bluuebunny/crossref_metadata_2025 huggingface dataset:
Aberrant glycerophosphocholine metabolism is a primary and targetable pathology in Alzheimer Disease
Authors: Xu Hongbin , Swayne Leigh Anne , Morin Katy , Fai Stephen , Figeys Daniel , Bennett Steffany A.L.
Published: June 2021

Glycerophospholipids are often overlooked as immediate response elements yet they exert fundamental control over cell viability. They represent the major building blocks of biological membranes and modulate membrane trafficking. Enzymatic processing of choline‐containing membrane phospholipids by cytosolic phospholipase A2 (cPLA2) generates powerful smaller intracellular second messengers (~450–600 Da) as well as arachidonic acid and its metabolites. Individual isoforms control distinct cellular processes, but little is known about how they respond to normal brain functions and neurodegenerative disease state. Recent advances in mass spectrometry are enabling large‐scale profiling of individual lipid isoforms in brain tissue and cells. We capitalize on these advances to address the question whether aberrant membrane lipid metabolism is a risk factor for neurodegenerative disease. Here, we employed high performance liquid chromatography combined with electrospray ionization mass spectrometry (LC‐ESI‐MS) to profile glycerophosphocholine second messenger metabolism in the post‐mortem human entorhinal cortex and hippocampus, as well as in the temporal cortex and hippocampus of C57BL/6 × 129SV/J hybrid mice over the course of a 24 h period.
Flipping the classroom: turning the traditional anatomy lecture on its head
Authors: Lyons Virginia , Muldoon Kathleen
Published: June 2021

It is widely accepted that students retain about 5% of what they learn in a lecture setting, while “practice by doing” yields about a 75% retention rate. Thus, there is a movement in education to utilize engaged learning practices in the classroom. Prior to this academic year, the pedagogy used in our medical gross anatomy course was traditional lectures, dissection laboratories and discussion groups. In the fall of 2012, we “flipped the classroom”, moving content delivery outside of the class setting, and introducing collaborative interactions and engagement activities into the classroom. Students were provided learning objectives and narrated slides to prepare for each laboratory; students assessed their preparation by completing readiness tests. Following laboratories, important concepts were revisited in faculty‐led large group sessions. These interactive sessions included activities such as questioning and polling students, peer teaching and collaborative construction of flow charts or nerve maps. Qualitative assessments of student performance suggest that students are better prepared for both laboratories and discussion groups. Preliminary quantitative results indicate that students of the flipped classroom are performing equally well or better than students from previous academic years on written quizzes. Successes and challenges for implementing a flipped classroom will be discussed.
Student‐Generated Content in the Gross Anatomy Laboratory:
Authors: Doubleday Alison French
Published: June 2021

Common challenges for faculty include finding ways to motivate students to stay on task and remain engaged with course content, as well as encouraging students to work collaboratively with their peers. The increased adoption of new technologies into the classroom provides unique opportunities to take advantage of existing applications in order to address these challenges. This presentation provides an example of how tablet (iPad)‐based applications were integrated into a human gross anatomy lab at University of Illinois at Chicago, College of Dentistry. Student‐generated photo and video data were used for formative assessment of student understanding by course faculty. A mobile scavenger hunt was also employed to increase student engagement and collaboration within the laboratory. Details and challenges of logistical planning, as well as implementation of the project are addressed. Additionally, results of student surveys highlighting student impressions and patterns of use demonstrate that careful integration of tablet‐based applications into the classroom can impact collaborative activity and engagement. This study illustrates a novel and innovative use of tablets within the gross anatomy laboratory and provides an example of the use of best practices for incorporating technology into a course.

Grant Funding Source: American Association of Anatomists
Which skinfold percent body fat equation performs best in American children?
Authors: Roberts Amy , Truesdale Kimberly P , Cai Jianwen , Stevens June
Published: June 2021

Many skinfold percent body fat (%BF) equations are available for specific groups and research settings; however, there is no standard equation for children.

Using a nationally representative sample of children (8–18y), we compared 16 published skinfold %BF equations with DXA measured %BF.

Selected equations contained variables available in the 1999–2004 NHANES (n=6,565). We tested equations using the overall sample and a subsample matching the demographics of the sample used for equation development. R2, and Root Mean Square Error (RMSE) were calculated based on DXA measured %BF regressing on predicted %BF using linear regression with appropriate sampling weights and DXA imputation procedures. Bland‐Altman plots were inspected.

Nine equations had a R2 ≥0.80 in any category, but 13 performed better than BMI (Girls: R2=0.63; Boys: R2=0.33). The Bray 2001 triceps and subscapular equation had the highest R2 and lowest RMSE (matched subsample: R2=0.82 RMSE=3.28; overall: R2=0.73 RMSE=4.23). Conversely, the Slaughter 1988 equation for 8–18y with skinfolds >; 35mm performed the most poorly for both boys (R2=0.12 RMSE=5.40) and girls (R2=0.40 RMSE=3.55). We found large differences in the performance of published skinfold %BF equations with the Bray 2001 performing the best in NHANES. While substantially better than BMI, %BF equations are needed that perform well in a variety of subpopulations.

