bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Large Conductance Ca2+‐Activated K+ (BK) Channels Dynamics in Living Cells
Authors: Miguelez Allende , Duncan Rory , Brown Euan
Published: November 2023

Large conductance Ca2+‐activated K+ (BK) channels are central in diverse cellular processes including neurotransmitter release or smooth muscle contraction. BK channel activation is driven by both intracellular Ca2+ and voltage, and they are essential for rapid membrane repolarisation. Moreover, BK channels are expressed in human β‐cells regulating insulin secretion. Indeed, in diabetes mellitus BK channels activity is disrupted.

Previous electrophysiological studies suggested that N‐type (Cav2.2) calcium‐ and BK‐channel molecules must be in close proximity in the plasma membrane. Therefore, we developed novel methods to analyze the dynamics and distribution of BK channels at the level of single molecules in cell membranes using super‐resolution microscopy, molecular manipulation and electrophysiology. We expressed a cDNA construct that encodes the BK‐channel α‐subunit (BKα) fused to a photoactivatable fluorescent protein mutant of mCherry (PAmCherry) and localized single channel molecules. We also analyzed BK channel localization with gated stimulated emission depletion (g‐STED) microscopy using a BKα‐EGFP construct. Furthermore, we integrated both total internal reflection fluorescence (TIRF) microscopy and patch‐clamp for the study of BK channels function and localization.

In order to study Ca2+ channel proximity with BK channels and organelles like secretory vesicles we transfected secretory cells with our BKα‐PAmCherry construct or use the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) system to create genetically modified cells, labelling endogenous Cav2.2 channels with fluorescent‐Conotoxin (specific blocker for Cav2.2) that can be photoactivated. With this experiment we could analyse both channel membrane localization and proximity to secretory vesicles and exocytosis sites, using caged Ca2+ to trigger secretory vesicle fusion with the cell membrane. By co‐transfecting cells with both a GCaMP construct localized in the inner cell membrane layer and BKα‐PAmCherry constructs we can track the intracellular Ca2+ rise due to GCaMP fluorescence emission and how depolarization affects BK channels dynamics.

These experiments revealed the dynamics, proximity and patterning of large cohorts of single ion channel protein molecules and their functional relationship with the secretory machinery.
Identification of the Eletriptan Binding Site on P‐glycoprotein Determined from Nuclear Magnetic Resonance Spectroscopy
Authors: Wilt Laura , Roberts Arthur
Published: November 2023

P‐glycoprotein (Pgp) serves as the gatekeeper across the blood‐brain barrier and protects the brain from chemical insults; however, this protective role reduces brain penetration of neurotherapeutics. The drug class triptans are used in the treatment of migraines and have a range of Pgp transport rates. We have chosen to work with eletriptan (ETT) because this triptan drug has a high transport rate and represents the best opportunity to decipher the mechanism of transport. The affinity and the number of binding sites to Pgp were estimated using fluorescence quenching. ATPase activity of reconstituted Pgp revealed ETT to have a monophasic curve and was fit to Michaelis‐Menten equation. Using paramagnetic relaxation enhancement (PRE) NMR of cysteine‐labeled Pgp, the ETT binding site was identified to lie in the central binding cavity. ETT molecules bound to Pgp were also found to be in an extended conformation by exchange‐transferred NOE (etNOE) spectroscopy. The position of ETT was validated using saturation transfer difference (STD) NMR.

Support or Funding Information

NIH ‐ 1021RR571390, AHA ‐ 1021RR571388, Pfizer, Inc., University of Georgia, Bioexpression and Fermentation Facility at UGA, Complex Carbohydrate Research Center at UGA
Using Mixed Methods Research in Anatomy Education: The Relevancy, Challenges, and Benefits
Authors: Fillmore Erin
Published: November 2023

Mixed methods research in academic medicine is becoming more prominent and has the potential to offer unique and important insights into the challenges surrounding the education of our doctors. Mixed methods accomplishes this by utilizing the strengths of both qualitative and quantitative approaches, particularly when the research question and data are complex and the use of either singular approach is inadequate to address the complexity. Even though mixed methods research poses unique challenges, including the time‐commitment to collect and analyse both inductive and deductive data, it has great potential due to its ability to combine the what, who, and when with the why and how. Using an illustrative case study that employed a two‐phase, sequential explanatory mixed methods design, this study demonstrates the relevancy, challenges, and benefits of mixed methods research in anatomy education. With gross anatomy an integral part of medical education, and considerable variability present in student performance and retention of the subject, it suggests there is potential in using a mixed methods approach to better understand the complex factors that contribute to these inconsistencies. This study explored the relationships between three areas: first, how medical students conceptualize intelligence, referred to as their implicit theory of intelligence (ITI), which reflects if they believe their intelligence is fixed (reflective of an entity theorist), or if they believe their intelligence to be malleable (reflective of an incremental theorist); second, a novel character trait coined “grit” (defined as the passion and perseverance for long‐term goals); and third, individual self‐regulatory processes involved in learning gross anatomy. Medical students (n=382) completed the validated ITI and Grit Scales in order to identify their ITI and grit score. Subsequent interviews (n=25) were conducted to explore how medical students set goals, operated while reaching those goals, and monitored their progress in achieving those goals. Entity and incremental theorists with high grit performed significantly better in gross anatomy when compared to those with low grit. Highly gritty incremental and entity theorists were hard workers and showed resilience in the face of challenges. Conversely, low grit individuals became overwhelmed by challenges, were more likely to show an inconsistent work ethic, and questioned their ability to master the material. An individual's ITI, more so than grit, drove the presence of negative emotions, with entity theorists feeling anxious and vulnerable, and incremental theorists feeling fewer negative emotions. Findings reinforce the value of using mixed methods in examining and understanding how medical students learn, and not just in anatomy. A mixed methods approach can provide educators with necessary tools to gain insight into complex, non‐academic factors that drive learning, factors that may otherwise remain hidden.
Transforming an Undergraduate Biochemistry Laboratory Courses: Do the Pros Outweigh the Cons?
Authors: Hazzard James T.
Published: November 2023

