONS: Administration of AVP to male humans enhances the encoding of both happy and angry social information to make this more memorable. Results suggest that AVP could facilitate both bonding and aggressive related behaviors in humans by enhancing the encoding of positive and negative social cues within everyday interactions.