bluuebunny/crossref_metadata_2025 huggingface dataset:
High Protein Diet and DHA Supplementation may be Effective to Recover the Impaired Immune Function in Irradiated Rats
Authors: Jung Ji‐Hye , Kim Kyoung‐Ok , Lim Sung‐Hee , Park Su‐Jin , Chun Mi‐Son , Kang Seung‐Hee , Kim Hyun‐Sook
Published: June 2021

Most cancer patients with radiation treatment have a tendency to avoid animal foods and prefer vegetables which may cause accelerated malnutrition with impairment of immune function. These overall conditions could contribute eventual poor prognosis and poor quality of life. The major goal of this study was to determine the effects of high protein diet (HP) and DHA supplementation in minimizing the adverse effects of radiation for cancer treatment. Rats were divided into four groups: normal protein diet (NP) and HP groups and NP + DHA and HP + DHA groups. Each diet group was further divided into treatment groups that received radiation (RT group) and one that did not (non‐RT group). The diet administration supplied from 12th day prior to radiation treatment with irradiation dose of 17.5 Gy. The diets were continued until 10th day after radiation treatment and animals were sacrificed. Radiation treatment significantly decrease the proportion of lymphocyte and increase the proportion of neutrophil and eosinophil. Radiation treatment also caused the significant increase in WBC and decrease in platelets. HP and DHA supplementation resulted the change of lymphocyte and neutrophil proportions into similar to non‐radiated group levels, thereby effective to recover the impaired immune function in irradiated rats.
Emergent Critical Phenomena in the Evolution of Heart Failure
Authors: Wu Fan , Zhang Jianyi , Beard Daniel A.
Published: June 2021

The failing heart is hypothesized to suffer from energy supply inadequate for supporting normal cardiac function. This study aims at quantitatively determining the energy state, represented by the cytoplasmic ATP hydrolysis potential (δGATPase), in the failing heart. Biopsy measurements and 31P‐Magnetic Resonance Spectroscopy experimental data show that at basal conditions total creatine pool (CRtot), ATP, and CrP decrease in left ventricular hypertrophy (LVH) hearts. These decreases are proportional to the degree of LVH, but not associated with cardiac underperfusion. By incorporating these changes into a recently developed computational model of cardiac energetics [Wu et al., J. Physiol. 586:4193‐4208, 2008], we are able to simulate local metabolite and ion concentrations and thus δGATPase in the LVH hearts. The simulations reveal the impacts of CRtot, total exchangeable phosphate, and total adenine nucleotides (TAN) on δGATPase at the maximal cardiac work rate. Model predictions indicate that the evolution of heart failure involves two distinct energetic stages: an early stage with relative stable cardiac reserve and a late stage with rapidly deteriorated energetics. Analysis reveals a critical phenomenon in which low and moderate reductions in TAN have no impact on oxidative capacity while reductions in TAN beyond the critical point lead to severely compromised energy state.
Mesenchymal stem cells (MSCs) grown from human prostate cancer can generate atypical glands in vivo
Authors: Croisille Laure , Crisan Mihaela , Yao Veronica , Sun Bin , Parwani Anil , Logar Alison , Matsko Christopher , Bacich Dean
Published: June 2021

Background / Aims

New therapeutic targets need to be identified in prostate cancer which remains the second cause of cancer related death in US men. Some studies suggest that MSCs may be candidates for cancer transformation in a gastric cancer model. We aim at understanding whether MSCs have a role in prostate tumorigenesis.

Methods

Cells were obtained and expanded in vitro from 7 CaPs specimens, after fluorescence‐activated cell sorting or after multiple steps of cell adhesion, and eventually characterized by immunocytochemistry and FACS then injected into a xenochimeric mouse model.

Results

MSCs markers (CD9, CD13, CD44, CD73 and CD90) were expressed by 95% to 100% of the cells. Eight weeks after in vivo injection under the renal capsule of immunodeficient mice, in presence of fetal rat UGM, cells from 3 specimens (3/3) generated xenografts, while fetal rat UGM alone and cells alone did not grow. Further analysis of the grafts show the presence of glandular structures with prostate intraepithelial neoplasia features and some glands were of human origin.

Conclusions

Our results suggest that MSCs grown from prostate tumors, under appropriate stimulation, are able to generate glandular structures with preneoplastic features. Further characterization of the respective origin of the glands, vessels, and stroma, is mandatory to further elucidate the potential of these MSCs.
The New Classification of Hepatic Segment
Authors: Liu Shuwei , Zhao Zhenmei , Lin Xiangtao , Lou Li , Li Zhenping
Published: June 2021

Objective

To re‐recognize the intrahepatic vessels and propose a new view of the hepatic segmental classification.

Methods

Using successive sections of 50 adult cadavers and three‐dimensional CT images of hepatic vessel of 300 patients, the branching pattern of intrahepatic vessels and hepatic segments were investigated.

Results

According to the branching pattern of intrahepatic vessel, the liver is divided into left and right hemilivers by the median fissure. The right hemiliver is divided into anterosuperior and posteroinferior lobes by the curved right interlobar fissure. The anterosuperior lobe is divided into ventral and dorsal segments by the vertical intersegmental fissure, and the ventral segment is divided into upper and lower subsegments. The posteroinferior lobe is divided into upper and lower segments by the horizontal intersegmental fissure. The left hemiliver is divided into posterosuperior and anteroinferior lobes by the interlobar fissure. The anteroinferior lobe is divided into medial and lateral segments by the intersegmental fissure, and the medial segment is divided into upper and lower subsegments by the horizontal subsegmental fissure. The caudate lobe is separated from other parts of the liver by the arcuate dorsal fissure.

