bluuebunny/crossref_metadata_2025_split huggingface dataset:
The C‐terminal fragment of parathyroid hormone‐related peptide promotes bone formation in diabetic mice with low‐turnover osteopaenia
Authors: Lozano D , Fernández‐de‐Castro L , Portal‐Núñez S , López‐Herradón A , Dapía S , Gómez‐Barrena E , Esbrit P 
Published: December 2010

BACKGROUND AND PURPOSE Current data suggest that parathyroid hormone (PTH)‐related peptide (PTHrP) domains other than the N‐terminal PTH‐like domain contribute to its role as an endogenous bone anabolic factor. PTHrP‐107‐139 inhibits bone resorption, a fact which has precluded an unequivocal demonstration of its possible anabolic action in vivo. We thus sought to characterize the osteogenic effects of this peptide using a mouse model of diabetic low‐turnover osteopaenia.EXPERIMENTAL APPROACH PTHrP‐107‐139 was administered to streptozotocin‐induced diabetic mice, with or without bone marrow ablation, for 13 days. Osteopaenia was confirmed by dual‐energy X‐ray absorptiometry and microcomputed tomography analysis. Histological analysis was performed on paraffin‐embedded bone tissue sections by haematoxylin/eosin and Masson's staining, and tartrate‐resistent acid phosphatase immunohistochemistry. Mouse bone marrow stromal cells and osteoblastic MC3T3‐E1 cells were cultured in normal and/or high glucose (HG) medium. Osteogenic and adipogenic markers were assessed by real‐time PCR, and PTHrP and the PTH1 receptor protein expression by Western blot analysis.KEY RESULTS PTHrP‐107‐139 reversed the alterations in bone structure and osteoblast function, and also promoted bone healing after marrow ablation without affecting the number of osteoclast‐like cells in diabetic mice. This peptide also reversed the high‐glucose‐induced changes in osteogenic differentiation in both bone marrow stromal cells and the more differentiated MC3T3‐E1 cells.CONCLUSIONS AND IMPLICATIONS These findings demonstrate that PTHrP‐107‐139 promotes bone formation in diabetic mice. This mouse model and in vitro cell cultures allowed us to identify various anabolic effects of this peptide in this scenario.
Ligand‐induced internalization of the orexin OX1 and cannabinoid CB1 receptors assessed via N‐terminal SNAP and CLIP‐tagging
Authors: Ward Richard J , Pediani John D , Milligan Graeme 
Published: December 2010

BACKGROUND AND PURPOSE Many G protein‐coupled receptors internalize following agonist binding. The studies were designed to identify novel means to effectively quantify this process using the orexin OX1 receptor and the cannabinoid CB1 receptor as exemplars.EXPERIMENTAL APPROACH The human OX1 and CB1 receptors were modified to incorporate both epitope tags and variants (SNAP and CLIP) of the enzyme O6‐alkylguanine‐DNA‐alkyltransferase within their extracellular, N‐terminal domain. Cells able to regulate expression of differing amounts of these constructs upon addition of an antibiotic were developed and analysed.KEY RESULTS Cell surface forms of each receptor construct were detected by both antibody recognition of the epitope tags and covalent binding of fluorophores to the O6‐alkylguanine‐DNA‐alkyltransferase variants. Receptor internalization in response to agonists but not antagonists could be monitored by each approach but sensitivity was up to six‐ to 10‐fold greater than other approaches when employing a novel, time‐resolved fluorescence probe for the SNAP tag. Sensitivity was not enhanced, however, for the CLIP tag, possibly due to higher levels of nonspecific binding.CONCLUSIONS AND IMPLICATIONS These studies demonstrate that highly sensitive and quantitative assays that monitor cell surface CB1 and OX1 receptors and their internalization by agonists can be developed based on introduction of variants of O6‐alkylguanine‐DNA‐alkyltransferase into the N‐terminal domain of the receptor. This should be equally suitable for other G protein‐coupled receptors.
Chronic administration of BMS309403 improves endothelial function in apolipoprotein E‐deficient mice and in cultured human endothelial cells
Authors: Lee Mary YK , Li Huiying , Xiao Yang , Zhou Zhiguang , Xu Aimin , Vanhoutte Paul M 
Published: December 2010

