bluuebunny/crossref_metadata_2025 huggingface dataset:
Diet‐induced alterations in lysine catabolism in pig liver
Authors: Gatrell Stephanie K. , Berg Levi E , Grimmett Juanita G , Wilmoth Tiffany A , Moritz Joseph S , Blemings Kenneth P
Published: June 2021

The objective was to investigate diet‐induced alterations in hepatic lysine catabolism via the saccharopine‐dependent pathway in pigs. This pathway depends on the bifunctional α‐aminoadipate δ‐semialdehyde synthase (AASS), which contains both lysine α‐ketoglutarate reductase (LKR) and saccharopine dehydrogenase (SDH) activities. In liver, LKR and SDH are restricted to the mitochondrial matrix and lysine is presumably transported through the inner membrane by one or both isoforms of ornithine transporters (ORC‐1/2). Weanling pigs (7 litters, 5/litter) were fed either a control (C, 18% CP, 0.95% lys), high protein (HP, 23% CP, 0.95% lys), low protein (LP, 13% CP, 0.95% lys), high lysine (HL, 18% CP, 1.25% lys) or low lysine (LL, 18% CP, 0.65% lys) diet for 10 days. No differences in weight gain or feed intake were detected. LKR (P<0.05) and SDH (P<0.05) activities and AASS protein abundance (P<0.01) were reduced 30, 35 and 52% respectively, in pigs consuming the LL diet relative to C. ORC‐1 mRNA expression increased (170%, P<0.05) with consumption of the HL diet and decreased (50%) with consumption of the LL diet; ORC‐2 mRNA expression was not affected by dietary treatment, although it tended to be higher (88%) in the HL and lower (76%) in the LL fed pigs relative to C. These data are consistent with ORC1/2 delivering lysine to the matrix and marks them as potential regulators of lysine catabolism (Support; HATCH WVA 470).
Effects of lead exposure and iron deficiency on the iron transporter expressions in rat brain
Authors: Koo Kyeon-ok , Oh Su Gyoung , Lee Mi-hyang , Chung Jayong
Published: June 2021

Both chronic Pb exposure and Fe deficiency (FeD) are known to impair learning ability in children and young animals. The aim of this study was to examine the effects of FeD and Pb on the levels of Fe and Pb and the expressions of iron transporters in the brain tissues of young rats. SD rats (3‐wk‐old) were fed either a control (36 ppm Fe) or FeD (<6 ppm Fe) diet with or without 0.25% Pb acetate in drinking water for 4 wk. Tissue Fe and Pb levels were determined by ICP‐AES or ICP‐MS. The mRNA levels of iron transporters (Fpn1 and DMT1) and N‐methyl‐D‐aspartate receptors (NMDAR) were measured by real‐time PCR analyses. FeD significantly decreased Fe levels in the liver and cortex, but not in hippocampus and striatum. Pb exposure significantly increased Pb levels in all sub‐regions of brains, as well as in the liver. FeD significantly decreased hepatic Fpn1 mRNA, but didn't change mRNA levels of either Fpn1 or DMT1 in the brain. On the other hand, Pb exposure significantly decreased both Fpn1 and DMT1 mRNAs in the brain. Further, Pb exposure significantly decreased NMDAR 1, 2A and 2B mRNAs in rat hippocampus, but FeD blocked the Pb‐induced decrease NMDAR 1, 2A and 2B mRNAs in rat hippocampus. NMDARs in hippocampus play an important role in learning. Our results suggest that Pb exposure affects iron transporter expressions in brain, and FeD may attenuate Pbinduced neurotoxicity in rats. (This work was supported by the NRF of Korea, 2011‐0004932).
Analysis of Se contents in Korean representative cereals and vegetables
Authors: Lee Okhee , Yu Jaeran , Moon Jongwha , Chung Yongsam
Published: June 2021

There are little reports on the Se nutritional status of Korean because of the deficient Se database on foods. The measurement of Se content is difficult compared to other micro‐minerals, because it is volatile and lost by heating during prereatment. This study was aimed to measure Se contents in vegetable foods by INAA using freeze‐drying method as pretreatment. The Korean representative cereal and vegetables were selected. To minimize contaminations, all the instruments and storage tools were used after washing with HNO3. The homogenized food samples of 10~20g were freeze‐dried at the temperature of 60C for 48~96 h. Subsequently, INAA‐method was employed to determine the contents of Se in the freeze‐dried food samples. Analytical quality control was conducted using NIST SRMs. The analysis limit of Se in foods by INAA was 0.01ppm. The LODs were different between cereal and vegetables, being in the range of 0.002~0.149. Se contents could not be detected in some cereal and vegetables. The Se contents in the detectable cereals ranged from 0.21 to 10.42ug in 100g cereals and were various by cereal type. The Se contents in vegetables were various and in the range of 0.56~18.35ug in 100g food. This result would be useful for establishment of food Se database and useful in assessment of Korean Se intake status
Chia seed extract does not affect zebrafish angiogenesis
Authors: Meaney Mary Pat , Nieman David C. , Leung TinChung , Cialdella-Kam Lynn , Jin Fuxia
Published: June 2021

Data suggest that consumption of omega‐3 fatty acids and phenolic acids can protect against cancer. Chia seeds, which contain high concentrations of alpha‐linolenic acid (ALA), an omega‐3 fatty acid, and protocatechuic acid (PCA), a phenolic acid, have a reported protective effect against cancer. However, whether chia seed extract inhibits tumor angiogenesis is presently unclear. The purpose of this study was to determine whether treatment with select fractions of milled chia seed extract (Mila ®, LifeMax: Orlando, FL) affects angiogenesis in zebrafish embryos. TG(flk1:GFP) transgenic zebrafish (Danio rerio) embryos were incubated in solutions containing an ALA‐rich fraction of chia seed extract, a PCA‐rich fraction of chia seed extract, pure ALA, or pure PCA. Alkaline phosphatase staining was used to determine the effects of these treatments on angiogenesis. None of the experimental treatments affected angiogenesis in zebrafish embryos. While fractions of chia seed extract used in this study did not prevent tumor angiogenesis, they may protect against cancer by some other mechanism. Funded by: LifeMax ® Inc. and Chia Farms, Inc.
Effects of Dehydroepiandrosterone (DHEA) treatment on Liver Steatosis using DMBA‐Induced Mammary Tumor Obese Zucker Rat Model
Authors: Hakkak Reza , Korourian Soheila
Published: June 2021