Conclusion

This new method of hepatic segment division will be helpful to the precise localization of minimal lesions in the liver.
DNA polymerases with improved reverse transcriptase activity
Authors: Fiss Ellen H , Suko Shawn , Budker Olga , Martinez Tomas , Stoffel Susanne , Schoenbrunner Nancy , Bauer Keith
Published: June 2021

There exists a need for enzymes with improved reverse transcriptase activity to increase the sensitivity of diagnostic assays which use RNA targets. In our lab we have produced a collection of chimeric mutant DNA polymerases with modulated proofreading activity. A mutagenized library of one of these DNA pols was screened for improved extension rates on a primed M13 template. Some of the mutants displayed the ability to perform improved RT‐PCR using either Mn2+ or Mg2+. One of the DNA pol mutations, D640G, was transferred to the parent DNA pols of the chimera, Thermatoga maritima and Thermus sp. Z05. These mutants also demonstrated the ability to perform efficient RT‐PCR with reduced RT incubation times.

In Z05 the D580 position was mutated to all 19 other amino acids and the resulting proteins were purified. The D580G and K mutants were found to have improved RT activity and increased RT‐PCR sensitivity using TaqMan‐based detection. Enzymatic characterization revealed a 12.5‐fold improvement in the catalytic efficiency of Mn2+‐activated RT for Z05 D580G over wild‐type. The Z05 D580K enzyme also showed significant activity when Mn2+ was replaced by Mg2+ allowing for higher fidelity RT‐PCR.
Benzoate Esters as Potential Apoptotic Agents
Authors: Sharma Bharat , Ellis Jamie , Foroozesh Maryam , Hopkins Nancy Eddy
Published: June 2021

Many natural products such as curcumin, capsaicin, and isoflavonoids are thought to have chemo‐preventative properties for cancer, especially prostate cancer. 4‐Hydroxy‐3‐methoxybenzoic acid methyl ester (methyl vanillate) has been shown to cause proliferation inhibition in the human and mouse prostate cancer cells. In this project, we have synthesized a series of related aromatic compounds containing an ester functional group and one or more hydroxyl or methoxy ring substituents. The newly synthesized benzoate esters are studied in cell culture studies with human and mouse prostate cancer cells. Due to their structural similarities to compounds known to cause prostate cancer cell apoptosis, these compounds are expected to provide us with new and valuable information about the structural requirements for optimizing that effect. Considering that prostate cancer is the second most common type of cancer in men in the United States (second only to skin cancer), these and related studies are of great importance in the fight against cancer. Here we will present the synthesis, purification, structural analysis and the preliminary assay data obtained for a number of these compounds.
Reporting of Systematic Reviews of Micronutrients and Health: A Critical Appraisal
Authors: Chung Mei , EPC Team Tufts
Published: June 2021

Background

Systematic review is a valuable tool for evaluating nutrition‐related research and formulating nutrition recommendations.

Objective

To evaluate reporting quality of published systematic reviews (SRs) and identify areas for improvement.

Design and Methods

Analysis of all English‐language systematic reviews linking micronutrient intakes to health outcomes in humans. Medline was searched through July 2007 for all eligible reviews. Descriptive and exploratory analyses of factors associated with reporting quality (7 nutrition variable factors and 28 systematic review reporting factors) were performed.

Results

We found 141 eligible SRs of 21 micronutrients in 84 journals. On the basis of the pre‐determined criteria systematic reviews including only interventional studies (n=90) had more complete reporting (median: 60%, interquartile range, IQR: 50%, 70%) than those including only observational studies (n=31) (median: 55%, IQR: 48%, 62%) or both types of study design (n=20) (median: 47%, IQR: 39%, 52%) (P<0.001). Quality assessments of the primary studies were performed in only 58 (41%) of SRs. Comparing 3‐years before to 3‐years after publication of reporting standards for SRs, the overall reporting quality has improved (51% to 58%, P=0.01) while reporting of nutrition variables remained unchanged (42%, P=0.75). The least reported nutrition variables were baseline nutrient exposures (28%) and impacts of the measurement errors from nutrition exposures (24%).

Conclusion

The reporting quality of SRs has improved but the reporting of nutrition variables remains incomplete. This limits their potential use as a tool when formulating nutrition‐related guidelines or recommendations, formulating research agendas and clinical guidelines.

Grant Funding Source

Agency for Healthcare Research and Quality (AHRQ), U.S. Department of Health and Human Services (DHHS), and National Institutes of Health (NIH)
Infant Breastfeeding Assessment Tool (IBFAT) scoring discrepancy between mothers and lactation consultants
Authors: Wetzel Katherine , Chapman Donna J , Kyer Nan , Bermudez‐Millan Angela , Young Sara , Perez‐Escamilla Rafael
Published: June 2021

Our objective was to determine the correlation between maternal vs. Internationally Board Certified Lactation Consultant's (IBCLC) rating of a breastfeeding (BF) session. We analyzed results from an ongoing study assessing BF techniques of low‐income, predominantly Latina, obese women. Two BF sessions were videotaped on days 2, 4, and 7 postpartum (pp) for a total of six sessions per participant. Maternal IBFAT scores (n=14) were obtained immediately after BF. A panel of three IBCLC's are independently rating each videotaped session. Spearman correlation coefficients were assessed to determine the similarity between maternal and IBCLC ratings. Preliminary ratings completed by one IBCLC showed essentially no correlation between maternal and IBCLC scores on day 2 pp (rho=.001) and a negative correlation on day 7 pp (rho=‐.464). Additionally, the maternal ratings of rooting, fixing, and sucking pattern were not significantly correlated to total maternal IBFAT scores on day 7 pp (rho=.272, .085, and .080 respectively) and IBCLC ratings of rooting and fixing items were not significantly correlated to the total IBCLC score on day 7 pp (rho=.117 and .139 respectively). These preliminary finding suggest a lack of maternal comprehension of the components of a successful BF session and demonstrate inconsistencies between maternal and IBCLC ratings for specific scale items. Funded by CDC via subcontract with APTR.
No relationship between egg consumption and cardiovascular risk factors in postmenopausal women
Authors: Chai Sheau C , Hooshmand Shirin , Saadat Raz L , Arjmandi Bahram H
Published: June 2021

