bluuebunny/crossref_metadata_2025_split huggingface dataset:
Substance P and CGRP are involved in the formation and maintenance of microabscesses in chronic infection with Nocardia brasiliensis
Authors: SOTO JUAN MANUEL SOLIS , Serrano J A , Ramirez J C Segoviano , Kouri J B , Carmona M C Salinas 
Published: June 2021

Actinomycetoma is caused by several pathogens; the main causal agent in Mexico is Nocardia brasiliensis. It is characterized by an infiltration of several inflammatory cell populations and the formation of microabscesses. To explore pathogenetic aspects of the immune response we injected N. brasiliensis in footpads of BALB/c mice. Seven, fifteen and thirty days postinfection immunocytochemical and ultrastructural studies were performed to compare presence and distribution of substance P and calcitonin gene‐related peptide (CGRP) during the formation of microabscesses. Analysis of serial skin sections showed colocalization of these immunomodulators in some macrophages (CD14 immunoreactive) at the periphery of the microabscesses. Substance P was also present in a few macrophages of the dermis, outside the microabscesses. Ultrastructural studies showed a grain of bacteria in the center of the microabscess. Surrounding the bacteria a layer of polymorphonuclear cells were present. Around the polymorphonuclear cell layer several lymphocytes (CD3) and macrophages were producing the cytokines IFN‐gamma, IL‐1beta, IL‐10 and IL‐4.The distribution of substance P and CGRP suggests that they act as immunomodulators of the formation and maintenance of the microabscesses during chronic infection with N. brasiliensis.This work was supported by grants from PROMEP 103.5/05/2485 and PAICYT SA1420‐06 (UANL).
Selective CD4 T cell help for B cell and antibody responses to vaccinia
Authors: Crotty Shane , Moutaftsi Magdalini , McCausland Megan , Quiroz Juan Moyron , Garboczi David , Felgner Philip , Sette Alessandro 
Published: June 2021

Selective CD4 T cell help for B cell and antibody responses to vacciniaIt remains unclear what parameters determine which pathogen proteins are targeted by the host antibody response. Peptide vaccination of mice with individual MHC II restricted vaccinia virus epitopes revealed that after vaccinia (smallpox vaccine) infection CD4 T cell help to B cells was surprisingly non‐transferable to B cells specific for different vaccinia virus proteins, including other virion surface or core proteins. This restriction had a direct impact on neutralizing antibody titers. Furthermore, large scale analysis of the antibody and CD4 T cell response specificities recognized during a vaccinia virus infection revealed that many of the CD4 T cell responses (identified in an unbiased screen) targeted viral virion proteins that were also targets of antibody responses, consistent with a deterministic linkage between the specificities (P < 0.0009). We then tested the deterministic linkage model by using this knowledge to efficiently predict new vaccinia virus MHC II epitopes (830% increase in identification efficacy). In contrast to the standard intermolcular help model, these data indicate that individual proteins are the primary unit of immunological recognition for a large virus, and therefore MHC II restriction at the protein level is a key selective event for the antiviral antibody response, which is likely of great relevance for vaccine development to large pathogens.
Comparisons of the regulatory function of ex vivo expanded polyclonal or antigen‐specific non‐human primate T regulatory cells
Authors: Johnson Jennifer Lynn , Pahuja Anil , Graham Melanie , Hering Bernhard , Blazar Bruce , Murtaugh Michael , Bansal‐Pakala Pratima 
Published: June 2021

T regulatory (Treg) cells play a critical role in controlling autoimmunity, suppressing allo‐ and xenogenic immune responses and preventing transplant rejection. To assess therapeutic potential of ex vivo expanded Tregs in islet transplant, we established Treg expansion in non‐human primates. Work in mice shows that Tregs expanded against a specific antigen better suppress response to that antigen. In this study, we isolated and expanded polyclonal and antigen‐specific Tregs from NHP and evaluated their regulatory capabilities.Tregs were isolated from rhesus macaque PBMCs and expanded with irradiated pig splenocytes or anti‐CD3/CD28 coated microbeads and IL‐2. FoxP3 expression at day 21 was 98% for both groups. Polyclonal stimulated Tregs (PST) underwent more robust expansion, compared to antigen specific Tregs (AST). AST more readily suppressed T effectors stimulated with specific xeno‐antigen when compared to PSTs.Our data suggest that polyclonal and antigen specific expanded NHP Tregs maintain their regulatory activity. The success of these ex vivo experiments suggest that Tregs can be used as part of immunomodulatory protocol paving the way to their use in clinical transplantation.
Daily patterns in phagocytosis by zebrafish kidney leukocytes
Authors: Chrenek Ryan , Ruksznis Catarina , Bagley Patrick , Kaplan Jessica , Hannum Lynn 
Published: June 2021

