bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanistic Insights into Membrane Remodeling Through BAR‐Domain Proteins
Authors: Frost Adam , Mim Carsten , Perera Rushika , Spasov Krasimir , Egelman Edward , De Camilli Pietro , Unger Vinzenz M 
Published: June 2021

Critical to cellular physiology, cells constantly manipulate the shape of their constituent membranes through processes whose mechanisms are poorly understood. A major limitation in the study of membrane remodeling is the lack of structural information that visualizes membrane‐remodeling domains in the context of their bilayer substrates. Overcoming this bottleneck, we obtained structural models for two membrane‐bound states of F‐BAR domains by electron cryomicroscopy and image reconstruction. The models suggest that F‐BAR domains can engage bilayers through two very different molecular surfaces that are aligned with functional states prior to, and after induction of membrane curvature. Moreover, the reconstructions reveal how curvature is generated through the cooperative assembly of a highly organized protein scaffold, and how subtle changes in the orientation of dimeric F‐BAR modules facilitate the generation of structures with a range of different curvatures.Supported by PHS grant DA024101
Comparative morphology of the optic nerve in nocturnal and diurnal birds
Authors: Grady Shauna Marie , Perkins Ashley R , Hall Margaret I 
Published: June 2021

Nocturnal and diurnal birds exhibit differences in retinal wiring, specifically with regard to "retinal pooling," or the number of photoreceptor cells providing information to a single ganglion cell in the retina. Diurnal birds have low retinal pooling, which acts to increase acuity, since each photoreceptor cell is responsible for a proportional angle of visual space. Nocturnal birds have high retinal pooling; if multiple photoreceptors provide information to a single ganglion cell, light sensitivity is increased. The optic nerve (CN II) is comprised of the ganglion cell axons delivering visual information to the brain. This study tests the hypothesis that nocturnal birds consistently exhibit a smaller optic nerve and chiasm than diurnal birds, based on area measurements. Whole bird heads are preserved in 4% paraformaldehyde, and the optic nerve and chiasm are dissected and mounted in modeling clay and photographed. Areas are measured from the photographs in SigmaScan. ANOVA and regression analysis of the comparative size of the optic nerve supports our hypothesis that nocturnal birds have consistently smaller optic nerve and optic chiasm areas.Grant Funding SourceAAA Student Travel Award
Fibroblast Differentiation in Dermal Equivalents Affected by Tension, Age in Culture, and TGF‐β
Authors: Palmer Tiffany Robin , Vaughan Melville Bailey 
Published: June 2021

The objective of this study was to determine if tension and/or transforming growth factor beta (TGF‐β) induce stress on human fibroblasts causing the development of stress fibers and differentiation into proto‐myofibroblasts (a transitional state) and myofibroblasts and if its affect varies with cell age. The study used three different age groups of normal dermal fibroblasts including young, old, and immortal, each individually mixed with collagen in the presence or absence of a tension‐maintaining ring. Each well was given media and half of each group was given TGF‐β‐treated media. The plate was then incubated at 37°C with new media on the fifth day. After seven days the cells were fixed and one from each treatment group was selected to be stained and photographed using immunofluorescence technology. Preliminary results showed the old and young cells reacted as expected as the percentage of myofibroblasts increased with tension and TGF‐β. However, the immortal line showed little differentiation which could be attributed to their proliferation in the lattice. The development of an epidermal equivalent by adding keratinocytes will follow.Grant Funding SourceNIH Idea Network of Biomedical Research Excellence P20 RR016478‐06
Purification and characterization of mutant exon 1 huntingtin polyglutamine expressed in a mammalian system
Authors: Feng Xia , Porat Yair , Ross Christopher A. , Poirier Michelle A. 
Published: June 2021

Huntington's disease is a neurodegenerative disorder characterized by neuronal degeneration and inclusions containing N‐terminal fragments of mutant huntingtin (htt). Polyglutamine aggregation is a complex process, involving the assembly of multiple intermediates prior to the formation of inclusions. Recent studies have suggested that soluble htt oligomeric or protofibrillar forms may be more toxic than late‐stage fibrils. Previously, we expressed recombinant mutant htt exon‐1 fragment in bacteria. We monitored aggregation over time and showed that globular and protofibrillar species comprised of β‐structure participate in the genesis of mature fibrils. In the present study, we have established a mammalian system for expression of GST‐tagged htt exon‐1 in HEK293 cells. Our preliminary aggregation data indicate that recombinant mutant htt exon‐1 produced in a mammalian system aggregates more slowly than the protein generated in bacteria, possibly resulting from post‐translational modifications. Future experiments will be aimed at isolating mammalian htt exon‐1 monomer and aggregation species and further investigating morphological and structural features of each form.Grant Support: NIH/NINDS
Interactions of native and aggregated HypF‐N with lipid monolayers and supported bilayers of varied lipid composition
Authors: Marano Nadia , Mackay Fraser , Nichino Daniela , Relini Annalisa , Rolandi Ranieri , Gliozzi Alessandra , Stefani Massimo 
Published: June 2021