Recommendations from a number of different agencies (ASBMB, NSF, HHMI, AAAS) have urged undergraduate laboratory courses to adopt a more research‐like curriculum. Often a justification is made that these courses potentially represent the only research experience an undergraduate might have at their institution, valid only for institutions or programs that do not have a mandatory capstone research requirement. Whereas this pedagogical approach is relatively simple for a two‐semester laboratory course, making this transformation in a one semester course requires much greater thought and planning. We have just completed a six year transformation of our upper level one semester biochemistry lab course from a traditional methods and techniques format to one in which the students are involved in an inquiry‐guided research project for three quarters of the semester. This presentation will focus on the pros and cons as well as the challenges of carrying out this transformation.
Pick A Color, Any Color: An Inquiry‐Based Laboratory Course Based On Fluorescent Protein Mutagenesis, Expression, Purification And Characterization
Authors: Kraut Daniel Adam
Published: November 2023

A major problem in science education is the disconnect between a typical laboratory class and the experience of doing research. In most laboratory classes, students are given background reading and a protocol to follow, follow the procedure, and then analyze and report their results in a lab report. They then move on to another experiment, typically unrelated to the previous one. Contrast this to the typical research experience in which students work towards a goal, using whatever techniques are needed, often troubleshooting experiments that fail or have outcomes different from those expected. Undergraduate researchers become intellectually and emotionally invested in their projects, and as a result can get more out of a research experience than a lab class. Unfortunately, the resources to give every undergraduate experience in a research lab are unlikely to become available. A potential solution is the growth of project‐based laboratory classes, which convert laboratory classes into more research‐like experiences where students pursue one project throughout the semester.

I implemented such a class for second‐semester junior biochemistry majors. Students were given the DNA sequence for a plasmid encoding a fusion protein derived from my research lab. Students first used bioinformatic tools to determine what these domains were, then, after doing some research, designed mutations to change the fluorescent properties of the Green Fluorescent Protein (GFP) portion (to create a blue, cyan or yellow variant). Students designed oligonucleotide primers for their chosen mutations, and then went on to use molecular biology techniques to make the mutations and determine if the mutations had been successfully made. In some cases this required troubleshooting and repetition of experiments (with variations), something that enhanced the “research‐like” aspect of the project. After successfully making their mutant plasmid, students over‐expressed the protein in bacteria, and purified the resulting fusion protein, visually determining if the mutation had the desired effect. More biochemical characterization (SDS‐PAGE, western blotting, absorbance, fluorescence) followed, including experiments to determine how the mutation changed both the fluorescence properties and the folding properties of the GFP domain. Finally, students were able to use their protein in a pull‐down assay to test a literature hypothesis. The semester culminated in a poster presentation designed to integrate the entire research experience, and ensure that students connected the dots between the weeks of the lab, rather than taking each lab as an isolated event. In the initial iteration of this class, students reported higher levels of learning than in the previous semester's more traditional biochemistry lab.
Development of course‐based undergraduate research experiences using a design‐based approach
Authors: Lo Stanley M. , Drane Denise L. , Swarat Su L. , Mordacq John C.
Published: November 2023

Laboratory experience is central to undergraduate biology education. In recent years, commissions and reports (such as Vision and Change and Engage to Excel) have called for the revision of traditional laboratory courses to provide authentic research experiences for all students, especially in the first two years of college. Many existing examples of course‐based undergraduate research experiences (CUREs) are designed for advanced undergraduates (Butler 2014, Caspers 2003, Murthy 2014, Taylor 2010), and some are limited to a small number of students (Kloser 2011, Kloser 2013). Here, we present an iterative, design‐based approach for developing CUREs for large introductory biology courses (over 300 students) that helps students develop scientific inquiry skills and expert‐like perceptions about biology.