The cyclic expression of clock genes creates daily variations in vertebrate behavior and physiology. Oscillations in leukocyte number and activity have been reported in mammalian systems, but little is known about daily rhythms in zebrafish immune function. Expanding the scope of our earlier work on patterns in zebrafish respiratory burst responses, we have examined daily patterns in the phagocytic activity of zebrafish kidney leukocytes. Phagocytosis of bacteria was monitored by flow cytometry at 4 hour intervals throughout 24‐hour periods. The percentage of phagocytes engulfing S. aureus peaked at 2 a.m. (ZT 18) and reached a low at 2 p.m. (ZT 6). Peak relative numbers of bacteria engulfed per cell occurred at 10 a.m. (ZT 2), after which levels fell steadily until dramatically increasing again at 10 a.m. These data provide evidence of rhythmic immune activity in zebrafish, and suggest that zebrafish can be a valuable model in which to study the relationship between circadian gene expression and the activity of immune system cells.This work was supported by NIH Grant Number P20 RR‐016463 from the INBRE Program of the National Center for Research Resources.
Methionine and S‐adenosylmethionine are potential biomarkers to determine safe intake levels for methionine
Authors: Toue Sakino , Chin Keigi , Kodama Riho , Amao Michiko , Kawamata Yasuko , Kimura Takeshi , Sakai Ryosei 
Published: June 2021

Although mammals maintain homeostasis in response to various intake levels of nutrients by controlling their metabolic activities, their excessive intakes cause adverse effects. Since intake levels within homeostatic range are considered to be safe, determination of metabolic upper limit for each nutrient could provide information for their safe intake levels. In this study we tried to identify the rate‐limiting step for methionine (Met) in its excess and to find biomarkers for Met excess determination.F344 male rats were fed a basal diet or diets containing additional Met (0.3, 0.6, 0.9, 1.2 and 2.4%) for 2 weeks. Postprandial plasma and liver samples were collected to measure Met metabolites. More than 0.9% of additional Met increased hepatic Met and S‐adenosylmethionine (SAM) markedly. Met loading at the same doses also decreased the ratio of S‐adenosylhomocysteine (SAH) to SAM, indicating that metabolism from SAM to SAH would be one of rate‐limiting steps for disposal of excessive Met and that both SAM and its upstream Met are possible biomarkers to assess metabolic upper limit of Met. Since NOAEL and LOAEL of additional Met in growing rats were 0.6 and 0.9%, respectively, hepatic SAM, plasma and hepatic Met concentrations discriminated safe intake levels from potentially toxic levels well. These suggest that both Met and SAM are potential biomarkers to determine safe intake level of Met.
Six‐month Changes in Dietary Behaviors, and Physical and Emotional Health of Recent Breast Cancer Survivors
Authors: Tangney Christy C , Ventrelle Jennifer C , Morris Laura R , Oleske Denise M 
Published: June 2021

Background: Breast cancer survivors often experience weight gain and clinical depression early in their treatment course. It is uncertain whether weight changes are attributable to changes in lifestyle behaviors or a product of adjuvant therapy.Methods: Twenty‐six breast cancer survivors (within 1 year of diagnosis) were enrolled in a weight management program at an urban medical center. Anthropometrics (height, weight, waist circumference, and body fat by bio‐impedance and near‐infrared interactance), resting metabolic rate (RMR) measurements, repeated telephone 24‐hour recalls (Nutrition Data System 2006, University of MN), functional performance tests, blood chemistries, and surveys to assess quality of life (FACT‐B) and possible depression (CES‐D) were obtained at baseline and 6 months.Results: At study entry, all participants were clinically depressed (CES‐D≥ 16), though FACT B scores (103 ± 10) were relatively high. Average age was 46.4 ± 8.1 years, and BMI, 30.4 ± 6.1. Exactly 20% were African Americans. By six months, two‐thirds of participants had either maintained or lost weight. These changes were accompanied by significant improvements in fruit and vegetable consumption (p=0.019), and in CES‐D scores (p=0.026), and reduction in body fat (p=0.051) when compared to those who had gained weight (mean, 3.2 lbs). Weight losers relative to “gainers” had non‐significant decrease in RMR and total sugar consumption with marginally significant increases in walking speed, dietary fiber intakes and energy density.Conclusion: Weight management support for recent survivors can be successful in improving not only dietary behaviors but also mental health.
α2‐Adrenoceptors increase glycogen synthesis in chick astrocytes: possible mechanism to increase memory formation
Authors: Hutchinson Dana Sabine , Gibbs Marie E , Summers Roger J 
Published: June 2021