Obesity, a known risk factor for cardiovascular disease (CVD), has also been linked to higher serum levels of C‐reactive protein (CRP), an independent atherogenic risk factor. The present study examined the relationship between body mass index (BMI) and high‐sensitivity CRP (hs‐CRP) and found that people in upper BMI categories had significantly elevated serum levels of hs‐CRP. Correlation analysis was also performed to assess the degree to which CVD risk factors such as BMI, hs‐CRP, and lipid profiles are influenced by dietary confounders including fiber, fat and egg consumption. Food frequency questionnaire and overnight fasting blood samples were collected from one hundred and forty‐six (146) postmenopausal women not on hormone replacement therapy. Although there is a general concern about egg consumption in relation to lipid profiles, especially serum total cholesterol, we did not find any relationship between egg consumption, lipid profiles, and hs‐CRP. On the other hand, dietary trans‐fat intake was positively and fiber and vitamin C intakes were negatively correlated with CVD risk factors. Previously, we have reported that BMI can be used as a predictor of hyperlipidemia and hyperglycemia in postmenopausal women, and in this study we report that BMI can also be used as a predictor of serum hs‐CRP level in this population.
Inhibition of soluble epoxide hydrolase attenuated atherosclerosis, abdominal aortic aneurysm formation and dyslipidemia in apolipoprotein E deficient mice infused with angiotensin II
Authors: Zhang Lening , Vincelette Jon , Cheng Ying , Mehra Upasana , Chen Dawn , Kumar‐Anandan Sampath , Gless Richard , Webb Heather , Wang Yi‐Xin (Jim)
Published: June 2021

Objective‐Epoxyeicosatrienoic acids (EETs) have been shown to have anti‐inflammatory effects. So they may play a role in preventing vascular inflammatory and atherosclerotic diseases. Soluble epoxide hydrolase (s‐EH) converts EETs into less bioactive dihydroxyeicosatrienoic acids. Thus, inhibition of s‐EH can prevent degradation of EETs and prolong their effects. The present study is aimed to test the hypothesis that inhibition of s‐EH has vascular protective effects. Methods and Results‐Six‐month old apolipoprotein E deficient mice were chronically infused with angiotensin II (1.44 mg/Kg/day) for 4 weeks to induce abdominal aortic aneurysm (AAA), accelerate atherosclerosis development and carotid artery ligation‐induced vascular remodeling. The mice were treated with a novel s‐EH inhibitor, AR9276 in drinking water or vehicle for 4 weeks. The results demonstrated that AR9276 significantly reduced the rate of AAA formation and atherosclerotic lesion area, but had no effect on ligation‐induced carotid artery remodeling. These effects were associated with a reduction of serum IL‐6, murine IL‐8 KC and IL‐1α, and down‐regulation of gene expressions of ICAM‐1, VCAM‐1 and IL‐6 in the arterial wall. AR9276 treatment also lowered LDL and elevated HDL levels. Conclusions‐The present data demonstrate that treatment with an s‐EH inhibitor attenuates AAA formation and atherosclerosis development. The attendant down‐regulation of inflammatory mediators and lipid lowering effects may both contribute to the observed vascular protective effects.
Mechanism on Insulin Sensitization and Corpulent‐reducing of Astragalus Polysaccharide
Authors: Zhang Jingfang , Liu Jian , Ouyang Jingping
Published: June 2021

To explore the mechanism on insulin sensitization and corpulent‐reducing of Astragalus Polysaccharide(APS).SD rats were randomly divided into four groups: normal control group, APS control group, Type II Diabetes Mellitus(TIIDM) group , TIIDM plus APS therapy group. The protein tyrosine phosphatase 1B(PTP1B) expression of adipose tissue of rats in each group was detected by immunohistochemistry. the PTP1B expression of adipose tissue of rats in each group was weakly positive, and the colour of surrounding part of adipose tissue was light yellow brown. The PTP1B expression of adipose tissue of rats in TIIDM group was obviously higher than that of normal control group by measuring the optical density value. The APS therapy could reduce the PTP1B expression of adipose tissue of rats in TIIDM group to close to normal level. The results of our research showed that the mechanism on insulin sensitization and corpulent‐reducing of APS may be related to increasing the sensitivity of Leptin by suppressing the PTP1B expression
Roles of ciliary polycystin and survivin in cardiovascular abnormality in PKD
Authors: AbouAlaiwi Wissam A , Nauli Surya M
Published: June 2021

Background

Polycystic kidney disease (PKD) is characterized by the development of fluid‐filled cysts in the kidney. However, cardiovascular hypertension and aneurysm represent the most serious life‐threatening complications in PKD patients. We have recently shown that polycystins are localized to the endothelial cilia and function in regulating intracellular calcium and nitric oxide synthesis in response to fluid‐shear stress.

Methods and Results

We show here that two different PKD endothelial cells, Pkd1 (29%) and Tg737 (32%), are characterized by abnormal cell division (p<0.05, compared to wild type cells). We also observe a significant centrosomal over‐duplication, multipolar spindle formation, nuclear fragmentation and polyploidism leading to chromosome instability and mitotic catastrophe in Pkd1 (16%) and Tg737 (20%). These mitotic abnormalities are associated with the down‐regulation of survivin, an inhibitor of apoptosis and a chromosomal passenger protein involved in mitotic spindle checkpoint and regulation of chromosomal segregation.