NIH 3U01HL103561

Grant Funding Source: NIH 3U01HL103561
Efficacy of Antenatal Multiple Micronutrient (MM) vs Iron‐Folic Acid (IFA) Supplementation in Improving Gestational and Postnatal Viability in Rural Bangladesh: The JiVitA‐3 Trial
Authors: West Keith Parker , Shamim Abu A , Labrique Alain Bernard , Ali Hasmot , Shaikh Saijuddin , Mehra Sucheta , Schulze Kerry Jean , Klemm Rolf DW , Wu Lee Shu‐Fune , Merrill Rebecca Day , Massie Allan , Katz Joanne , Christian Parul
Published: June 2021

Antenatal micronutrient deficiencies may impair fetal and infant health. We conducted a cluster‐randomized, double‐masked trial among 44,567 pregnant women and 28,516 infants to assess efficacy of daily MM vs IFA supplementation, from the 1st trimester to 12 wk postpartum, in improving fetal and infant viability. Groups were similar in sample size (Nmm=22,162, NIFA=22,405), baseline SES, diet, maternal and gestational (GA) ages at enrollment, and supplement adherence [median: ~94 (IQR: ~84–100)%]. MM vs IFA supplementation was associated with the following relative risks (RR; 95% CI, adjusted for design effect): Still birth (.89; .81‐.99), low birth weight (.88; .85‐.91), preterm birth (.87; .82‐.92), SGA (.99; .96–1.01) and 6 (.95; .86–1.06) and 12 (.94; .85–1.04) mo mortality. Lower mortality occurred by ages 6 and 12 mo in girls (.87; .74–1.01 and .85; .73‐.97) but not boys (1.02; .89–1.17, both ages), with PInterax=.08 and .06, respectively. MM supplementation increased weight, length, arm, chest and head circumference by 55 g, .21 cm, .11 cm, .25 cm and .21 cm, respectively, explained by a 0.30 wk longer gestation in both sexes (all p<0.0001). In rural Bangladesh, antenatal MM reduced risk of still birth and lengthened gestation, lowering risk of preterm birth, increasing birth size, and reducing risk of low birth weight. Supported by The Bill and Melinda Gates Foundation (Grant GH614).
Measuring the Food Security Status of Cambodian Women
Authors: Cordeiro Lorraine S , Peterman Jerusha Nelson , Chen Shanshan , Mouth Ronnie , An Rasy
Published: June 2021

While household food insecurity is public health concern, there is limited data on the food security status of refugee populations in the U.S. Refugees from Cambodia were resettled in the U.S. in the 1980's. This study assessed the food security status of pregnant and post‐partum Cambodian women (15–30 YO) in Massachusetts. We held focus group discussions and administered surveys to study participants. Household food insecurity was measured using the 6‐item form of the U.S. Household Food Security Survey (HFSS) and a modified version of the Household Food Insecurity Access Scale (HFIAS). In this sample, 37.5% lived in food insecure households, 35.5% reported frequent consumption of less preferred food due to insufficient resources, and 31.3% reported that they sometimes/often worried that food would run out. Our findings suggest that the HFSS and HFIAS captured different aspects of the food security construct. Although responses to some questions in the HFSS were significantly correlated with responses to similar questions in the HFIAS, the variation in participant responses was different across measures. This mixed method approach provided valuable insight on the range of food security experiences among Cambodian women. We found a high prevalence of food insecurity among pregnant Cambodian women living in MA, which may have negative implications for maternal and child health.
Toddler Obesity Prevention Study (TOPS) increases toddler health‐promoting behaviors
Authors: Black Maureen M , Hurley Kristen , Wang Yan , Candelaria Margo , Latta Laura , Caulfield Laura , Hager Erin
Published: June 2021

Objective

To examine if an 8 session RCT grounded in social cognitive theory (SCT) and focused either on maternal diet and physical activity (PA) or on responsivity and behavior management increases toddler health promoting behaviors.

Method

274 low‐income mother‐toddlers completed a baseline evaluation: PA (ankle accelerometer worn 7 days, average time/day in moderate/vigorous physical activity), diet (USDA Automated Multi‐Pass Method), video‐taped meal (Emotional Availability Scales), weight & height (converted to age & gender‐specific z‐scores). Randomized to MOM TOPS: maternal diet and PA, TOT TOPS: responsivity and behavior management, or SAFE TOPS: toddler safety (placebo). Follow‐up at 6 months. Intent‐to‐treat longitudinal mixed modeling and generalized estimating equations, adjusted for baseline.

Results

Baseline: 17% toddlers and 51% mothers were obese, 70% Black, 2% Hispanic, & 22% White. At follow‐up, MOM TOPS/TOP TOPS improved over SAFE TOPS in fruit intake (0.49 and 0.93 servings, p=0.014, 0.014) and PA (14.7 and 14.6 minutes, p=0.025, p=0.025. TOT TOPS improved significantly over MOM TOPS in 5 of 6 EAS categories (child involvement & responsively, parent sensitivity, structure, & parent non‐hostility).

Conclusions

A brief intervention built on principles of SCT is effective in increasing toddler health‐promoting behaviors of diet, PA, and mealtime responsivity.
The low level of EPA in brain phospholipids is maintained by multiple compensatory mechanisms
Authors: Chen Chuck Tzu‐Huan , Domenichiello Anthony F , Trepanier Marc‐Olivier , Liu Zhen , Masoodi Mojgan , Bazinet Richard P
Published: June 2021

Objective

To examine if mitochondrial fatty acid beta‐oxidation is necessary for maintaining low EPA levels in brain phospholipids.

