A preliminary investigation of digital media supplements for head and neck anatomy: Does production format matter?

From cassettes to digital, use of video in education has evolved. Supplemental digital media is a common educational adjunct within gross anatomy courses. As these aids have advanced technologically, so has production cost. Traditional lecture (T-lect) productions tend to be more efficient. Traditional gross anatomy laboratory (T-lab) productions requiring cadaver dissection and high-definition video are comparatively less efficient. This preliminary study pragmatically assessed T-lect and T-lab supplemental learning tools in a head and neck anatomy course for first-year dental students. Two videos of similar length were developed for different anatomical regions. Learning objectives were similar while format differed. A carotid triangle supplement was created using a T-lab production format and an infratemporal fossa aid was created using a T-lect format. Both incorporated recommended elements for facilitating learning. Development time and costs were documented. Student exam performance on topic specific questions was collected along with survey data. Group mean exam score comparisons between students who viewed (n = 74 T-lect, n = 70 T-lab) versus did not view (n = 27 T-lect, n = 30 T-lab) each aid revealed higher scores for the "viewed" group. The T-lab production cost ($15,190 versus $10,003) and time (19 hr. versus 18 hr) were greater than T-lect. Descriptive survey data did not reveal a format preference. Students valued previews/summaries and structure highlighting/labeling within the supplements. Students appreciated the supplemental learning aids and mean exam scores were higher for users. Since production format did not noticeably alter exam performance and satisfaction was similar, production efficiency should take precedence.

Master in oral biology program: A path to addressing the need for future dental educators.

In dental education, the anatomical sciences, which include gross anatomy, histology, embryology, and neuroanatomy, encompass an important component of the basic science curriculum. At Creighton University School of Dentistry, strength in anatomic science education has been coupled with a solid applicant pool to develop a novel Master of Science in Oral Biology, Anatomic Sciences track degree program. The program provides a heavy emphasis on developing teaching skills in predoctoral students as well as exposure to research processes to encourage the cohort to pursuing a career in academic dentistry. The individuals considered for this program are applicants for admission to the School of Dentistry that have not been accepted into the entering dental class for that year. The students undertake a two year curriculum, studying anatomic sciences with a special emphasis on teaching. The students also must complete a research project that requires a thesis. The students in the program are guaranteed acceptance to dental school upon successful completion of the program. After six years, the first ten students have received their Master of Science degrees and continued in dental school. The program is favorably viewed by the faculty and participating students. It is also considered successful by metrics. Nine of the ten graduates have said they would like to participate in academic dentistry in some capacity during their careers. Anat Sci Educ 10: 607-612. © 2017 American Association of Anatomists.

A non-contact technique for measuring eccrine sweat gland activity using passive thermal imaging.

An approach for monitoring eccrine sweat gland activity using high resolution Mid-Wave Infrared (MWIR) imaging (3-5 µm wave band) is described. This technique is non-contact, passive, and provides high temporal and spatial resolution. Pore activity was monitored on the face and on the volar surfaces of the distal and medial phalanges of the index and middle fingers while participants performed a series of six deep inhalation and exhalation exercises. Two metrics called the Pore Activation Index (PAI) and Pore Count (PC) were defined as size-weighted and unweighted measures of active sweat gland counts respectively. PAI transient responses on the finger tips were found to be positively correlated to Skin Conductance Responses (SCRs). PAI responses were also observed on the face, although the finger sites appeared to be more responsive. Results indicate that thermal imaging of the pore response may provide a useful, non-contact, correlate measure for electrodermal responses recorded from related sites.

Changes in the frequencies of human hematopoietic stem and progenitor cells with age and site.

This study enumerated CD45(hi)/CD34(+) and CD45(hi)/CD133(+) human hematopoietic stem cells (HSCs) and progenitor granulocyte-macrophage colony forming cells (GM-CFCs) in blood and trochanteric and femoral bone marrow in 233 individuals. Stem cell frequencies were determined with multiparameter flow cytometry and using an internal control to determine the intrinsic variance of the assays. Progenitor cell frequency was determined using a standard colony assay technique. The frequency of outliers from undetermined methodological causes was highest for blood, but less than 5% for all values. The frequency of CD45(hi)/CD133(+) cells correlated highly with the frequency of CD45(hi)/CD34(+) cells in trochanteric and femoral bone marrow. The frequency of these HSC populations in trochanteric and femoral bone marrow rose significantly with age. In contrast, there was no significant trend of either of these cell populations with age in the blood. Trochanteric marrow progenitor GM-CFCs showed no significant trends with age, but femoral marrow GM-CFCs trended downward with age, potentially because of the reported conversion of red marrow at this site to fat with age. Hematopoietic stem and progenitor cells exhibited changes in frequencies with age that differed between blood and bone marrow. We previously reported that side population (SP) multipotential HSC, which includes the precursors of CD45(hi)/CD133(+) and CD45(hi)/CD34(+), decline with age. Potentially the increases in stem cell frequencies in the intermediate compartment between SP and GM progenitor cells observed in this study represent a compensatory increase for the loss of more potent members of the HSC hierarchy.

