bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of cardiovascular fitness and training history on heart rate variability before, during, and after a progressive maximal intensity exercise test (881.2)
Authors: Flanagan Shawn , Comstock Brett , Looney David , Sterczala Adam , Dupont William , Dunn‐Lewis Courtenay , Kraemer William
Published: June 2021

Heart rate variability (HRV) is a non‐invasive clinical indicator of cardiovascular health. We sought to examine differences in HRV as a function of exercise choice, frequency, length of regular participation, and aerobic capacity. 83 men (age: 23 ± 4 yr; height: 181 ± 8 cm; body mass: 83 ± 12 kg) with varying exercise preferences participated in the investigation. Heart rate was monitored with a five‐lead electrocardiogram before, during, and after exercise. Each experimental stage was two minutes long: subjects sat, stood, and then cycled in 35 W increments until volitional failure, before sitting in recovery (heart rate max: 184 ± 13 BPM; max power output: 256 ± 54 W; estimated VO2peak 3.16 ± 0.63 [L ● Min ‐1]). Measures of HRV were provided by time domain, frequency, and non‐linear analyses. Principal component analysis was used to distinguish contributory factors for HRV; the reliability of this analysis was confirmed with Chronbach’s Alpha test. Despite the use of a seemingly homogenous sample of college students, our analysis indicated consistent differences in HRV. Specifically, HRV varied with exercise preferences (p蠄0.05), and higher aerobic capacity (determined by the cycle exercise test) was associated with significantly lower HRV (p蠄0.05). We conclude that the unique and specific health benefits of exercise may be reflected in HRV. While further work on long‐term training outcomes is needed, HRV may serve as an indicator of cardiovascular and neuronal adaptations to exercise.
Effect of 6‐weeks voluntary wheel running on the sex‐hormone and cytochrome P450 aromatase of high‐fat feeding impuberism male SD rats (884.12)
Authors: Yan Yi , Xie Minhao , Sun Jinquan , Zhao Yan
Published: June 2021

To compare the levels of sex hormone and cytochrome P450 aromatase in gonad and extragonadal tissues of high‐fat feeding and normal diet SD rats in response to 6‐weeks voluntary wheel running.

METHOD:3‐weeks SD rats were randomly assigned to normal diet sedentary(C, n=10), normal diet exercise(E, n=10), high‐fat diet sedentary(D, n=10), high‐fat diet exercise(ErD, n=10) groups. After 2‐weeks adaption, rats of E and ErD group were individually placed into the wheel‐cage to do voluntary wheel running,1 hour each half day, 5days per week for 6 weeks. Food intake and running distance were monitored daily and body weigh weekly. Serum lipids, testosterone and estradiol were determined. The protein expression of P450arom was analyzed by immunohistochemical method.

RESULTS:There were significant negative effects of high‐fat diet on serum lipids, testosterone and estradiol (P0.05). High‐fat diet significantly increased the expression of P450arom in testis, quadriceps femoris (P<0.05), liver and kidney (P<0.01), but the P450arom in cardiac muscle was significantly low (P<0.05); 6‐weeks voluntary wheel running could improve these changes.

CONCLUTION:Long term high fat diets have a negative impact on metabolism of sex hormone. 6 weeks voluntary wheel running can improve the sex hormone metabolism disorders induced by high fat diets, through decreasing the expression of P450arom in gonad and extragonadal tissues.

Grant Funding Source: National Natural Science Foundation of China
Exercise capacity and ventilatory efficiency with afferent blockade in heart failure (884.3)
Authors: Keller‐Ross Manda , Johnson Bruce , Joyner Michael , Eisenach John , Curry Timothy , Olson Thomas
Published: June 2021

Increased locomotor muscle afferent feedback may be linked to the reduced exercise capacity (peak VO2) and poor ventilatory efficiency (high VE/VCO2 slope) observed in heart failure (HF). We examined the relationship between peak VO2 and change in VE/VCO2 with afferent inhibition during exercise in HF. 9 HF (60±6 yr) and 9 controls (CTL) (63±7 yr) completed 3 visits. Visit 1: cycle exercise to volitional exhaustion. Visits 2‐ 3: 5 min constant‐load cycling (65% of peak work) randomized to lumbar intrathecal fentanyl injection (afferent block) or placebo. VO2, ventilation (VE), carbon dioxide production (VCO2), and end‐tidal CO2 (PETCO2) were measured. In HF, peak work (120±34 vs 176±54 W, p<0.05) and VO2 (18.4±2.7 vs 27.2±4.7 ml/kg/min, p<0.05) were reduced, whereas VE/VCO2 slope was elevated (39.7±1.8 vs 35.3±0.8, p<0.05) compared with CTL. With afferent inhibition, HF patients had a greater reduction in VE/VCO2 (‐18.8±8.1 vs ‐5.4±13.3%, p<0.05) and increase in PETCO2 (20.3±10.5 vs 6.1±9.5%, p<0.01) during constant‐load cycling. Lower VO2peak was related to a greater decline in VE/VCO2 and rise in PETCO2 after afferent inhibition in HF (r=0.82, p<0.01 and r=‐0.69, p<0.05, respectively) but not CTL (p>0.05). Our data demonstrate that patients with the lowest VO2peak have the greatest improvement in VE/VCO2, suggesting a close link between afferent feedback, ventilatory efficiency and exercise capacity in HF.