Methods

Adult male free‐living Sprague Dawley rats were administered vehicle or methyl palmoxirate (MEP), a carnitine palmitoyltransferase I (CPTI) antagonist prior to being infused intravenously with 150 μCi/kg of 14C‐radiolabeled palmitate, DHA or EPA. Blood samples were collected during the five minute infusion via the jugular vein. At 5 minutes with continual radiotracer infusion, rats were subjected to high‐energy, head‐focused microwave irradiation and brains were collected for radioactive and biochemical analyses.

Results

Using equations from our fatty acid model, we found that that incorporation coefficient (k*) into the aqueous fraction (marker of β‐oxidation) decreased significantly in MEP‐treated brains compared to vehicle controls for palmitate (3.8‐fold) and EPA (2.2‐fold) but not DHA. This was accompanied by a significant increase in the k* into total phospholipids of MEP‐treated brains as compared to controls for 14C‐EPA infused rats (1.5‐fold) but not 14C‐palmitate and 14C‐DHA infused rats. However, after identification and correction for metabolized 14C‐EPA, the increase in k* was attributed to an increase in synthesis of the EPA elongation product, n‐3 docosapentaenoic acid. Furthermore, the incorporation (Jin) and recycling (FFA) of EPA into brain phospholipids were significantly lower than palmitate and DHA by up to 56‐fold and 9‐fold, respectively.

Conclusion

The low level of EPA in brain phospholipids is maintained via beta‐oxidation, elongation and rapid metabolisms.

Grant Funding Source: NSERC
Novel neuropathology in fetal alcohol syndrome
Authors: Folkerth Rebecca , Smith Johan , Zaharie Dan , Odendaal Hein
Published: June 2021

Behavioral, imaging, and epidemiologic data on Fetal Alcohol Syndrome (FAS) are abundant, as are data in experimental animal models. By contrast, brain tissue studies in human FAS are scarce. From the files at our institutions we found 10 cases with maternal alcohol histories and neuropathology (NP) slides. Subjects lived <1d‐22mos; 7 were premature. 6 were growth‐restricted; 3 had microcephaly; 9 had facial features of FAS; 8 had major systemic anomalies. Novel NP findings include: A) disturbances of neuronal migration/organization in 7, e.g. columnar (“fetal”) cortex and dentate gyrus abnormalities; B) hypoxic‐ischemic lesions in 3, e.g. white matter damage, germinal matrix hemorrhage, mineralization, neuronal loss, and gliosis of gray matter; C) lesions of uncertain pathogenesis in 3, such as decreased white matter volume and hypomyelination, patchy internal granule cell hypodensity, and arcuate nucleus hypoplasia. The findings expand upon those seen in the meager human literature to date, and assist in understanding the neurologic deficits in FAS.
Egr3‐dependent muscle stretch receptor morphogenesis and innervation homeostasis
Authors: Fernandes Michelle Oliveira , Gruner Katherine , Tourtellotte Warren G
Published: June 2021

Muscle spindles are skeletal muscle receptors that mediate stretch reflexes and proprioception in vertebrates. Proprioception abnormalities are observed in many human neuropathies with unknown etiology and factors involved in sensory nerve‐stretch receptor homeostasis are poorly understood. During skeletal muscle development, sensory (Ia‐afferent) innervation is restricted to only a few myotubes which induces their transformation into intrafusal muscle fibers that form the stretch receptor core. The transcriptional regulator Egr3 is induced by sensory innervation and it has an essential role in stretch receptor morphogenesis, but whether its function is restricted to developing receptors and whether it has a role in innervation homeostasis is not known. Ablation of Egr3 using skeletal muscle specific knockout mice demonstrated its autonomous function in developing stretch receptors. Lineage tracing experiments using Egr3‐Cre knock‐in mice showed that stretch receptor differentiation is blocked in the absence of Egr3 and innervation fails to be maintained. Thus, Egr3 has an essential function in intrafusal muscle fiber differentiation and gene regulation required to maintain innervation homeostasis. (Support: NIH R01‐NS063078 and K26‐OD010945).
Functional Divergence of Fanconi Anemia Genes
Authors: Wang Yucai , Leung Justin W , Jiang Yingjun , Lowery Megan G , Do Huong G , Vasquez Karen M , Chen Junjie , Wang Weidong , Li Lei
Published: June 2021

The Fanconi anemia (FA) pathway is a major mechanism countering DNA interstrand crosslinking lesions. Deficiencies in FA leads to DNA damage sensitivity and profound cancer predisposition. The DNA remodeling enzyme FANCM and its DNA‐binding partner, FAAP24, constitute a complex involved in activation of FA pathway, but neither gene has distinct patient mutants. We created isogenic models for both FANCM and FAAP24 and investigated their integrated functions in DNA damage response. We found that FANCM and FAAP24 coordinately facilitate FA pathway activation and suppress sister chromatid exchange. Importantly, we show that FANCM and FAAP24 possess non‐overlapping functions such that FAAP24 promotes ATR‐mediated checkpoint activation particularly in response to DNA crosslinking agents, whereas FANCM participates in recombination‐independent interstrand crosslink repair by facilitating recruitment of lesion incision activities which requires it translocase activity. Our results suggest divergent roles played by FANCM and FAAP24 in maintaining genomic integrity.
Future Directions for Implementing Nutrition Across the Continuum of Medical and Health Professions Education and Training, and Research
Authors: Kris‐Etherton Penny M , Akabas Sharon , Pratt Charlotte , Saltzman Edward , Krebs Nancy , Levy Matthew
Published: June 2021

