A meta-analysis of anatomy laboratory pedagogies.

The debate regarding anatomy laboratory teaching approaches is ongoing and controversial. To date, the literature has yielded only speculative conclusions because of general methodological weaknesses and a lack of summative empirical evidence. Through a meta-analysis, this study compared the effectiveness of instructional laboratory approaches used in anatomy education to objectively and more conclusively synthesize the existing literature. Studies published between January 1965 and December 2015 were searched through five databases. Titles and abstracts of the retrieved records were screened using eligibility criteria to determine their appropriateness for study inclusion. Only numerical data were extracted for analysis. A summary effect size was estimated to determine the effects of laboratory pedagogies on learner performance and perceptions data were compiled to provide additional context. Of the 3,035 records screened, 327 underwent full-text review. Twenty-seven studies, comprising a total of 7,731 participants, were included in the analysis. The meta-analysis detected no effect (standardized mean difference = -0.03; 95% CI = -0.16 to 0.10; P = 0.62) on learner performance. Additionally, a moderator analysis detected no effects (P ≥ 0.16) for study design, learner population, intervention length, or specimen type. Across studies, student performance on knowledge examinations was equivalent regardless of being exposed to either dissection or another laboratory instructional strategy. This was true of every comparison investigated (i.e., dissection vs. prosection, dissection vs. digital media, dissection vs. models/modeling, and dissection vs. hybrid). In the context of short-term knowledge gains alone, dissection is no better, and no worse, than alternative instructional modalities. Clin. Anat. 31:122-133, 2018. © 2017 Wiley Periodicals, Inc.

Potential roles of high salt intake and maternal malnutrition in the development of hypertension in disadvantaged populations.

1. It has been argued that all major risk factors for cardiovascular disease have been identified. Yet, epidemiological studies undertaken to identify risk factors have largely focused on populations in developed nations or on the urban or relatively affluent rural populations of developing countries. Poor rural populations are seldom studied. 2. Somewhat different risk factors may operate in poor rural populations. Evidence for this is provided by the finding that, in disadvantaged rural India, the prevalence of hypertension is greater than would be expected based on established risk factors in these populations. One risk factor to be considered is a poor intrauterine environment. 3. In animals, maternal macro- and micronutrient malnutrition can lead to reduced nephron endowment. Nephron deficiency, in turn, can render blood pressure salt sensitive. The combination of nephron deficiency and excessive salt intake will predispose to hypertension. 4. Human malnutrition may have similar effects, particularly in regions of the world where malnutrition is endemic and where women are disadvantaged by existing social practices. 5. Moreover, high salt intake is endemic in many parts of Asia, including India. Therefore, we propose that maternal malnutrition (leading to reduced nephron endowment), when combined with excessive salt intake postnatally, will account, at least in part, for the unexpectedly high prevalence of hypertension in disadvantaged rural communities in India and elsewhere.

Breaking with Tradition: A Scoping Meta-Analysis Analyzing the Effects of Student-Centered Learning and Computer-Aided Instruction on Student Performance in Anatomy.

While prior meta-analyses in anatomy education have explored the effects of laboratory pedagogies and histology media on learner performance, the effects of student-centered learning (SCL) and computer-aided instruction (CAI) have not been broadly evaluated. This research sought to answer the question, "How effective are student-centered pedagogies and CAI at increasing student knowledge gains in anatomy compared to traditional didactic approaches?" Relevant studies published within the past 51 years were searched using five databases. Predetermined eligibility criteria were applied to the screening of titles and abstracts to discern their appropriateness for study inclusion. A summary effect size was estimated to determine the effects of SCL and CAI on anatomy performance outcomes. A moderator analysis of study features was also performed. Of the 3,035 records screened, 327 underwent full-text review. Seven studies, which comprised 1,564 participants, were included in the SCL analysis. An additional 19 studies analyzed the effects of CAI in the context of 2,570 participants. Upon comparing SCL to traditional instruction, a small positive effect on learner performance was detected (standardized mean difference (SMD = 0.24; [CI = 0.07, 0.42]; P = 0.006). Likewise, students with CAI exposure moderately outscored those with limited or no access to CAI (SMD = 0.59; [CI = 0.20, 0.98]; P = 0.003). Further analysis of CAI studies identified effects (P ≤ 0.001) for learner population, publication period, interventional approach, and intervention frequency. Overall, learners exposed to SCL and supplemental CAI outperformed their more classically-trained peers as evidenced by increases in short-term knowledge gains. Anat Sci Educ. © 2018 American Association of Anatomists.

Effects of dietary protein restriction on nephron number in the mouse.

In rats, maternal protein restriction reduces nephron endowment and often leads to adult hypertension. Sex differences in these responses have been identified. The molecular and genetic bases of these phenomena can best be identified in a mouse model, but effects of maternal protein restriction on kidney development have not been examined in mice. Therefore, we determined how combined prenatal and postnatal protein restriction in mice affects organ weight, glomerular number and dimensions, and renal expression of angiotensin receptor mRNA, in both male and female offspring. C57/BL6/129sv mice received either a normal (20% wt/wt; NP) or low (9% wt/wt; LP) protein diet during gestation and postnatal life. Offspring were examined at postnatal day 30. Protein restriction retarded growth of the kidney, liver, spleen, heart, and brain. All organs except the brain weighed less in female than male offspring. Protein restriction increased normalized (to body weight) brain weight, with females having relatively heavier brains than males. The effects of protein restriction were not sex dependent, except that normalized liver weight was reduced in males but increased in females. Glomerular volume, but not number, was greater in female than in male mice. Maternal protein restriction reduced nephron endowment similarly in male and female mice. Renal expression of AT(1A) receptor mRNA was approximately sixfold greater in female than male NP mice, but similar in male LP and female LP mice. We conclude that maternal protein restriction reduces nephron endowment in mice. This effect provides a basis for future studies of developmental programming in the mouse.

Combined prenatal and postnatal protein restriction influences adult kidney structure, function, and arterial pressure.

The effects of prenatal protein restriction on adult renal and cardiovascular function have been studied in considerable detail. However, little is known about the effects of life-long protein restriction, a common condition in the developing world. Therefore, we determined in rats the effects of combined pre- and postnatal protein restriction on adult arterial pressure and renal function and responses to increased dietary sodium. Nephron number was also determined. Male Sprague-Dawley rats were born to mothers fed a low [8% (wt/wt), LP] or normal [20% (wt/wt), NP] isocaloric protein diet throughout pregnancy and maintained on these diets after birth. At postnatal day 135, nephron number, mean arterial pressure (MAP), and renal function were determined. A high-NaCl [8.0% (wt/wt), high-salt] diet was fed to a subset of rats from weaning. MAP was less in LP than in NP rats (120 +/- 2 vs. 128 +/- 2 mmHg, P < 0.05) and was not significantly altered by increased salt intake. Nephron number was 31% less in LP than in NP rats (P < 0.001). The volume of individual glomeruli was also less in LP than in NP rats, as were calculated effective renal plasma flow and glomerular filtration rate. Glomerular filtration rate, but not effective renal plasma flow, appeared to be increased by high salt intake, particularly in LP rats. In conclusion, protein restriction induced a severe nephron deficit, but MAP was lower, rather than higher, in protein-restricted than in control rats in adulthood. These findings indicate that the postnatal environment plays a key role in determining the outcomes of developmental programming.