Grant Funding Source: Supported by AHA 12GRNT11630027 and National Center for Advancing Translational Science KL2TR000136.
The early part of the aldosterone sensitive distal nephron is the primary site of increased sodium absorption in a mouse model for Liddle’s syndrome (892.25)
Authors: Korbmacher Christoph , Bertog Marko , Dahlmann Anke , Nesterov Viatcheslav
Published: June 2021

Liddle’s syndrome (pseudohyperaldosteronism) is caused by gain‐of‐function mutations of the epithelial sodium channel (ENaC) and clinically mimics hyperaldosteronism with severe salt‐sensitive hypertension. ENaC is expressed in the aldosterone sensitive distal nephron (ASDN) comprising the late distal convoluted tubule (DCT2), the connecting tubule (CNT) and the entire collecting duct (CD). In the cortical collecting duct (CCD) ENaC is known to be regulated by aldosterone. In contrast, we recently reported aldosterone‐independent ENaC regulation in the early part of the ASDN (Nesterov V et al. Am J Physiol Renal Physiol 2012, 303:F1289‐99). Here we investigated ENaC function in the transition zone of the DCT2/CNT or the CNT/CCD in a mouse model for Liddle’s syndrome. Whole‐cell amiloride‐sensitive ENaC currents (ΔIami) were measured in microdissected nephron fragments from mice maintained on different sodium diets to vary plasma aldosterone levels. Our data indicate that the primary site of increased sodium reabsorption in mice with Liddle’s syndrome is the DCT2/CNT. Compensatory suppression of plasma aldosterone is likely to mask at least in part the stimulatory effect of Liddle’s syndrome mutation on ΔIami in CNT/CCD. Our findings highlight the importance of ENaC function and regulation in the DCT2/CNT for the maintenance of sodium balance and for blood pressure control.
Kidney injury molecule‐1 mediates endocytosis of albumin in renal proximal tubule (892.40)
Authors: Zhao Xueying , Zhang Yuanyuan , Emmett Nerimiah
Published: June 2021

Kidney injury molecule‐1 (Kim‐1) is a scavenger receptor that is upregulated in proximal tubule epithelium in diabetic kidney disease. In this study, we examined the cellular location of Kim‐1 in proximal tubule cells and its role in renal handling of filtered protein. Immunostaining of primary mouse kidney tubular cells revealed that Kim‐1 was expressed in the plasma membrane and also prominent in the intracellular vesicles. An increase in binding and internalization of albumin was observed in both primary cultured tubular cells expressing endogenous Kim‐1 and the rat kidney cell line (NRK‐52E) overexpressing exogenous human Kim‐1. Kim‐1‐induced albumin accumulation was abolished by its specific antibody. Moreover, internalized proteins traffic through endosomes and are delivered to the lysosome for degradation in a clathrin‐dependent pathway. Supportive evidence includes a) detection of Kim‐1 in Rab5‐positive early endosomes, Rab7‐positive late endosomes/multivesicular bodies, and LAMP1‐positive lysosomes, b) colocalization of Kim‐1 and clathrin in the intracellular vesicles, and c) inhibition of Kim‐1‐mediated albumin uptake in the presence of chlorpromazine. In primary cultured tubular cells, the expression of Kim‐1 was significantly increased when exposed to elevated albumin concentration in culture medium. Taken together, our data indicate that Kim‐1 mediates albumin uptake in renal tubular epithelial cells, at least partly through a clathrin‐dependent mechanism. Kim‐1 may represent a potential therapeutic target in proteinuric nephropathy.

Grant Funding Source: Supported by the NIH SDK096441 and NIH/NCRR/RCMI 5G12RR03034‐23
Renal phenotype of inwardly rectifying potassium channel Kcnj16 (Kir 5.1) knockout in the Dahl salt‐sensitive rats (893.16)
Authors: Palygin Oleg , Levchenko Vladislav , Lowing Andrea , Ilatovskaya Daria , Pavlov Tengis , Geurts Aron , Jacob Howard , Staruschenko Alexander
Published: June 2021

The inward‐rectifying channels play an important role in the control of resting membrane potential and tubular homeostasis in the kidney. To illuminate the importance of Kcnj16 (Kir 5.1) in the context of a disease state in vivo, we generated a Kcnj16 knockout rat model in Dahl salt‐sensitive (SS) background by using zinc finger nuclease (ZFN) technology. ZFN against Kcnj16 caused a 18‐bp in‐frame deletion that occurred in the second protein transmembrane domain. IHC analysis demonstrated highly specific expression of Kcnj16 on the basolateral membranes of cortical collecting ducts and distal convoluted tubules in the control kidneys of SS and Sprague Dawley rats, which was completely abolished in Kcnj16‐/‐ rats; thus, successful knock out of this protein and consequent degradation of the channel in renal tubules were shown. The mean arterial pressure was significantly lower in Kcnj16‐/‐ compared to wild type SS rats (91.3±1.8 to 104.7±5.5 mmHg) when animals were fed a low salt (0.4%) diet. BUN, potassium and magnesium plasma concentrations were significantly modulated in knock out rats. Urea electrolyte balance was also disturbed compared to wild type animals. Importantly, change of the diet to high salt (4%) chow resulted in mortality of KO rats within 1‐2 days. These data demonstrate critical role of Kcnj16 channels in renal salt handling and in the development of salt‐sensitive hypertension.

