bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary Potassium a Neglected Factor in Hypertension: Morphofunctional Evidence for Regulation of Cyclooxygenase‐2 and Kallikrein by Potassium
Authors: Vio Carlos , Salas Daniela , Hernandez Alejandra , Pedraza Paulina , Cespedes Carlos
Published: June 2021

The importance placed on dietary potassium on health and disease is underscored compared with dietary sodium, and less effort has been placed on studies on adequate dietary potassium. The benefits of potassium rich‐food are known, however, the mechanisms of action are lacking. With the hypotheses that dietary potassium regulates renal sodium excretory hormones, we studied the effect of enriched potassium diet on kallikrein (Kall) and cyclooxygenase‐2 (COX‐2)

SD male rats on normal potassium diet (0.9%, NK) or higher potassium diet (3%, HK) for 4 weeks, Kidney tissue was used for protein (Western blot), mRNA (RT‐qPCR), and cell features using immunohistochemistry (IHC). Kall was restricted to connecting tubule cells CNTc, HK increased the CNTc size and immunostaining with an hypertrophied pattern, increased Golgi and secretory‐like vesicles. Kallikrein increased its enzyme activity (42±3 vs 27±3 mU, p<0.005), protein by Western blot (1.3 fold p<0.05), and mRNA by qRT‐PCR (1.4 fold p<0.05). Kall activity correlated with UV potassium excretion (r=0.66, p<0.001). COX‐2 containing cells were restricted thick ascending limb cells TAL, in response to HK was observed a decreased COX‐2 cells number, a decreased protein level (0.4 fold p<0.05) and mRNA (0.5 fold p<0.05).

There is a different cellular response of CNTc and TAL to higher potassium diet, Kallikrein CNTc respond with hypertrophy and increased synthesis, COX‐2 TAL cells respond by decreasing the number of cells, a recruitment phenomenon. Upregulation of Kall is consistent with its vasodilatory, natriuretic effect. Downregulation of COX‐2 requires further studies to elucidate its response to potassium.
Role of NaDC1 in Control of Urinary Excretion of α‐Ketoglutarate
Authors: Hering‐Smith Kathleen , Coleman‐Barnett Joycelynn , Huang Weitao , Hamm Lee
Published: June 2021

Recent studies have suggested that urinary α‐Ketoglutarate (α‐KG) increases with alkali loads and decreases with acid loads. Also luminal α‐KG stimulates distal bicarbonate secretion via the Oxgr1 (GPR99) receptor.

To investigate the role of sodium dependent dicarboxylate transporter, NaDC1, in regulation of α‐KG excretion, we studied NaDC1 knockout (KO) and Heterozygous (Het) mice on normal diet and with 72 hrs acid loading. Plasma and urine samples were analyzed by LC/Mass Spec.

Also 14C‐α‐KG uptake was studied using HRPE cells overexpressing hNaDC1 (CUBS) and the proximal tubule (PT) OK cell line. OK cells express a novel calcium (Ca)‐sensitive dicarboxylate transport system.

In mice, fractional excretion (FE) of α‐KG was dramatically increased in the KO and Het mice (WT 0.38+/‐0.05, Het 2.8+/‐1.3, KO 4.7+/‐0.9; p<0.05). Acidosis lowered FE significantly in all mice.

In CUBS α‐KG uptake decreased when competed with the dicarboxylate succinate (Suc 2 mM) in both normal and <60 µM Ca buffers (0.64±0.11 to 0.25±0.10 and 0.63±0.15 to 0.29±0.11, p<0.01).

In OK cells, α‐KG uptake increased when extracellular Ca was lowered to <60 µM (1.7±0.49 vs 2.5±0.6, p<0.01). Transport decreased when competed with Suc in both Ca buffers (1.3±0.39 vs 1.6±0.34, p<0.01).

NaDC1 transports α‐KG and is the predominant, but not exclusive, mechanism of control of distal α‐KG delivery. Also α‐KG is transported via a Ca‐sensitive transporter in OK cells. Furthermore based on the FEs > 1.0, α‐KG is secreted into the PT simultaneously with reabsorption.

Thus NaDC1 in the PT regulates acid‐base transport in the distal tubule via the control of α‐KG transport. NaDC1 represents a novel mechanism of PT–distal tubule communication in the kidney.

NIH/NIDDK
TLR3 Activation Preferentially Enhances IL‐17F Expression in SHR Immune Cells
Authors: Singh Madhu , Cicha Michael , Chapleau Mark , Abboud François
Published: June 2021

We have shown abnormally large age‐related increases in CD161+ immune cell populations in splenocytes from spontaneously hypertensive rats (SHR). A subpopulation of CD161+ cells (Th17, CD4+CD161+) expresses IL‐17A and IL‐17F. IL‐17A plays a key role in hypertension and related vascular injury. However, structurally and functionally similar IL‐17F has not been studied in hypertension. Using flow cytometry, we found a greater abundance of CD4+CD161+ cells in prehypertensive SHR splenocytes than in normotensive Wistar‐Kyoto rats (WKY). These cells increased with age reaching levels of 14.7 ± 0.1% in spleens from 38 week old SHR compared to 8.5 ± 0.6% in age matched WKY. While PMA‐ionomycin caused equivalent induction of TNF‐α (WKY 6.7 fold, SHR 6.7 fold) and IL‐17A RNA (WKY 14.3 fold, SHR 12.4 fold), the induction of IL‐17F RNA was significantly greater in SHR splenocytes (WKY 46.3 fold, SHR 65.2 fold). When challenged with poly‐IC, a TLR3 agonist, TNF‐α and IL‐17A expressions were modestly increased in SHR, however, expression of IL‐17F was markedly and specifically increased in SHR compared to WKY (27 fold SHR vs. 3 fold in WKY). We conclude that (1) SHR splenocytes have significantly greater potential for IL‐17F induction under inflammatory conditions, and (2) increased expression of IL‐17F is much more pronounced than that of IL‐17A in response to TLR3 activation in SHR. IL‐17F may be a novel and preferred therapeutic target in hypertension. Funded by NIH PPG HL14388.
Pro Inflammatory Cytokines in Smokers and Non‐Smokers Following Different Intensity of Exercises
Authors: Martinez Diego , Medina Erika , Valdez Ruben , Solis Leslie , Park Kyung‐Shin
Published: June 2021

Purpose

The purpose of the study was to examine changes in C‐reactive protein (CRP) and TNF‐a in blood before and after exercise at different intensities in smokers compared to non‐smokers.