Obesity has been epidemic in the US for over two decades. Obesity has been linked with the risk of development of various cancers, including breast cancer. Dehydroepiandrosterone (DHEA) is an over‐the‐counter dietary supplement used as an anti‐cancer agent and anti‐obesity supplement. The objectives of this study were to investigate the long‐term effects of obesity and DHEA treatment on body weight gain and liver steatosis using 7,12‐dimethylbenz(a)anthracene (DMBA)‐induced mammary tumor model. Forty‐three six‐week‐old obese female Zucker rats were used. Rats were randomly assigned and had ad libitum access to water and a diet of either chow (2016) as a control diet or chow with the addition of DHEA at a concentration of 6 g/kg of chow as a DHEA diet. All rats were orally gavaged at age 50 days with 65 mg DMBA/kg body weight and were sacrificed 155 days post‐DMBA treatment. Obese rats fed the DHEA diet gained significantly less weight (P<0.001) and less liver steatosis (P<0.001) than control fed rats. Fifty‐five percent (55%) of the control diet group developed mammary tumors, while no tumors were detected in the DHEA diet group (P<0.001). Our results suggest that DHEA treatment can reduce body weight gain and protects against liver steatosis caused by obesity. These data suggest that there might be a link between liver damage and breast cancer development. Supported by ABI to RH.
The role of folate status and methylenetetrahydrofolate reductase gene C677T polymorphism in sonic hedgehog signal and its altered methylation pattern in human colorectal carcinoma
Authors: Feng Hsin Chun , Kuo Chang-Sheng , Tian Yu-Feng , Sun Ding-Ping , Li Chien-Feng , Huang Rwei-Fen S.
Published: June 2021

Aberrant activation of the hedgehog (Hh) signaling pathway plays a critical role in human colorectal carcinomas (CRC) with unclear mechanisms. The objectives of the study was to determine the expression of sonic hedgehog (Shh), Gli effector and hedgehog interacting protein (HIP), the altered methylation of the promoter regions, tissue folate status as well as the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in a total of 70 CRC tissues and the counter‐paired non‐cancerous tissues. The methylation status of Shh and HIP was determined by methylation‐specific PCR by bisulfate treatment of DNA from tissues followed by amplification using specific designed primer pairs. Among the detectable CRC (38 pairs), 63% and 44.7% of CRC tissues had increased expressions of Shh and Gli transcripts, whereas 60.5% exhibited reduced the HIP expressions (P < 0.05) as compared with the counterpart paired non‐cancerous tissues. Compared with the MTHFR 677 CT/TT variants, CRC with 677CC genotype compared appears to be associated with increased Shh expression and reduced HIP expressions, yet without reaching a statistical significance. Folate status did not differ among the C677T variants or among the cancerous vs noncancerous tissues. For several CRC tissues, altered methylation of Shh and HIP promoter region corresponds with their gene expression pattern. Taken together, CRC has increased expressions of Shh signaling molecules, which may be differentially related to their promoter methylation pattern and MTHFR 677CT genotype.

Grant Funding Source: national science council
Sorghum extract increases the biliary secretion of cholesterol in rats
Authors: Kim Juyeon , Noh Sang K. , Seo Myung Chul , Woo Guan Sik
Published: June 2021

Recently, we have shown that sorghum extract lowers significantly the lymphatic absorption of cholesterol and fats in rats. This study was conducted to examine if sorghum extract would affect the biliary secretion of cholesterol in rats. Initially, female rats were fed an AIN‐93G diet with or without sorghum extract at 0.5%. At 3 wk, each rat with bile duct cannula was infused continuously at 3.0 mL/h for 8 h via an intraduodenal catheter with a lipid emulsion containing 20.7 μmol cholesterol, 452 μmol triolein, and 3.1 μmol α‐tocopherol, and 396.0 μmol Na‐taurocholate with or without sorghum extract (control) in PBS buffer (pH, 6.4). Simultaneously, bile was collected hourly via the bile cannula for 8 h. Sorghum extract significantly increased the hourly rate of bile flow for 8 h (0.75 ± 0.05 mL/h vs. 0.91 ± 0.08 mL/h). The biliary secretion of cholesterol for 8 h was also significantly increased in rats given sorghum extract, compared with controls (3.01 ± 0.33 μmol vs. 3.73 ± 0.21 μmol). The results indicate that sorghum extract has a stimulatory effect on the biliary secretion of cholesterol in rats. The mechanism(s) by which sorghum extract enhances the biliary secretion of cholesterol remains to be investigated. Supported by the Korea Rural Development Administration (PJ007513).
EFFECTS OF SELECT HUMAN MICROBES ON CITROBACTER RODENTIUM INFECTION IN MICE
Authors: mitmesser susan hazels , Russell William Michael , O'Mahny David , MacSharry John , Lyons Anne , Ceddia Michael , O'Mahony Liam
Published: June 2021

Background

A balanced microbiota is important in preventing intestinal disorders and microbial infections.

Objective

To evaluate the effects of feeding Bifidobacterium longum AH1206, Bifidobacterium breve AH1205, and Lactobacillus salivarius AH102, all of human origin, on Citrobacter rodentium infected mice.