Grant Funding Source: Supported by NIH HL108880 and ADA 1‐10‐BS‐168 to A.S., NHLBI 5RC2HL101681 to H.J.J
Signaling through the cardiac Na/K‐ATPase/phosphoinositide 3‐kinase IA pathway: role in ouabain‐induced protection against ischemia/reperfusion injury (893.31)
Authors: Duan Qiming , Kalisz Jennifer , Pierre Sandrine
Published: June 2021

Acute myocardial infarction (AMI), the clinical manifestation of ischemia‐reperfusion (IR) injury, is a leading cause of death worldwide. Like ischemic preconditioning (IPC) induced by brief episodes of ischemia and reperfusion, ouabain preconditioning (OPC) induced by activation of Na/K‐ATPase signaling protects the heart against IR injury. PI3K‐I activation is required for IPC, but its role in OPC has not been investigated. The hypothesis that OPC and IPC rely on distinct PI3K‐I isoforms was tested. In Langendorff‐perfused mouse hearts, OPC was initiated by 4 min of ouabain 10μM and IPC by 4 cycles of 5 min ischemia and reperfusion prior to 40 min of global ischemia and 30 min of reperfusion. Without affecting PI3K‐IB, ouabain doubled PI3K‐IA activity and Akt phosphorylation. The PI3K‐IA inhibitor PI‐103 (100 nM) blocked ouabain‐induced Akt activation but not a PKCε translocation previously shown to be critical for OPC. IPC and OPC significantly preserved cardiac contractile function and tissue viability as evidenced by improved recovery of left ventricular developing pressure and end‐diastolic pressure, reduced lactate dehydrogenase release, and decreased infarct size. OPC protection was blunted by PI‐103 but not by the PI3K‐IB inhibitor AS‐604850 (1 μM). In contrast, IPC‐mediated protection was not affected by PI‐103 but blocked by AS‐604850. These data suggest that PI3K‐IA activation is required for OPC but does not regulate the previously shown PKCε translocation. The finding that OPC and IPC pathways rely on distinct PI3K‐I isoforms may be of clinical relevance in AMI patients presenting with diseases and medications that impact PI3K‐IA and IB differently.

Grant Funding Source: Supported by HL‐36573
Ablation of intestinal brush‐border Na+/H+ exchanger NHE3 impairs iron absorption in the mouse (900.1)
Authors: Shawki Ali , Engevik Melinda , Kim Robert , Anthony Sarah , Knight Patrick , Baik Rusty , Worrell Roger , Shull Gary , Mackenzie Bryan
Published: June 2021

Divalent metal‐ion transporter‐1 (DMT1) is critical for intestinal iron absorption. DMT1 is energized by the H+ electrochemical potential gradient but the provenance of the H+ required to drive apical iron uptake is not known. To assess the role of the brush‐border acidic microclimate in aiding intestinal iron transport, we have examined iron homeostasis and intestinal iron handling in mouse models lacking the brush‐border Na+/H+ exchangers NHE2 and NHE3. We found that liver nonheme iron stores (a preferred indicator of chronic iron status) were modestly depleted in NHE2‐null mice compared with wildtype mice. In animals stressed on a low‐iron diet, hematological and blood‐iron variables were no different between NHE2‐null and wildtype mice and we observed no difference in the expression of genes associated with iron metabolism. Liver nonheme iron stores were severely depleted (by 70–90%) in NHE3‐null mice compared with wildtype mice. We observed substantial decreases in serum iron and transferrin saturation in NHE3‐null mice but no overt anemia. mRNA expression of DMT1, the brush‐border ferrireductase Cybrd1, and the basolateral iron‐exporter ferroportin were each increased >10‐fold in NHE3‐null mice, and expression of liver Hamp1 (hepcidin) suppressed by over 99%, compared with wildtype. Absorption of 59Fe (administered by intragastric gavage) was profoundly impaired in NHE3‐null mice but not NHE2‐null mice compared with wildtype. The low 59Fe content of enterocytes in the NHE3‐null revealed a deficit in brush‐border iron uptake. Our data indicate that ablation of NHE3 severely impairs iron absorption and homeostasis in the mouse and suggest that the acidic microclimate drives DMT1‐mediated iron uptake at the intestinal brush border.

Grant Funding Source: Supported by PHS Grant DK080047
Effect of calcium on amino acid and dipeptide transport by intestines of American lobster (Homarus americanus) and Atlantic white shrimp (Litopenaeus setiferus) (908.6)
Authors: Peterson Maria , Lane Amy , Ahearn Gregory
Published: June 2021

Previous work using L‐histidine and zinc in American lobster intestine has shown these solutes can be transported as bis‐complexes (Histidine‐Zinc‐Histidine) across the intestine using a peptide transporter. Furthermore, transport of L‐leucine has been shown to be inhibited by high calcium concentrations. Dipeptide and bis‐complex transport and the role of calcium were investigated in the perfused intestine of lobster and Atlantic white shrimp. Samples of serosal medium were analyzed for amino acid composition by gas chromatography. In lobster, the transport of glycylsarcosine (Gly‐Sar) from mucosal to serosal medium was measured for a range of pH values and either 0.5mM or 25mM calcium chloride. The rate of Gly‐Sar transport was stimulated two‐fold with pH 8.5 in the lumen. Reduced calcium chloride concentration stimulated Gly‐Sar transport two‐fold. In shrimp, the transport of L‐histidine from mucosal to serosal medium was measured. The addition of 50µM zinc chloride increased the rate of histidine transport, while Gly‐Sar inhibited transport. The rate of histidine transport was significantly higher with 1mM calcium chloride than with 25mM. These results indicate that shrimp transport bis‐complexes in a manner similar to lobster, which is inhibited by the presence of a competing dipeptide. High calcium concentration has an inhibitory effect on both amino acid and dipeptide transport.

Grant Funding Source: Supported by USDA Agricultural and Food Research Initiative Competitive Grant no. 2010‐65206‐20617
Programming effects of metformin exposure during gestation on offspring pancreatic β‐cell mass and glucose homeostasis (910.5)
Authors: Gregg Brigid , Alejandro Emilyn , Smith Michelle , Elghazi Lynda , El‐Gabri Deena , Cras‐Meneur Corentin , Bernal‐Mizrachi Ernesto
Published: June 2021

Background: Epidemiologic studies have linked abnormal maternal nutrition to increased offspring susceptibility to type 2 diabetes (T2D). The developing pancreas is extremely sensitive to metabolic stressors, and exposure to energy or nutrient imbalances during gestation impacts its development leading to long‐term changes in β‐cell mass and function (β‐cell programming). How nutrients affect developing β‐cells to induce long‐lasting consequences is unclear, but signaling pathways that convey information about energy and nutrient status are prime candidates. The AMP‐activated protein kinase (AMPK) is a nutrient sensor that it is indirectly activated by metformin, the most widely used oral agent for T2D.