Methods

Fourteen physically inactive smokers (SM, n=7) and non‐smokers (NS, n=7) aged 18 to 26 were recruited. Each subject completed three treadmill runs at different intensities in a random order (60%, 70%, and 80% of VO2max). Running distance for all three runs was equivalent to 30‐min run at 70% VO2max. Plasma samples were collected at rest (PRE), immediately after (POST), and 1 h following (1H) each run to measure CRP and TNF‐a. Data was analyzed using two‐way repeated measures ANOVA with P<0.05.

Results

SM had greater values of CRP than NS at POST following 70% (3.3±.3mg/L vs. 2.5±.1, Mean±SE, P=.014) and 80% (3.9±.3 vs. 3.0±.3, P=.005) VO2max runs. CRP at POST increased relative to intensity in SM (60% < 70% < 80%, P<0.05), but not in NS (only 60% < 80%, P<0.027). TNF‐α was higher in SM at all measurements points (P=.015). TNF‐α at POST elevated above PRE at 60% (40.4±2.1mg/L vs. 52.4±4.2, P=.028), 70% (41.7±3.3 vs. 56.3±5.6, P=.019), and 80% (39.8±3.3 vs. 57.8±6.1, P=.023) VO2max runs in SM and 70% (27.9±3.1 vs. 34.3± 4.4, P=.041) and 80% (28.8±3.8 vs. 35.3±2.9, P=.033) VO2max runs in NS.

Conclusion

Results indicate SM having higher levels of inflammation even at rest as compared to NS, suggesting higher risk of cardio vascular disease. To exercise intensity CRP and TNF‐a elevate both groups. However, SM responded more sensitively to relatively equal intensity of exercise. These greater elevation in CRP and TNF‐α at POST suggest that high intensity aerobic exercise may be avoided in SM at least in the beginning phase of exercise training.
Vascular Adjusts Induced by Low Intensity Resistance Training
Authors: Macedo Fabricio , Mesquita Thassio , de Melo Vitor , Santos Rodrigo , Santana Michael , Santos Robervan , Oliveira Larissa , Mota Marcelo , Silva Tharciano , Barreto André , Santos Marcio , Lauton‐Santos Sandra , Santana‐Filho Valter
Published: June 2021

The aim of this study was to evaluate the vascular effects and participation of nitric oxide (NO) after a period of resistance training (RT). One group was submitted to RT (Ex). Control animals (SED) were fictitious trained (no exercise). After 8 weeks, mesenteric artery was removed and divided, one part was sliced in rings for vascular reactivity analysis (Acetilcholine (ACh): 10‐9 ‐ 10‐4 M; Nω‐nitro‐L‐arginine methyl ester hydrochloride (L‐NAME): 100µM; Phenylephrine (Phe): 10‐6 M) and the other half was probed with DAF‐FM dye to evaluation of NO bioavailability. Other animals were used to verify the nitric oxide synthases (NOS) expression using western blot technique. RT was able to increase percentage of ACh‐induced relaxation of mesenteric arterial rings (pD2: SED 6.2 ± 0.1 vs Ex 7.1 ± 0.1) and addition of L‐NAME abolished this effect (SED 52.0 ± 3.2% vs Ex 35.8 ± 3.7%). Moreover, RT reduced the level of tension in mesenteric rings with Phe‐induced contraction (SED 0.39 ± 0.06 vs Ex 0.20 ± 0.05) and addition of L‐NAME abolished this effect (SED 0.65 ± 0.05 vs Ex 0.88 ± 0.07). RT also increased the bioavailability of NO in both, basal (SED 0.99 ± 0.1 vs Ex 2.22 ± 0.16) and stimulated with ACh 10‐7 (SED 2.32 ± 0.16 vs 2.95 ± 0.2). In addition, RT increased eNOS (SED 0.21 ± 0.03 vs Ex 0.71 ± 0.07) and nNOS expression (SED 0.28 ± 0.06 vs Ex 0.76 vs 0.21). In conclusion, RT were able to promote endothelial adjustments, probably mediated by increased NO synthases.
Resistance Training with Instability Increase Levels of Spinal Inhibition and Decrease the Motor Symptoms of Parkinsonians
Authors: Silva‐Batista Carla , Kanegusuku Hélcio , Roschel Hamilton , Mattos Eugenia , Tricoli Valmor , Forjaz Cláudia , Ugrinowitsch Carlos
Published: June 2021

Objective

To investigate the effects of resistance training with instability in the level of reciprocal inhibition and in the motor symptoms of individuals with Parkinson's disease (PD).

Methods

26 individuals with PD (8.9±0.5 disease duration) on dopaminergic therapy stable in stages 2 and 3 were divided equally into two groups: control group (CG) and RTI group (RTIG). RTIG underwent 12 weeks (twice a week) of hypertrophy‐oriented RT in the squat, leg press and plantar flexion exercises with the addition of instability devices (i.e., bosu, dyna disk, balance disk, Swiss ball). Soleus muscle reciprocal inhibition (RI) of the most affected leg and motor symptons using the Unified Parkinson's Disease Rating Scale (UPDRS) section III were measured before and after the training period. Significance level was set at p蠄0.05. Results: RI was significantly increased after RTIG (from 5.1±7.6% to 34.8±10.4% p<0.0001). Motor symptons were significantly decreased after RTIG (from 42.2±7.6 to 38.1±5.6, p<0.001).