Methods

C. rodentium infected mice (N=8/group) were fed B. longum AH1206, B. breve AH1205, L. salivarius AH102, or placebo for 15 days. A clinical score was determined (based on stool, anus, fur texture and color, posture, and activity) and weight measured daily. On day 15, animals were sacrificed and tissues were harvested and measured. The expression of host protective genes (IL6, IL10, CCL2, IL12p70, IFNy) was assessed by cytometric bead array (CBA). Mann‐Whitney t‐test was used to determine statistical differences, p≤0.05.

Results

There was no significant difference among treatment groups in clinical score. AH1205 had significantly higher weight gain (p=0.012) and colon length (p<0.05) than placebo. AH1206 had significantly increased colon weight (p<0.05) and significantly decreased caecum weight (p<0.05) compared to placebo. There was a significantly higher level of CCL2 in AH1202 compared to placebo (p=0.027), but no differences were observed in any of the other cytokines measured.

Conclusion

Overall, the human microbes only had a modest effect on C. rodentium infection in mice, however strain‐related differences could be seen in important physiological markers of health.
Development of Functional Korean Traditional Pancake(Jeon) for the Global Marketing
Authors: jung ji-hye , yang jinyoung , park junghyun , shin junghee , kim hyunsook
Published: June 2021

Korean traditional pancake, a popular traditional food, is often consumed as a side dish in Korea. However, it is very greasy and contains a lot of oil, sodium so not ideal for modern people. We tried to develop functional Korean traditional pancake low in calorie, with a good taste for the world. Black soybean was cultivated at Jeollanam‐do in autumn season and blueberry was cultivated at Chungcheong‐do in summer season. The Korean traditional pancake was made with black soybean or blueberry(BSBP 1~16, BBP 1~30). To develop the tasty Korean traditional pancake, evaluation of physical properties, sensory test(color, flavor, moistness, tenderness, mouth feel, and overall acceptability) and to confirm the functionality, clinical demonstration were conducted. The weight, volume, and hardness of the developed pancake changed. The springiness, cohesiveness were increased in BSBP 16 and the chewiness, gumminess were increased in BBP 30. From the result of sensory test, the taste of BSBP 16 and BBP 30 received high grade. After consuming developed pancake, the serum isoflavone and anthocyanin contents were measured, it was increased in a dose dependent manner.

Grant Funding Source: Korean Food Foundation
Association of vitamin D levels to blood pressure among blacks and whites
Authors: Sakamoto Rose O , Tonstad Serena , Jaceldo-Siegl Karen , Haddad Ella , Oda Keiji , Fraser Gary
Published: June 2021

Cardiovascular risk factors such as hypertension remain a huge health burden and Blacks have been recognized to have higher prevalence of hypertension compared to non‐Hispanic Whites. The relationship of vitamin D [25(OH)D] to blood pressure among biethnic cohort remains unclear. Utilized cross‐sectional design based on data of the calibration sub‐study of the Adventist Health Study −2 (AHS‐2) cohort: 284 Whites and 284 Blacks. Participants attended clinics during which anthropometric and blood pressure were measured, food‐frequency questionnaires completed and fasting blood samples were obtained in 2003–2007. Multiple regression analyses were used to assess independent relationships between blood pressure and 25(OH)D levels. After control for age, gender, BMI, and use of BP‐lowering medications, levels of 25(OH)D were inversely associated with systolic BP in Whites (β‐coefficient −0.23 [95% CI, −0.43, −0.03; p = .02]). This relationship was not seen in Blacks (β‐coefficient 0.08 [95% CI, −0.14, 0.30; p = .4]). Results were similar when controlling for waist circumference or percentage body fat instead of BMI. No relationship between serum 25(OH)D and diastolic BP noted. Systolic BP is inversely associated with 25(OH)D levels in Whites but not in Blacks. Vitamin D may not be a major contributor to the White‐Black differential in BP. Research supported by the Glen Blix Foundation and AHS‐2 Seed Grant.
Overweight in early HIV predicts slower disease progression in HIV+ Adults in Botswana
Authors: Martinez Sabrina Sales , Campa Adriana , Makhema Joseph , Burns Patricia , Farahani Mansour , Bussmann Hermann , Dusara Priti , Essex Max , Marlink Richard , Baum Marianna K
Published: June 2021

Objective

To determine the predictive value of higher BMI on HIV disease progression in asymptomatic, ART naïve HIV+ adults.

Methods

After consenting 218 participants, blood was drawn for measures of HIV disease progression (CD4 cell count, CD4 cell % and HIV viral load) at baseline and every 6 months for 24 months. Height, and weight were obtained and BMI calculated. BMI was categorized as underweight (<18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2), and obese (>30 kg/m2).

Results

The mean age was 34.21±8.33 years, 76.04% were female and the mean CD4 cell count was 468.26±161.21 cells/μL. The mean BMI was 24.07±4.64 kg/m2. The prevalence of overweight and obesity was 26.42% (N=56) and 9.91% (N=21), respectively, similar to that in the general population of Botswana. Using mixed models, higher levels of BMI were predictive of higher levels of CD4 cell % over time after controlling for age (β=0.914, p=0.001). BMI category 25–29.9 kg/m2 was significantly predictive of lower HIV viral load log10 over time (β= −0.145, p=0.0295) after controlling for age and gender.

Conclusions

In this HIV+ ART naïve cohort, being overweight predicted a slower HIV disease progression. Mechanistic studies on the relationship between higher BMI and HIV disease progression are needed to support recommendations for HIV care in developing countries.