The NHLBI in collaboration with the NIH Office of Disease Prevention and Division of Nutrition Research Coordination convened a Working Group Meeting in September 2012 on implementing nutrition across the continuum of training medical students through residency, and training other health professionals. The objectives were to make recommendations on 1) the content and implementation of nutrition and healthy lifestyles education, training and competency testing, and 2) the integration of nutrition education, training and research to improve population health, patient care and health outcomes. Guiding principles for nutrition education in professional schools were defined. Cross‐cutting Themes for Health Professional Training recommendations were: 1) Nutrition Academic Award Curriculum Guide update and documentation with learning objectives and competencies for all relevant health professionals; 2) a Nutrition Education and Research Coordinating Center that would serve as an oversight and coordinating body for nutrition education and research; and 3)multi‐disciplinary team approaches and referral systems across the continuum of health professional training. Research priorities were identified to advance nutrition education in health professional training programs. Implementation of these recommendations would require partnerships with a broad coalition of organizations.
A Multidisciplinary and Formal Nutrition Education is Needed in Graduate Medical Education
Authors: Daley Brian James , McClave Stephen , Van Way Charles , Gramlich Leah , Cherry‐Bukoweic Jill , Collier Bryan , Lawson Christy
Published: June 2021

Introduction

A needs assessment survey was constructed to determine faculty resources and commitment for nutrition education from Graduate Medical educators. The null hypothesis was all specialties had insufficient faculty resources to educate about current nutritional practice.

Methods and A needs assessment was sent in a survey format of 25 questions to 495 ACGME Residency Program Directors in Anesthesia, Family Medicine, Medicine, Pediatrics, Obstetrics and Gynecology and Surgery. There was a 14% response rate (72 programs), consistent with similar studies on the topic.

Results

The majority of respondents were primary care programs (32 Family Medicine, 23 Medicine and one Pediatric). Most program directors had a fair knowledge of nutrition themselves, with 10% reporting expert knowledge, and 41 programs did not identify an expert. The majority of experts were often not considered formal Graduate Medical educators (MDs = 37, RD = 38, Pharm D= 13, RN= 12 and PhD =7). Nutrition education occurs informally, by non‐MD providers as only 19 residencies had a formal nutrition course. Seventy seven percent of residencies felt they did not meet the required educational goals for and 72% felt a national curriculum would overcome this obstacle.

Conclusions

There is indeed a dearth of nutrition education in current graduate medical education. Most programs lack the expertise/commitment to teach a formal course but recognize the need to meet educational requirements. Most programs rely on non‐MD multidisciplinary experts to teach residents. A broad based, diverse specialty educational program taught by MDs and other non‐MD experts is needed for training in nutrition during residency.
Evaluation of rational prescribing skills assessment for graduating medical students
Authors: Moch Shirra
Published: June 2021

Prescribing medicines is the primary intervention that doctors offer to influence their patients’ health; however concerns have been expressed about the adequacy of prescribing training in medical school. This study analysed the exit‐level written assessment component of final‐year medical students at the University of the Witwatersrand, with respect to fitness‐for‐purpose to test rational prescribing skills. Examination questions were selected via an adjudicative process to determine a prescribing mark. Question items were then analysed according to Bloom's Revised and the SOLO Taxonomies. The framework of constructive alignment was used to interrogate fitness‐for‐purpose. A comparison of “A‐Type” (single best answer) multiple choice questions (MCQs) with “R‐Type” (extended matching) MCQs paradoxically highlighted students’ greater proficiency in the R‐Type questions (p<0.0001). Students scored well on questions which tested recall and application of knowledge, but struggled with those involving evaluation. Questions were poorly distributed according to prescribing skills to be tested. Examination marks showed that 83.6% of students were competent to prescribe according to the graduating standards of the University. Despite high examination scores, this study illustrates a lack of constructive alignment between assessment requirements, curriculum delivery and objectives of the course.
A hands on model of skeletal muscle reflexes, tone and innervation
Authors: Nielson Jonathan , Carvalho Helena
Published: June 2021

Neuroscience is rapidly advancing field and a large body of information is becoming available. The complexity of these topics can create misconceptions and lead students to feel overwhelmed in their approach to the large amount of information. In an effort to facilitate the learning process and engage students we developed a model of a skeletal motor unit and its innervations. The model is easily constructed of a wood base, 1″×3″ wood boards, a hinge, elastic, string and images of a spine segment. It can be manipulated to demonstrate the action of muscle across a joint with the motor input and sensory output that allow purposeful movement and maintenance of muscle tone. The model also demonstrates how the sensory information changes as the muscle moves and what affect that has on motor nerve action. The interactive model was developed and demonstrated with a group of first and second year medical students at VTCSOM. The students were given a 5‐minute didactic style lecture and then given 5 minutes with the model. 55% of students identified the model as useful to their understanding of the topics it presents, several suggestions we given to improve the model. In conclusion a simple model was constructed with an inexpensive material that addresses a complex and important topic in neuroscience.