Conclusion

RTIG is effective to improve the motor control of individuals with PD. Thus, RTIG may be a important training strategy for this population, once changes in the motor control are apparently indicative of an abnormal supraspinal influence on spinal mechanisms due to disease. Financial support: FAPESP: 2013/04970‐4.
ROS production from endothelial cells during in vitro simulated dives: effects of hydrostatic and gas pressures
Authors: Theron michael , Wang Qiong , Lambrechts Kate , Mazur Alexandra , Buzzacott Peter , Guerrero François
Published: June 2021

ROS are known to be involved in post‐dive endothelial dysfunction which is itself thought to be associated with decompression sickness. The aims of this study were to assess the impact of air diving on ROS production from endothelial cells (EC) during diving, and to differentiate the effects of physical parameters of the dive (hydrostatic ‐HP‐ and gas pressures). This work particularly focused on the mitochondria, one the pathways of ROS production.

During in vitro diving simulation (45 min at 8 ATA, compression 1ATA/min), superoxide (O2°‐) production, mitochondrial membrane potential (MMP) and cell death were analyzed on EC when HP, oxygen and nitrogen pressures were increased together (air dive) or independently. Then, O2°‐, peroxynitrite, NO° productions and mitochondrial calcium concentration were examined during air dive.

Air diving increased O2°‐, decreased MMP and promoted endothelial cell death. O2°‐ production was mainly due to oxygen partial pressure but also to HP. HP, oxygen and nitrogen pressures modified mitochondrial membrane potential and cell death. During air diving, endothelial cells showed excessive O2°‐ and peroxynitrite production, attenuation of NO production and up‐regulation of mitochondrial calcium storage.

This study clearly demonstrates the overproduction of ROS and RNS (O2°‐ and peroxinitrite) during a dive; it furthermore shows that MMP and mitochondrial calcium are modified. It is proposed that, during diving, mitochondrial calcium may promote peroxynitrite formation and O2°‐ overproduction through the activation of mitochondrial NO° generation. These phenomena could explain the observed decreased viability of endothelial cells.
S‐Nitrosoglutathione Reductase Null Mice Display Increased Brain Glutamic Acid Decarboxylase Activity and Seizure Resistance in Hyperbaric Oxygen
Authors: Gasier Heath , Tatro Lynn , Demchenko Ivan , Suliman Hager , Piantadosi Claude
Published: June 2021

An imbalance between glutamatergic and g‐aminobutyric acid (GABA)ergic synaptic transmission is associated with hyperbaric oxygen (HBO2) induced seizures. Here we explored the impact of S‐nitrosylation in preventing oxygen toxicity in S‐nitrosoglutathione reductase (GSNOR) null mice and tested whether S‐nitrosylation of brain glutamic acid decarboxylase (GAD) may alter its activity, thus the synthesis of inhibitory GABA. Wild type (WT) and GSNOR ‐/‐ mice were exposed to HBO2 at 4 ATA for up to 100 min and seizure latency was recorded. The medulla, cerebellum and forebrain were harvested from HBO2 exposed and control mice for determination of GAD activity (fluorometrically) and S‐nitrosylated GAD‐65 (Biotin‐switch). The mean (± SE) seizure latency was significantly delayed in the GSNOR ‐/‐ (63 ± 7 min) compared to WT (34 ± 6 min) mice, and the proportion of GSNOR ‐/‐ mice that experienced seizures (56%) was significantly less than WT mice (87%). Relative to controls, GAD activity in the medulla and cerebellum was significantly increased in the GSNOR ‐/‐ compared to a reduction in WT mice: medulla (GSNOR ‐/‐: +22% and WT: ‐13%) and cerebellum (GSNOR‐/‐: +23% and WT: ‐12%). A significant fall in the degree of GAD‐65 S‐nitrosylation was observed in GSNOR ‐/‐ (‐63%) compared to WT (‐17%) mice suggesting augmented denitrosylation after GSNOR deletion. Dysregulated S‐nitrosylation increased seizure latency and reduced the percentage of mice that developed seizures. The protection afforded by reduced S‐nitrosylation may be explained in part by increased GAD activity that would favor GABA synthesis, thus inhibit neuronal excitation and seizures.
Effects of Hypercapnic Exercise on the Severity of Hypobaric Hypoxia Induced Pulmonary Injury
Authors: Sheppard Ryan , Hall Aaron
Published: June 2021

Humans operating at altitude are susceptible to high altitude pulmonary edema (HAPE), a form of altitude sickness resulting from exaggerated pulmonary vasoconstriction and increased pulmonary capillary pressures. Naval Special Warfare (NSW) operators appear to be more susceptible than other military personnel. We hypothesize that this is due to a unique underwater training and selection process which leads to a suppression of respiratory drive when exposed to hypobaric hypoxia. This hypothesis is being tested in a rodent model using hypercapnic exercise and simulated altitude. Male Wistar rats are exposed to 3.5% CO2 with and without moderate treadmill exercise (15m/min, 5%), 1hr/day, 5days/week for 5 weeks. Vascular reactivity to bolus CO2 (12%) was then assessed via rheoencephalography and laser Dopplar flow. Hypoxic respiration (10‐18% O2) is monitored in modified plethysmography chambers, and animals are exposed to hypobaric hypoxia at altitude equivalents ranging from 18,000‐30,000ft for 5‐24 hours. End points include respiratory rate and volume, lung wet/dry ratios, BAL protein and cell counts, arterial blood gases, pulmonary histology, and gene expression of HIF1α, IL‐6, and TNFα. Cerebral vascular reactivity to bolus CO2 is reduced with exercise alone (‐53% of control), CO2 alone (‐46% of control), and exercise+CO2 (‐62% of control). Right lung wet/dry weight ratios are not significantly increased by altitude exposure under any of the conditions tested. Severe dehydration, up to 12% loss of body weight in 24 hours, is a significant impediment that we are unable to adequately address and which we believe is a fundamental problem with rodent HAPE models. Analysis of respiration, BAL fluid, blood gases, lung pathology and gene expression is ongoing.
Carotid body response to intermittent hypoxia requires Cav 3.2 T‐type Ca2+ channels
Authors: Makarenko Vladislav , Nanduri Jayasri , Fox Aaron , Kumar Ganesh , Prabhakar Nanduri
Published: June 2021