Conclusion

Taken together, our findings provide a novel evidence of the roles for ciliary polycystins in regulating cell division through survivin expression and confirm the proposed involvement of cilia in cell division, parallel to their roles as fluid mechanosensors.
Endothelial function and vascular oxidative stress in long‐lived GH/IGF‐deficient Ames dwarf mice
Authors: Ungvari Zoltan , Labinskyy Nazar , Podlutsky Andrej , Austad Steven , Mukhopadhyay Partha , Pacher Pal , Bartke Andrzej , Csiszar Anna
Published: June 2021

Hypopituitary Ames dwarf mice have low circulating GH/IGF‐1 levels and they have extended longevity and exhibit many symptoms of delayed aging. To elucidate the vascular consequences of Ames dwarfism we compared endothelial O2(‐) and H2O2 production, mitochondrial ROS generation, expression of antioxidant enzymes and NO production in aortas of Ames dwarf and wild type control mice. In Ames dwarf aortas endothelial O2(‐) and H2O2 production and ROS generation by mitochondria were enhanced compared to those in vessels of wild type mice. In Ames dwarf aortas there was a less abundant expression of Mn‐SOD, Cu,Zn‐SOD, Gpx‐1 and eNOS. NO production and acetylcholine‐induced relaxation were also decreased in aortas of Ames dwarf mice. In cultured wild type mouse aortas and in cultured coronary arterial endothelial cells treatment with GH and IGF significantly reduced cellular ROS generation and up‐regulated expression of Mn‐SOD, Cu,Zn‐SOD, Gpx‐1 and eNOS. Thus, GH and IGF‐1 promote anti‐oxidant phenotypic changes in the endothelial cells, whereas Ames dwarfism leads to vascular oxidative stress.
Distinctive phenotypic, metabolic and contractile properties of Ins2Akita+/− and streptozotocin‐induced diabetic skeletal muscles.
Authors: Krause Matthew Paul , Riddell Michael C , Gordon Carly S , Imam S Abdullah , Cafarelli Enzo , Hawke Thomas J
Published: June 2021

The impact of type 1 diabetes on skeletal muscle (diabetic myopathy) during adolescence is largely unknown. Diabetic myopathy studies commonly use streptozotocin‐induced diabetic (STZ) rodents; however, streptozotocin has known detrimental effects on muscle cell growth. Here, we examined mechanisms of diabetic myopathy in adolescent Akita and STZ mice following 8 weeks of diabetes. Both models exhibited reduced muscle mass (Akita: 0.124 ± 0.008g; STZ: 0.124 ± 0.024g; Con: 0.162 ± 0.015g) and IIB/D fiber area (Akita: 57.7 ± 4.2% and STZ: 78.9 ± 7.3% of Con). Intramyocellular lipid was increased in STZ (122.9 ± 3.6% of Con) but not Akita muscle, resulting from lower citrate synthase and β‐HAD activities in STZ muscle. Functional analyses revealed lower absolute peak force in Akita (70.2 ± 8.2% of Con) but not STZ muscle (87.6 ± 7.9% of Con). Corrected for muscle mass, no relative force difference was observed between Akita and Con, while STZ relative force was significantly elevated. STZ muscle exhibits contractile, metabolic and phenotypic properties distinct from Akita, despite similarity in hyperglycemia, furthering concerns of toxic effects of streptozotocin on muscle. In Akita mice, muscle atrophy and specific fiber type loss did not affect contractile properties (relative to muscle mass), suggesting that pathological metabolic changes within diabetic muscle precede alteration of contractile properties.
Skeletal Muscle Mitochondria in Microembolism‐induced Heart Failure
Authors: Rosca Mariana G , Stanley William , Sabbah Hani , Hoppel Charles
Published: June 2021

Bioenergetic failure is proposed as the primary mechanism responsible for the skeletal muscle myopathy in heart failure (HF). We analyzed the two populations of skeletal muscle mitochondria (subsarcolemmal, SSM, and interfibrillar, IFM) in moderately severe canine coronary microembolization‐induced HF. Activities of the electron transport chain (ETC) complexes, and integrated function (oxidative phosphorylation) in freshly isolated intact mitochondria were measured. The yield of SSM was unchanged while that of IFM was increased in HF. These IFM showed decreased oxidative phosphorylation with complex I substrates while respiratory rates with complexes II, III and IV substrates were normal. The activities of individual ETC complexes, including complex I, were normal. Thus, the content of skeletal muscle IFM is increased by HF, but these mitochondria have a selective defect in oxidative phosphorylation through complex I. We are exploring whether the organization of oxidative phosphorylation in supercomplexes (respirasomes) is disrupted in these skeletal muscle IFM in HF.
Gender differences in the renal sympathetic nerve response to myocardial infarction
Authors: Malpas Simon , Pinkham Max , Guild Sarah‐Jane , Barrett Carolyn
Published: June 2021

The aim of this project was to determine if there are gender differences in the renal sympathetic nerve activity (RSNA) response immediately following a myocardial infarct (MI). RSNA, arterial pressure and ECG were recorded in anaesthetized male and female rats before and for two hours following MI, induced by coronary artery ligation. In male rats coronary ligation resulted in abrupt increase (32 ± 12%) in RSNA before subsiding to lower steady state within 10 minutes of the infarct for the next 2 hours (13 ± 4 % above the baseline level, P < 0.05). In contrast in female rats no significant changes in RSNA were observed in response to myocardial infarction. No change in RSNA was observed in sham operated rats. Arterial pressure responses were also different between the male and female rats; two hours post‐infarct arterial pressure was 10 ± 5mmHg below that seen in the sham group (P < 0.05), whereas arterial pressure in the male rats was not significantly different to the shams. Post‐mortem analysis showed the coronary ligation resulted in a non‐perfused area of left ventricle of 35‐50%. These results support the concept that different treatment strategies may justified based gender post‐MI.
Autonomic Responses of Men and Women to Particulate Exposures
Authors: Evans Joyce McClendon , Patwardhan Abhijit , Jenkins Roger , Ilgner Ralph , Hartman Eric , Jayanthi Ashwin , Knapp Charles
Published: June 2021

Nonsmokers have demonstrated harmful (decreased heart rate variability) cardiovascular effects when seated in smoking, compared to non smoking, waiting rooms (Pope, 2001), but this study did not control for gender, environmental effects, or exposure to other particulates. We studied 40 (21 w, 19 m) volunteers exposed to 4 aerosols: 3 particulates, environmental tobacco smoke (ETS), cooking oil fumes (Coil), wood smoke (WS), and a nonparticulate, water vapor (Sham). Exposures were conducted in a controlled environmental chamber. Each subject was tested on 3 days and results averaged.