Financial support: Center for Instructional Development and Educational Research at Virginia Tech
Aerospace physiology within an exercise physiology curriculum
Authors: Carter Jason R. , West John B.
Published: June 2021

Compare and contrast strategies remain common pedagogical practice within physiological education. We have developed a curriculum for exercise physiology that compares and contrasts the physiological adaptations of chronic terrestrial exercise (TEx) and microgravity (MG). We use a series of peer‐review publications to demonstrate that many of the physiological adaptations to TEx and MG are opposite. For example, TEx typically improves cardiovascular function and orthostatic tolerance, while microgravity can lead to declines in both. TEx leads to muscle hypertrophy and MG elicits muscle atrophy. TEx increases bone mineral density (BMD) and red blood cell (RBC) count, while MG decreases BMD and RBC. Importantly, exercise during spaceflight is a crucial countermeasure to limit some of these adverse physiological adaptations to MG. This curriculum develops critical thinking skills by dissecting peer‐review articles and discussing the strengths and weaknesses associated with simulated and actual microgravity studies. Moreover, the curriculum includes studies on both animals and humans, providing a strong translational component to the curriculum. In summary, we have developed a novel aerospace physiology curriculum delivered during the final two weeks of an exercise physiology course in which students gain critical new knowledge that reinforces key concepts presented throughout the semester.
BioTeach: an Innovative Professional Development for High School Biology Teachers
Authors: Wyss J Michael , Jarrett Kevin , Busch Katie
Published: June 2021

As science information increases at exponential rates, professional development is needed to keep teachers current and innovative in their discipline. BioTeach provides teachers throughout Alabama and adjacent states tools and training to implement high‐level, inquiry‐based biology labs. Teachers participate in a 3‐week summer course and return for 3 professional development sessions (school year), providing teachers the first‐hand knowledge of how to guide their students in molecular biology experiments in a classroom. The teachers continue their professional development by bringing their students to hands‐on, molecular biology labs in the GENEius Lab, where high school students conduct college‐level labs, which the teachers previewed in BioTeach. 91% of the BioTeach teachers bring their class to the GENEius lab twice per year or more and >;90% implement the skills they learned from BioTeach/GENEius in their classroom. >;75% of the 192 BioTeach graduates (past 10 years) continue to use materials and pedagogy they received in BioTeach, and >;50% of the inquiry‐based experiences the teachers develop in BioTeach continue to be used in the classroom after 5 years. Student assessment shows significantly improvement (>;155%), and teachers have noted increased student performance after their GENEius experience. Thus, BioTeach develops inquiry‐based, biology educators, who are improving science education.
3D‐based approach for efficient analysis of immunostained histology images in evaluating downstream pathway activation in malignant tumors with molecular targets
Authors: Yagi Yukako , Bautista Pinky Abarca , Klepeis Veronica , Mino‐Kenudson Mari
Published: June 2021

In malignant tumors with molecular targets, the evaluation of downstream pathway activation, which could be heterogenous, may be important to predict and assess response to targeted therapy. Immunohistochemical staining is often used to examine the activation of multiple downstream markers in this setting while H&E staining provides the morphological and structural information to locate the tumor cells. With the evaluation of one immunostained slide at one time, it may be difficult to assess the simultaneous activation of multiple pathways within tumor cells, especially when reactive tumor cells are limited or scattered in the background of benign cells. By reconstructing the series of H&E and immuno stained images into a 3D composite image it would be easier to identify tumor cells that are reactive to multiple immunomarkers and assess the presence and/or heterogeneity of downstream pathway activation. In our experiment, serial sections of a lung adenocarcinoma with an EGFR mutation were obtained and stained with H&E and several immunomarkers, and then later scanned using the whole slide imaging in the laboratory. From the resulting 3D reconstructed image of the H&E and immunostained scanned images we could easily evaluate the expression of multiple immunomarkers within the tumor cells.
The pea‐shaped human pisiform results from the evolutionary loss of a growth plate
Authors: Kjosness Kelsey Marie , Hines Jasmine E. , Lovejoy C. Owen , Reno Philip L.
Published: June 2021

The human pisiform is a small nodular bone that serves as the distal attachment for the powerful forearm muscle, the flexor carpi ulnaris. In contrast, most other mammals, including primates and the ancestral hominid Australopithecus afarensis, possess a pisiform that is substantially elongated. An underappreciated fact is that in these species the pisiform develops from two separate ossification centers. A secondary center implies the presence of a growth plate (similar to the calcaneus) whose loss could serve as an evolutionary mechanism underlying human pisiform reduction. Here we perform a histological analysis of pisiform ossification in juvenile mice. We confirm the existence of a pisiform growth plate with distinct organized columnar and hyptertrophic chondrocyte zones. We also conducted a comparative analysis of hominoid pisiform ossification and confirm that epiphyses are present in Pan, Gorilla, and Pongo but not in humans. In addition, the initial ossification occurs substantially earlier in apes relative to humans, thus raising questions concerning the homology of the human pisiform and the two distinct ossification centers of other mammals. The research is funded by Penn State University.

Grant Funding Source: Pennsylvania State University
An Experimental Study Comparing Active Mobilization to Passive Flexion‐Active Extension‐Active Flexion after Flexor Tendon Repair in Zone Two
Authors: Ding Zihai , Lee Hongliang
Published: June 2021

Purpose

Both passive flexion‐active extension and active rehabilitation have shown advantages and disadvantages in tendon healing, but few studies have combined these two rehabilitation protocols to identify their ideal balance.