Previous studies showed that intermittent hypoxia (IH) augments carotid body response to hypoxia, but the underlying cellular mechanisms are not known. We recently reported that carotid body glomus cells express α1H subunit of Cav 3.2 T‐type Ca2+ channels, which contribute to hypoxia‐evoked Ca2+ influx. In the present study we examined the role of Cav 3.2 in glomus cell responses to IH. Carotid bodies from IH exposed rats exhibited 3 fold increase in α1H mRNA as compared with control rats reared under normoxia. IH exposed glomus cells exhibited augmented [Ca2+]i response to acute hypoxia. TTA‐A2 (25 µM), a selective blocker of T‐type Ca2+ channels, attenuated hypoxia‐evoked [Ca2+]i elevation in by ~45% in controls and by ~80% in IH‐exposed glomus cells. The IH‐evoked augmented [Ca2+]i responses to acute hypoxia was absent in α1H null glomus cells. These results demonstrate that Cav 3.2 T‐type Ca2+ channels contribute to IH‐induced augmented [Ca2+]i responses in glomus cells. Supported by NIH HL‐90554.
Protein Kinase G Regulated H2S Governs Oxygen Sensing by the Carotid Body
Authors: Kumar Ganesh , Yuan Guoxiang , Peng Ying‐Jie , Makarenko Vladislav , Raghuraman Gayatri , Nanduri Jayasri , Vasavda Chirag , Gadalla Moataz , Snyder Solomon , Prabhakar Nanduri
Published: June 2021

Previous studies showed that O2 sensing by the carotid body (CB) requires carbon monoxide (CO) generation by heme oxygenase (HO)‐2 and hydrogen sulfide (H2S) synthesis by cystathionine‐γ‐lyase (CSE). However, the mechanism(s) underlying O2‐dependent gaseous messenger generation are not known. Here, we report that CO but not H2S generation is sensitive to changes in O2 levels. The O2‐dependent CO generation requires two cysteine residues (C265 and C282) located in the heme‐regulatory motif of HO‐2. Carbon monoxide, in turn inhibits H2S generation from CSE via protein kinase G (PKG)‐dependent phosphorylation of serine 377. Hypoxia, by reducing CO generation, decreases the inhibition of CSE resulting in elevated H2S, which mediates the increased CB neural activity. These results demonstrate that PKG‐dependent regulation of H2S governs O2 sensing by the carotid body (Supported by NIH‐HLBI PO1 HL‐090554).
Regulation of Insulin Metabolism by Intermittent Hypoxia. Molecular Mechanisms
Authors: Nanduri Jayasri , Wang Ning , Khan Shakil , Semenza Gregg , Prabhakar Nanduri
Published: June 2021

Intermittent hypoxia (IH) is the hallmark manifestation of sleep disordered breathing (SDB) with recurrent apnea. A large body of clinical evidence suggests that SDB patients are at increased risk to develop Type II diabetes. However, molecular mechanism(s) underlying the effects of IH on pancreatic beta cell function have not been established. Hypoxia‐inducible factor 1 (HIF‐1) mediates many of the systemic and cellular responses to IH. Mice with partial deficiency of HIF‐1α (Hif1a+/‐) exhibit a remarkable absence of IH‐induced hypertension and breathing abnormalities, suggesting that activation of HIF‐1 contributes to the autonomic morbidities associated with IH. In the present study, we tested the role of HIF‐1α in IH‐induced pancreatic beta cell dysfunction. Experiments were performed on male littermate wild type (WT) and Hif1a+/‐ mice exposed to either 30 days of IH or normoxia. HIF‐1α levels were elevated in pancreatic islets from IH‐exposed WT mice but not in Hif1a+/‐ littermates. IH‐exposed WT mice exhibited elevated fasting plasma insulin levels and impaired glucose stimulated insulin secretion, but these effects were either absent or attenuated in IH‐ exposed Hif1a+/‐ mice. Furthermore, IH augmented basal insulin secretion and this effect was prevented by treating islets from WT mice with either digoxin or YC‐1, which blocked HIF‐1α accumulation. These results suggest that HIF‐1 mediates IH‐induced pancreatic beta cell dysfunction. Supported by NIH‐HL‐090554
Fine particulate matter in the air within the limits recommended by WHO alters placental structure
Authors: Soto Sonia , Marchesi Guilherme , Lopes Karen , Veras Mariana , Heimann Joel
Published: June 2021

Objective

To evaluate the effects of PM during the perinatal period on placenta.

Methods

Female Wistar rats (7‐9/group) were exposed to filtrated air (F) or PM2.5 (P) for 15 days. After mating, rats were divided in 4 groups and again exposed to F or P (FF, FP, PF, PP). At the 19th day of pregnancy, fetal (fPl) and maternal (mPl) portions of placenta were collected. Several placental parameters and renin‐angiotensin system were evaluated.