This study involves the design, implementation, evaluation, and revision of a sequence of introductory biology laboratory courses, where students work collaboratively on research projects developed from faculty laboratories on campus. We define authentic research as students performing the same tasks as scientists would in the same setting (legitimate), even though students’ level of competence may not be as sophisticated (peripheral). This idea of legitimate peripheral participation emerges from the theoretical framework of situated learning, which posits that learning takes place in the same context in which it is applied (Lave 1991). Students in these courses learn scientific inquiry in research projects that can result in novel data and conclusions. Research projects include studying protein‐folding diseases using transgenic C. elegans (Brignull 2006) and examining the role of macrophage phagocytosis of apoptotic cells in atherosclerosis (Thorp 2011).

Quantitative surveys (Denofrio 2007, Semsar 2011) and qualitative focus groups are used to evaluate these courses and to provide continuing feedback for improvement over three implementation cycles. Pre‐ vs. post‐survey data indicate that students gain self‐efficacy in scientific inquiry skills (statistically significant gains in 13 out of 14 items) and develop more expert‐like perceptions of biology (statistically significant gains in 5 out of 7 categories). These gains are more significant and have larger effect sizes in the second and third implementation years, a trend also supported by qualitative data. Together, these data indicate a progression of improvement of the effectiveness of these CUREs over three design cycles. Our design‐based approach and our experience with the design process provide valuable suggestions for other practitioners who plan to develop CUREs at their own institutions.

Support or Funding Information

This project was supported in part by an institutional award for undergraduate education from the Howard Hughes Medical Institute to Northwestern University.
Simulating the Influence of Changes in Macronutrient Composition and Amounts in the American Diet From 1971–2008 on Body Composition Changes and Their Contribution to the Obesity Epidemic
Authors: Davidson Robert T , Hippard Michelle
Published: November 2023

Background

The obesity epidemic in the US has many suggested causes. We investigated the role that changes in diet macronutrient composition (carbohydrate, protein and fat) and amounts had in contributing to the observed changes in body weight and composition between 1971 and 2008.

Methods

Using a previously validated physiologically‐based mathematical model that simulates the effect of dietary macronutrient composition and amounts on body weight and composition changes in sedentary men and women, we simulated body weight changes from 1971 through 2008 based on dietary macronutrient composition and amounts reported from NHANES and the Centers for Disease Control and Prevention (CDC).

Results

Simulated body weight change patterns for both men and women were similar to those actually observed, though body weight values for men were generally over‐predicted and for women were under‐predicted. Final simulated body weights for men and women were +9.3% and −10.4% actual reported values, respectively.

Conclusions

We conclude that the obesity epidemic has been predominantly driven by the amounts and types of consumed macronutrients in food, and that if the American diet were to return to pre‐epidemic macronutrient levels and composition the obesity epidemic would likely reverse and disappear.
Differences in Plasma Metabolites in Insulin Resistant and Insulin Sensitive Obese Individuals during a Hyperinsulinemic/Euglycemic Clamp
Authors: Casey James L. , Van Pelt Douglas W. , Burant Charles , Horowitz Jeffery , Evans Charles
Published: November 2023

Although the vast majority of obese adults are insulin resistant (IR), some obese individuals remain relatively insulin sensitive (IS), though the underlying mechanisms for this difference are unclear. The hyperinsulimemic‐euglycemic clamp (HEC) is the gold standard test for insulin sensitivity. However, it is not clear if the differences in insulin‐mediated changes in glucose metabolism between IS and IR obese individuals extend to other key metabolites.

In this study, we monitored the dynamics of 49 metabolites in obese IR vs. IS during a HEC. From an original screening of 28 obese adults, twelve non‐diabetic subjects, matched for age, sex, BMI, fat mass and fat‐free mass were divided into the 6 most IS and 6 most IR women based on glucose uptake during a HEC clamp. Mean glucose uptake during the clamp was 7.4±1.2 vs 15.6±2.47 mg/kg FFM/min for IR and IS, respectively (p <0.0001).Serum metabolite levels were measured at 8 time points during the clamp using liquid chromatography‐mass spectrometry (LC‐MS): 2 samples at baseline, immediately prior to insulin infusion, every 20 minutes during the insulin infusion (4 samples), and 2 samples at steady state glucose levels (after ~2h of insulin infusion).Metabolite levels were quantitated by peak area, with stable‐isotope internal standards used to allow absolute quantitation of select metabolites. Statistical differences between IS and IR groups were assessed using t‐tests.

Compared with IS, IR individuals had higher baseline levels of valine (p=0.023) and leucine and isoleucine (LI) (combined peak area) (p=0.006). However, the rate of decline in LI in response to insulin was greater in IS compared with IR. At steady‐state glucose infusion (~2 hr of HEC) most metabolites were either unchanged or fell from baseline levels. LI and valine concentrations fell about 50% in response to insulin in both groups, but LI and valine continued to be 40–100% greater in IR compared with IS (p=0.022 and 0.007, respectively). Likewise, threonine, lysine and glutamate levels were greater in IR than IS (all p<0.019) when glucose reached steady‐state during the HEC. No significant differences between IR and IS were found in various fatty acid, TCA cycle intermediates, or lactate levels at baseline or at steady‐state of the HEC.