Heterogeneity of functional properties of Clone 66 murine breast cancer cells expressing various stem cell phenotypes.

INTRODUCTION: Breast cancer grows, metastasizes and relapses from rare, therapy resistant cells with a stem cell phenotype (cancer stem cells/CSCs). However, there is a lack of studies comparing the functions of CSCs isolated using different phenotypes in order to determine if CSCs are homogeneous or heterogeneous. METHODS: Cells with various stem cell phenotypes were isolated by sorting from Clone 66 murine breast cancer cells that grow orthotopically in immune intact syngeneic mice. These populations were compared by in vitro functional assays for proliferation, growth, sphere and colony formation; and in vivo limiting dilution analysis of tumorigenesis. RESULTS: The proportion of cells expressing CD44(high)CD24(low/neg), side population (SP) cells, ALDH1(+), CD49f(high), CD133(high), and CD34(high) differed, suggesting heterogeneity. Differences in frequency and size of tumor spheres from these populations were observed. Higher rates of proliferation of non-SP, ALDH1(+), CD34(low), and CD49f(high) suggested properties of transit amplifying cells. Colony formation was higher from ALDH1(-) and non-SP cells than ALDH1(+) and SP cells suggesting a progenitor phenotype. The frequency of clonal colonies that grew in agar varied and was differentially altered by the presence of Matrigel™. In vivo, fewer cells with a stem cell phenotype were needed for tumor formation than "non-stem" cells. Fewer SP cells were needed to form tumors than ALDH1(+) cells suggesting further heterogeneities of cells with stem phenotypes. Different levels of cytokines/chemokines were produced by Clone 66 with RANTES being the highest. Whether the heterogeneity reflects soluble factor production remains to be determined. CONCLUSIONS: These data demonstrate that Clone 66 murine breast cancer cells that express stem cell phenotypes are heterogeneous and exhibit different functional properties, and this may also be the case for human breast cancer stem cells.

Changes in human bone marrow fat content associated with changes in hematopoietic stem cell numbers and cytokine levels with aging.

Hematological deficiencies increase with aging, including anemias, reduced responses to hematopoietic stress and myelodysplasias. This investigation tested the hypothesis that increased bone marrow (BM) fat content in humans with age was associated with decreased numbers of side population (SP) hematopoietic stem cells, and this decrease correlated with changes in cytokine levels. BM was obtained from the femoral head and trochanteric region of the femur removed at surgery for total hip replacement (N = 100 subjects). In addition, BM from cadavers (N = 36), with no evidence of hip disease, was evaluated for fat content. Whole trabecular marrow samples were ground in a sterile mortar and pestle, and cellularity and lipid content determined. Marrow cells were stained with Hoechst dye and SP profiles were acquired. Plasma levels of insulin-like growth factor (IGF)-1, stromal-derived factor (SDF)-1 and interleukin (IL)-6 were measured using ELISA. Fat content in the BM of human subjects and cadavers increased with age. The numbers of SP stem cells in BM as well as plasma IGF-1 and SDF-1 levels decreased in correlation with increased BM fat. IL-6 had no relationship to changes in marrow fat. These data suggest that increased BM fat may be associated with a decreased number of SP stem cells and IGF-1 and SDF-1 levels with aging. These data further raise a more general question as to the role of adipose cells in the regulation of tissue stem cells.

Inflammation associated with obesity: relationship with blood and bone marrow endothelial cells.