Funded by NIDA
Relation of mother‐infant interaction to infant weight and length in rural Southern Ethiopia
Authors: Woltamo Tesfaye , White Shauntia D , Hubbs-Tait Laura , Stoecker Barbara J , Hambidge Michael
Published: June 2021

Study objective was to identify mother‐infant (n= 60) behaviors linked to 6‐mo infant weight and length in breastfed infants in 2010 in Sidama, Ethiopia, a region stricken by famine in 2009. Preliminary data on videotaped behaviors are reported for 26 mother‐infant pairs. Interrater reliabilities on infant behaviors ranged from r =.65 to .89; on maternal behaviors they ranged from r =.53 to.81. Behaviors were validated with mothers’ Edinburgh Postpartum Depression Scale (EPDS, translated into Amharic) and social support (SS) scores. Correlations were: infant vocalizations with EPDS and SS, r = −.34 and r = .46, ps < .05; infant distress with EPDS, r = .50, p < .01; infant activity with SS, r = .47, p < .01; mother response to infant vocalization with EPDS and SS, r = −.38 and r = .45, ps < .05. Infants’ vocalizations and mothers’ responses were linked to infant weight‐for‐length: r = .27, p < .10 and r = .35, p < .05. Infant distress was linked to infant weight‐and length‐for‐age: r = .45 and r = .50, ps < .01. Findings on distress and growth are consistent with research on alertness and growth. Vocalization findings are congruent with functional isolation hypothesis. Funding: NICHD R01 053053.
The feoB ferrous iron uptake pathway contributes to the intracellular survival of F. tularensis LVS
Authors: Thomas-Charles Cindy Arisa , Zheng Huaixin
Published: June 2021

Francisella tularensis is a Gram‐negative, facultative intracellular bacterium and the agent of tularemia. During infection, F. tularensis targets the liver and grows extensively within hepatocytes. This study investigates the role of iron acquisition pathways in F. tularensis virulence and replication within hepatocytes. Deletion mutants of the candidate fslC and feoB iron acquisition genes and their complemented counterparts were generated in the live vaccine strain (LVS). The ΔfeoB but not the ΔfslC mutant exhibited severely inhibited growth in chemically‐defined medium with restricted iron and FL83B hepatocytes, but replication in macrophages was similar to wild‐type bacteria. Ability of the ΔfeoB mutant to establish infection in mice was studied by measuring organ burden at three days post‐infection. The ΔfeoB mutant showed impaired colonization of the lungs, liver, and spleen compared to wild‐type bacteria, and complementation partially rescued this phenotype. The intracellular environment is reducing, providing an abundance of ferrous iron. These results identify FeoB, which functions to acquire ferrous iron in other bacteria, as a contributor to F. tularensis intracellular replication and virulence. Furthermore, these results designate FeoB as a potential therapeutic target. Funding sources: NIAID T32 A1007539 and P01 AI055621
Modulatory role of Peroxisome Proliferator‐Activated Receptor γ on Citrate Carrier activity and expression
Authors: Bonofiglio Daniela , Santoro Antonella , Vizza Donatella , Rovito Daniela , Martello Emanuela , Cappello Anna Rita , Barone Ines , Giordano Cinzia , Catalano Stefania , Dolce Vincenza , Andò Sebastiano
Published: June 2021

The citrate carrier (CiC), a nuclear‐encoded protein located in the mitochondrial inner membrane, plays an important metabolic role in the transport of acetyl‐CoA from the mitochondria to the cytosol in the form of citrate for fatty acid and cholesterol synthesis. Citrate has been reported to be essential for fibroblasts differentiation into fat cells. Since expression of Peroxisome Proliferator‐Activated Receptor gamma (PPARγ) is known to be induced at the early stage of adipocyte differentiation, we aimed to study the regulation of CiC by PPARγ ligand Rosiglitazone (BRL) in rat fibroblast and in differentiated adipocytes 3T3‐L1 cells. We provided evidences for the first time that BRL was able to up‐regulate CiC mRNA and protein levels in fibroblasts, while CiC expression was unchanged in adipocytes. The enhancement of CiC levels upon BRL treatment was reversed using a PPARγ antagonist GW9662, addressing how this effect was mediated by PPARγ. In transfection experiments with rat CiC gene promoter featured by the abundance of Sp1 sites, we observed that BRL‐induced enhancement of CiC activity was reversed by the Sp1 inhibitor mithramycin, suggesting that Sp1 sequence could be crucial in modulating CiC expression in fibroblasts. Our results address how PPARγ may be involved in the molecular mechanism regulating CiC activity and expression along the differentiation stages of fibroblasts into adipocytes.
Effects of selected adrenergic receptor agonists on human prostate cancer progression, in vitro
Authors: Patel Kartik K. , Philipose Christina , Bavadekar Supriya A.
Published: June 2021

Numerous studies suggest that various adrenergic receptor (AR) agonists play a role in the progression of cancer affecting multiple characteristics such as cell survival, proliferation, metastasis, and angiogenesis. These effects are thought to be mediated via the β2‐AR. The aim of this study was to examine the effects of the AR agonists, norepinephrine (NE), epinephrine (E), and isoproterenol (ISO) on survival and/or proliferation of human metastatic, androgen‐sensitive, prostate cancer cells, LNCaP, which express β2‐AR. Cells were treated with increasing concentrations (10−9 − 10−3 M) of NE, E, and ISO for 24 hr, and viability was assessed using the XTT cell proliferation assay. All agonists exhibited a concentration‐dependent increase in cell viability in the 10−5 – 10−3 M range; increase in viability at 10−3 M for all three agonists being about 8–9‐fold. Interestingly, there was no rank order of potency observed between the ligands. Furthermore, pretreatment with α‐and β‐AR selective antagonists, phentolamine (10 μM), propranolol (10 μM), and ICI 118,551 (10 μM) did not inhibit the increase in viability. Further studies are underway to better understand the mechanism of the increase in cell viability with these agonists, and to determine their effects on metastasis and angiogenesis in these cells. This research is supported by the Division of Pharmaceutical Sciences at Long Island University, Brooklyn, NY.
Methylenedioxypyrovalerone (MDPV): Self‐administration and acute drug challenges in rats
Authors: Aarde Shawn M. , Huang Pai-Kai , Creehan Kevin M , Vaillancourt Brittani D , Vandewater Sophia A , Wright Mayo J , Miller Michelle L , Taffe Michael A
Published: June 2021