These findings indicate that obese adults, who are seemingly “protected” against a decline in insulin‐mediated glucose uptake, also demonstrate improved response of insulin to lower BCAA and other amino acids that have been associated with and increase risk of development of type 2 diabetes. These results suggest that changes in the plasma level of metabolites associated with risk of type 2 diabetes is driven by insulin resistance and not obesity per se.
In Search of Novel Genes in Branchio‐oto‐renal Spectrum Disorders
Authors: Moody Sally A.
Published: November 2023

Several members of the Six family of transcription factors play important roles in vertebrate craniofacial development. Six1 is particularly important for the development of the cranial sensory organs including the inner ear. Mutations in either Six1 and one co‐factor gene, Eya1, result in human Branchiootorenal spectrum disorders that have mild craniofacial defects and hearing loss. However, these mutations only account for about half of the patients, indicating that other mutations underlie this spectrum. To discover potential new causative genes, we identified over 30 Xenopus genes with high sequence identity to proteins previously shown to interact with Drosophila Six, and we determined that many of these genes are expressed in the otocyst, the precursor of the inner ear. We now show that 4 of the novel candidate co‐factors biochemically interact with Six1 and thus may modify its transcriptional activity. When the endogenous expression level of each of these candidate co‐factors is reduced, there is a loss of otic placode genes and expansion of neural plate genes. When the endogenous expression level of each of these candidate co‐factors in increased, Six1 expression is reduced. These results suggest that these previously uncharacterized Six‐interacting partners have potential important roles in vertebrate craniofacial development and congenital syndromes.

Support or Funding Information

NIH R01 DE022065
Cranial Nerve Dysmorphogenesis in 22Q11 Deletion (DiGeorge) Syndrome
Authors: LaMantia Anthony‐Samuel , Karpinski Beverly A. , Maynard Thomas M. , Moody Sally A. , Mendelowitz David , Wang Xin , Popratiloff Anastas , Zohn Irene , Lee Norman H
Published: November 2023

Pediatricdysphagia—feeding and swallowing difficulties that begin at birth, last throughout childhood, and continue into maturity—is one of the most common, least understood complications in children with developmental disorders. Weargue that a major cause of pediatric dysphagia is altered hindbrain patterning during pre‐natal development. Such changes can compromise craniofacial structures including oropharyngeal muscles and skeletal elements as well as motor and sensory circuits necessary for normal feeding and swallowing. Animal models of developmental disorders that include pediatric dysphagia in their phenotypicspectrum can provide mechanistic insight into pathogenesis of feeding and swallowing difficulties. A fairly common human genetic developmental disorder, DiGeorge/22q11.2 Deletion Syndrome(22q11DS) includes a substantial incidence of pediatric dysphagia in its phenotypic spectrum. Children with 22q11DS from birth onward gain weight slower than their typically developing counterparts, struggle with nursing, and aspirate liquid and solid food into the nasal sinuses, middle ear and lungs. This results in frequent infections that require constant clinical intervention. Infant mice carrying a parallel deletion to 22q11DSpatients have feeding and swallowing difficulties that approximate those seen in pediatric dysphagia. We have devised several assays to evaluate the behavioral as well as cellular consequences of disrupted feeding and swallowing in the mouse model of 22q11DS. Altered hindbrain patterning, craniofacial malformations, and changes in cranial nerve growth prefigure these difficulties. Thus, in addition to craniofacial and pharyngeal anomalies that arise independently of altered neural development, pediatric dysphagia may result from disrupted hindbrain patterning and its impact on peripheral and central neural circuit development critical for feeding and swallowing. The mechanisms that disrupt hindbrain patterning and circuitry may provide a foundation to develop novel therapeutic approaches for improved clinical management of pediatric dysphagia.

Support or Funding Information

NIH R01 DE022065 (SAM)

HD 042182, DC011534 (A‐S.L.), HD083157 (A‐S.L. and SAM)
Predictors of improved HAZ in rural Egyptian children
Authors: Winham Donna M.
Published: November 2023