The purpose of this study was to assess the inflammatory nature of obesity and its effect on blood and bone marrow endothelial cell populations. Obese patients (BMI ≥30) had significantly higher concentrations of the inflammatory marker C-reactive protein (CRP) (P = 0.03) and lower concentrations of the anti-inflammatory cytokine interleukin-10 (IL-10) (P = 0.05). This cytokine profile is consistent with obesity being an inflammatory condition and is further supported by the significant correlation between total white blood cell count and BMI (r = 0.15; P = 0.035). High BMI was associated with significantly lower numbers of early endothelial cells (CD45(-)/CD34(+)) in the bone marrow (r = -0.20; P = 0.0068). There was also a significant inverse correlation between BMI and a more mature endothelial cell phenotype (CD45(-)/31(+)) in the blood (r = -0.17; P = 0.02). In addition, there was a significant correlation between BMI- and endothelial-related cells of hematopoietic origin (CD133(+)/VEGFR-2(+)) in the bone marrow (r = -0.26; P = 0.0007). Patients with higher plasma IL-10 and insulin-like growth factor (IGF) concentrations had higher numbers of endothelial phenotypes in the bone marrow suggesting a protective effect of these anti-inflammatory cytokines. In conclusion, this work confirms the inflammatory nature of obesity and is the first to report that obesity is associated with reduced endothelial cell numbers in the bone marrow of humans. These effects of obesity may be a potential mechanism for impaired tissue repair in obese patients.

Sealant adaptation and penetration into occlusal fissures.

PURPOSE: To evaluate the adaptation and penetration into occlusal fissures of two different types of fissure sealants. METHODS: Extracted third molars (n=10) with evident occlusal fissures were cleaned with a pumice/water slurry and randomly divided into two groups and sealed following the manufacturers' directions as follows: Group 1--Embrace fissure sealant (Pulpdent). Surfaces were cleaned and dried, then etched for 15 seconds. Excess water was removed leaving the surface slightly moist. Sealant was applied from cusp to cusp without covering marginal ridges and light cured for 20 seconds using a halogen light at 500 mW/cm2. Group 2--ClinPro (3M Espe). Surfaces were cleaned and dried then etched for 15 seconds. The etched surface was rinsed and thoroughly dried. Dried surfaces appeared frosty white. Sealant was placed making sure not to go beyond etched area, and light cured for 20 seconds. Teeth were thermocycled (500x) and sectioned with an Isomet in a mesio-distal direction (4 slices per tooth). The sections were examined under the SEM. The marginal adaptation of the sealants was evaluated under the SEM using the following criteria: 1 = Smooth adaptation. Sealant flows with enamel. No ledges; 2 = Sealant is not well adapted. Ledge may be present. The penetration ability of the sealants was evaluated under the SEM using the following criteria: 1 = Sealant penetrated 1/3 the total length of the fissure; 2 = Sealant penetrated 1/2 the total length of the fissure; 3 = Sealant penetrated the total length of the fissure. The results were statistically analyzed using a t-test. RESULTS: Embrace showed consistently more intimate marginal adaptation than ClinPro in fissures of the same approximate width and depth (P < 0.05).

Visual performance with night vision goggles after photorefractive keratectomy for myopia.

OBJECTIVE: To evaluate visual performance and resolution through night vision goggles (NVG) before and after photorefractive keratectomy (PRK). DESIGN: Nonrandomized, comparative (self-controlled) trial. PARTICIPANTS: Nineteen patients (38 eyes) of active-duty US Army Special Forces soldiers. INTERVENTION: PRK for myopia and astigmatism. MAIN OUTCOME MEASURES: Visual acuity with best optical correction was measured preoperatively and postoperatively (3 months) using acuity charts of various contrast (100%, 10%, 2.5%, 1.25%). Preoperative and postoperative (3 month) uncorrected and best-corrected visual resolutions through NVGs were assessed using a high contrast tribar chart presented at four light levels (3.44 x 10(-3), 1.08 x 10(-3), 1.04 x 10(-4), 1.09 x 10(-5) foot Lamberts) simulating a range of night sky conditions. Subjects were trained before testing. RESULTS: Uncorrected visual acuity at the 3-month postoperative assessment was greater than or equal to 20/20 in 33 of 38 (86.8%) eyes. No eyes lost 2 or more lines of best spectacle-corrected visual acuity. Preoperative and 3-month postoperative best-corrected low-contrast acuity measurements showed no significant differences at all levels of resolution. Preoperative visual resolution through NVGs decreased systematically with decreasing night sky condition. Visual acuities before PRK were reduced without optical correction. Postoperative visual performance with NVGs (without optical correction) equaled or exceeded performance preoperatively with best correction. CONCLUSIONS: This prospective case series provides data on the safety and efficacy of PRK with respect to visual performance under night sky conditions using NVGs. There was no significant loss of visual acuity across a range of contrast levels 3 months postoperatively. There was no change in best-corrected NVG visual resolution postoperatively, whereas uncorrected visual resolution was significantly enhanced compared with preoperative levels. This improvement may translate into better function for soldiers who are unable to or choose not to use optical correction in operational environments.