Objective: To establish how metformin administration during pregnancy impacts β‐cell mass and susceptibility to diabetes later in life in a rodent model.

Methods: Metformin was delivered in drinking water to c57bl/6 mice from embryonic day 0.5 (E0.5) and continued throughout gestation (Met group). Animals were examined during embryonic stages, at birth and as adults.

Results: Pancreatic buds were examined at E14 by staining for markers of pancreatic and endocrine progenitor populations, Pancreatic and duodenal homeobox 1 (Pdx‐1) and neurogenin 3 (Ngn3) respectively. Met embryos had an increase in Ngn3 and Pdx‐1 number. The Met offspring did not differ from controls in terms of birth weight or length but had a lower random glucose. Met neonates were found to have increased β‐cell mass at birth when compared to controls. On examining offspring for adult metabolic phenotype, the Met animals displayed improved glucose tolerance and insulin secretion compared to controls.

Conclusions: In utero exposure to metformin may have a positive impact on regulation of endocrine cell development. Metformin is currently in clinical trials for use in gestational diabetes. Thus, careful characterization of the effect of in utero exposure to metformin on offspring metabolic phenotype is essential.

Grant Funding Source: Supported by DK‐084236‐03‐S1
Changes in diacron‐reactive oxygen metabolites and biological antioxidant potential in maternal serum during pregnancy (910.6)
Authors: Kawashiro Yukiko , Ishii Kuniko , Hosoyamada Yasue , Miyaso Hidenobu , Matsuno Yoshiharu , Kubonoya Kiyoshi , Mori Chisato , Hanazato Masamichi
Published: June 2021

The objective of this research is to identify changes in serum oxidative stress and antioxidant levels during normal pregnancy using the diacron‐reactive oxygen metabolites (d‐ROMs) test and biological antioxidant potential (BAP) test. This cross‐sectional study enrolled 126 pregnant women who attended a maternity clinic in Japan. Healthy, non‐pregnant women of reproductive age were recruited as controls. Serum d‐ROMs and BAP were measured within 72 hours using a Free Radical Elective Evaluator. Subjects were divided into five groups: 8‐13 w (n=15), 14‐27 w (n=42), 28‐32 w (n=31), 36‐37 w (n=38), and control (n=7). The pregnant women’s average d‐ROMs and BAP levels were 499.4 ± 99.0 U.CARR and 1977.1 ± 179.3 μmol/l, respectively. The d‐ROMs level in 36‐37 w group increased significantly compared with the control, 8‐13 w and 14‐27 w groups (p=0.000, p=0.009, p=0.006). The BAP level in the 36‐37 w group decreased significantly compared with all other groups (p=0.000). These results suggest that oxidative stress increases and antioxidant power decreases throughout the gestational period, and that the pro‐oxidant antioxidant balance is disturbed most at the end of gestation.

Grant Funding Source: KAKENHI（Grants‐in‐Aid for Scientific Research)
Maternal protein restriction during pregnancy alters vasodilator mechanisms in fetal placental arteries (910.9)
Authors: Sane Mukta , Lekatz Leslie , Shukla Praveen , Vonnahme Kimberly , O'Rourke Stephen
Published: June 2021

Maternal undernutrition during pregnancy reduces uterine blood flow. We hypothesized that reduced maternal protein intake during pregnancy alters vasodilator responses in placental arteries. Pregnant ewes were fed an isocaloric diet containing 100% (control) or 60% (protein‐restricted) of protein requirements from day 100‐130 of gestation (term= 145 d). Fetal placental arteries (FPA) were isolated on day 130. Sensitivity to bradykinin (BK)‐induced relaxation was increased 5‐fold in FPA from protein‐restricted ewes. In control FPA, BK‐induced relaxation was unaffected by indomethacin (Indo) but was inhibited by nitro‐l‐arginine (NLA). In FPA from protein‐restricted ewes, neither Indo nor NLA affected the response to BK. Sodium nitroprusside‐induced relaxation, phenylephrine (PE)‐induced contraction, and expression of eNOS, guanylyl cyclase (GC), and BK‐receptors, was similar in FPA from both dietary groups. In ewes fed a control diet, BK‐induced relaxation of FPA is mediated primarily by NO. In ewes fed a protein‐restricted diet, FPA are more sensitive than controls to BK‐induced relaxation and the mechanism is independent of NO and PGI2. The altered BK response is not due to changes in sensitivity to NO or PE, or to altered expression of eNOS, GC or BK receptors and may represent an adaptive mechanism to ensure adequate blood supply to the fetus during adverse maternal dietary conditions.