From experiments using a discriminated bead task in chicks, we have defined when and where adrenoceptors (ARs) are involved in memory modulation. All 3 AR subtypes (α1‐, α2‐ and β‐ARs) are found in the chick brain and in regions associated with memory formation. Glucose and glycogen are important in memory formation since an increase in glucose levels improves while inhibiting glucose transporters (GLUTs) or glycogen breakdown inhibits memory consolidation. α2‐ARs are expressed on chick astrocytes (Bmax 66.3 ± 17.7 fmol/mg protein) and stimulation with clonidine increases glycogen synthesis in a concentration‐dependent manner, whereas stimulation of β‐ or α1‐ARs has no effect on increases in glycogen synthesis. The effect of clonidine was sensitive to inhibition by both pertussis toxin (Gi) and inhibitors of PI3K. With respect to memory, injection of α2‐AR agonists into the medial striatum (MSt), but not the intermediate medial mesopallium (IMM) of chicks, increased memory consolidation. Injection of the postsynaptic α2‐AR antagonist ARC239 decreased memory consolidation when injected into either the MSt or IMM. These results show that α2‐ARs increase glycogen synthesis in chick astrocytes and are involved in memory consolidation in the chick.This research was supported by National Health and Medical Research Council Project Grants 236884 and 491169.
The Wilms’ tumor transcription factor WT1 regulates expression of the VE‐cadherin gene
Authors: Kirschner Karin Michaela , Scholz Holger 
Published: June 2021

The Wilms’ tumor transcription factor, WT1, is an important regulator of embryonic development. A predominant feature of Wt1‐deficient mouse embryos is their lack of kidneys and gonads in addition to a failure of normal formation of the vasculature in the heart. Identification of downstream target genes is necessary to understand the function of WT1 during normal embryogenesis.Here we demonstrate, that WT1 stimulates expression of the vascular endothelial (VE) cadherin gene. VE‐cadherin transcripts were increased more then 15‐fold in a cell line with inducible WT1 expression. WT1 enhanced VE‐cadherin expression also at the protein level in these cells. With the combinatorial use of luciferase reporter gene assays and electrophoretic mobility shift experiments we identified cis‐regulatory elements in the promoter and the first intron of the VE‐cadherin gene. Activation of the reporter constructs by WT1 was abolished upon introducing mutations into the identified binding sites.Immunohistochemical staining revealed co‐expression of WT1 and VE‐cadherin in the developing glomeruli of normal kidneys. VE‐cadherin expression was significantly reduced in the hearts and livers of Wt1‐deficient mouse embryos. These findings indicate that WT1 stimulates transcription of the VE‐cadherin gene, which, in turn, may promote vascular endothelial cell survival through stabilization of cell‐cell contacts.
TIMP‐1 is increased by shear stress in the skeletal muscle microvasculature
Authors: Uchida Cassandra , Milkiewicz Malgorzata , Fudalewski Tom , Gee Eric , Haas Tara L. 
Published: June 2021

Luminal splitting via internal division of capillaries is a form of angiogenesis caused by increased shear stress. A feature of luminal splitting is a lack of extracellular matrix proteolysis, which correlates with a decreased production of matrix metalloproteinase‐2 (MMP‐2). We hypothesized that the MMP inhibitor, tissue inhibitor of matrix metalloproteinase‐1 (TIMP‐1), is upregulated in response to shear stress. TIMP‐1 mRNA expression increased 3.8‐fold in the EDL of prasozin‐treated rats (p<0.05, n=4). Skeletal muscle endothelial cells were exposed to 2, 4, or 24 hours of shear stress (12 dyne/cm2). TIMP‐1 mRNA expression increased 7.0 and 9.0‐fold in cells after 2 and 24 hours of exposure to shear stress respectively (p<0.05, n=3), and TIMP‐1 protein increased 1.5 and 2.2‐fold after 2 and 24 hours of shear stress (p<0.05, n=3). TIMP‐1‐mediated inhibition of MMP‐2 also was increased 1.5 and 1.3‐fold after 2 and 24 hours of shear stress (n=2 and p<0.05, n=3 respectively). Our results show that TIMP‐1 is upregulated by shear stress, and suggest a mechanism for the absence of extracellular matrix proteolysis observed during luminal splitting.Funded by the Heart and Stroke Foundation of Canada.
Liposomal preparation for the in vivo monitoring of osmolality
Authors: Bingaman Susan , Meixsell Marsha , Huxley Virginia H. 
Published: June 2021