Results

(mean±SEM – p<0.05):

FF
FP
PF
PP

Mass (g)
fPl
0.42±0.01
0.44±0.01
0.40±0.011,2,4
0.43±<0.01

mPl
0.13±0.01
0.14±0.01
0.12±0.011,2
0.12±0.011,2

Thickness (mm)
fPl
4.42±0.10
4.16±0.06
3.93±0.091,4
4.40±0.11

mPl
3.15±0.10
2.77±0.091
2.92±0.09
2.95±0.11

Surface area (mm2)
fPl
117.6±2.37
90.20±2.191
101.1±2.971,2
101.7±2.281,2

mPl
32.64±1.46
24.0±0.601
28.4±1.111,2
26.73±1.461

TGFβ (%)
fPl
100
76.93±8.581
76.63±3.761
83.30±5.96

mPl
100
72.70±6.351
48.58±5.901,2
49.54±5.771,2

AGTO (%)
fPl
100
121.7±15.69
127.9±10.29
115.3±11.36

mPl
100
104.9±10.75
114.6±19.30
85.87±4.28

ECA (%)
fPl
100
90.17±5.27
74.20±4.841,2
59.78±3.361,2

mPl
100
96.96±4.39
82.04±3.161,2
80.41±4.961,2

Renin (%)
fPl
100
192.8±27.791
204.3±21.371
149.9±20.021

mPl
100
139±11.06
113.5±18.57
120.7±26.42

ANG II (%)
fPl
100
90.52±3.711
90.82±2.311
83.28±2.131

mPl
100
104.5±11.72
105.2±8.82
75.97±3.291,2,3

AT1R (%)
fPl
100
202.1±41.161
118.7±17.69
142.3±15.91

mPl
100
99.71±11.19
75.58±5.21
36.63±4.021,2,3

AT2R (%)
fPl
100
97.06±8.51
63.69±11.221,2
39.46±7.541,2

mPl
100
91.10±7.97
73.86±10.37
39.77±7.101,2

P<0.05 1vs FF; 2vs FP; 3vs PF; 4vs PP.

Conclusions

Particulate matter alters placental structure and local renin‐angiotensin system with a possible prejudice on maternal‐fetal interface.
Nuclear and cytosolic expression of placental PKM2 in preeclampsia and intrauterine growth restriction
Authors: Mejia Camilo , Bahr Brigham , Reynolds Paul , Arroyo Juan
Published: June 2021

The placenta facilitates nutrient and gas exchange between the mother and the fetus. As such, placental metabolism is important for successful pregnancies. Intrauterine growth restriction (IUGR) and preeclampsia (PE) are placental pathologies that cause pre‐term delivery and disorders in neonates. Pyruvate kinase M2 (PKM2) is a metabolic enzyme expressed in embryos and cancer tissues. Our objective was to determine the cytosolic and nuclear expression of placental PKM2 protein and related signaling molecules in normal human control, PE and IUGR placentas. Placental samples were homogenized and cytoplasmic and nuclear proteins were extracted for western blot analysis. Placental tissues were also embedded for histological studies. Syncytiotrophoblast and cytotrophoblast cell lines were cultured and stained for PKM2. We observed: 1) localization of PKM2 to the villi of the human placenta; 2) increased total PKM2 expression during PE with no difference during IUGR (1.4‐fold, p<0.02); 3) elevated PKM2 nuclear expression in PE (1.65‐fold, p<0.01) and IUGR (1.5‐fold, p<0.01); 4) increased activation of ERK in PE (2.6 fold, p<0.02) and in IUGR (1.5 fold, p<0.05); 5) increased immunostaining of beta‐catenin and lactose dehydrogenase (LDH) in the villi of PE placenta; and 6) increased PKM2 nuclear expression in the invasive cytotrophoblasts cells when compared to syncytiotrophoblast cells. We conclude that PKM2 is expressed in normal, PE and IUGR placentas, but that its expression is increased in the PE placenta when compared to controls. Furthermore, our results suggest that PKM2 is a mediator of trophoblast cell invasion and its abundance influences the development of PE and IUGR. (Supported by NIH grant 7K99HD055054‐02).
Effect of canola oil on bone structure of ovariectomized rats
Authors: dos Santos Aline , Albuquerque Karine , Gonzalez Gabrielle , Boaventura Gilson , Costa Carlos Alberto , Nascimento‐Saba Celly Cristina
Published: June 2021

The low n‐6/n‐3 ratio of canola oil promotes bone formation and evidences that bone metabolism is modulated by lipids. However, it would be possible to prevent bone loss when associated to estrogen deficiency? The aim of this study was to evaluate bone structure of ovariectomized rats, fed with a diet containing canola oil. Female Wistar rats were fed, from weaning, with a manufactured diet containing 7% canola oil. At 90 days, rats were ovariectomized (OVX C,n=8) or sham‐operated (ShamC, n=8). In parallel, control groups (n=16) were fed with a diet containing soybean oil (ShamS; OVXS). At 180 days rats were euthanazed and food intake, body and uterine mass, body length, glucose tolerance test, serum lipid profile, insulin and estradiol were evaluated. In Femur and lumbar vertebrae were analyzed the bone mineral content (BMC), bone mineral density (BMD), bone area (BA), radiodensity of femur head (RFH) and vertebral body (RVB). Food intake, body length and insulin levels were similar among the groups. OVXS and OVXC groups presented higher body mass (8% and 10%, respectively) and adiposity (49% and 46%) and lower: lean mass (‐28% and ‐19%), BMD of femur (‐10% and ‐9%) and lumbar vertebrae (‐13% and ‐14%), RFH (‐15% and ‐15%) and RVB (‐17% and ‐21%), uterine mass (‐53% and ‐60%) and estradiol (‐53% and ‐29%). Glucose intolerance was more evident in OVXC group and hypercholesterolemy in OVXS group. In conclusion, canola oil did not prevent bone loss or body composition changes associated with estrogen deficiency. In addition, provides indicative of being deleterious to glucose metabolism.
Cellular Localization of the (Pro)renin Receptor within the Paraventricular Nucleus of the Hypothalamus
Authors: Pioquinto David , de Kloet Annette , Rodriguez Vermali , Hiller Helmut , Krause Eric , Sumners Colin
Published: June 2021