Little is known regarding the abuse liability or the behavioral and physiological effects of MDPV. We present data on the effects of MDPV in rats from both intravenous self‐administration (IVSA) and acute drug challenge experiments. IVSA of MDPV was established on an FR5 schedule to stable intake patterns and high lever discrimination. Dose‐dependent rates of responding were observed under both FR and PR schedules wherein as per‐infusion dose increased, infusions decreased under FR but increased under PR. In acute challenge studies, bolus s.c. injections of MDPV showed a biphasic effect on both body temperature (compared to saline, low doses increased body temperature while high doses decreased body temperature) and activity counts (compared to saline, low doses increased activity while high doses suppressed activity). These initial data indicate that MDPV has an abuse liability that is similar to that of other stimulant drugs of abuse. Additionally, the observed biphasic effects in body temperature and activity may be related to the observed increase in stereotypy at higher doses of MDPV. (Grant DA024105).
Opioid/sphingosine‐1‐phosphate1 (S1P1) interactions in antinociception
Authors: Welch Sandra P. , Selley Dana E. , Lynch Kevin R. , Sim-Selley Laura J.
Published: June 2021

The antinociceptive effects of morphine are mediated in part by activation of the S1P1 receptor as indicated by attenuation of morphine‐induced antinociception by a S1P1 receptor antagonist VPC44116 in mice. In addition, as tested in SphK2 knockout mice, activation of sphingosine kinase2, the kinase responsible (along with SphK1) in the phosphorylation and activation of S1P is required for the fully efficacious effect of morphine in antinociceptive testing in mice. The antinociceptive effects of morphine are enhanced by the administration of subactive doses of the S1P analog FTY720 (fingolimod) and the S1P1 receptor‐selective drug, CYM‐ 5442. Morphine‐induced antinociception and G‐protein activation via [35S]GTPγS autoradiography in several brain regions are not attenuated in FTY720‐tolerant mice. Thus, S1P and opioid receptors appear to have distinct receptor signaling systems. However, these data indicate that opioid and S1P1 receptor‐activated processes are highly dependent upon one another in the production of antinociception. The Presidential Research Incentive Grant (VCU) and NIDA RO3DA‐05274 supported this work.
Effects of in utero cocaine exposure on cocaine‐food delay discounting procedures in adult rhesus monkeys
Authors: Brutcher Robert E , Nader Michael A.
Published: June 2021

This research examines the behavioral and neuropharmacological consequences of in utero cocaine (COC) exposure in adult male and female rhesus monkeys. Previous data from our laboratory found that monkeys exposed to cocaine in utero acquired cocaine self‐administration more rapidly under a simple fixed‐ratio schedule of reinforcement and, under concurrent food‐food schedules, display a preference for smaller, non‐delayed food reinforcers relative to the larger delayed reinforcers compared to controls. In this study, we extended these findings to a cocaine‐food delay discounting procedure. Under baseline conditions, COC (n = 8) and control (n = 7) monkeys chose between cocaine (0.001–0.3 mg/kg) and three 1‐g food pellets; COC monkeys preferred cocaine to food at lower doses compared to controls. When delays (5–300 sec) were associated with cocaine choice, the indifference points (ED50 values) were similar for both groups (~ 120 sec). However, COC monkeys were highly variable – half were well above 120 sec and the others well below. Compared to food‐food delay discounting, control monkeys ED50s were similar, while COC monkeys had lower food values (~ 65 sec). These findings suggest in utero cocaine exposure may make adults less sensitive to contingency changes involving cocaine relative to non‐drug reinforcers, which would be problematic for contingent management treatment strategies. DA025120
Assessing neurobehavioral function with the rat psychomotor vigilance task
Authors: Davis Catherine Marie , Hienz Robert D
Published: June 2021

The human psychomotor vigilance task (PVT) was developed as a sensitive and standardized assay capable of quantifying changes in sustained attention. The procedure requires subjects to respond to a light stimulus as soon as it appears; a response extinguishes the stimulus and displays the subject's reaction time. The PVT is widely used in risk assessments in operational environments to provide feedback on fatigue levels and alertness.

Given the importance and widespread use of the PVT, we have adapted a rodent PVT (rPVT) for use in the laboratory, primarily to detect drug‐ and radiation‐induced changes in neurobehavioral function in rats. Rats performing on the rPVT and humans on the PVT display similar mean reaction times, lapses in attention, premature responding, and normal variations in sustained attention. Amphetamine altered performances in a manner similar to the effects of psychostimulants; Zolpidem produced dose‐dependent decreases in rPVT performance. Further, rPVT performance is sensitive to individual differences in dopamine function following head‐only radiation exposure: rats showing significant changes in dopamine protein levels displayed performance deficits. Future work is focused on further examining the neurochemical systems involved in performing the rPVT and developing therapeutic strategies aimed at improving performance degraded by various environmental manipulations.
The 6‐hydroxydopamine unilaterally‐lesioned rat as an in vivo model for novel dopaminergic compounds and antipsychotic drugs
Authors: Boyd Kevin N , Murthy Vishakantha , Mailman Richard B.
Published: June 2021