We studied the effect of the model amyloid‐forming protein, HypF‐N (the N‐terminal domain of the prokaryotic hydrogenase maturation factor HypF), in its native and aggregated form on the integrity of model lipid membranes, including those more representative of natural membranes, using AFM and surface pressure measurements. Using fluorescence spectroscopy, we studied the effect of lipids on the structure of HypF‐N. We find that native protein has a larger effect on model membranes than aggregated protein. Model membranes composed of lipid raft forming mixtures (phosphatidylcholine: sphingomyelin: cholesterol, 1:1:1) were much more resistant to insertion of protein and membrane disruption than those composed of a 1:1 mixture of phosphatidylcholine (PC) and phosphatidylserine (PS). Addition of cholesterol to the latter mixture made the membranes less resistant to protein insertion. Liposomes containing the negatively charged lipid PS induced a strong quenching in fluorescence of HypF‐N (indicating a change in the environment of tryptophan and tyrosine residues) while those containing only PC had little effect. Preliminary denaturation experiments indicate relatively strong binding of HypF‐N to PS:PC liposomes.Research was supported by Saint Lawrence University, University of Genoa and University of Florence.
Hepatic steatosis induced by methionine‐choline deficiency alters the response to ischemia/reperfusion
Authors: Tevar Amit D , Clark Calissia , Wang Jiang , Edwards Michael , Lentsch Alex B 
Published: June 2021

Hepatic steatosis has been associated with poor outcomes in liver surgery and transplantation. The mechanism of this has not been fully elucidated.In the present study, we examined the effect of liver steatosis, induced by a methionine‐choline deficient (MCD) diet, on the response to hepatic ischemia/reperfusion. MCD mice and controls were sacrificed at 3, 6 and 9 weeks and pathologic examination was performed to determine degree of steatosis, inflammation and fibrosis. Mice at these times also underwent 90 min of partial hepatic ischemia followed by 1, 4 and 8 hours of reperfusion. Serum and histological analyses were performed to assess functional and pathologic injury to the liver.At 3, 6 and 9 weeks MCD mice showed progressive fibrosis and consistent severe hepatic macrosteatosis. In control mice, hepatocellular damage, as measured by serum transaminases, was increased as reperfusion time increased. Surprisingly, MCD mice had less necrotic liver injury than control mice. In contrast, liver accumulation of neutrophils, as measured by myeloperoxidase content, was increased in MCD mice compared to controls.The data suggest that the response to ischemia/reperfusion in steatosis induced by the MCD diet is different than other steatotic models. This may be due to progressive inflammatory and fibrotic change and warrants further investigation of the MCD diet model.
Comparison between Mediterranean type diet and Mediterranean fat effects in rats neoplastic lesions
Authors: Pereira Paula Cardoso , Cabrita António Silvério , Vicente Filipa 
Published: June 2021

Research had shown some implication of dietary factors in breast cancer, according to epidemiologic and experimental results. This study pretends to establish a relationship between the consumption of a diet with olive oil and a Mediterranean diet in the number and volume of breast cancer tumours. A total of 72 female rats 50 days old constituted the sample. These were divided in three groups of 24 and housed 5 in each plastic cage in a holding room under constant conditions of 22±2 °C, 55±10% humidity and a 12 h light/dark cycle. All the animals were submitted to the administration of 20 mg of 7, 12 dimethylbenzanthracene (DMBA) in olive oil, by gavages and were feed with standard diet. The Group II also received a Mediterranean‐type supplement (mixture of sardine, pepper, tomato, potato, onion lyophilized) while Group III received Olive oil in the standard food (50ml/Kg).After 150days the animals were sacrificed and the neoplastic lesions were evaluated according to the general score and the volume. In this series we can observe a non‐significant variation in the tumours number between the three groups but the tumours volume were significantly different between the groups two and three (p<0,05). The olive oil supplemented group suffered from a greater number of neoplastic lesions but the size was significantly smaller than the other groups.
Resistin, but not adiponectin is elevated in Caucasian prostate cancer patients
Authors: Smith Brennan Kerr , Robinson Lindsay , Nam Robert , Ma David 
Published: June 2021