Over activation of renin angiotensin system (RAS) signaling in cardiovascular control centers of the brain causes inflammatory responses that are associated with the onset of neurogenic hypertension. The (pro)renin receptor (PRR) is an early component of RAS, that binds (pro)renin resulting in an increase in angiotensin II (Ang‐II) generation and ensuing neurogenic hypertension. Additionally, activation of the PRR leads to Ang‐II independent signaling that has been hypothesized to similarly initiate hypertensive and proinflammatory responses. Here, we sought to identify which cell types co‐localize with the PRR in the paraventricular nucleus of the hypothalamus (PVN), an important brain region in regulating systemic blood pressure and neuroendocrine responses. To characterize which cell types contained the PRR we performed RNAscope in situ hybridization (ISH) coupled with immunohistochemistry for cell‐type‐specific markers on perfused mouse brains. Dense localization of PRR mRNA to the PVN was observed and these mRNAs were predominantly localized to cells labeled with the neuronal‐specific marker, HuC/D. PRR mRNAs were also localized to cells expressing the microglial (Iba‐1) and astroglial (GFAP) markers. However, the expression of PRR mRNAs within these cell‐types was less robust. Subsequent ISH studies in corticotrophin‐releasing hormone and angiotensin type‐1 receptor reporter mice localized PRR to these specific neuronal phenotypes. Phenotyping PVN‐localized cells in this manner works towards understanding the mechanisms PRR binding may play in affecting neurogenic hypertension.
Effects of androgen on the folic acid‐induced inhibitions of endothelial cell proliferation and migration
Authors: Huo Yen‐Nien , Yeh Shauh‐Der , Lee Wen‐Sen
Published: June 2021

Folic acid (FA) has been suggested as an important daily dietary supplement, especially for women during pregnancy need to add a lot of FA to prevent some of the embryonic development of the lesions. Our previous studies have indicated that FA has anti‐angiogenic effect. However, there is no relevant studies indicated that pregnant women ingestion of FA induce lesions due to anti‐angiogenesis. Therefore, we proposed that estrogen might be able to antagonize the folic acid‐induced anti‐angiogenesis activity, and this hypothesis has been proved. However, previous studies showed endothelial cells also express androgen receptors (AR). Accordingly, this study was aimed to investigate whether androgen could influence the FA‐induced anti‐angiogenesis. We conducted in vitro study to investigate whether androgen has any impact on proliferation and migration. The preliminarydata showed that treatment with androgen agonist, R1881 or FA alone could inhibit cell proliferation and migration. However, co‐treatment will abolish the FA‐induced inhibitions on cell proliferation and migration. Moreover, we previously found that FA inhibits proliferation by increasing the levels of p21 and p27 proteins, and reduced the cell migration activity by inhibiting the RhoA activity. Thus, we examined the androgen on the signaling pathway involved in cell proliferation and migration. Our results showed R1881 could reduce the cSrc and up‐regulations of p21 and p27. Taken together, the results of this study suggest that activation of AR could abolish the FA‐induced inhibitions on endothelial cell proliferation and migration.
Variation in Branchial Expression Among insulin‐like growth‐factor binding proteins (igfbps) During Atlantic Salmon Smoltification
Authors: Fujimoto Chelsea , Phipps‐Costin Silas , McCormick Stephen , Breves Jason
Published: June 2021

In preparation for migration from freshwater to marine habitats, Atlantic salmon (Salmo salar) undergo smoltification, a springtime transformation that includes the development of salinity tolerance. The growth hormone/insulin‐like growth‐factor (Igf) network is known to mediate the development of branchial ionoregulatory functions underlying salinity tolerance. Igfs interact with a suite of Igf binding proteins (Igfbps) that modulate hormone activity. In Atlantic salmon, igfbp4, ‐5a, ‐5b1, ‐5b2, ‐6b2 and ‐6b1 are highly expressed in branchial tissue. Here, we characterized the dynamics of igfbp expression during smoltification and following acute seawater (SW) challenges. We observed increased branchial Na+, K+‐ATPase activity and Na+,K+,2Cl‐‐cotransporter expression characteristic of smoltification. igfbp5a, ‐5b1 and ‐5b2 expression did not peak in Spring. Nonetheless, igfbp5a, ‐5b1 and ‐5b2 showed diminished expression following SW challenge in March. igfbp6b1 and ‐6b2 expression, however, did increase in Spring, peaking with smoltification. Following a SW challenge in March, igfbp6b1 showed increased expression while igfbp6b2 exhibited diminished expression. These data suggest that dynamic igfbp expression accompanies smoltification and SW challenges. Transcriptional control of igfbps may thus provide a mechanism for the local modulation of Igf activity in gill.
Neuromodulator Permeability of a Ganglionic Sheath in the Lobster, Homarus americanus
Authors: Keller L , Christie A , Dickinson P
Published: June 2021

Rhythmic movements, controlled by hard‐wired neuronal networks, must be flexible in order to respond to environmental changes. Neuromodulators, released either locally within the nervous system or hormonally, provide one source of flexibility. The pyloric motor pattern, which is generated in the lobster stomatogastric ganglion (STG) and controls rhythmic movements of the foregut, is extensively modulated by neuropeptides. However, the STG is encased in a connective tissue sheath that can limit access to the ganglion; medium‐sized, hydrophobic crustacean cardioactive peptide can permeate the sheath but large, hydrophilic Val1‐SIFamide cannot. We hypothesize that size and hydrophobicity, which can be combined as total polar surface area (TPSA), are two factors that dictate this selective permeability. The pyloric pattern was recorded extracellularly in the isolated stomatogastric nervous system. Neuropeptides spanning a range of TPSA values were superfused over the STG; the threshold concentration for activation and the intensity of activation for each peptide were compared with the sheath intact and after its removal. The modulatory threshold for both red pigment concentrating hormone, a large, hydrophobic peptide with a medium TPSA, and proctolin, a small, hydrophilic peptide with a small TPSA, was between 10‐9 and 10‐8M both with and without the sheath present. However, the intensity of activation for proctolin was greater without the sheath than with, indicating the sheath may partially block proctolin. These results suggest that TPSA is a possible determinant of the permeability of the connective tissue sheath encasing the STG.