Grant Funding Source: Supported by NIH
Effects of prenatal food restriction on reproductive function in adult female rats (911.13)
Authors: Frazier Rebecca , Keen‐Rhinehart Erin
Published: June 2021

The percentage of adults born low birth weight (LBW) is increasing due to advances in neonatal medicine. Studies in a variety of model organisms indicate that LBW offspring have global perturbations several physiological systems, making it likely that LBW offspring have impaired reproductive physiology. Therefore, we hypothesized that prenatal food restriction that produces LBW offspring would cause female hypothalamic pituitary gonadal (HPG) axis dysfunction as evidenced by differences in hypothalamic gonadotropin releasing hormone (GnRH), estrous cyclicity and age at puberty and reproductive senescence. In this study, pregnant rats were fed ad libitum or 50% of their normal caloric intake from e10 to e21, all pups were cross‐fostered to control dams and litters were culled to 8 pups. Female offspring weight and size from birth through lactation, age at puberty, estrous cyclicity and PND1 hypothalamic GnRH protein expression via western blot. Restricted offspring exhibited LBW (5.6±0.08vs.6.5±0.06, p<0.05). LBW offspring had earlier onset puberty (33.5±0.2vs.38.2±0.2, p<0.01) and significantly longer estrous cycles by PND90 (6.1±0.4vs.4.7±0.3, p<0.05). Although all control offspring had normal estrous cycles at 8 months of age, 80% of restricted offspring had stopped cycling. In addition, hypothalamic GnRH protein expression was decreased at PND1 in LBW offspring (1±0.1vs.0.5±0.1, p<0.05), suggesting that HPG axis dysfunction is present at birth. These data indicate that prenatal food restriction impedes neuroendocrine development and shortens female reproductive lifespan. Further studies are needed to provide a more complete picture of the consequences of LBW for female reproductive physiology.
Study of stress induced failure of the blood‐gas barrier and the epithelial‐epithelial cells connections of the lung of the domestic fowl, Gallus gallus variant domesticus after vascular perfusion (913.9)
Authors: Maina John , Jimoh Sikiru
Published: June 2021

Complete blood‐gas barrier breaks (BGBBs) and epithelial‐epithelial cells connections breaks (E‐ECCBs) were counted in the lungs of free range chickens, Gallus gallus variant domesticus after vascular perfusion at different pressures. The E‐ECCBs exceeded the BGBBs by a factor of ~2. This showed that the former parts of the gas exchange tissue were structurally weaker or more susceptible to failure than the later. The differences in the numbers of BGBBs and E‐ECCBs in the different parts of the lung supplied with blood by the four main branches of the pulmonary artery (PA) corresponded with the diameters of the branches, the angles at which they branched from the PA, and the positions along the PA where they branched. Most of the BGBBs and the E‐ECCBs occurred in the regions supplied by the accessory‐ and the caudomedial branches: the former is the narrowest branch and the first blood vessel to separate from the PA while the latter is the most direct extension of the PA and is the widest. The E‐ECCBs appeared to separate and then fail from tension in the blood capillary walls as the perfusion‐ and the intramural pressures increased. Compared to the mammalian lungs on which data are available, i.e., those of the rabbit, the dog, and the horse, the BGB of the lung of free range chickens is substantially stronger for its thinness.

Grant Funding Source: Supported by The national Research Foundation of South Africa
Variant leg muscles involved with tarsal tunnel syndrome: cadaveric case studies (915.11)
Authors: Lambert H Wayne , Kennedy Patrick , Whipp Kylen , Anderson Zachary , Clarkson Mackenzie , Fox Jacob
Published: June 2021

Tarsal tunnel syndrome, or posterior tibial neuralgia, is diagnosed when the tibial nerve is compressed as it travels within the tarsal tunnel. Two variant leg muscles, flexor digitorum accessorius longus (FDAL) and peroneocalcaneus internus (PCI), have gained recent attention in the clinical literature for their involvement in this compressive entrapment neuropathy. Both of these muscles course within the tarsal tunnel and, when present, may act as space‐occupying lesions, leading to numbness, paresthesia, and pain in the foot. However, low prevalence of these two muscles and discrepancies within the literature have led to confusion distinguishing between these variants muscles. During 317 leg dissections, examples of the FDAL and PCI muscles were identified and ways to differentiate between the two muscles were determined based upon origin, course, location within the tarsal tunnel, and insertion of the muscle. The results of this study also led to the first gross anatomical photograph of the rare peroneocalcaneus internus muscle. Radiologists and clinicians should be aware of these muscles when embarking in diagnosis and imaging interpretation, especially when tarsal tunnel syndrome is within the differential diagnoses.
The cranial morphology of large captive versus wild felids (918.11)
Authors: Hartstone‐Rose Adam , Selvey Hannah , Boyde Bryttin , Villari Joseph
Published: June 2021

Most captive members of the genus Panthera are fed a nutritionally supplemented diet consisting almost entirely of ground meat. While the Association of Zoos and Aquariums discusses (but comes short of recommending) the supplementation of this diet with more complete carcass elements, the fact remains that large captive felids are fed diets that require substantially less masticatory effort than those of their wild counterparts. The osteological effects of this dietary difference have not been fully evaluated. We compared 3D geometric morphometric landmarks on a population of captive and wild lions and tigers. Though the first principal component (21.3% of the variation) separates the two species, the second principal component is driven not by the sex differences in these highly dimorphic species, but rather by their captivity status. In fact, captivity status drives nearly twice as much of the morphological variation as sexual dimorphism (15.6% vs. 8.0% for PC1 vs. PC2). If a causal relationship can be seen between mechanical diet and morphology, curators and nutritionists who oversee the diets of captive carnivores should consider modifying these diets to account for not only nutritional but also mechanical value as well.
The effect of AFO stiffness on the knee joint during the heel strike phase of gait in stroke patients (919.12)
Authors: Singer Madeline , Kobayahi Toshiki , Lincoln Lucas , Orendurff Michael , Foreman K. Bo
Published: June 2021