We wished to develop a tool to monitor changes in our in vivo microvascular preparations. Our criteria were to have the probe be biocompatible, emit a reproducible signal from a microvascular compartment (vessel or lymphatic) as a function of osmotic pressure, and posses the means to monitor the probe concentration. We chose to use liposomes containing a fluorescent dye excited at visible wavelengths at a concentration that was self‐quenched, resulting in increasing fluorescence intensity (FI) with decreasing osmolality. A lipid film was made by combining 1,2‐Diestearoyl‐sn‐Glycero‐3‐Phosphotidyl choline (DSPC), cholesterol, and 18:0 PEG(2000)PE (DSPE‐PEG) (Avanti Polar Lipids) at a molar ratio of 1:0.3:0.08 (Jayaraman, S., J. Gen. Physiol., 2001) in 2 ml ethanol. Following ethanol evaporation the lipid film was rehydrated with 2 ml buffer (pH 7.4, 300 mOsm) containing 4.7 mM KCL, 2.0 mM CaCl2, 1.2 mM MgSO4, 1.2 mM NaH2PO4, 3.0 mM NaHCO3, 111 mM NaCl, and 30 mM Calcein. Liposomes of uniform size were created with an Avanti mini‐extruder fitted with 0.4 μm pore polycarbonate membrane filters. Unencapsulated dye was removed by size exclusion chromatography over Sephacryl S‐200 HR (GE Healthcare). After brief equilibration over a range of osmolalities, (264–326 mOsm) the liposomes were excited at 480 nm and emission was monitored at 530 nm. The FI was inversely related to osmolality (r2=0.99). Absorbance read at 480 nm did not change over the same range of osmolalities (slope not different from 0, p>0.5). The stability of the absorbance value allows it to be used as a reference for the calibration of FI to osmolality. Finally, as the ratio of absorbance to FI was related directly to osmolality (r2=0.99) these liposomes can be used to monitor quantitatively osmotic changes in vivo.Supported by NIH HLO78816, NASA NN04GA50G, AHA 0615515Z (RS), and NIHCO6RRO17353
Cytotoxicity of single wall carbon nanotubes to mesothelial cells and effects of alveolar surfactant
Authors: Das Monisha , Quinn Tim , Hagler Louis , Herndon Betty , Kostoryz Elisabet 
Published: June 2021

Carbon‐based nanoparticles have promising applications in the field of medicine and drug delivery. However, studies in rodents continue to reflect tissue inflammatory responses and cytotoxicity. Single wall carbon nanotubes (SWCNT) were also shown in cell culture to produce cytotoxicity similar to asbestos exposure. After intraperitoneal injection with nanoparticles, a lack of 50 nm silica in lungs of mice was demonstrated although particles were present at high levels in other organs, suggesting passage from the lung to the more stable pleural space. To investigate this activity, we proposed that pulmonary mesothelial cells would exhibit effects following exposure to SWCNT that would reflect in vivo cytotoxicity.MeT5A a non‐malignant mesothelial cell line was cultured as recommended by the supplier (ATCC). SWCNT (15 nm average diameter 100 nm length) 2.5‐100 μg/mL were suspended in pediatric surfactant B (Survanta) and/or medium, and dose response comparisons were assayed with a soluble formazan (WST‐1). C60 particles were used for comparison.Comparable weights of C60 and SWCNT without surfactant demonstrated significantly lower cell viability with SWCNT (p=0.04). SWCNT‐surfactant ratio of 1:5 was optimum for highest survival although mesothelial cell viability was significantly decreased at 10 and 20 μg/mL SWCNT concentration (p=0.04 and 0.001 respectively) compared to the same concentration of SWCNT with surfactant added.Surfactant protein mitigated the in vitro cytotoxicity produced by SWCNTs on mesothelial cells in culture.
Dietary glutamine supplementation reduces inflammation and hyperplasia during Helicobacter pylori infection in the mouse stomach
Authors: Hagen Susan J. , Ohtani Masahiro , Zhou Jin‐Rong , Blackburn George L. , Taylor Nancy S. , Rickman Barry , Fox James G. 
Published: June 2021