Emerging evidence suggests that adipokines, such as resistin and adiponectin, play a role in modulating cancer risk. However, the role of resistin and adiponectin in prostate cancer (PCa) risk is poorly understood. 275 archived plasma samples consisting of 138 PCa cases and 137 controls were analyzed for resistin and total adiponectin protein using a Bio‐Plex human adipokine assay and xMAP technology. Overall, resistin, but not adiponectin, was significantly elevated (p=0.02) in PCa patients compared with controls. Future studies are warranted to determine the functional role of resistin in PCa. When examined by ethnicity, there was no difference between cases (n=16) and controls (n=8) in African American subjects for either adipokine. In contrast, among Caucasians, adiponectin (p=0.07) and resistin (p=0.03) were higher in PCa patients (n=114) compared with controls (n=110). Our data suggests that differences in circulating adipokines may exist between ethnic groups, but this requires further study in a larger population. (D. Ma. is funded by an NSERC Discovery grant. B.K. Smith is funded by an OGS and Sun Life Financial Research Fund)Grant Funding SourceOntario Graduate Scholarship and Sun Life Financial Research Fund
Dietary fat intake and lung cancer: results from the Lower Mississippi River Interagency Cancer Study
Authors: Zhang Zhenzhen , Su Joseph L. , Luckett Brian G. , Fontham Elizabeth T. H. 
Published: June 2021

Lung cancer remains to be the leading cause of cancer deaths in the United States. Besides smoking, many dietary factors can also influence the development of lung cancer. This analysis is based on a population‐based case‐control study designed to assess lung cancer risk associated with occupational and/or environmental exposures. The relationship between dietary fat intake and lung cancer is examined. A food frequency questionnaire was used to assess nutrient intake prior to cancer diagnosis for cases and prior to interview for controls. After excluding subjects with extreme daily caloric intakes, 420 cases (average age 61; 51% men) and 401 controls (average age 60; 49% men) were included in the analysis. After adjusting for age, sex, race, marital status, body mass index, total caloric intake and smoking, odds ratios (OR) and 95% confidence intervals(CI) for upper quartile versus lower three quartiles of daily intake of cholesterol, saturated fat and total fat were calculated using multiple logistic regression. ORs (95% CI) for intakes of cholesterol (> 357 mg/day), saturated fat (> 28 mg/day), and total fat (> 83 mg/day) were 1.93 (1.30, 2.87), 1.77 (1.19, 2.63), and 1.62 (1.09, 2.42), respectively. In conclusion, consumption of high cholesterol, saturated fat and total fat was associated with an increased risk of lung cancer, even after controlling for cigarette smoking.Supported by the U.S. EPA Fund R825548.
Immunomodulatory effect of Avian 3000 in chickens
Authors: Lohani Madhukar , Maurice Denzil , Scott Thomas 
Published: June 2021

Our study evaluated the immunomodulatory and performance properties of a nanotechnology‐based product Avian 3000® administered in drinking water to broilers. In this field trial, 48 broilers were selected from grower farms representing control and treated groups. Body and organ weights, feathering score, leg score, and bone density were the performance indicators. The immune response was assessed by measurement of serum alpha‐1‐acid glycoprotein (AGP), IgG, IgA and IgM concentrations.Statistically significant differences were not detected in any of the performance variables measured but among the organ weights, spleen weights approached significant difference between the two groups of broilers. Serum IgG and alpha‐1‐ acid glycoprotein concentration were found to be higher in the treated as compared to the untreated (P< 0.0003 and P<0.03, respectively) but serum IgM concentration was higher (P< 0.01) in the untreated birds. The groups did not differ in serum IgA (P>0.65) and total serum protein (P>0.11). The results indicate that Avian 3000® has immunomodulatory properties in chickens and controlled experiments are needed to reproduce and expand the findings.
Energy intake from snacks by children in public primary schools in 11 States in Mexico
Authors: Ramírez‐Silva Claudia Ivonne , Campirano_Nuñez Fabricio , Hernadez‐Cordero Sonia , Herrera de Vicente Verónica , Concha‐Caloca Karina , Rivera‐Dommarco Juan 
Published: June 2021