BACKGROUND AND PURPOSEAdipocyte fatty acid‐binding protein (A‐FABP) is up‐regulated in regenerated endothelial cells and modulates inflammatory responses in macrophages. Endothelial dysfunction accompanying regeneration is accelerated by hyperlipidaemia. Here, we investigate the contribution of A‐FABP to the pathogenesis of endothelial dysfunction in the aorta of apolipoprotein E‐deficient (ApoE−/−) mice and in cultured human endothelial cells.EXPERIMENTAL APPROACHA‐FABP was measured in aortae of ApoE−/−mice and human endothelial cells by RT‐PCR, immunostaining and immunoblotting. Total and phosphorylated forms of endothelial nitric oxide synthase (eNOS) were measured by immunoblotting. Changes in isometric tension were measured in rings of mice aortaeKEY RESULTSA‐FABP was expressed in aortic endothelium of ApoE−/− mice aged 12 weeks and older, but not at 8 weeks or in C57 wild‐type mice. Reduced endothelium‐dependent relaxations to acetylcholine, UK14304 (selective α2‐adrenoceptor agonist) and A23187 (calcium ionophore) and decreased protein presence of phosphorylated and total eNOS were observed in aortae of 18 week‐old ApoE−/− mice compared with age‐matched controls. A 6 week treatment with the A‐FABP inhibitor, BMS309403, started in 12 week‐old mice, improved endothelial function, phosphorylated and total eNOS and reduced plasma triglyceride levels but did not affect endothelium‐independent relaxations. The beneficial effect of BMS309403 on UK14304‐induced relaxations was attenuated by Pertussis toxin. In cultured human microvascular endothelial cells, lipid‐induced A‐FABP expression was associated with reduced phosphorylated eNOS and NO production and was reversed by BMS309403.CONCLUSIONS AND IMPLICATIONSElevated expression of A‐FABP in endothelial cells contributes to their dysfunction both in vivo and in vitro.
The novel phospho‐non‐steroidal anti‐inflammatory drugs, OXT‐328, MDC‐22 and MDC‐917, inhibit adjuvant‐induced arthritis in rats
Authors: Huang L , Mackenzie GG , Ouyang N , Sun Y , Xie G , Johnson F , Komninou D , Rigas B 
Published: December 2010

BACKGROUND AND PURPOSEThe use of non‐steroidal anti‐inflammatory drugs (NSAIDs) in the treatment of rheumatoid arthritis (RA) is limited by their toxicity. We evaluated the anti‐inflammatory efficacy and safety of three novel modified NSAIDs, phospho‐aspirin, phospho‐ibuprofen and phospho‐sulindac.EXPERIMENTAL APPROACHWe determined the anti‐inflammatory effects and gastrointestinal safety of the phospho‐NSAIDs in the rat adjuvant arthritis model and studied their mechanism of action in cultured cells, Cytokines were measured withelisaand activation of nuclear factor‐κB (NF‐κB) by immunohistochemistry.KEY RESULTSAll three phospho‐NSAIDs showed less gastrointestinal toxicity than their parent compounds and demonstrated strong anti‐inflammatory effects, essentially reversing joint inflammation and oedema. They have a broad but not uniform effect on the expression of relevant cytokines, in general decreasing IL‐6 and IL‐1β and increasing IL‐10 levels in rat plasma and cultured cells. Phospho‐sulindac and phospho‐ibuprofen but not phospho‐aspirin suppressed PGE2productionin vitro, whereas phospho‐aspirin (in contrast to aspirin) showed the same effectin vivo. In joint tissues, phospho‐aspirin inhibited NF‐κB activation, and suppressed inflammation and bone resorption. Phospho‐aspirin also inhibited Jurkat T cell proliferation. In general, phospho‐aspirin had greater efficacy but different effects upon inflammatory mediators compared with aspirin. The chemical modification of the parent NSAIDs seems crucial for their safety and efficacy.CONCLUSIONS AND IMPLICATIONSPhospho‐aspirin, phospho‐ibuprofen and phospho‐sulindac were safer than their parent NSAIDs, were highly effective in rat adjuvant arthritis and inhibited many key mediators in the pathophysiology of RA. These novel compounds are promising candidate drugs for the treatment of RA and merit further evaluation.
Biochemical characterization of a novel high‐affinity and specific plasma kallikrein inhibitor
Authors: Kolte D , Bryant JW , Holsworth D , Wang J , Akbari P , Gibson GW , Shariat‐Madar Z 
Published: December 2010