Results

Sympathetic control of heart rate (Lo/Hi frequency spectral power RRI), was greater in men than women, for ETS and Coil, compared to WS and Sham. Sympathetic control of vasomotion (LF spectral power of systolic pressure (LFSAP)), increased across particulate, not sham, exposures, peaking in recovery. At breathing frequency, men's LFSAP doubled after 10 min ETS exposure.

Conclusions

Exposures to particulates increased sympathetic control of heart rate and peripheral vasomotion, with a greater response in men than women during ETS and Coil. In controlled conditions, autonomic activity in non smoking men and women exposed to low level, short term particulate concentrations (this study) were similar to longer term, higher level exposures to ETS and to direct smoking. Supported by the External Research Program of Philip Morris USA.
Tolerance to central hypovolemia: The influence of cerebral blood flow velocity oscillations
Authors: Rickards Caroline A. , Ryan Kathy L. , Convertino Victor A.
Published: June 2021

Higher oscillations in cerebral blood flow velocity (CBFV) and blood pressure (BP) induced by breathing with inspiratory resistance are associated with delayed onset of symptoms and increased tolerance to central hypovolemia. We hypothesized that subjects with high tolerance (HT) to central hypovolemia would display higher oscillations in CBFV and BP at presyncope compared with subjects with low tolerance (LT). 107 subjects were exposed to progressive lower body negative pressure (LBNP) until the presence of presyncopal symptoms. Subjects were classified as HT if they completed at least the ‐60 mmHg level of LBNP (76 subjects; LBNP time, 1893 ± 31 sec) and LT if they did not complete this level (31 subjects; LBNP time, 1333 ± 21 sec). CBFV was measured at the middle cerebral artery by transcranial Doppler, and mean arterial pressure (MAP) was measured at the finger by photoplethysmography. Mean CBFV and MAP decreased progressively from baseline until presyncope for both LT and HT subjects (P=0.001), with a minimum CBFV of 55 ± 3 cm/s for LT compared with 49 ± 1 cm/s for HT (P=0.043). However, total oscillations (sum of high and low frequency oscillations) in mean CBFV and MAP increased in HT subjects (CBFV: baseline, 8.3 ± 1.2 vs. presyncope, 12.6 ± 1.1 cm/s2, P=0.014; MAP: baseline, 6.4 ± 0.6 vs. presyncope, 19.5 ± 1.6 mmHg2, P<0.001), but did not change in LT subjects (CBFV: baseline, 8.5 ± 1.1 vs. presyncope, 9.0 ± 1.0 cm/s2, P=1.0; MAP: baseline, 6.3 ± 0.5 vs. presyncope, 9.4 ± 0.9 mmHg2, P=0.733). Consistent with our previous findings using inspiratory resistance, high oscillations in CBFV and MAP are associated with HT to central hypovolemia.
Acute mountain sickness (AMS) at 3048m is exacerbated by dehydration
Authors: Sils Ingrid , Castellani John W , Beidleman Beth A , Muza Stephen R
Published: June 2021

Epidemiological evidence suggests that AMS has a higher incidence (IAMS) in people who are dehydrated, yet the effect of dehydration on IAMS and severity (SAMS) has not been prospectively tested. This study assessed AMS following rapid ascent to 3048m (ALT) in euhydrated (EU) and dehydrated (DE) subjects (SS). Seven males (mean±SD, 25±7yr, 82±11kg) participated in four trials over two weeks. On the day before a trial, SS either DE by 4% or remained EU while exercising in a climatic chamber (50oC, 20%RH). The next morning they ascended either to ALT or remained near sea‐level (152m, SL) for 8h in a hypobaric chamber (27oC, 34%RH). IAMS and SAMS were assessed using the cerebral factor score (AMS‐C) calculated from the Environmental Symptoms Questionnaire at 45min, 3h and 71/2h after ascent. Between 45min and 3h SS performed tasks ranging from low to high exertion.

Results

Arterial oxygen saturation (SaO2) was lower at ALT vs SL (90±2% vs 97±1%, p< 0.001). IAMS increased with DE (SL‐EU: 0/7 (0%); SL‐DE: 1/7 (14.3%); ALT‐EU: 2/7 (28.6%); ALT‐DE: 5/7 (71.4%)). SAMS increased somewhat with DE at SL (EU, 0.14±0.20; DE, 0.52±0.45; p<0.07) and at ALT (EU, 0.41±0.26; DE, 1.11±0.98; p<0.07). These results suggest that 4% DE increases SL resident's susceptibility and severity of AMS with rapid ascent and exposure to 3048m. Funded by US Army MRMC ATO IV.MD.2006.01. Authors' views are not official U.S. Army or DoD policy.
Intact peripheral chemoreflex regulation of sympathetic vasomotor tone in breath hold divers after detraining period
Authors: Breskovic Toni , Valic Zoran , Lipp Axel , Heusser Karsten , Ivancev Vladimir , Tank Jens , Dzamonja Gordan , Jordan Jens , Shoemaker Kevin J , Dujic Zeljko
Published: June 2021