Methods

A tendon injury model was employed in white Leghorn chickens. Thirty‐two animals were randomly assigned into four groups. We compared a UA group (UA=Unrestricted Active flexion rehabilitation regimen) with PAA‐5, PAA‐9.5 and PAA‐14 groups (PAA‐X=Passive flexion‐Active extension regimen followed by Active mobilization at 5 days, 9.5 days, and 14 days post operation, respectively). The tensile properties and range of motion of the three interphalangeal joints were evaluated for three postoperative weeks.

Results

In terms of tensile properties of operated foot, PAA‐14 was higher than any other group, and PAA‐5 was the lowest. There was no significant difference between the PAA‐9.5 and UA. For the range of motion, there were significant differences between all four groups: UA increased the most, PAA‐14 increased the last and PAA‐5 increased more than did PAA‐9.5. For the rupture rate, UA and PAA‐5 were higher than were PAA‐9.5 and PAA‐14.

Conclusion

The results indicate that the PAA‐9.5 and UA may give the best balance (tensile properties, range of motion, rupture rates) of these rehabilitation protocols. PPA‐9.5 and UA have the similar moderate tensile properties. When considering an increased range of motion, the UA method may be the most appropriate despite its higher rupture rate. When considering a lower rupture rate, PAA‐9.5 may be the most suitable.
Comparing various epithelial cell lines as in vitro models for Francisella tularensis non‐phagocytic infections
Authors: Lo Karen Y , Chua Michael D , Abdulla Salima , Law HT , Guttman Julian A
Published: June 2021

The potential bioterrorism agent Francisella tularensis subspecies tularensis (F. tularensis) causes the disease tularemia; if untreated the disease can result in up to 60% mortality. As an intracellular bacterium, F. tularensis invades and occupies non‐phagocytic epithelial cells of its host – a process critical to the development of disease. To study epithelial infections, many cell culture models have been developed; yet choosing a suitable model from the literature is challenging due to varied infection parameters and inaccurate assessments of intracellular bacterial loads. In our lab, we have developed an epithelial cell model using a murine surrogate of F. tularensis Francisella tularensis subspecies novicida (F. novicida) and the cultured hepatocyte cell line BNL CL.2. Since our model emulates the murine model of tularemia, we hypothesize BNL CL.2 cells will be more susceptible to F. novicida infection compared to other models currently present in the literature. We assessed 8 different models with the same parameters using antibiotic survival assays and an immunofluorescence strategy to label intracellular vs extracellular bacteria. We found that while COS‐7, CMT‐93, and HEK‐293 cell lines may be suitable for studying specific aspects of infection such as invasion or replication; overall, BNL CL.2 cells were the most appropriate cell line to study F. tularensis epithelial infections in vitro.

Grant Funding Source: NSERC and CIHR
Incorporation of myosin heavy chains into the A‐bands of living skeletal muscle cells
Authors: Sanger Joseph W , Wang Jushuo , Fan Yingli , Mittal Balraj , Sanger Jean M
Published: June 2021

A‐bands of muscle present a paradox: A‐bands must be stable for contraction and yet permit the insertion of newly synthesized molecules without disrupting A‐bands. We have investigated how myosin heavy chains (MHC) are incorporated into A‐bands of muscle cells. In our studies, living myocytes were transfectd with plasmids encoding Yellow Fluorescent Protein (YFP) ligated to MHC or a proteolytic domain of MHC, i.e., Light Meromyosin (LMM). We used the technique of Fluorescent Recovery After Photobleaching (FRAP) to determine how unbleached YFP‐MHC exchanged with their bleached counterparts. Our results demonstrated that the exchange of YFP‐MHC took place uniformly throughout the A‐bands. In contrast, YFP‐LMM incorporated and exchanged into the edges of A‐bands and in the middle of the A‐bands. The exchange of LMM was more rapid than the exchange of MHC. Previous studies with electron microscopic (EM) studies of fixed muscle cells and myosin antibodies led to contradictory results: one study stated myosin molecules were first incorporated on the edges of A‐bands, while the other study reported that myosin was detected first throughout the A‐bands. Our results indicate that YFP‐MHC can exchange throughout the length and diameter of the A‐band in living muscle cells. This dynamic exchange would allow replacement of damaged myosin molecules and entry of new isoforms of myosin during development. NIAMS/NIH Support.
Pericytes connect the blood vessels of hosts and grafts within 24 hours after cell sheet transplantation
Authors: Morikawa Shunichi , Ezaki Taichi
Published: June 2021

The prompt establishment of blood circulation between grafts and hosts is indispensable for the success of transplantation. In this study, we sought to elucidate how the blood circulation between grafted cell sheets and host tissues is accomplished. The multi‐layered cell sheets were fabricated by culturing rat heart cells; the heart cells contained vascular endothelial cells, which eventually formed tubular structures in the cell sheets during the cultivation period before grafting on rat dorsal muscles.

As early as 24h after grafting, blood vessels were extended from host tissues and entered into grafted cell sheets. At the same time, blood inflow from the hosts into the cell sheets was confirmed by intravenous injection of tracer dyes into the hosts. In the cell sheets, the host blood vessels were chimerically connected with intrinsic endothelial tubes of the cell sheets. Interestingly, the chimeric vessel junctions were surrounded by NG2 proteoglycan / alpha smooth muscle actin‐positive pericytes; moreover, type‐IV collagen / griffonia simplicifolia lectin I‐positive vascular basement membrane ensheathed these pericytes and the vessel junctions collectively.