Modulation of dopamine systems is an important therapeutic strategy, but desired effects and side effects are often elicited simultaneously. Recent advances (e.g., allosteric or functionally selective drugs) provide a route to superior drugs, but translating in vitro data to the intact animal is difficult. We investigated whether the 6‐OHDA unilateral‐lesioned rat model could differentiate functionally selective dopamine ligands and antipsychotic drugs (APDs). Male Sprague‐Dawley rats were lesioned (MFB) and verified by apomorphine‐induced contralateral rotations. Typical and atypical APDs and functionally selective ligands were tested alone and versus quinpirole. Quinpirole‐mediated rotations were inhibited by typical and most atypical APDs, but not by functionally selective ligands. Importantly, no clinically approved APD caused rotations on its own, but several APD compounds that failed clinical trials caused rotations on their own and did not block quinpirole. Although widely considered a model of Parkinson's disease, these data suggest that this model may be a useful addition for screening novel APDs. The pattern of action on dopamine signaling pathways highlights some of the critical signaling pathways and may help translate novel drugs to the clinic.
Modifying a high fat diet with mono‐and poly‐unsaturated fats improves coronary dysfunction
Authors: Oltman Christine L. , Dake Brian L. , Sivitz William I. , Yorek Mark A. , Lamping Kathryn G.
Published: June 2021

We tested whether partial replacement with mono‐or poly‐unsaturated fats improves coronary vascular dysfunction induced by a high saturated fat diet. We fed C57BL6 male mice high saturated fats (60% lard) for 12 weeks before substituting half of the fat with poly‐[n‐3 menhaden oil: MO or n‐6 safflower oil: SO] or mono‐unsaturated fat [olive oil: OO] for 4 weeks. After 16 weeks weight and basal glucose were elevated and glucose tolerance was reduced in lard fed compared to normal mice (4% fat). Substitution with MO but not SO or OO restored basal glucose and glucose tolerance to normal. Responses to insulin, acetylcholine (ACh) and sodium nitroprusside (SNP) were evaluated in isolated pressurized coronary arteries. Insulin–induced relaxation was attenuated in coronary arteries from mice fed a high saturated fat diet and improved with MO, OO and SO modified diets. There was a modest reduction in relaxation to ACh in mice fed high fat diet, which was not improved with any modification of diet (MO, OO or SO). SNP responses were not altered by high saturated fat diet. We conclude that short‐term enrichment of high saturated fat diet with mono‐and poly‐unsaturated fats selectively improves insulin vasoreactivity despite persistent abnormal glucose tolerance with SO and OO enriched diets. Even when glucose tolerance was restored to normal with MO, ACh‐induced relaxation was not improved in coronary arteries.
ATP release and activation of P2Y2 receptors in the regulation of cardiac fibroblasts
Authors: Lu David , Soleymani Sahar , Madakshire Rohit , Insel Paul A.
Published: June 2021

Cardiac fibroblasts (CFs), which play an essential role in cardiac remodeling, are activated and convert to a pro‐fibrotic phenotype in response to a variety of extracellular factors, including nucleotides. In previous work we showed that activation of P2Y2 (nucleotide) receptors is pro‐fibrotic. Here, using CFs isolated from adult rats and mice, we assessed ATP release and receptor activation by released ATP. We find that hypotonic conditions rapidly produce a ~10‐fold increase in extracellular ATP concentration. Rat CFs express connexins (Cxˈs) 43 and 45, which both, based on knockdown with siRNA, contribute to ATP release. Released ATP activates ERK via P2Y2 receptors; this activation is blunted by treatments that inhibit ATP release: carbenoxolone, apyrase and Cx siRNA. Pharmacological inhibition of ERK and knockout of P2Y2 receptors both decrease ATP‐stimulated increases in collagen production and expression of pro‐fibrotic markers, e.g., plasminogen activator inhibitor‐1 (PAI‐1) and monocyte chemotactic protein‐1 (MCP‐1). The pro‐fibrotic response to released extracellular ATP via P2Y2 receptors and ERK thus is an autocrine/paracrine mechanism that likely contributes to CF activation in response to cardiac injury. Supported by grants from NIH (GM007752, HL980621, HL066941, GM066232).
Chronic developmental hypoxia alters the cardiovascular baroreflex phenotype of embryonic Common snapping turtles
Authors: Crossley Dane A , Tate Kevin B , Elfwing Magnus , Eme John
Published: June 2021

Regulatory mechanisms that alter cardiovascular function to meet convective transport demands are present in all adult vertebrates, from hagfish to reptiles to mammals and birds. Logical and rapidly expanding fields of inquiry are when do these systems become evident during an organism's life span and how are physical, regulatory and functional development altered by environmental stresses? Addressing these questions using reptiles is important due to the evolutionary position of this taxa and the vulnerability of their eggs. We hypothesized that chronic 10% O2 during snapping turtle development, a vulnerable period, would alter baroreflex function. Assessment of this classic adult cardiovascular regulatory system revealed an active reflex at 70% of incubation, similar to American alligators and some birds and mammals. Absolute baroreflex sensitivity is altered by chronic hypoxic stress prior to hatching, which coincides with hypotensive and tachycardic resting values as well as relative cardiac enlargement (2‐way ANOVA, P<0.05). Overall, the presence of a functional baroreflex for in ovo developing vertebrates suggests this mechanism plays a role in cardiovascular homeostasis, possibly coupled to variation in embryonic environment. NSF CAREER IBN IOS‐0845741 to DAC
The effect of temperature on the compliance of the rainbow trout heart
Authors: Shiels Holly A , Rizvi Hamid , Fenna Andrew , Samuel Diana
Published: June 2021

The rainbow trout (Oncorhynchus mykiss) can vary stroke volume considerably to vary cardiac output. This requires that the chambers of the heart be compliant. Given that trout are exposed to a wide range of temperatures, it is plausible that compliance will also vary as a result of thermal acclimation. The aim of this investigation was to compare the compliance and material properties of the heart chambers (atrium, ventricle, and bulbus arteriosus) from acclimated trout (4C, 11C, and 18C). Pressure‐volume curves were generated for each chamber and compliance was determined from the gradient of these curves. Results show warm acclimation increased compliance of all chambers compared with cold acclimation. As collagen plays an integral role in tissue compliance, histology and qPCR were performed on cardiac tissue from warm and cold acclimated fish. Histological experiments established significantly higher levels of collagen in cold acclimated fish than warm acclimated fish. Furthermore, there were significantly higher levels of collagen in the compact layer than the spongy layer. In contrast there was a significant decrease in the relative abundance of collagen type I α II mRNA in cold fish suggesting multiple collagens are important in the acclimation response. This is further supported by increases in MMP2 and MMP9 (negative regulators of collagen IV) mRNA in the ventricles of warm acclimated fish.
Impact of antenatal inflammation on diaphragm muscle function in the preterm lamb
Authors: Pinniger Gavin Jon , Lavin Tina , Bakker Anthony , Berry Clare , Noble Peter , Pillow Jane J
Published: June 2021