Glutamine (GLN) protects cultured gastric mucosal cells against injury. The purpose of this study was to test whether dietary GLN supplementation protects gastric mucosal cells against injury in vivo.METHODSC57BL/6 mice were fed a purified test diet without or with 5% GLN and, after 2 weeks of pre‐feeding, were sham‐ or Helicobacter pylori (HP‐SS1)‐infected. Body weight and food consumption were recorded and tissues were analyzed for pathology at 6, 12, and 20 weeks post‐infection (WPI). HP colonization and the level of pro‐ or anti‐inflammatory cytokines were determined by quantitative RT‐PCR.RESULTSGLN supplementation resulted in a robust early (6 WPI) inflammatory response to HP followed by a significant reduction in inflammation by 20 WPI. Hyperplasia was notable by 12 WPI on either diet but decreased significantly with GLN by 20 WPI. There was a robust anti‐inflammatory response with GLN, consisting of a significant increase in IL‐4, IL‐10, and TGF‐β at 6 WPI. After this initial response, there was a reduction or no change in anti‐inflammatory mRNA levels over time. Food consumption and HP colonization were not different in mice fed the GLN diet nor was there a significant change in atrophy or metaplasia scores.CONCLUSIONSOur results demonstrate that supplemental dietary GLN reduces inflammation and hyperplasia during HP‐infection in the mouse stomach. Supported by R01 DK15681 from the NIH.
Castration Modulates Systemic Venoconstrictor Responses to PVN Stimulation
Authors: Martin Doug S. 
Published: June 2021

Our previous work showed that venous tone is elevated during hypertension development in the spontaneously hypertensive rat (SHR) and that the hypothalamic paraventricular nucleus (PVN) contributes to the control of venous tone. Androgens exacerbate hypertension development in the SHR. This study tested the hypothesis that androgens modulate PVN control of venous tone in SHR.Five week old male SHR or WKY underwent sham operation or castration. At ~ 12 weeks of age they were anesthetized and fitted with arterial and venous catheters. A latex balloon was placed in the right atrium for assessment of mean circulatory filling pressure (an index of venous tone). The rats were placed in a stereotaxic frame and an injector lowered into the PVN. Mean arterial pressure, heart rate (HR) and MCFP were recorded at baseline and during graded PVN stimulation with bicuculline (50–200 pmol).Injection of bicuculline into the PVN caused dose dependent increases in MAP, HR and MCFP. The MAP and MCFP responses obtained in SHR were greater than those recorded in WKY. Castration of SHR reduced the maximum MAP (Sham; 32±1 vs Castrated 19±4 mm Hg) and MCFP (Sham; 2±0.6 vs Castrated; 1±0.3 mm Hg) responses to PVN stimulation.These data suggest that: 1) PVN induced changes in venous tone are exaggerated in the SHR and 2) removal of endogenous androgens via castration modulates systemic venous constrictor responses induced by PVN stimulation. Supported by NIH #63053 and AHA #0515443Z.
Functional genomics of diabetic nephropathy in a newly‐characterized rat model
Authors: McMahon K. Wyatt , Zanescu Dora I , Sehli Sharmila , Prabhakar Sharma 
Published: June 2021

Diabetic nephropathy (DN) is the most common cause of end stage renal disease in the United States and approximately 40% of all diabetics eventually develop the disorder. A meta‐analysis of publicly available microarray data was performed to find genes that were consistently misexpressed in DN. From this list, those genes that also segregate with a predisposition for DN in humans were identified. Thus, a list of genes that are misexpressed both in patients and mouse models of DN, as well as linked to DN susceptibility, was prepared. This list of candidate genes, likely important for the onset and progression of DN, included vascular endothelial growth factor (VEGF), protein kinase B (Akt/Pkb), phospholipase Cγ (PLCγ), and interestingly PLCε, which is mutated in a familial form of nephrotic syndrome. These analyses, together with our recent observation of increased urinary VEGF in very early DN, suggest a central role for the VEGF pathway in DN onset and progression. The role of these genes is currently being investigated in ZSF rats, a newly‐characterized rat model for DN (Prabhakar et al., JASN, 2007). The identification of genes involved in DN pathogenesis could lead to better diagnostics and therapies for DN.Supported by the Larry and Jane Woirhaye Foundation for renal research.