Stroke patients suffering from foot drop are often prescribed ankle‐foot orthoses (AFOs) to improve foot clearance during gait. However, excessive restriction of plantarflexion (PF) during the heel strike phase of gait has been shown to cause biomechanical changes at the knee joint. This pilot study aimed to determine how increasing the PF stiffness of an AFO affects knee joint kinematics and kinetics during heel strike in hemiplegic stroke patients with varying levels of active ankle range of motion. We hypothesized that increased PF resistance would cause an increase in anterior tibial rotation at heel strike with resulting increases in knee flexion angle and knee extension moment. To test this hypothesis, 5 stroke patients with foot drop were clinically evaluated, instrumented with reflective markers, and fitted with a spring modified AFO (Orthocare Innovations). A compression spring in the posterior aspect of the AFO was changed to increase the external dorsiflexion torque from 0.3 Nm/deg (Spring 1) to 2.0 Nm/deg (Spring 2). Kinematic and kinetic data were collected during walking on an instrumented treadmill (Bertec) in a motion analysis lab. Five steps with each spring were examined. Two patients exhibited an increase in knee flexion angle and knee extension moment with the stiffer spring. Clinical findings revealed that these 2 patients had minimal active PF while the other 3 patients had full active PF. From these initial results, we cautiously conclude that stroke patients with decreased active PF cannot overcome excessive PF resistance during the heel strike phase of gait, and as a result exhibit compensation strategies at the knee joint. These results will be used to create a more objective method for the prescription of AFOs in hopes to improve the long‐term quality of life for stroke patients.

Grant Funding Source: Supported by National Institutes of Health (2R44HD069095‐02)
Application of ischium‐pubis index for sex determination using ihree‐dimensional models (919.13)
Authors: Kim Dong‐Ho , Jung Go‐Un , Kim Yi‐Suk , Lee U‐Young
Published: June 2021

For sex estimation with the pelvis, ischium‐pubis index is commonly chosen along the greater sciatic notch. This index is the percentage value of the pubic length divided by the ischium length and known that female has greater value than male. The pubic length is a distance from the upper edge of the pubic symphysis to the acetabulum, and the ischium length is the distance from the most distinct point on the ischial tuberosity to the acetabulum. The point in the acetabulum is customarily marked on the point where the three parts of the pubic bone meet, however, due to irregular shape of the acetabulum; there is possibility to be marked differently due to observer. Thus, we studied a landmark which is more objectively to be marked and ischium‐pubis index applicable to Korean population. We studied 103 sides (52 female and 51 male) of the Digital Korean Database stored in the Catholic Institute for Applied Anatomy. Landmarks chosen near the acetabulum to measure the pubis length and ischium length were those: the point where the pubis, the ilium and the ischium meet, the deepest point of the acetabulum, and a point on the acetabular border. Mimics (ver. 15, Materialise, Belgium) was used to enable three‐dimensional measurement by a template programmed for this study. There were nine measurement items related to the distance and angle between each point. Discriminant analysis for sex determination was done by SPSS (ver. 20.0, IBM, USA). The method using the deepest point of the acetabulum showed the highest accuracy of sex estimation compared to the traditional method using the contacting point of the three innomiates and another method of upper border of the acetabulum. Therefore, we suggest through this study that utilising the deepest point of the acetabulum is suitable for calculating the ischium‐pubis index. For this study, mean the ischium‐pubis index of male was 98 and of female was 114, and the demarking point of both sexes was 106.

Grant Funding Source: Supported by Basic Science Research Program through the National Research Foundation of Korea (NRF)
Bone regeneration is not affected by medullary canal size in four different mouse strains after marrow ablation (922.16)
Authors: Moran Meghan , Virdi Amarjit , Sena Kotaro , McNulty Margaret , Sumner D.
Published: June 2021

It is well established that mouse strains exhibit different bone phenotypes, however, there is limited data on intramembranous bone regeneration post‐injury challenge in different mouse strains. Here, we determined if intramembranous bone regeneration differed in four wild‐type inbred mouse strains in response to marrow ablation and if bone geometry (medullary canal size) impacted the bone regeneration response. Mechanical femur ablation was performed in 27‐33 week old females of four mouse strains (FVB/N, C3H/He, C57Bl/6, BALB/C). Animals were euthanized 3 weeks post‐ablation; all bone within the medullary canal of the ablated and intact femurs as well as medullary area at the midshaft of the intact femur was analyzed by µCT. In ablated femurs, mean BV/TV showed clear quantitative differences among the four strains (p = 0.002, 1‐way ANOVA). FVB/N (p = 0.007) and C3H/He (p = 0.002) mice had approximately a 4‐fold increase in BV/TV compared to BALB/C mice. Medullary area varied among the four strains (p < 0.001, 1‐way ANOVA). The BV/TV of the regenerated bone was not correlated with the size of the medullary canal. Our results suggest that genetic differences among mouse strains contribute to the bone regeneration response independent of bone geometry. We identified relatively good (FVB/N and C3H) and poor (BALB/C) bone regeneration mouse strains. This differential bone regenerative response to injury was not affected by bone geometry, specifically medullary canal size.
Crystal structure of Homo sapiens neuroblastoma, suppression of tumorigenicity 1 from DAN (differential screening‐selected gene aberrative in neuroblastoma) gene (933.3)
Authors: Wang Guan
Published: June 2021

There are over thirty‐three ligands in transforming growth factor‐β (TGF‐β) family, among of which the bone morphogenetic protein (BMP) class is the largest one. BMP ligands could be inhibited by some extracellular antagonists, such as noggin, follistatin and members of the DAN (differential screening selected gene abberative in neuroblastoma) family. Other than BMP antagonists’ numerous developmental functions like germ layer specification and temporospatial gradients, elevated levels of one BMP antagonist gremlin has been tested to associated with pulmonary fibrosis and diabetic nephropathy. Besides, certain tumors block the anti‐proliferative functions by increasing levels of BMP antagonists. Strong evidents have been establised that BMP antagonists are highly related with some tumors which leads to an attemp to utilize extracellular BMP antagonists as tumor suppressors.