Support: APS UGSRF, NIH 5P20‐RR‐016463, 8P20‐GM‐103423 (INBRE)
Hepatic insulin‐like growth‐factorbinding protein (igfbp) Transcriptional Responses to Fasting in Atlantic Salmon
Authors: Phipps‐Costin Silas , Fujimoto Chelsea , McCormick Stephen , Breves Jason
Published: June 2021

The growth hormone (Gh)/insulin‐like growth‐factor (Igf) axis is important to growth regulation of fishes, including responses to food restriction. The role of Igf binding proteins (Igfbps) in the regulation of Igf function during food restriction is unresolved. We examined changes in the circulating levels of Gh and Igf1 and hepatic igfbp expression during food restriction of Atlantic salmon (Salmo salar) smolts. Smolts were fasted for either 3 or 10 days at the peak of smoltification (late April to early May). Branchial Na+, K+‐ATPase activity, which increases during smoltification, was not altered by food restriction. Condition factor (weight:length ratio) of food restricted fish was significantly lower than controls after 10 days. We measured the expression levels of igfbps that exhibit robust expression in Atlantic salmon liver, including igfbp1a1, ‐1b1, ‐1b2, ‐2a, ‐2b1 and ‐2b2. We observed a marked increase in the expression of igfbp1a1 following both 3 and 10 days of food restriction. No other investigated hepatic igfbps responded to food restriction. We will also present information on igfbp transcription in muscle and circulating levels of Gh, Igf1, cortisol and thyroid hormones. We will discuss the relationship between hepatic igfbp expression and circulating Igf1 with an aim to resolve how the activities of the Gh/Igf axis are modulated during food restriction of juvenile Atlantic salmon.
Student Evaluation of Case Studies.
Authors: Jagadeesh Ashraya , Volodymyr Mavrych , Bolgova Olena , Maroun Leonard , Rajasekaran Senthil Kumar
Published: June 2021

There is strong research evidence that supports the implementation of learner centered approach as opposed to instructor centered approach in expanding knowledge base as well as increasing motivation.

This study attempts to assess student evaluation and acceptance of learner centered teaching within the basic science program of a Caribbean medical school through the use of case studies in Microbiology and Anatomy to help determine its usefulness in the basic science curriculum. In addition, we gathered data to assess differences in perception relative to the student's progression in the curriculum.

In both the Microbiology ((M)(3rd Trimester) and Anatomy (A)course (1st Trimester), case studies were prepared at the end of the relevant lecture series and handed out to students during class time. Further, students were encouraged to work in small groups to facilitate collaborative thinking in solving the case. At the end of the exercise, students answer questions in the form of multiple choice questions (MCQ ) pertaining to the cases.Upon completion of the case studies, students were surveyed using a questionnaire.

We found that students in Anatomy were less comfortable with the use of case studies when compared to the Micro students (46%vs 66%)

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This difference appeared to be related to the stage of progression of the student in the curriculum with senior students being more receptive to the case studies. 55% of the Micro students felt it was a good use of their time while only 21% of anatomy students did so.There was a consistent opinion among students regardless of their stage in the curriculum that they did not want this activity to be graded (96% (A) and 81%(M)).

Conclusion

It appears that more advanced students provided a more positive evaluation.
So You Flipped It?
Authors: Osborne David , Janssen Herbert
Published: June 2021

Flipping your classroom is in vogue, reaching a level of enthusiasm previously enjoyed by problem‐based learning (PBL) and team‐based learning (TBL). Briefly stated, flipping is accomplished when students are asked to complete tasks previously conducted in the classroom as homework before completing homework tasks during the face‐to‐face class time. This simplistic approach has been shown effective in engaging students and increasing test scores. The work students are asked to do outside the classroom, before class, must be carefully crafted to provide the foundation for the in‐class activities. This should go beyond traditional textbook assignments and may involve watching videos of traditional lectures, viewing voice‐over PowerPoints, etc. The activities to be conducted in class should be designed to enhance the student's understanding by encouraging discussions of case examples, scenario questions, problem sets, etc. This crucial step in the “flip” is an essential part of the learning process. While no one activity can be considered most appropriate for all situations, our experience suggests that it should expand on the knowledge gained outside the classroom in a way that “demands” the students complete their outside assignment before class. Something similar to the initial readiness assurance test (iRAT) used in TBL would seem appropriate to help ensure that students have gained the essential knowledge to engage in critical‐thinking during these class activities. For maximum effectiveness in medical physiology courses, the classroom activities should expand the basic knowledge and include higher‐level thinking to ensure success of the flip classroom pedagogy.
Assessment Driven Learning: The Use of Clinically Integrated Questions in the Anatomy Laboratory Practical Exam
Authors: Hanna Jandy , Scopa Kelso Rebecca , Thompson Andrew , Ward Peter , Wines Karen
Published: June 2021

In the gross anatomy laboratory, assessment is traditionally achieved through free‐response identification questions. Because student learning is strongly driven by assessment, it is natural that the trend of curricular integration should extend into the laboratory setting. Asking case‐based and higher‐order questions on anatomy practical exams illustrates the importance of anatomy knowledge in clinical reasoning and assesses students' ability to apply foundational information from an early point in their medical career. In this study, several years of data from anatomy practical exams were analyzed to assess the impact that these alternative testing modalities have on various measures of student performance. Performance on multiple years of exam items (N>300) were categorized by question type, Bloom's taxonomy, structure type and discipline. Categories were compared with Wilcoxon rank sum tests. Difficulty, discrimination index (DI) and point bi‐serial (PBS) were calculated for each item. Results demonstrated that integrated, multiple‐choice items with structures tagged on cadavers were significantly more difficult for students (p=0.0015) and tended to have a higher mean DI and PBS. Questions categorized to higher Bloom's taxonomic levels were significantly harder than questions from lower on Bloom's taxonomy (p=0.05‐0.0039). Interestingly, identification of vessels was significantly harder than many other structure types (p=0.005‐0.0432). These results support the use of alternative and integrated testing modalities in the anatomy laboratory as an effective way to reinforce important concepts that better fit with the objectives of an integrated curriculum.
The Evaluation of Learning Curves in Novice Laparoscopists: Incorporating Direct Visualization into the Simulation Training Program
Authors: Dawidek Mark , Roach Victoria , Wilson Tim
Published: June 2021