The incidence of respiratory failure is higher in preterm babies than at any other time of life and clinically relevant antenatal exposures such as inflammation and sepsis may affect the development and function of the fetal diaphragm. We hypothesised that the preterm diaphragm is susceptible to phenotypic alteration induced by in utero exposure to inflammation.

We used an established newborn sheep model of neonatal lung disease to determine the impact of in utero inflammatory exposure on the contractile function of the newborn diaphragm. Pregnant ewes received intra‐amniotic injections of saline or LPS (10 mg, E coli O55:B5; Sigma, Melb, Aust) at 2 d or 7 d prior to delivery. Ewes were sedated (IV Ketamine 10 mg/kg, Medetomidine 0.02 mg/kg) and received a spinal anaesthetic (2% Lignocaine, 3 mL) prior to the premature delivery of lambs at 121 d gestation (term = 150 d). At post‐mortem, the diaphragm was removed for assessment of contractile function.

Acute in utero exposure to an inflammatory stimulus caused significant (~30%) weakness in the diaphragm muscle. Maximum specific forces from twitch and tetanic contractions were significantly lower after 2 d and 7 d exposure to LPS compared to saline controls. After 2 d LPS exposure, the twitch half‐relaxation time was significantly longer than both 7 d LPS and saline controls. There were no significant differences in the susceptibility to fatigue or to stretch‐induced muscle damage between the treatment groups.

These data indicate that both short term (2 d) and longer term (7 d) in utero exposure to inflammation causes contractile dysfunction in the pre‐term diaphragm. This muscle weakness is likely to further impair the functional capacity of the diaphragm and limit the ability to cope with the increased mechanical loads associated with a structurally and functionally immature respiratory system.
Doublet Discharges Improve Force During Fatigue in Single Fibers
Authors: Cheng Arthur Junn-Hay , Bruton Joseph D. , Westerblad Håkan
Published: June 2021

Doublet discharge is the brief high discharge of motor units recorded at the very onset of a voluntary muscle contraction, which increases both force and maximal rate of force development in submaximal contractions. However, whether doublet discharges ameliorate or worsen fatigue‐induced reductions in force have not been investigated.

Methods

Twenty‐four mechanically‐dissected intact single fibers from flexor digitorum brevis muscles of C57 mice were injected with indo‐1 to assess free myoplasmic tetanic Ca2+ ([Ca2+]i). Fatigue was induced with 150 brief 60 ms tetani every 300 ms, using either a constant frequency 70 Hz stimulation protocol or a doublet stimulation protocol that added a 200 Hz interpulse interval at the start of 70 Hz constant frequency trains.

Results

During the first 25 contractions of the fatigue protocol, doublets produced greater force‐time integral and peak force compared with the constant frequency tetani. There was no significant difference between protocols in the plateau tetanic force loss from contractions 50 up to 150. No significant differences in mean tetanic [Ca2+]i were observed between the two stimulation fatigue protocols.

Conclusion

Without requiring greater mean tetanic [Ca2+]i than constant frequency stimulation, our findings show that initial doublets increase tetanic force in early but not late stages of fatigue. Supported by The Swedish Research Council
Effects of glutamine supplementation on muscle function in a mouse model of spinal cord injury
Authors: Huey Kimberly , Chamney Carissa , Godar Michelle , Garrigan Ethan
Published: June 2021

Spinal cord injury (SCI) results in loss of muscle function due to rapid breakdown of contractile proteins. Glutamine (GLN) supplementation improves clinical outcomes, but its effects on muscle function after SCI are unknown. Improvements with GLN in non‐skeletal muscle tissues have been related to elevated heat shock protein 70 (Hsp70) and Hsp25, but the muscle response may differ since it is the largest contributor to plasma GLN. We tested the hypothesis that GLN preserves muscle function after SCI and this is associated with increased Hsp levels. Changes in plantarflexor mass, force, fatigability, and Hsp70 and 25 protein were measured 7 d after sham or spinal cord transection (ST) surgery in mice receiving daily placebo (PL) or GLN. ST reduced muscle mass with PL or GLN (p<0.05). Maximal isometric force relative to body mass was not different among groups, but GLN prevented greater fatigability seen with ST + PL (59±4 vs. 34±4% of initial force after 10 contractions, respectively, p<0.05). ST was associated with decreased Hsp70 and 25 with GLN only (49±3 and 44±5% of PL, respectively, p<0.05). Functionally, early increases in fatigability after SCI were reversed with GLN. ST‐associated reductions in Hsp70 and 25 with GLN vs. PL suggest lower stress in the muscle, possibly related to a reduced need to produce GLN. These findings support GLN as a therapeutic intervention to accelerate recovery of muscle function after SCI.
Locally‐Mediated Cutaneous Vasoconstriction is Augmented in Essential Hypertensive Humans
Authors: Smith Caroline J , Holowatz Lacy A
Published: June 2021