Dan gene is highly conserved among various eukaryotic species. Usually, Dan family proteins are small, single‐domain, glycoproteins consisting of at least five mammalian proteins which are DAN (Human differential screening‐selected gene aberrative in neuroblastoma), Gremlin/DRM, Cer1 (Cerberus‐related), Dante and PRDC (protein related to DAN and cereberus). Basically, the whole structure includes an NH2‐terminal hydrophobic signal sequence, two potential casein kinase II target sites, COOH‐terminal (HX) repeats and a core cysteine knot region (DAN domain) which is thought to be the common feature. The knot structure is observed to have a conserved 8‐residue circle due to a pair of disulfide bonds that connect two antiparallel β‐sheets. And experimental evidents have shown that DAN domain is essential for binding to BMP ligands.

In our study, we crystallized NBL1 (Homo Sapiens Neuroblastoma, Suppression Of Tumorigenicity 1) which is another member in DAN family, still working on the X‐ray diffraction data collection currently and will solve this protein structure in the future.
Double gene knockdown leads to X‐chromosome reactivation (939.7)
Authors: Thomas Stacy , Sripathy Smitha , Leko Vid , Foss Eric , Lao Uyen , Bedalov Antonio
Published: June 2021

Rett Syndrome is a X‐linked brain disorder caused by a mutation in one copy of the MeCP2 gene. This gene is only expressed in some cells due to X‐chromosome silencing, a phenomenon that occurs in all cells with two X chromosomes. After four cell divisions, each cell of the embryo randomly inactivates one X‐chromosome (Xi) and the other (Xa) provides the X‐linked genetic code for the cell. This choice is propagated through subsequent cell divisions. The exact mechanism of the initiation and maintenance of X‐chromosome silencing is unknown, but some factors are known. Xist RNA coats Xi, acting as a signal to initiate and maintain X‐silencing. DNA methylation at CpG islands makes the chromatin less available and hypoacteylated histones alter the chromatin packaging to maintain X‐silencing. We hypothesize that a future treatment option for Rett Syndrome will be to use Small hairpin RNAs (shRNAs) to knockdown genes fundamental to X‐chromosome silencing to reactivate Xi and cause more cells to produce functional. shRNAs can reduce the expression of a gene by imposing post‐transcriptional control on mRNAs, with which they complementary base‐pair. A shRNA library screen using (Xa)MeCP2/(Xi)MeCP2‐Luciferase‐Hygromycin Resistance mouse tail fibroblasts generated 82 possible genes involved with X‐silencing. In order to validate these screens, the knockdown efficiency of genes has been tested using qPCR and was used to measure the amount of X‐reactivation. Reducing the expression of Acvr1 and dnmt1 in cells results in some X‐reactivation. In combination with a dnmt1 knockdown, a Xist knockdown increases the frequency of reactivation.

Grant Funding Source: This research is supported in part by the Cancer Center Support Grant (CCSG) CURE Supplement: NCI 5
Poly(A)‐dependent transcription termination does not require poly(A) site cleavage (947.1)
Authors: Zhang Huimin , Martinson Harold
Published: June 2021

Termination of transcription by RNA polymerase II, for genes encoding polyadenylated mRNA, requires a functional poly(A) signal in the nascent RNA. Since the poly(A) signal is best known for 3'‐end processing of RNA by cleavage and polyadenylation, it was assumed early on that the requirement of a poly(A) signal for termination reflects a need to cleave the transcript at the poly(A) site. Cleavage was proposed to provide entry for a 5’ to 3’ exonuclease that would be targeted to the elongating polymerase by degrading the nascent transcript. Subsequent discovery of the exonuclease Rat1/Xrn2, and the finding that it did indeed participate in PDT, led to almost universal acceptance of this view, which was dubbed the torpedo model. However, a number of results over the years have raised doubts about the torpedo model by suggesting that PDT can occur without cleavage at the poly(A) site‐‐‐an absolute requirement of the torpedo model. We undertook to examine definitively the validity of the torpedo model. To this end we developed an assay in which PDT and pre‐mRNA 3’‐end cleavage activities can be measured simultaneously in Hela nuclear extract. Using this assay, we have established unequivocally that cleavage at the poly(A) site is not a prerequisite for PDT. Therefore, the torpedo model cannot be correct. Moreover, we showed that PDT can be inhibited by α‐amanitin, which binds to the trigger loop in the active site of RNA polymerase II. Other methods of stopping transcription do not interfere with PDT, suggesting that it is not simply the inhibition of transcription, but an effect of α‐amanitin on the conformation of the polymerase active site that blocks PDT. Thus, neither cleavage at the poly(A) site nor degradation of the 3’ flanking RNA are required for PDT. Rather, a conformational change within the polymerase is required, presumably triggered by the apparatus that assembles on the poly(A) signal.

Grant Funding Source: Supported by the UC CRCC, the UCLA Jonsson Cancer Center Foundation and the UCLA Academic Senate.
Assessing the dual orientations of vaccine candidate P6 in nontypable Haemophilus influenzae (948.5)
Authors: Barnard David , Bettinger John , Shaw Juliana , Pichichero Michael , Michel Lea
Published: June 2021

Nontypable Haemophilus influenzae (NTHi) is a pathogenic bacterium that is known to cause otitis media and other respiratory diseases, mostly in children and older adults. P6, a protein vaccine candidate for protection against NTHi infection, has recently been shown to be inserted into the outer membrane of NTHi in two orientations; one being surface exposed and the other oriented facing in toward the peptidoglycan layer. For P6 to be considered a good vaccine candidate, it must be surface exposed and conserved in the majority of NTHi strains. Using confocal microscopy, flow cytometry, and a biotinylation technique, we have determined the common orientation of P6 in multiple strains of NTHi. Results suggest that a minority of the total P6 population is surface exposed. Implications for P6’s vaccine candidacy are discussed.