Linear growth restriction in children remains a complex problem globally. Describing the nature of catch‐up or growth recovery from stunting has been hampered by lack of quality serial anthropometric and environmental data on children. Large data sets through late adolescence and adulthood have been collected in Bangladesh, Philippines, Bolivia, and Gambia among others. Study findings are mixed with some indicating catch‐up growth does occur even without intervention, others suggest stunting before 24 months is permanent, or in contrast some indicate catch‐up growth can occur in later childhood and adolescence. The differentiating factors between children who show catch‐up growth and those who do not, or who even become more stunted, are situation specific and include sociocultural, environmental, and biological influences The revised 2006 WHO growth standards may confound earlier results as well if data are not converted and reanalyzed. There are few longitudinal studies of child growth in rural Egyptian children. One data set is provided by the USAID Nutrition CRSP which collected anthropometric, dietary, biomarkers, environmental, sanitation and household for mothers and children from birth to 36 months in a semi‐rural Egyptian village. Follow up data were collected on the former infants and toddlers at ages 10–13. In the past 5 years, Egypt has become more conservative and economically deprived. Improvements in child nutrition have been eroded with about 1 out of 3 children under 5 stunted. The study purpose was to examine the Nutrition CRSP and follow up data to evaluate growth status with the revised WHO standards and assess predictors of growth recovery. Anthropometric data on 133 children aged 11–13 were evaluated (65 girls, 68 boys).At ~24 months, the mean HAZ value was −2.08 ± 1.07, with a range of −5.08 to 0.50. Ten years later, the mean HAZ was −1.21 ± 0.83; range −3.15 to 2.01. The average Z‐score change was .88 ± .93; range −0.87 to 3.83. Catch‐up growth was defined as a positive increase of .67 or greater. Fifty‐three percent of the sample had an HAZ change of .67 or greater. There were no significant differences by gender in HAZs or change in HAZ. Dietary diversity, gender, parental education, sanitation scores, household assets, and morbidity variables from time 1 (CRSP) and time 2 were regressed on HAZ change. The best predictive model included father's occupation as farmer, the percent of income spent on food, and father's years of education (F=6.576; p=0.000.).These findings suggest that children in farming families – not professional or higher income households – were able to recover growth more so than others. This may be due to more consistent access to food in general. Gender differences were not observed. These issues require further investigation in other cohorts.
Validity of photographic imaging for assessing standing height of preschoolers
Authors: Beintema Joni Jade Serena , Solomons Noel W. , Orozco Mónica N. , García‐Meza Rosario , Gwaltney Rebecca , Rolker Heike B. , Doak Colleen M.
Published: November 2023

Background

In an exercise aimed at assessing trunk‐to‐leg ratio from photographic imaging, a derivative study examined its accuracy to estimate standing height.

Objective

To compare photographic imaging procedures to measured standing height in preschool children.

Methods

The photographic images of 200 preschool children, 100 each from Sololá and Quetzaltenango were evaluated for estimation of standing height. Original standing height was measured with a wall‐stadiometer. A photograph was taken from a 3‐m distance with the child standing sideways and looking forward in the Frankfort Plane Gaze while standing in front of a color‐coded metric ruler. An ocular estimation of height, at the intersection with the ruler was made from print outs, enlarge don a computer screen and from the zoomed camera screen.

Results

The mean measured standing height was 108.8 cm (median: 109 cm) compared to 109.0 cm (median: 109cm)(p<0.05) determined by a photo‐image. The Pearson correlation coefficient was r=0.988 and the Lin concordance correlation was r=0.987. According to the Bland‐Altman agreement analysis, height derived from a photo‐image overestimates measured height by 0.20 cm. For 34.5% of the photo‐image data, the estimates were identical, and for an additional 50.0% they were ±1 cm of theme asured value.

Conclusion

This study shows a high correlation to measured height from photographic imaging, using the same sagittal photograph applied to body‐segment analysis. Equivalent validity was obtained with direct reading from the camera or computer screen as with measurement from a photographic print.
Nutritional Status of Children Under Five Years and Associated Factors in Kalale District, Benin
Authors: Taren Douglas , Alaofe Halimatou , Burney Jennifer , Naylor Rosamond
Published: November 2023

Background

Variations in inter district nutritional status have puzzled both social policy makers and health workers in developing regions worldwide, including in Benin.

Objective

This study sought to determine the nutritional status of children under five years and associated factors in Kalalé District in Benin.

Methods

A cross‐sectional descriptive study was conducted using a structured questionnaire. A total of 774 households were sampled and the nutritional status of one child from each household was assessed using anthropometric measurements. Multivariate analysis was performed to determine what independent variables were significantly associated with the nutritional status of children.

Results

Up to 40% of the children were stunted; 11% were wasted; and 24% underweight. The prevalence of underweight was significantly greater in boys than in girls (P =0.023). The individual dietary diversity score showed that the most consumed food group was cereals (71%). Eggs and legumes were the least consumed foods. Low food diversity was recorded for 54% of the children (<4 food groups), 33% had medium scores (4–5 food groups); while 13% had high scores (6–8 food groups). Stunting had a significant association with low child dietary diversity scores [OR=2.33; 95% CI (1.21–4.50)], low mother dietary diversity scores [OR=1.96; 95% CI (1.92–3.77)] and poor access to health services [OR=1.84; 95% CI; (1.75–3.54)]. In addition, 6–11 months old children [OR=1.58; 95% CI (1.08–2.53)], male sex [OR=1.53; 95% CI (1.06–2.21)], and large family size [OR=4.14; 95% CI (1.18–15.11)] were found to be associated factors for underweight. Predictors of wasting in this study were low child dietary diversity scores [OR= 1.17; 95%CI (1.07–2.95)] and poor access to health services [OR=2.05; 95% CI; (1.60–4.85)].