IntroductionChildren attending public primary schools (PPS) in Mexico spend 4‐6 h at school every day. Some schools offer breakfast but none of them offer lunch.ObjectiveTo evaluate the caloric content of foods and beverages consumed as a snack by children in PPS in Mexico, excluding breakfast.MethodsThe caloric intake from snacks of 309 children in 44 PPS in 11 States in the North, Center and South regions was assessed. Energy content of foods was estimated based on weight and preparation methods. Mean energy intakes were computed and adjusted for sex, age and BMI using linear regression modelsResultsThe average energy intake of children from snacks while at schools was 463 Kcal or 24% of the energy daily recommendations (EDR) for children. Children in the Center region had the highest energy intake (495 Kcal) (p<0.05) compared to the North (396 Kcal) and South (376 Kcal) regions. It was found that 26.9% of children brought foods from home (BFH), 42.5% purchased the foods at scchool (PFE) and the remaining 30.5% did both (MIX). The energy content of the FBH (130 Kcal) was lower (p<0.05) than FPE (249.7 Kcal) and MIX (281 Kcal).ConclusionThe energy contribution of snacks consumed at school is higher that the recommended intake of 15%‐20% of snacks at school. On average, FBH usually have a lower caloric content. These findings call for regulation of the foods and beverages sold in PPS in Mexico.
Analysis of leptin receptor and vascular reactivity changes in aorta and isolated heart rat with low weight at birth and with high hypercaloric diet/ Diabetes type 2 model.
Authors: Castillo‐Hernandez Maria del Carmen , Manuel‐Apolinar Leticia , Guevara‐Balcazar Gustavo , Velazquez‐Dominguez J. Antonio , Zarate‐Treviño Arturo , Castillo‐Henkel Carlos 
Published: June 2021

This work study the expression of leptin ObRb receptor and the functional changes in the vascular reactivity in thoracic and abdominal aorta and isolated heart, obese and control Sprague Dawley rats were study, in one group was induced intrauterine malnutrition (E) due to the 50% food restriction in the pregnant rats and was compare with another group with any food restriction, control (C). The newborns with low weight at birth (BPN) group E had been feed with hypercaloric diet (60% lipids) until 6 months older. Recognize the vascular effect of angiotensin II and phenylephrine in thoracic and abdominal rings and isolated heart rat, and in the other hand we analyze the RNA total expression and RT‐PCR for ObRb receptor.ResultsIntrauterine malnutrition showed BPN in the group E (p<0.01) compare with group C, and at 6 months older the difference between 2 groups was ±100g for group E with the hypercaloric diet. Group E showed a hyperglycemic (p<0.01), like an increment in the leptin receptor ObRb expression (p<0.01) compared with the group C. On the other hand both groups showed differences in the vascular reactivity and heart responses for angiotnesin II, it's possible that those could be by the changes in the leptin receptor expression in the obese rat.
Effects on ventilation of Lung Volume Reduction Surgery in Emphysema
Authors: Bartels Matthew N , Gerardo Renee E , Layton Aimee M , Downey John A , Demeersman Ronald E 
Published: June 2021

AIMTo evaluate efficiency of ventilation during exercise in emphysema after lung volume reduction surgery (LVRS) compared to medical treatment (MED).METHODS41 patients with emphysema were randomized into LVRS (33) or MED (8). Data were compared from a cardiopulmonary exercise test (CPX) using a 5 or 10 watt protocol. CPX was performed at baseline and 12 months post randomization. T‐test with a Bonferroni correction was used determine statistical differences at p<0.01.RESULTSBaseline demographics and exercise evaluations were the same between groups. LVRS demonstrated improved work capacity [37 (17) vs 50 (18) Watts, p<0.01], improved PetCO2 [42.9 (6.0) to 38.4 (3.8) mmHg, p<0.001)], and increased ventilation [(VE) (24.9 (7.2) vs 31.6 (10.6) liters/min, p<0.005)] while no change was found in the MED group. At 12 months LVRS improved versus MED for VE [(31.6 (10.6) vs 22.1 (6.9) liters/min, p<0.01)], and Wattage [50 (18) vs 33 (15) Watts, p<0.005], with a trend in PetCO2 [38.4 (3.8) vs 47.1 (8.7) mmHg, p<0.001].DISCUSSIONLVRS improved ventilation allowing improved exercise capacity. These improvements may be due to removal of alveolar dead space in the LVRS group with improved pulmonary mechanics and improved ventilatory efficiency. Further elucidation of the mechanisms of improvement needs to be done with more detailed analysis of ventilatory mechanics with exercise. Supported by the VIDDA foundation
Physical Training does not Influence Vasodilatation Responses in Individuals with M235T AGT and I/D ECA Gene Polymorphisms
Authors: Dias Rodrigo Goncalves , Alvim Rafael O. , Rene Cleber R. , Alves Guilherme B. , Pereira Alexandre C. , Krieger Jose E. , Negrao Carlos E. 
Published: June 2021