We conclude that pericytes connect the blood vessels of hosts and grafts by producing basement membrane as a scaffold for the blood vessels that extend from host tissues toward grafted cell sheets within 24 h after transplantation.
Lung bioscaffolds: comparative lung decellularization techniques
Authors: Ferng Alice , Qu Ning , Hemphill Courtney , Khalpey Zain
Published: June 2021

While the final treatment for end‐stage lung failure remains lung transplantation, less than 20% of donor lungs are considered suitable for transplantation. An innovation to improve the donor lung pool supply involves decellularization of lungs to provide an acellular three‐dimensional bioscaffold that can be reseeded with lung specific progenitor cells. With no existing gold standard method for lung decellularization to date, it is important to establish an efficient and effective method that removes all DNA and intracellular structural proteins. These techniques also involve testing the bioscaffold integrity, and instituting a cryopreservation method such that a lung bioscaffold repository can be created.

Rat lungs were decellularized using static and continuous perfusion decellularization protocols. Static decellularization was done using a 24 and 72‐hour protocol, and continuous decellularization was done using a 75 hour protocol. Triton X‐100, Sodium Deoxycholate or Sodium Dodecyl Sulfate, NaCl, and porcine pancreatic DNAase was used to decellularize the lungs, with the variation being a difference in incubation times. Differences between techniques were determined by histological analysis via H&E and DAPI stains evaluating nuclei and structural proteins. Bioscaffold integrity tests following both decellularization and cryopreservation were also performed.

Grant Funding Source: N/A
Profiling miRNAs in Renal Neoplasms for Diagnosis and Biomarker Discovery
Authors: Sam Soya , Schned Alan R. , Tsongalis Gregory J. , Tafe Laura J.
Published: June 2021

Introduction

Renal cell carcinoma (RCC) consists of three main histologic subtypes each with a distinct biological behavior and response to current therapeutics. Oncocytomas (OC) are an important differential diagnosis. Altered miRNA expression plays a critical role in tumorigenesis and cancer progression. The objective of this study was to profile miRNA expression signatures of histologically categorized renal neoplasms (RN).

Methods

MiRNA was isolated from archived samples of a clear cell (ccRCC) and papillary (pRCC) RCC, an OC and normal kidney using the miRNeasy FFPE Kit (Qiagen). MiRNA was tailed and ligated to FlashTag‐Bitoin‐HSR and run on the Affymetrix GeneChip miRNA v3.0 Arrays as per the manufacturer's protocol. Data were analyzed using the Expression Console software and Partek Genomics Suite.

Results

All 4 specimens had analyzable results. Our initial data demonstrate differential expression of miRNAs in the RN: miR‐210, miR‐1269, and miR‐205 are up‐regulated in ccRCC, miR‐187 is up‐regulated in OC and miR‐31 is up‐regulated in pRCC.

Conclusion

The GeneChip miRNA 3.0 Array includes 1733 mature human miRNAs and can be used with FFPE. MiRNA profiling of RN is warranted to generate an algorithm to accurately subtype small biopsies and histologically challenging cases for treatment stratification.
Epigenetic and stem cell biomarkers in experimental melanoma metastases
Authors: Lian Christine Guo , Ma Jie , Shi Yujiang Geno , Zhan Qian , Lezcano Cecilia , Frank Markus H. , Murphy George F.
Published: June 2021

Little is know regarding epigenetic and cancer stem cell participation in melanoma metastases. We recently described two relevant biomarkers to address this issue, and herein utilize them to immunohistochemically evaluate metastases in the NSG murine‐human melanoma xenograft model. Subcutaneous xenografts derived from the C8161 cell line produced lymph node and lung, but rarely liver, metastases within four weeks. Metastases differed from primary xenografts by expressing increased immunoreactivity for the melanoma stem cell marker, ABCB5 (Nature 2008), and selective loss from the ABCB5+ stem cell component of the epigenetic mark, 5‐hydroxymethyl cytosine (5‐hmC; Cell 2012). Reciprocal patterns of ABCB5 and 5‐hmC expression were prominent in lung metastases, which showed perivascular and peribronchial distributions, and in lymph node metastases, where vasculogenic mimicry‐like growth focally was documented. These data support the importance of cancer stem cells in the production and growth of melanoma metastases, and implicate loss of 5‐hmC as a potential epigenetic mediator of the metastatic stem cell phenotype. Study funded by NIH‐GM078458 and NIH‐NCI 5P50CA093683–09.
Nuclear factor one controls a voltage‐sensitive developmental switch required for late neuronal maturation
Authors: Ding Baojin , Wang Wei , Kilpatrick Daniel L.
Published: June 2021

The objective of this study was to examine how gene expression related to synapse formation is regulated during neuronal maturation. Lentiviral transduction of mouse cerebellar granule neurons (CGNs) and cerebella tissues of gene knock out mouse were used together with microarray, qRT‐PCR, and chromatin immunoprecipitationon (ChIP) assays. These approaches identified a Nuclear Factor One (NFI)‐regulated temporal switch program linked to dendrite and synapse formation in developing mouse CGNs. One central feature of this program was temporally‐regulated NFI occupancy of late‐expressed gene promoters. Further, the NFI switch program and NFI occupancy were regulated by membrane potential‐dependent activation of the calcineurin (CaN)/Nuclear factor of activated T‐cell, cytoplasmc (NFATc) pathway. NFATc4 occupied the promoters of late‐expressed NFI program genes in immature mouse cerebellum, and its binding was temporally down‐regulated with development. NFI temporal binding and switch gene expression were up‐regulated in the developing cerebellum of Nfatc4 (−/−) mice. These findings suggest that NFI‐regulates transcription of late expressed genes through its temporal occupancy, which serves as a critical link between membrane potential and synapse formation via the CaN/NFATc4 pathway.