Technological developments have led to resurgent interest in stereoscopic visualization for laparoscopy. Evidence suggests that trainees achieve proficiency on the McGill Inanimate System for Training and Evaluation of Laparoscopic Skills (MISTELS) in less total training time when using stereo visualization. Data from trainees using the Fundamentals of Laparoscopic Surgery (FLS) curriculum to train the MISTELS tasks indicate that the peg transfer task requires the greatest training time to reach proficiency. This task challenges basic hand‐eye coordination that is critical to performing more complex tasks. As monoscopic visualization remains the standard of care, our goal remains to train proficiency under monoscopic visualization. However, we propose incorporating stereo‐direct visualization (SDV) using open FLS box trainers, into the curriculum to accelerate learning. Novice surgery residents will train with the peg transfer task. Half will train to proficiency (< 54 sec) under standard monoscopic video visualization. The SDV group will train to proficiency, then switch to traditional monoscopic video visualization and continue to train until proficiency is reached. We hypothesize that SDV training will facilitate the perceptual switch to reach proficiency in less total time. Results from this study may be employed to further guide the development of laparoscopic training curricula.
Medical Gross Anatomy: Interdisciplinary Efforts to Increase Active Learning through Collection and Histological Assessment of Biopsies
Authors: Davies David , Quick Charles
Published: June 2021

Objective

In a 9‐week anatomy course, collaboration between Anatomy and Pathology faculty members facilitated the pairing of an investigative approach with traditional dissection to: encourage self‐directed active learning, link gross anatomical observations with normal and pathologic histological findings, and build teamwork and communication skills.

Methods and Results

While engaged in dissection, each of 35 teams independently obtained seven biopsies prioritized by their scientific interest and processing cost. A clinical pathology laboratory processed the tissues to histopathological slides that teams initially reviewed with a pathologist. Subsequently, teams examined their slides using microscopes equipped with mounts to support cell phone cameras. This enabled students to document and share their findings using techniques applicable to telemedicine. The investigative proficiency of the teams was assessed by capstone reports and 12‐min presentations that were evaluated by three faculty members during an intramural biomedical conference.

Conclusions

Faculty scoring and narrative assessments indicated that this endeavor: 1) firmly grounded student learning of anatomy and histology in a clinical context, 2) fostered self‐directed learning, 3) encouraged students to explore their personal interests as prospective lifelong learners, and 4) documented their ability to present accurate, concise, and well‐organized reports. Moreover, interviews with students suggested that this investigative approach to learning was popular and effective.

Support: 1) Arkansas Medical Society's Medical Education Foundation for Arkansas, 2) Dept. of Pathology, and 3) Dept. of Neurobiology and Dev. Sciences.
Does the Use of Clinical Vignettes in Anatomy Education Increase Clinical Knowledge? A Survey of Congenital Cytomegalovirus (cCMV) Knowledge Among Medical and Allied Health Students
Authors: Muldoon Kathleen , Demmler‐Harrison Gail
Published: June 2021

Many medical schools have adopted an education model that integrates clinical and basic science education. However, there are little data to examine whether clinical vignettes increase student knowledge of diseases not covered in a traditional curriculum. Cytomegalovirus (CMV) is a common virus and the leading cause of congenital disabilities, yet physicians and allied health practitioners have little knowledge of congenital CMV (cCMV) infection. We hypothesize that incorporating a clinical vignette using cCMV into a basic science anatomy class will increase student awareness of cCMV, and hence translate into improved medical and therapeutic practice. The first aim in our study is to collect data on student knowledge of cCMV. Students in the medical and allied health programs at Midwestern University (Glendale AZ) were sent an online survey to assess their knowledge of cCMV prior to taking their first term anatomy course. 450 survey invitations were distributed and 127 responses were received. Less than 1% of respondents indicated that they were familiar with cCMV in contrast to 43.4% and 53.3% familiarity with Down syndrome and HIV/AIDS, respectively. Only 4.7% of respondents were able to identify anatomical sequelae of cCMV infection (e.g., microcephaly, white matter calclifications, enlarged liver and spleen). The pre‐vignette survey documents significant knowledge gaps regarding cCMV, representing an opportunity to assess the effectiveness of clinical vignettes in anatomy education. The same survey will be sent to the students after course completion to evaluate improvements in cCMV knowledge.
Anatomy and Additive Manufacturing: Imaging Methods and 3D Printing in Anatomy Education and Research
Authors: Adams Justin , Bertram John , McMenamin Paul
Published: June 2021

The combined challenges of maintaining bequest programs, accessing and retaining human cadavers, and minimising staff and student exposure to formalin has led to variable (and oftentimes reduced) use of dissection‐based teaching in medical and allied health professional programs. As a supplement to our current dissection‐based curriculum, we have developed methods for applying imaging and additive manufacturing to reproduce prosected human cadaver and other specimens that obviates many of the above issues.

This report presents the results of several years of methods research and development to produce high resolution, full color reproductions of prosections from medical imaging (CT/MRI) and surface scanning datasets. We describe how this approach of preserving anatomy offers several advantages over other techniques, including: (1) capturing anatomy too complex for traditional physical moulding and casting methods; (2) the rapid production of multiple identical copies; (3) scale manipulation; and (4) false coloring to enhance structure visibility. We also present statistical results (concordance and intraclass correlation coefficients) which demonstrate that 3D prints from surface scanned specimens have high concordance to the original, and accurately resolve the morphology of extremely small structures without reliance on CT/MRI for primary data collection.

Our ongoing development of 3D printing for anatomy education represents a significant methodological advance impacting the range of resources available to training programs, particularly in avoiding some of the financial, cultural and ethical issues associated with cadaver specimens either in an embalmed or plastinated form.