Grant Funding Source: This study was supported by NIH NIDCD RO1 08671 (to MEP) and the Rochester Institute of Technology.
Anti‐inflammatory compounds from Cordyceps bassiana (973.3)
Authors: Kim Tae‐Woong , Yoon Deok‐Hyo , Cho Jae‐Youl , Sung Gi‐Ho
Published: June 2021

Cordyceps bassiana has long been used as an oriental medicine. Anti‐inflammatory effects of Cordyceps bassiana, were investigated. Cordyceps bassiana was extracted with ethanol and then further fractionated with n‐hexane, ethyl acetate, n‐butanol and water. Butanol fraction from Cordyceps bassiana (CBBF) showed the best effective in anti‐inflammation activity in RAW 264.7 macrophages among extracts from Cordyceps bassiana. We tested the role of CBBF on the anti‐inflammation cascade in LPS‐stimulated RAW 264.7 cells. To investigate the mechanism by which CBBF inhibits NO, iNOS and COX‐2, we examined the activation of IκB and MAPKs in LPS‐activated macrophage. Also, CBBF suppressed activation of MAPKs including p38 and SAPK/JNK. Furthermore macrophages were stimulated with generation of reactive oxygen species (ROS) via the activation of a membrane‐bound NADPH oxidase, and ROS plays an important role in NF‐κB and MAPKs activation. It is showed that CBBF blocked the intracellular accumulation of reactive oxygen species in RAW 264.7 cells stimulated with LPS as both NADPH oxidase inhibitor. The suppression of NADPH oxidase also inhibited NO production and iNOS protein expression. From the results, we demonstrate that CBBF suppresses the production of these mediators in LPS‐activated macrophages through the inhibition of IκB/NF‐κB pathway, JNK and p38 activation, which may play an important role in inflammatory disorders and, LPS‐induced ROS generation was inhibited by CBBF. Also, anti‐inflammatory compounds, 4‐quinolinol and 1‐naphthol were found from Cordyceps bassiana, and their anti‐inflammatory activities were compared. Therefore, Cordyceps bassiana can be used as a useful medicinal food or drug. Supported by a grant from RDA(No. PJ009241), Korea.
An investigation of novel AMPs (976.6)
Authors: Greenberger Virginia , Stevens‐Truss Regina
Published: June 2021

Antibiotic resistance continues to pose a threat to the human race as bacteria become more and more resistant to antibiotics. New multi‐drug resistant (MDR) strains of tuberculosis, methicillin‐resistant staphylococcus aureus (MRSA), and vancomycin resistant enterococci (VRE), amongst other bacteria, are causing expensive, painful and deadly diseases (Nikaido 2009). A need for new antibiotics to treat these infections has fueled scientists to revisit studying antimicrobial peptides (AMPs). These AMPs, which are derived from a wide variety of natural sources, are categorized by their shape. In this project we investigated the ability of a series of cationic, amphipathic , α‐helical peptides derived from sequences within nitric oxide synthases (NOS) to inhibit growth of E. coli and S. aureus. Cell growth in the presence and absence of peptide was monitored as a change in optical density (OD) of a culture at 600 nm. Assays to determine the minimum inhibitory concentrations (MIC) were also conducted, and the peptides’ ability to rupture cell membranes were assessed by measuring the rise in fluorescence of a solution containing dye encased liposomes. The result show that the peptide derived from the inducible NOS was not effective against either bacteria at the concentrations tested, nor did it cause leakage of dye from liposomes, while the peptide derived from the neuronal NOS was bacteriocidal to both E. coli and S. aureus, but also did not cause liposome leakage. These results are encouraging as potential starting points in the search for new antibacterial agents.

Grant Funding Source: Supported by a grant from the GLCA NDI.
Genesis of antibiotic resistance IV: limited control measures in eradication of vector borne and zoonotic diseases in southwestern border regions of United States and Mexico (986.4)
Authors: Kannan Subburaj , Salinas Monica , Trevino Edith , Martinez Karenny , Iracheta Alyssa , Subburaj Prabavathy
Published: June 2021

The USDA‐APHIS sponsored US Fever Tick Eradication Program essentially employs tick riders to look for animals that are infested with ticks and employ quarantine. Methods to control infected animals as an effective tick control strategy; the tick infested animal is subjected to “Dirty Dipping” for a 14 day interval followed by “Clean Dipping”. With appropriate medical evaluations the tick free animal is released to the “Owner” on to its normal environment. The main concern with these methods is that pre‐existing bacterial pathogens in tick infested animals, such as Borrelia burgdorferi, (Lyme borreliosis) Francisella tularensis, Bartonella spp., Rickettsioses, and Anaplasma phagocytophilum. Become resistant to treatments. If these pathogens have acquired antibacterial resistance, subsequent infections in animals or humans via vector borne contamination or by Zoonosis will be more difficult to cure. Through the efforts of the Vector Control Department of The City Administration and County agents sponsored by the Texas Agricultural and Mechanical University, in College Station, the incidence of such bacterial infections are monitored and reported immediately to the City, County, State and Federal authorities; however the existing chemical means to eradicate these bacterial pathogens has become inept. Developing new pesticides specifically aimed at controlling disease vectors, without bioaccumulation and no effect on non‐target organisms with a high virulence and low susceptibility to resistance, would be beneficial in controlling the AR pathogen induced infectious diseases.

Grant Funding Source: Professional Development Funds ‐ SWTJC, Eagle Pass, Texas