Grant Funding Source: PHS grant NS063047 to DLK
DEAD DNA Transport: a mutational analysis of a competence helicase/translocase
Authors: Chilton Scott Sinclair , Burton Briana M.
Published: June 2021

In bacteria, horizontal gene transfer (HGT) is a major mechanism for generating genetic diversity. The predominant HGT processes all involve the transfer of large macromolecules across cell membranes. Genetic competence is one such process in which cells are able to take up DNA from their environment in a processive manner. These cells become transformed when the acquired genes are maintained a part of the organism's genome or as an extra‐chromosomal element such as a plasmid. Many bacteria carry homologs of the central DNA uptake machinery that has been well characterized in Bacillus subtilis. The core machinery is comprised of a DNA binding receptor (ComEA), an aqueous pore (ComEC), and a helicase/translocase (ComFA). It has been postulated that ComFA belongs to a family of low processivity helicases/translocases, the DEAD‐box family. Thus, it is currently unclear how ComFA contributes to the high processivity exhibited during DNA uptake. In the work presented here, we conduct a mutational analysis of ComFA based upon sequence homology to conserved DEAD‐box helicase/translocase motifs. Mutating the conserved residues disrupts DNA uptake and transformation, suggesting that ComFA is in fact a member of the DEAD‐box family. Understanding how the uptake machinery functions expands our understanding of the diversity of cellular functions that employ DEAD‐box helicases, and possibly the diversity of behaviors of the protein family.
Mass spectrometry characterization of acrolein protein targets in the liver: Focus on site‐specific analysis
Authors: Zhu Yiying , Bazemore‐Walker Carthene R.
Published: June 2021

Acrolein is the most reactive α, β‐unsaturated aldehyde and this property also makes it extremely cytotoxic. Toxicity is mediated, in part, by carbonylation of amino acids through Michael addition, which potentially alters the structure and function of target proteins. Acrolein can be generated endogenously: It is a product of lipid peroxidation and of metabolism of exogenous substances, such as the chemotherapeutic cyclophosphamide and the herbicide allyl alcohol. Total protein carbonylation is elevated in mouse hepatocytes due to acrolein exposure. However, the specific proteins that are modified by acrolein, and importantly, the amino acid sites changed by the aldehyde are not known. Thus, in this study, we determined the identity of the proteins selectively adducted by acrolein with a focus on characterizing carbonylated amino acid residues. Rat liver microsomes were resuspended in buffer and the non‐denatured mix was treated with acrolein. Microsomal proteins were kept in their native conformations in this experiment in order to determine acrolein accessible sites that may have relevance in vivo. Carbonylated proteins were labeled with biotin hydrazide and digested with trypsin. Then, biotinylated peptides were isolated from the mixture with avidin affinity chromatography and analyzed via LC‐MS/MS. Eighty‐seven different proteins and 125 unique modification sites were discerned using a Mascot score >; 30 and a precursor mass error < 20 ppm. Identified proteins include 9 isotypes of cytochrome P450, which plays an important role in metabolism, and 12 ribosomal proteins that are critical for protein synthesis. Our results validate this peptide‐centric methodology and should facilitate an understanding of the role that protein carbonylation plays in acrolein's toxicity within the liver.
Cytotoxicity screening of a series of semiconductor quantum dots for their potential biomedical use
Authors: Ermilov Eugeny , Kuzyniak Weronika , Adegoke Oluwasesan , Sekhosana Kutloano , Hoffmann Bjoern , Nyokong Tebello , Pries Axel R. , Höpfner Michael
Published: June 2021

Background

Quantum dots (QDs) are promising candidates for a wide variety of biomedical applications, such as imaging, biosensing and drug delivery. However, the major drawback of QDs is their potential cytotoxicity. The major goal of the present study was to examine cytotoxic effects of a series of newly synthesized CdTe or CdSe QDs with/without ZnS shell and different cappings to estimate their potential use in biomedicine.

Methods & Results

Proliferation studies using the human pancreatic carcinoid cell line BON and the esophageal squamous carcinoma cell line Kyse70 revealed that CdTe and CdSe QDs with or without ZnS shell and coated with 3‐mercaptopropionic acid were highly cytotoxic even at low nanomolar concentrations. By contrast capping with L‐glutathione (GSH) or thioglycolic acid (TGA) reduced the cytotoxicity of CdTe and CdSe QDs to reach IC50 values in the micromolar range. Additional investigations using chorioallantoic membranes of fertilized chicken eggs (CAM assay) to which QDs were applied topically or injected intravenously confirmed the good tolerability in vivo.

Conclusion

The specific surface coating as well as core material has significant impact on QD toxicity in cells and tissues. The novel TGA‐ and GSH‐capped QDs characterized in this investigation merit further elucidation as promising candidates for biomedical applications.