We tested the hypothesis that peripheral chemoreceptor function in response to hypoxia is normal in breath‐hold divers (BHD) after detraining period. We compared ventilatory, sympathetic (MSNA), heart rate and blood pressure responses to isocapnic hypoxia in 11 BHD and 11 control subjects. The study was carried out at least one month after all divers finished most intensive apnea training. After baseline period for instrumentation, subjects breathed isocapnic hypoxic mixture to reduce arterial saturation to 0.8. During hypoxia burst frequency (MSNAf) and total activity (MSNAt, au/min) increased similarly in both groups (27% and 60% in BHD and 30% and 66% in controls), respectively. Increased MSNAf and MSNAt returned to baseline after 20 min after termination of hypoxia. Hypoxia‐induced stimulation of minute ventilation was similar in both groups. Cardiac output was increased during hypoxia and since mean blood pressure was unchanged, total peripheral resistance was similarly reduced in both groups. We conclude that elite divers at least 1 month after the end of intensive training/competition period have normal peripheral chemosensitivity without any ventilatory, hemodynamic and autonomic differences from those observed in control subjects.

This study was supported by the Croatian Ministry of Science, Education and Sports.
Resveratrol prevents RV/T changes in a neonatal model of hypoxia induced pulmonary hypertension
Authors: Slutzky Jessica Lauren , Natale Elizabeth K , Sprinkle Spencer L , Chicoine Louis G
Published: June 2021

Abstract

Resveratrol (trans‐3,5,4′‐trihydroxystilbene) is a polyphenolic compound found in red wine and possesses anti‐inflammatory, antioxidant, and antifibrotic properties. We tested the hypothesis that daily resveratrol treatment would attenuate the development of hypoxia induced pulmonary hypertension (PHT). Two day old Spague‐Dawley rats were treated with daily SQ injections of resveratrol (100 mg/kg) or vehicle and placed in normoxia or hypobaric hypoxia (435 torr) for 14 days. Measurement of right ventricle wall weight divided by the total heart weight (RV/T) was used as a measure of PHT. RV/T was greatest in vehicle treated neonatal rats exposed to chronic hypoxia (0.46 ± 0.03, P<0.05 compared to the other 3 groups), whereas, normoxic vehicle treated (0.23 ± 0.02), normoxic resveratrol treated (0.24 ± 0.02), and hypoxic resveratrol treated (0.29 ± 0.03) RV/T where not different from each other. Hypoxic exposure resulted in lower (P<0.05) body weights than in normoxic exposure, and resveratrol did not affect body weight in either normoxic or hypoxic pups (weight at harvest was 36.0 ± 0.8 g normoxic vehicle, 39.3 ± 1.3 g normoxic resveratrol, 27.1 ± 1.2 g hypoxic vehicle, and 25.6 ± 1.1 g hypoxic resveratrol). These results suggest that resveratrol prevents chronic hypoxia induced pulmonary hypertension and may be clinically useful in the treatment of pulmonary hypertensive disease.
Myosin Light Chain Kinase and Regulatory Myosin Light Chain are more tightly co‐localized in fetal compared to adult ovine carotid arteries
Authors: Pearce William Julian , Injeti Elisha R , Abrassart Jenna , Graupner Gerhart
Published: June 2021

We have previously shown that maximal Myosin Light Chain Kinase (MLCK) activity measured in situ is greater in fetal than adult ovine carotid arteries, even though the absolute abundances of MLCK and its substrate, MLC20, are greater in adult than in fetal arteries. Conversely, maximal MLCK velocity and substrate affinity are similar in fetal and adult artery homogenates, suggesting that in situ fractional activation of MLCK is greater in fetal than in adult arteries. One possible explanation for these observations is that MLCK and MLC20 are more tightly co‐localized in fetal than in adult arteries. To test this hypothesis, the distributions of both molecules were examined in coronal sections of carotid arteries from both age groups using fluorescent immunolabeling and confocal microscopy. The ratio between MLCK and MLC20 expression was highly variable and in some cases, very different ratios were observed in adjacent smooth muscle cells. In adult smooth muscle cells, co‐localization appeared greater near the sarcolemma than in the cell interior, whereas in fetal smooth muscle cells co‐localization was more uniform throughout the cell. These results suggest that co‐localization of MLCK and MLC20 is not uniform in ovine carotid arteries, and that differences in co‐localization can help explain age‐related differences in MLCK activity, in situ. Supported by USPHS Grants HL54120, HD31266, & HL64867.
Caveolin‐1 regulates eNOS derived superoxide production under condition of tetrahydrobiopterin depletion and oxidation
Authors: Karuppiah Kanchana , Druhan Lawrence , Kearns Patrick , Brabham Dione , Cardounel Arturo
Published: June 2021

The paradoxical finding of a concomitant increase in eNOS expression and reduced endothelium‐dependent vasodilation has drawn attention to the fact that eNOS itself in pathological states may be a source of superoxide anions, a process which has been termed "eNOS uncoupling". eNOS uncoupling has been shown to result from oxidation of the critical NOS cofactor, tetrahydrobiopterin (BH4). In the current study, we identified caveolin‐1 as a novel regulator of eNOS derived superoxide under condition of both BH4 oxidation and depletion. In‐vitro results demonstrated that cav‐1 peptide was able to dose dependently inhibit eNOS derived superoxide with >70% inhibition observed at 400nM. Cellular studies demonstrated that pharmacological depletion of endothelial BH4 resulted in an 88% decrease in eNOS derived NO with no significant increase in eNOS derived superoxide. Immunoprecipitation studies demonstrated a 3 fold increase in cav‐1‐eNOS association following BH4 depletion which was hypothesized to sequester and thus prevent uncoupling of pterin‐free eNOS. This was verified using cav‐1 gene silencing techniques which demonstrated a 5 fold increase in eNOS derived superoxide following BH4 depletion. Similar finding were observed under conditions of hyperglycemia which are known to cause oxidation of BH4. These studies identify cav‐1 as a novel regulator of eNOS derived superoxide.
Experimental analysis of nitric oxide‐red blood cells interactions using a novel micron scale flow system
Authors: Deonikar Prabhakar , Kavdia Mahendra
Published: June 2021