BACKGROUND AND PURPOSE Kallikrein acts on high molecular weight kininogen (HK) to generate HKa (cleaved HK) and bradykinin (BK). BK exerts its effects by binding to B2 receptors. The activation of B2 receptors leads to the formation of tissue plasminogen activator, nitric oxide (NO) and prostacyclin (PGI2). An elevated kallikrein‐dependent pathway has been linked to cardiovascular disease risk. The aim of this study was to investigate whether our novel plasma kallikrein inhibitor abolishes kallikrein‐mediated generation of BK from HK and subsequent BK‐induced NO and PGI2 formation, thereby influencing endothelial pathophysiology during chronic inflammatory diseases.EXPERIMENTAL APPROACH Kinetic analysis was initially used to determine the potency of PF‐04886847. Biochemical ligand binding assays, immunological methods and calcium flux studies were used to determine the selectivity of the kallikrein inhibitor. In addition, the effect of PF‐04886847 on BK‐induced relaxation of the rat aortic ring was determined in a model of lipopolysaccharide‐induced tissue inflammation.KEY RESULTS Evidence was obtained in vitro and in situ, indicating that PF‐04886847 is a potent and specific inhibitor of plasma kallikrein. PF‐04886847 efficiently blocked calcium influx as well as NO and PGI2 formation mediated through the BK‐stimulated B2 receptor signalling pathway. PF‐04886847 blocked kallikrein‐induced endothelial‐dependent relaxation of isolated rat aortic rings pre‐contracted with phenylephrine.CONCLUSIONS AND IMPLICATIONS PF‐04886847 was shown to be the most potent small molecule inhibitor of plasma kallikrein yet described; it inhibited kallikrein in isolated aortic rings and cultured endothelial cells. Overall, our results indicate that PF‐04886847 would be useful for the treatment of kallikrein‐mediated inflammatory disorders.
The protective effect of tianeptine on Gp120‐induced apoptosis in astroglial cells: role of GS and NOS, and NF‐κB suppression
Authors: Janda Elzbieta , Visalli Valeria , Colica Carmela , Aprigliano Serafina , Musolino Vincenzo , Vadalà Nuria , Muscoli Carolina , Sacco Iolanda , Iannone Michelangelo , Rotiroti Domenicantonio , Spedding Michael , Mollace Vincenzo 
Published: December 2010

BACKGROUND AND PURPOSE Tianeptine is an antidepressant affecting the glutamatergic system. In spite of its proven clinical efficacy, molecular effects of tianeptine are not entirely clear. Tianeptine modulates cytokine expression in the CNS and protects the hippocampus from chronic stress effects. HIV infection is associated with inflammation and neuronal loss, causing HIV‐associated dementia (HAD). The human immunodeficiency virus type‐1 glycoprotein gp120 has been proposed as a likely aetiological agent of HAD. In this study, we determined whether tianeptine protects astroglial cells from the neurodegenerative effects of gp120.EXPERIMENTAL APPROACH Human astroglial cells were treated with gp120 and tianeptine, and viability and apoptosis was monitored by TUNEL, annexin V, and activated caspase‐3 staining and flow cytometry. Protein levels of glutamine synthase (GS), inducible and constitutive nitric oxide synthases (iNOS, cNOS) and nuclear factor κB (NF‐κB) pathway were determined by Western blot analysis. The respective activities were assessed indirectly by measuring glutamine and nitrite concentrations or by luciferase reporter assays.KEY RESULTS Tianeptine showed an anti‐apoptotic effect and prevented caspase‐3 activation by gp120. The mechanism of tianeptine's action involved GS and cNOS stabilization and iNOS suppression. Moreover, tianeptine increased IκB‐α levels in the absence of gp120 and blocked its degradation in response to gp120. This correlated with the suppression of basal and gp120‐induced NF‐κB transcriptional activity.CONCLUSIONS AND IMPLICATIONS Tianeptine clearly exerts neuroprotective effects in vitro by suppressing the molecular pro‐inflammatory effects of gp120. Studies in animal models should be performed to evaluate the potential of tianeptine as a treatment for HAD.
Mitochondrial genome depletion dysregulates bile acid‐ and paracetamol‐induced expression of the transporters Mdr1, Mrp1 and Mrp4 in liver cells
Authors: Perez MJ , Gonzalez‐Sanchez E , Gonzalez‐Loyola A , Gonzalez‐Buitrago JM , Marin JJG 
Published: December 2010