Essential hypertension (HT) is associated with augmented vasoconstriction (VC) which may be secondary to increased Rho/Rho‐Kinase (ROCK)‐dependent mechanisms. Our aim was to assess the magnitude of cutaneous VC to local cooling as a stimulus to induce ROCK‐mediated VC. Four microdialysis fibers were placed in the forearm of 5 hypertensive (MAP: 103 ± 4 mmHg) and 7 normotensive (NT; 89 ± 7 mmHg) men and women: Ringers (control; C), 3 mM fasudil (ROCK inhibited), 5 mM yohimbine + 1 mM proprananol (α‐ and β‐adrenoceptor inhibited; Y + P), Y + P + 3 mM fasudil (ROCK and adrenocepor inhibited; Y + P + F). Skin blood flow was measured and cutaneous vascular conductance was calculated (ΔCVC) during early and late stage local cooling (24°C) to induce VC via adrenergic and ROCK‐dependent mechanisms, respectively. Greater basal VC (Tsk 34°C) was observed in HT compared to NT (0.00 ± 0.05 vs. 0.28 ± 0.06 CVC, P < 0.05). HT show significantly greater VC at both early (1–5 min; −0.10 ± 0.06 vs. 0.21 ± 0.07 ΔCVCbaseline, p < 0.01) and late (36–40 min; −0.32 ± 0.11 vs. −0.07 ± 0.04 ΔCVCbaseline, p < 0.05) stage cooling compared to NT, with a trend towards augmented ROCK‐mediated VC (1–5 min; −0.97 ± 0.26 vs. −0.25 ± 0.22 ΔCVCbaseline, p = 0.07). These data suggest that VC to local cooling was augmented in HT, which may be linked to increased Rho/ROCK mechanisms.

Supported by NIH RO1‐HL093238‐02
Diagnostic power of computed tomography in the helmeted human skull using a trauma‐limiting protocol
Authors: Pan Jennifer , Tobin Brian W , Islas Arthur
Published: June 2021

Current Emergency Medicine guidelines recommend removal of a football helmet prior to radiological examination. This procedure can result in further bone, neurological, and vascular trauma. To evaluate a trauma‐limiting protocol (TLP), we used computed tomography (CT) to visualize surrogate markers of skull, spine, and brain within newly designed football helmets. A cadaveric human skull and watermelon were used as skeletal and soft tissue surrogates, respectively. Each surrogate was immobilized in a helmet and multiple CT images were obtained. All CT images were filmed at bone and soft tissue windows and reviewed by a Board‐certified radiologist for image clarity and diagnostic capability. Lateral scout films demonstrated mild star and band‐like artifacts depending on the location of metallic snaps. The minimal metallic artifact did not affect the diagnostic quality of CT images. Reconstructed images were also of clinical diagnostic quality. As a unit, the CT scans provided diagnostic clinical information with minimal aberrations using the TLP. Therefore, we recommend utilizing the TLP and leaving newly‐designed football helmets in place during the initial CT evaluation of an athlete with suspected bone, neurological, or vascular injury. Supported by HRSA ‐ HCOE.
Time Course of Compensatory Physiological Responses to Central Hypovolemia Varies with Tolerance
Authors: Ryan Kathy L , Rickards Caroline A , Hinojosa-Laborde Carmen , Convertino Victor A
Published: June 2021

While it is known that human subjects with high tolerance (HT) to central hypovolemia induced by lower body negative pressure (LBNP) have a greater ability to increase total peripheral resistance (TPR) and heart rate (HR) than low tolerant (LT) subjects, the time course of these compensatory events is unknown. We hypothesized that the rate of increase in HR and TPR would be greater in LT subjects. Subjects were instrumented to record beat‐by‐ beat arterial pressure, TPR and HR (Finometer) during a progressive LBNP protocol taken to the point of tolerance (presyncope). Subjects were classified as HT (n=113) if they completed at least the −60 mmHg level and LT (n=59) if they did not complete this level. LT reached maximal TPR (24.3 ± 0.9 mmHg*min/L) in 756 ± 31 s, while HT reached a higher (p=0.003) maximal TPR (27.7 ± 0.7 mmHg*min/L) in 1265 ± 37 s (p<0.001); rates of change from baseline did not differ statistically (p=0.17). Similar results were obtained for HR (max HR, LT: = 111 ± 2 bpm at 923 ± 27 s; HT: 130 ± 2 bpm at 1489 ± 23 s; both p<0.001); again, rates of change were comparable (P=0.20). LT subjects therefore vasoconstrict and increase HR at similar rates as HT subjects during central hypovolemia, but their ability to continue these compensatory responses is limited. A relative vasodilation occurs in both groups before maximal HR is attained, which may contribute to eventual hemodynamic decompensation. (Funded by US Army MRMC)
Exercise capacity is influenced by thermal balance at onset of active/inactive phases of circadian cycle
Authors: Machado Frederico Sander Mansur , Coimbra Candido Celso
Published: June 2021

The aim of this study was to verify if circadian phase at which exercise is performed influences performance and thermoregulatory adjustments.

Wistar rats (n=8), in a L/D cycle of 14/10h with free access to water and food, were used. To establish active and inactive phase of each animal, spontaneous locomotor activity and core temperature (Tc) were continuously recorded during 48h with an implanted telemetric sensor. After acclimatized to running animals were submitted to incremental exercise until fatigue during both the onset of active and inactive phases of circadian Tc rhythm. Time to fatigue (TF), Tc and skin tail temperature (Ttail) were monitored during exercise. Workload (W) and TF were used as performance index.

Results confirmed that onset of active phase was followed by peak Tc (p<0.05) while trough was observed just after inactive phase onset (p<0.05). This was accompanied by superior TF and W during inactive compared to active phase (p<0.05). Exercise capacity differences were followed by higher Tc and Ttail before exercise at active phase (p<0.05). After fatigue Ttail remained higher at active phase (p<0.05).

We have demonstrated that exercise capacity was indirectly influenced by time of the day through a circadian‐related modulation of heat production and dissipation before and during exercising until fatigue.

Financial support: CAPES, CNPq and FAPEMIG.