Conclusion

Under nutrition is an important public health problem among Kalalé children aged 6–59 months of Benin. In addition, dietary diversity, family size and poor access to health services are major challenges to good nutrition. Therefore, future interventions should focus on improving food access and availability for enhanced diet diversification for the rising population.
How should undernutrition be diagnosed in Nigerian hospitalised infants aged under six months?
Authors: Wright Charlotte M , Ezeofor Ifeyinwa , Garcia Ada
Published: November 2023

It is often assumed that breast fed infants aged under 6 months are at low risk for undernutrition, but where there is non‐exclusivity or underlying medical problems the risk is high. Because of extremely high energy requirements this rapidly impacts on weight gain, causing wasting and weight faltering (WF).Common screening methods for undernutrition have largely not been standardised or validated for very young infants, in particular for skin folds. The WHO growth chart project published standards for subscapular and triceps skin folds in 2007, but only from age 3 months to 5 years.

Objectives

To assess the prevalence of undernutrition in hospitalised infants aged 0.5–6 months, defined as either WF or low fat stores and then to assess the utility of different screening methods to identify these infants.

Methods

Norms for weight gain were established using retrospective weights of 411 healthy infants age < 6 months attending a large well baby clinic in Eunugu, Nigeria; the lower 5th percentile for weight gain conditional on birth weight was defined as WF. Skin folds measured in 195 UK hospitalised infants 0–1 years with very low rates of undernutrition were used to identify the lower 5th percentile for sum of skin folds (10mm) (SSF). A sample of infants age 2 weeks to < 6 months admitted to the teaching hospital in Eunugu were studied. Measures of weight, length, mid‐upper arm circumference (MUAC) and triceps and subscapular skin folds were taken.

Results

Of the 125 hospitalised infants, 86 (69%) were admitted for infectious causes and only 6 (5%) because of undernutrition. Low SSF were found in 41 (33%). Birth weight was known in 105 infants, from these 25 (24%) had WF and a total of 45 (36%) had WF or low SSF, or both. Low MUAC showed high sensitivity to identify WF and/or low fat stores, but at a cost of more children being mislabelled. Low weight for age also showed high sensitivity, particularly for WF, but with a higher positive predictive value (PPV) and thus fewer children being mislabelled. Low WFH showed both low sensitivity and low PPV.

Conclusions

In hospitalised infants under six months a MUAC <11 cm is a reasonably effective screening threshold for identification of undernutrition, but low weight is more specific, while low WFH would miss over half the undernourished infants.

Support or Funding Information

Ifeyinwa Ezeofor was supported by a Ford Foundation Scholarship

Sensitivity and positive predictive value of different screening measures to predict undernutrition, as defined by WF and/or low fat or measure or low fat or WF individually.

Screening Measure

To predict WF and/or low fat
Low fat (SSF)
Low CWG (WF)

Prevalence
Sensitivity
PPV
Sensitivity
PPV
Sensitivity
PPV

MUAC <11cm
36% (45)
73%
73%
73%
67%
80%
51%

WFHZ <‐2
25% (30)
49%
67%
46%
57%
65%
51%

WAZ <‐2SD
29% (36)
69%
86%
66%
75%
92%
77%
Developing food‐based recommendations to complement distribution of a meat‐based fortified food product for school‐aged children from rural Quetzaltenango, Guatemala using the Optifood linear programming tool
Authors: Vossenaar Marieke , Escobar Marta Lucía , Bonorden Melissa J. L. , Solomons Noel W
Published: November 2023

Background

Current diets of school‐aged children in Guatemala are nutritionally inadequate. Spammy®, a meat‐based fortified food product was developed to complement the local diet.

Objective

To develop food‐based recommendations (FBRs) using linear programming for children from a low socio‐economic, rural area in the department of Quetzaltenango according to habitual dietary practices and the local food supply, and to examine the effect of this modeling with the addition of Spammy® given as food aid.

Methods

24‐h dietary recall data for 100 school‐aged children were used to derive linear programing inputs, including foods consumed, their portion sizes and frequency of intake. Optifood was used to develop FBRs based on existing dietary patterns using locally available and acceptable foods, and with the addition of Spammy®. The cost of the most affordable and nutritionally best diet was also modeled.

Results

A total of 5 food‐based recommendations (promoting dairy, fortified grains, eggs, meat/poultry and fruit consumption) can help achieve nutrient adequacy for 7 of 12 nutrients examined. With the additional of a daily portion of Spammy®, 4 food‐based recommendations (promoting dairy, fortified grains, eggs, and tortillas) can help achieve nutrient adequacy for 10 of 12 nutrients examined and the daily cost of the most affordable and nutritionally best diet is reduced from $2.23 to 1.75 (USD).

Conclusion

Context‐specific FBRs could ensure adequate levels of most nutrients examined. Used alone, however, the proposed FBRs are unlikely to contribute sufficiently to calcium, vitamins C and D, iron and zinc intakes. With the addition of Spammy®, more nutrient requirements are met, but calcium and iron intakes remain problematic.