BACKGROUND AND PURPOSE Mitochondria are involved in the toxicity of several compounds, retro‐control of gene expression and apoptosis activation. The effect of mitochondrial genome (mtDNA) depletion on changes in ABC transporter protein expression in response to bile acids and paracetamol was investigated.EXPERIMENTAL APPROACH Hepa 1‐6 mouse hepatoma cells with 70% decrease in 16S/18S rRNA ratio (Rho cells) were obtained by long‐term treatment with ethidium bromide.KEY RESULTS Spontaneous apoptosis and reactive oxygen species (ROS) generation were decreased in Rho cells. Following glycochenodeoxycholic acid (GCDCA) or paracetamol, Rho cells generated less ROS and were more resistant to cell death. Apoptosis induced by GCDCA and Fas was also reduced. The basal expression of Mdr1 was significantly enhanced, but this was not further stimulated by GCDCA or paracetamol, as observed in wild‐type (WT) cells. Basal expression of Mrp1 and Mrp4 was similar in WT and Rho cells, whereas they were up‐regulated only in WT cells after GCDCA or paracetamol, along with the transcription factors Shp and Nrf2, but not Fxr or Pxr. Increased expression of Nrf2 was accompanied by its enhanced nuclear translocation. Glycoursodeoxycholic acid failed to cause any of the effects observed for GCDCA or paracetamol.CONCLUSIONS AND IMPLICATIONS The Nrf2‐mediated pathway is partly independent of ROS production. Nuclear translocation of Nrf2 is insufficient to up‐regulate Mdr1, Mrp1 and Mrp4, which requires the participation of other regulatory element(s) whose activation in response to GCDCA and paracetamol is impaired in Rho cells and hence probably sensitive to ROS.
Regulation of nausea and vomiting by cannabinoids
Authors: Parker Linda A , Rock Erin M , Limebeer Cheryl L 
Published: December 2010

Considerable evidence demonstrates that manipulation of the endocannabinoid system regulates nausea and vomiting in humans and other animals. The anti‐emetic effect of cannabinoids has been shown across a wide variety of animals that are capable of vomiting in response to a toxic challenge. CB1agonism suppresses vomiting, which is reversed by CB1antagonism, and CB1inverse agonism promotes vomiting. Recently, evidence from animal experiments suggests that cannabinoids may be especially useful in treating the more difficult to control symptoms of nausea and anticipatory nausea in chemotherapy patients, which are less well controlled by the currently available conventional pharmaceutical agents. Although rats and mice are incapable of vomiting, they display a distinctive conditioned gaping response when re‐exposed to cues (flavours or contexts) paired with a nauseating treatment. Cannabinoid agonists (Δ9‐THC, HU‐210) and the fatty acid amide hydrolase (FAAH) inhibitor, URB‐597, suppress conditioned gaping reactions (nausea) in rats as they suppress vomiting in emetic species. Inverse agonists, but not neutral antagonists, of the CB1receptor promote nausea, and at subthreshold doses potentiate nausea produced by other toxins (LiCl). The primary non‐psychoactive compound in cannabis, cannabidiol (CBD), also suppresses nausea and vomiting within a limited dose range. The anti‐nausea/anti‐emetic effects of CBD may be mediated by indirect activation of somatodendritic 5‐HT1Areceptors in the dorsal raphe nucleus; activation of these autoreceptors reduces the release of 5‐HT in terminal forebrain regions. Preclinical research indicates that cannabinioids, including CBD, may be effective clinically for treating both nausea and vomiting produced by chemotherapy or other therapeutic treatments.LINKED ARTICLESThis article is part of a themed issue on Cannabinoids in Biology and Medicine. To view the other articles in this issue visithttp://dx.doi.org/10.1111/bph.2011.163.issue‐7
The ABCG family of membrane‐associated transporters: you don't have to be big to be mighty
Authors: Kerr Ian D , Haider Ameena J , Gelissen Ingrid C 
Published: December 2010