NO consumption by RBCs in blood vessels is reported to be several folds lesser than free Hb. Mechanisms of reduced NO uptake by RBCs are under intense investigation. NO delivery to the RBCs is critical in quantification of interactions. Common methods of NO delivery include saturated NO solutions and NO‐donors that create localized NO concentration and have unsteady NO release rates, respectively. We designed a micron scale flow system in which precise amounts of gaseous NO can be delivered over longer periods through polymeric semi‐permeable membrane. The flow system simulates in vivo conditions like the constant NO flux from endothelium to the lumen, diffusional resistances for NO transport in the lumen and NO reaction with flowing RBCs. Using the flow system, we studied the effect of NO concentration, RBC flow rates and hematocrit on NO‐RBC interactions. NO‐RBC reaction products (nitrite and total nitrogen species (NOx)) were measured using chemiluminescence analyzer. Nitrite and total NOx formation increased with NO concentrations, however, nitrite and total NOx formations nearly doubled when RBC flow rate was halved. Nitrite and total NOx formations decreased with hematocrit. Results obtained from this study further enhance our understanding of the effects of hemodynamic parameters on the NO‐RBC interactions. Supported by: AHA 0530050N and NIH R01 HL084337 & R15 HL087287.
Use of resveratrol and quercetin combination as potential therapeutic for treatment of in‐stent restenosis and thrombosis
Authors: Khandelwal Alok Radheyshyam , Hebert Valeria , Dugas Tammy R
Published: June 2021

Recent epidemiological studies suggest restenosis and acute in‐stent thrombosis as important complications of carotid angioplasty and stenting. Our objective was to identify a drug combination that would inhibit both restenosis and thrombosis. We studied two red wine polyphenols, resveratrol (RESV) and quercetin (QUER) that emerged as lead candidates in our prior in vitro studies using platelets and vascular smooth muscle cells. B6.129 female mice were fed a high fat diet containing RESV (50 mg/kg), QUER (10 mg/kg) and RESV plus QUER for 2 weeks. The carotid artery denudation procedure was performed and the mice were again administered the high fat diet‐containing polyphenols for 2 weeks. After sacrifice, the carotid arteries were excised for morphometric analysis and serum, collected for measurement of TXB2 as a marker for platelet activation. Our results indicate RESV, but not QUER, significantly decreased the restenotic index (p<0.05). Interestingly, with combination treatment, QUER potentiated RESV‐mediated decrease in neointimal hyperplasia (p<0.01). Conversely, QUER, but not RESV, significantly decreased serum TXB2 levels, with RESV potentiating the effects of QUER (p<0.01). In conclusion, our studies suggest that in combination, RESV and QUER can synergize to effectively reduce the pathogenesis of restenosis. Future implications include the use of this drug combination in drug eluting stents.

Grant Funding Source

RO1‐HL082472
Thyroid hormone analogue 3,5‐diiodothyropropionic acid (DITPA) promotes healthy vasculature in the adult myocardium independent of thyroid metabolic effects
Authors: Liu Yingheng , Wang Dajun , Redetzke Rebecca , Gerdes Anthony Martin
Published: June 2021

Patients with hypothyroidism are at higher risk for coronary vascular disease. Patients with diabetes and related vascular complications also have an increased incidence of low thyroid function. While thyroid hormones (THs) may be key regulators of healthy vasculature, potential undesirable side effects hinder their use in the treatment of vascular disorders. TH analogs such as DITPA may provide a safer treatment option. We hypothesized that the vascular growth promoting effects of DITPA can be obtained with little or no effect on cardiac function and metabolism. Thyroidectomized Sprague Dawley rats were given slow‐release pellets with either thyroxine (T4, 2.7‐mg or 5.2‐mg) or DITPA (80‐mg) for 6 weeks and compared to placebo. Hypothyroidism led to reductions in cardiac function, heart mass, body temperature, and myocardial arterioles. High dose T4 prevented arteriolar loss and development of hypothyroidism. Low dose T4 partially prevented the reduction in cardiac function but had minimal effects on arteriolar loss. In contrast, DITPA treatment prevented myocardial arteriolar loss but not progression of hypothyroid‐induced changes in cardiac function and metabolism. Results suggested that DITPA can promote healthy vasculature independently from its thyroid related metabolic effects. Drugs in this class may provide new therapeutic options for patients with vascular disease.

Grant Funding Source

P20RR017662 from the National Center for Research Resources
Obstetrical adaptation in the human bony pelvis: A morphometric approach
Authors: Brown Kirsten Marie , DeLeon Valerie , Ruff Christopher
Published: June 2021

Previous work documenting pelvic sexual dimorphism and variation in humans has relied primarily on typology and linear measurements. However, these allow only limited interpretation of adaptive changes in pelvic morphology. The bony pelvis is a complex, 3D structure, and anatomical features are expected to respond differentially to obstetric selective pressures. This study is a 3D geometric morphometric analysis of pelvic morphology in a cadaveric sample of American black males (n=19) and females (n=20). Forty‐four biologically relevant landmarks were digitized on articulated pelves. Generalized Procrustes Analysis (GPA) and Euclidean Distance Matrix Analysis (EDMA) were used to localize areas of shape changes between the sexes.