Support or Funding Information

Hormel Foods Corporation, Austin, USA
Do Mass Media and Mobile Technology Nutrition Education Campaigns Improve Infant and Young Child Feeding Knowledge, Attitudes, and Practices in the Developing World? A Systematic Review of the Evidence
Authors: Graziose Matthew , O'Brien Quentin , Downs Shauna , Fanzo Jessica
Published: November 2023

The first 1000 days from conception until a child reaches two years of age is a critical window of opportunity to optimize the health and nutritional status of children. Improving infant and young child feeding (IYCF) practices during this period can reduce malnutrition and lead to long‐term health gains. The objective of this study was to examine the impact of mass media and mobile technology nutrition education campaigns targeting IYCF knowledge, attitudes and practices in the developing world. A systematic review was conducted using the Pubmed, EMBASE and PsychINFO databases. We also examined the first 20 pages of Google in order to identify grey literature. Studies that examined mass media (e.g., posters, television, radio, etc.) or mobile technology (e.g., text or voice messages) interventions in developing countries, had a pre‐ and post‐test design and were published in English were included in the review. The primary outcomes examined were changes in IYCF practices including breastfeeding. Secondary outcomes were knowledge and attitudes related to IYCF. Two members of the research team (MG and QO) independently screened titles, abstracts and full texts of the studies identified in the searches. The search resulted in 2733 records, which were subsequently screened by title. We then reviewed abstracts (n=565) and determined that 69 were eligible for full text review. Of these, the majority (n=46) were excluded for not meeting the intervention inclusion criteria. Other reasons for exclusion included, the study country (n=8), language (n=8) and design (n=3). In total, 9 studies met our inclusion criteria and were included in the review. These studies were conducted in Nigeria, Mexico, Bolivia and Madagascar, Cambodia, Taiwan, Zimbabwe, and Iran. Two of the reviewed studies used a cluster‐randomized design; the remaining studies employed quasi‐experimental designs. The most common mass media components used in these studies included: songs or dramas (n=3), videos (n=3), radio messages or testimonials (n=2), television messages (n=3) and text and/or voice messages delivered to cellphones (n=1). Seven studies measured exclusive breastfeeding – six found a positive significant effect of the intervention on exclusive breastfeeding rates. Many of the studies provided little detail regarding the content of the messages included and only three explicitly mentioned a behavior change theory used for intervention design. Overall, our review found evidence to suggest that mass media and mobile technology interventions may lead to improved exclusive breastfeeding rates. However, given the small number of studies that met our inclusion criteria, the diversity in the interventions and the overall poor study quality more evidence is required to determine the most effective means of improving IYCF knowledge, attitudes and practices.
Women's Dietary Diversity in Rural Bangladesh: Pathways through Women's Empowerment
Authors: Sinharoy Sheela , Waid Jillian , Gabrysch Sabine
Published: November 2023

Objective

To assess how women's dietary diversity is influenced by enabling resources and to quantify possible pathways through women's agency.

Methods

We analyzed cross‐sectional data collected in early 2015 from 2,600 women during the baseline survey for Food and Agricultural Approaches to Reducing Malnutrition (FAARM), a cluster‐randomized controlled trial in Sylhet Division in northeastern Bangladesh. Resources were measured as years of schooling and household wealth. Agency was measured through a latent factor for decision‐making and a measured variable for mobility. Nutrition was defined as dietary diversity as measured through a standard 10‐Food Group Indicator (FGI‐10R). We used confirmatory factor analysis to create the latent factor for decision‐making and a linear mediation model to estimate indirect effects, direct effects, and total effects, adjusting for women's age.

Results

In adjusted models, the total effect of schooling on dietary diversity was 0.042 (p<.001). The direct effect of schooling on decision‐making was 0.004 (p=.02) and of schooling on mobility 0.075 (p=.001). Neither decision‐making nor mobility had significant direct effects on dietary diversity (p=.57 and p=.23, respectively). The direct effect of schooling on dietary diversity was 0.041 (p<0.001). For household wealth, the total effect on dietary diversity was 0.104 (p<.001). The direct effect of household wealth on decision‐making was −0.018 (p<.001) and on mobility −0.074 (p=0.004). The direct effect of household wealth on dietary diversity was 0.106 (p<.001).

Conclusions

In our study population in Bangladesh, women with more schooling had higher decision‐making power, mobility, and dietary diversity. Women with greater household wealth also had higher dietary diversity but lower decision‐making power and mobility. The positive effect of schooling and household wealth on dietary diversity is not mediated by women's decision‐making or mobility. Research is needed to examine other possible pathways, potentially through other dimensions of women's agency. Additionally, programs should monitor the potential negative effects of increasing household income on women's empowerment.

Support or Funding Information

German Federal Ministry for Education and Research; Laney Graduate School, Emory University
Shifting Grounds: Perceptions of Factors that Affect Agricultural and Nutrition Transitions in Remote Hill Villages of Nepal
Authors: Lei Ann Z , Rai Uddhav
Published: November 2023

Nepal is a landlocked country in South Asia with some of the highest malnutrition rates in the world, with over half of children stunted in rural hill and mountain areas. The Chepang are a highly marginalized indigenous group representing <1% of the Nepali population and often face discrimination because of their ethnicity. Nonetheless, this traditionally nomadic population had experienced an agricultural transition over the past 2 decades, in which they have shifted from khoriya (slash‐and‐burn) cultivation to terraced farming. This has increased both household food access and dietary diversity. However, community perceptions of the factors driving these nutritional transitions have not been explored. This pilot study qualitatively investigated how these factors affected Chepang peoples’ perceptions of their nutritional situation in rural mid‐hill villages of central Nepal.