We hypothesized that: 1)Reflex muscle vasodilatation to exercise is attenuated in individuals with 235T or D alleles and 2)Physical training would improve muscle vasodilatation responses in these individuals.Methods108 healthy individuals were genotyped for the M235T AGT (MM=20; MT=49; TT=39) and I/D ACE (DD=38; DI=48; II=22) genes variants. Mean blood pressure (MBP) and forearm blood flow (FBF, plethysmography) were evaluated at rest and at 30% handgrip exercise. Physical training was performed for 17 weeks (3 running sessions/week).ResultsResting forearm vascular conductance (FVC) and MBP were similar among AGT or ACE genotypes. During exercise, FVC increased significantly and similarly among MM, MT and TT (3.6±0.4; 3.3±0.2; 3.6±0.2 units, respectively, P=.91) and DD, DI and II (3.4±0.2; 3.6±0.3; 3.3±0.3 units, respectively, P=.92). Physical training significantly increased peak VO2(P=.001). Resting FVC was unchanged by physical training. Physical training improved slightly and similarly FVC responses to exercise in MM, MT and TT (4.1±0.5; 3.8±0.2; 3.8±0.3 units, respectively, P=.81) and DD, DI and II (3.6±0.2; 4.0±0.3; 3.7±0.4 units, respectively, P=.38).ConclusionsM235T AGT and the I/D ACE gene polymorphisms do not influence reflex muscle vasodilatation to exercise and the vascular response to physical training in healthy individuals.
Development of a cell culture system to assess the effect of Cryptosporidium parvum infection on bystander cells
Authors: Foster Derek Michael , Stauffer Stephen Howard , Gookin Jody L. 
Published: June 2021

Research has shown that the uninfected bystander cells in a C. parvum infected monolayer are at times preferentially apoptotic when compared to infected cells, and our goal was to further elucidate this effect in a nontumorgenic porcine intestinal cell line, IPEC‐J2. The effect of infective dose and duration of infection on the monolayer were assessed by determining the number of organisms, each life stage of C. parvum, total IPEC cells, infected cells, organisms per infected cell, total apoptotic cells, and infected, apoptotic cells. Coculture of infected monolayers with uninfected monolayers was used to assess the bystander effect on transepithelial electrical resistance and cell fate.The percentage of IPEC cells that became infected was similar with each dose, ranging from 37‐41% and peaked at 48 hours with the higher doses leading to multiple organisms per infected cell. All doses similarly decreased the total number of cells per high power field with no difference in the effect on bystander cells. During the first 24 hours, bystander cells appeared to be preferentially lost and accounted for the decrease in total cell numbers with significantly more apoptotic, bystander cells than apoptotic, infected cells per field. Early in C. parvum infections, bystander cells appear to play a significant role in the pathophysiology of disease.
Interaction of RNA‐binding protein CUG‐BP1 with c‐Myc mRNA 3′‐untranslated region represses its translation following polyamine depletion
Authors: Liu Lan , Rao Jaladanki N , Zou Tongtong , Xiao Lan , Yu Tingxi , Wang Pengyuan , Zhang Xian , Turner Douglas J , Wang Jian‐ying 
Published: June 2021

Polyamines are required for normal gut mucosal growth by regulating c‐Myc expression, but the mechanism underlying polyamines remains unclear. The RNA‐binding protein CUG‐BP1 binds to GC‐rich sequence of the given mRNAs and regulates translation of its target transcripts. This study determined if polyamines regulate c‐Myc translation by altering CUG‐BP1 interaction with c‐Myc 3′‐untranslated region (3'UTR).MethodsStudies were conducted in intestinal crypt cells (IEC‐6 line). RNA‐binding was examined by biotin pull‐down and RNP‐IP assays. CUG‐BP1 function was investigated by its silencing and overexpression; c‐Myc translation was examined by the chimeric Luc‐Myc‐3'UTR reporter.ResultsCUG‐BP1 overexpression increased its association with c‐Myc 3'UTR, repressed c‐Myc translation, and decreased its protein level (by ~60%). CUG‐BP silencing reduced its binding to c‐Myc 3'UTR, promoted c‐Myc translation, and induced its protein (by ~5‐fold). Polyamine depletion by inhibiting ODC increased [CUG‐BP1/c‐Myc mRNA] complex, which was associated with repressed c‐Myc translation. CUG‐BP1 silencing rendered the c‐Myc mRNA translatable and prevented decrease in c‐Myc protein in polyamine‐deficient cells.ConclusionThese results indicate that polyamine depletion represses c‐Myc translation by inducing CUG‐BP1 interaction with c‐Myc 3′‐UTR. (This work was supported by NIH and VA grants)