GPA analysis showed significant shape differences between the sexes; relative to other landmarks, the pubis moves inferiorly, the sacrum moves posteriorly, and the ischial tuberosities and the ischial spines move laterally in the female. EDMA analysis demonstrated that the posterior space is more sexually dimorphic than the anterior space. These results suggest that obstetrical adaptation involves the mediolateral expansion of the pelvic midplane and outlet and the posterior displacement of the sacrum. Obstetric adaptation is more pronounced posteriorly, suggesting that variation in the anterior space may be contrained by biomechanical requirements.

Grant Funding Source

None
Double whole‐mount staining for bone deposition and resorption
Authors: Edsall Sara , Franz‐Odendaal Tamara
Published: June 2021

Methods to detect osteoblasts, bone depositing cells, and osteoclasts, bone resorpting cells are known. These methods involve enzymatic procedures (alkaline phosphatase and tartrate‐resistant acid phosphatase) and are usually conducted on sectioned material; with the procedure for each type of staining conducted on adjacent serial sections. We have optimised a procedure to whole‐mount stain the same zebrafish for both bone deposition and resorption. The alkaline phosphatase procedure stains osteoblasts a purple colour and the tartrate‐resistant acid phosphatase gives a red colour; making the two cell types easily distinguishable. The stained specimen can be decalcified if necessary and sectioned, with preservation of the cell staining. We have applied this methodology to whole fish at various stages of development and have focused our investigations on the jaw, fins and vertebral column regions. Bone deposition was clearly observed in the mandible and maxilla; the developing fins, the ends of fin ray segments and the edges of the developing calvariae. On similarly aged fish, bone resorption was detected in the neural spines of the vertebrae; mandible and maxilla; with very limited amounts within the fins. We believe this methodology would be useful to the field of skeletal biology as it enables double staining of the same specimen and avoids lengthy resin embedding procedures. Funding NSERC, Canada

Grant Funding Source

NSERC, Canada
Interplay between Mre11 nuclease and Dna2 nuclease/helicase in DSB repair and at telomeres
Authors: Campbell Judith L , Budd Martin E , Polaczek Piotr
Published: June 2021

The Mre11/Rad50/Xrs2 complex is a central player in DSB repair and is the first protein to arrive at a newly formed break. 5' to 3' resection at the end of a break is an early and a necessary step for repair. Although MRX may be important for this step, the associated nuclease has 3' to 5' polarity, opposite to the expected 5' to 3' polarity; and more important, Mre11 nuclease deficient mutants are only mildly sensitive to DSB‐inducing agents. Thus, there is some gene that compensates for Mre11 nuclease deficiency. We show that the Dna2 nuclease/helicase, which is essential for DNA replication, can perform this role, probably working in 5' to 3' resection. The helicase activity of Dna2 is toxic in this reaction in the absence of the nuclease activity. 3' to 5' resection by Dna2 is inhibited by RPA.

Dna2 and Mre11 are also known to play important but ill‐defined roles at telomeres. We show, however, that their interaction at telomeres may have a different outcome from that at internal DSBs, since double mutants show significant accumulation of single‐stranded DNA at telomeres.

Supported by USPHS.
Tiling Microarray Analysis of NMD and Splicing mutants reveal novel functions for the NMD in the quality control of the splicing process and in subtelomeric gene silencing
Authors: Chanfreau Guillaume , Janis Michael , Kawashima Tadashi , Nery Camille , Sayani Shakir , Toesca Isabelle
Published: June 2021

We have analyzed global transcriptome in yeast strains lacking the NMD component Upf1p or Xrn1p using tiling microarrays. Using these arrays, we showed recently that NMD eliminates many unspliced precursors that arise from inefficient splicing (Sayani, Mol.Cell 2008). We pursued this analysis by generating double mutants where splicing factors and the NMD are both inactivated. Arrays of these double mutants showed that unspliced precursors of many genes are detectable only when both NMD and these splicing factors are inactivated, indicating that NMD eliminates unspliced precursors resulting from splicing factors inactivation. This is a new function for NMD, as the nuclear exosome was thought to be responsible for degrading unspliced RNAs resulting from splicing factors mutations. Finally, we found that many subtelomeric genes accumulate 5′‐extended species in NMD mutants. These extended RNAs function to repress transcription at the normal promoters. NMD mutants are deficient for induction of these genes, but inactivation of the Histone Deacetylase Hda1p is sufficient to rescue this defect, suggesting a connection between silencing due to these 5′‐extended RNAs and chromatin modifications. Overall, these results have revealed novel functions for NMD in quality control of splicing in yeast, and identified an intriguing connection between NMD function and subtelomeric gene silencing.
Functional Rescue of Mutant Human Cystathionine Beta‐Synthase by Manipulation of Hsp26 and Hsp70 Levels in Saccharomyces cerevisiae
Authors: Kruger Warren D , Singh Laishram
Published: June 2021

Many human diseases are caused by missense substitutions that result in misfolded proteins that lack biological function. Here, we express a mutant form of the human cystathionine beta‐synthase protein, I278T, in S. cerevisiae and show that it is possible to dramatically restore protein stability and enzymatic function by manipulation of cellular chaperone environment. We demonstrate that Hsp70 and Hsp26 bind specifically to I278T, but that these chaperones have opposite biological effects. Ethanol treatment induces Hsp70 and causes increased activity and steady‐state levels of I278T. Deletion of the SSA2 gene, which encodes a cytoplasmic isoform of Hsp70, eliminates the ability of ethanol to restore function, indicating that Hsp70 plays a positive role in proper I278T folding. In contrast, deletion of HSP26 results in increased I278T protein and activity, while overexpression of Hsp26 results in reduced I278T protein. The Hsp26‐ I278T complex is degraded via a ubiquitin/proteosome dependent mechanism. Based on these results we propose a novel model in which the ratio of Hsp70 and Hsp26 determine whether misfolded proteins will either be refolded or degraded.