Individual interviews (n=18) and focus group discussions (n=2, 5–12 people each) were conducted in 4 village wards in the Chitwan district in April 2015. Participants were recruited through key informants, snowball sampling, and random household visits. They were all Chepang aged 18‐81y and had lived in their respective village for their entire lifetime. Interviews and discussions focused on perceptions of transitions in agriculture and food access, were translated by a Nepali research assistant, and coded using the software dedoose. Unfortunately, the April 2015 earthquake prematurely terminated the study.

Participants believed agricultural improvements such as fertilizer use, terraced farming, and increased farming knowledge improved crop yields. Most households claimed their crops sustain their families for the entire year, compared to <6 months 2 decades beforehand. Factors believed to increase household income and subsequent food access include out‐migration labor to Gulf countries of Southeast Asia and improved animal husbandry through NGO support. Footpaths were the only method of reaching the hilltop villages, but improvements in transportation infrastructure enhanced accessibility to foods in markets and increased opportunities for agricultural knowledge exchange. Although most participants were optimistic about obtaining not only sufficient but also more diverse foods, one village perceived water security and unsuitable, high‐elevation farmland to limit crop productivity.

Despite perceived improvements in food access, additional research regarding factors that affect food accessibility and targeted support may have the potential to increase the high‐risk population's food access, especially during post‐earthquake recovery. Identifying these determinants can also assist community leaders and NGOs effectively address existing barriers to food access as well as ones that may have been worsened by the earthquake.

Support or Funding Information

This study was conducted through the Cornell‐Nepal Study Program in partnership with Cornell University and Tribhuvan University.
Consumption of Novel Thiamin‐Fortified Fish Sauce Improves the Thiamin Status of Rural Cambodian Women of Childbearing Age and Their Children <5 Years
Authors: Whitfield Kyly C , Karakochuk Crystal D , Kroeun Hou , Chan Benny , Borath Mam , Lynd Larry D , Li‐Chan Eunice CY , Kitts David D , Green Timothy J
Published: November 2023

Infantile beriberi, a disease caused by thiamin deficiency, remains a public health concern in Cambodia and other Southeast Asian countries that rely on thiamin‐poor white polished rice as a dietary staple. Infantile beriberi presents in exclusively breastfed infants of thiamin‐deficient mothers, and is often fatal if not treated within ~24 hours. Infantile beriberi has been nearly eradicated in regions where dietary diversity is high, or staple foods are fortified with thiamin. Food fortification is an inexpensive, sustainable, and passive means of improving the diet when micronutrients are lacking. We formulated a novel thiamin‐fortified fish sauce (a traditional condiment consumed daily by rural Cambodians) to determine whether ad libitum consumption over six months could improve erythrocyte thiamin diphosphate concentrations (TDP) among women of childbearing age and their youngest child aged 12–59 m, compared to a control sauce.

In this double‐blind, randomized controlled efficacy trial 276 non‐pregnant, non‐lactating women aged 18–45 y and their families in Prey Veng, Cambodia, were randomized to receive one of three fish sauce formulations: low concentration thiamin (LC; ~2g/L), higher concentration thiamin (HC; ~8g/L), or control (C; no thiamin). TDP was analyzed using HPLC‐FLD.

Women were 30 ± 6 y, and 71% of women had a normal BMI (18.5–25 kg/m2). Children were 30 ± 15 m at baseline. Women's baseline mean (95% CI) TDP for HC (n=91), LC (n=93), and C (n=92) was 179 nM (167, 191), 172 nM (162, 183), and 150 nM (142, 158), respectively. Children's baseline mean (95% CI) TDP for HC (n=87), LC (n=88), and C (n=87) was 211 nM (197, 225), 194 nM (183, 206), and 172 nM (163, 181), respectively.

Fish sauce consumption was not significantly different between groups (p=0.186). In intent‐to‐treat analysis, women's endline TDP (adjusted for baseline) significantly increased among women in HC (53 nM) and LC (49 nM) groups compared to C (p<0.001). Similarly, at endline children's (baseline adjusted) TDP was 47 nM and 36 nM higher in the HC and LC groups, respectively, compared to C (p<0.001).

Consumption of thiamin‐fortified fish sauce at concentrations of 2g/L and 8g/L over six months significantly improved biochemical thiamin status of Cambodian women of childbearing age and young children under 5 years. Effectiveness trials, as well as further research to identify the optimal dose for thiamin fortification, are needed.

Support or Funding Information

Research supported by Grand Challenges Canada Stars in Global Health Grant (Round VI), Canadian Institutes of Health Research (CIHR) Doctoral Award, and International Development Research Centre (IDRC) Doctoral Research Award.