Along with many other mammalian ATP‐binding cassette (ABC) transporters, members of the ABCG group are involved in the regulated transport of hydrophobic compounds across cellular membranes. In humans, five ABCG family members have been identified, encoding proteins ranging from 638 to 678 amino acids in length. All five have been the subject of intensive investigation to better understand their physiological roles, expression patterns, interactions with substrates and inhibitors, and regulation at both the transcript and protein level. The principal substrates for at least four of the ABCG proteins are endogenous and dietary lipids, with ABCG1 implicated in particular in the export of cholesterol, and ABCG5 and G8 forming a functional heterodimer responsible for plant sterol elimination from the body. ABCG2 has a much broader substrate specificity and its ability to transport numerous diverse pharmaceuticals has implications for the absorption, distribution, metabolism, excretion and toxicity (ADMETOx) profile of these compounds. ABCG2 is one of at least three so‐called multidrug resistant ABC transporters expressed in humans, and its activity is associated with decreased efficacy of anti‐cancer agents in several carcinomas. In addition to its role in cancer, ABCG2 also plays a role in the normal physiological transport of urate and haem, the implications of which are described. We summarize here data on all five human ABCG transporters and provide a current perspective on their roles in human health and disease.LINKED ARTICLES This article is part of a themed section on Transporters. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2011.164.issue‐7
Sodium Balance in Maintenance Hemodialysis
Authors: Santos Sergio F. F. , Peixoto Aldo J. 
Published: December 2010

AbstractMaintenance of extracellular fluid volume balance is an essential role of chronic maintenance hemodialysis (HD). In this population, this balance is determined by salt intake during the interdialytic period and sodium removal in HD sessions. Most of the sodium in a HD session is removed by ultrafiltration of plasma water, and the diffusion process becomes responsible for the fine tuning of sodium balance. The observation of little variation in pre‐HD serum sodium denotes that HD patients have an individual, stable osmolar set point. A positive dialysate‐to‐plasma sodium gradient is associated with increased thirst, interdialytic weight gain, and hypertension. To achieve an isonatric HD session, dialysate sodium concentration should approximately match patient’s serum sodium, and all sodium gained in the interdialytic period must be removed by convection. The pre‐HD serum sodium concentration may be used as a reference for dialysate sodium prescription in chronic HD. In this article, we also discuss new aspects of sodium balance, with particular attention to new observations on nonosmolar interstitial sodium storage.
Transfusion‐transmitted human immunodeficiency virus (HIV) from seroconverting donors is rare in England and Wales: results from HIV lookback, October 1995 through December 2008
Authors: Byrne Lisa , Brant Lisa J. , Davison Katy , Hewitt Patricia 
Published: December 2010

BACKGROUND: Lookback is considered when human immunodeficiency virus (HIV) is detected in a repeat blood donor in case the immediately previous negative donation was donated in the infectious window period (IWP) or the assay(s) produced a false‐negative result. HIV lookback investigations undertaken by NHS Blood and Transplant and the Welsh Blood Service between October 1995 and December 2008 are described.STUDY DESIGN AND METHODS: Investigations were undertaken into the previous negative donations of 113 HIV‐infected donors, including retrospective testing of archive samples, tracing of components, and identification of recipients who were offered HIV testing when appropriate. Data were collated on HIV seroconverters and outcome of the lookback was summarized.RESULTS: Two previous negative donations given before the introduction of minipool nucleic acid testing (MP‐NAT) screening were confirmed positive by individual retrospective polymerase chain reaction (PCR) testing of the archive specimen. Red blood cell components had been transfused from both donations. One recipient died after transfusion, and the other was alive and tested HIV positive. All 23 (20%) donations previously testing negative by MP‐NAT were confirmed to be PCR negative on individual testing of an archive specimen and none of the tested recipients of these donations had evidence of transfusion‐transmitted HIV.CONCLUSION: The yield of lookback was low with one positive recipient identified over 13 years of surveillance: HIV transmission occurred from a window period donation given before the introduction of MP‐NAT screening and would have been detected using current testing methods. Current residual risk estimates for the United Kingdom predict that HIV lookback will be of limited benefit, as demonstrated by our data.
Tomographic, Histological, and Immunohistochemical Evidences on the Use of N‐Butyl‐2‐Cyanoacrilate for Onlay Graft Fixation in Rabbits
Authors: de Oliveira Neto Patricio José , Cricchio Giovanni , Hawthorne Ana Carolina , Okamoto Roberta , Sennerby Lars , Lungren Stefan , Salata Luiz Antonio 
Published: December 2010

ABSTRACTBackground: The bone tissue responses to Cyanoacrylate have been described in the literature, but none used N‐butyl‐2‐cyanoacrilate (NB‐Cn) for bone graft fixation.Purpose: The aims of the study were: (a) to analyze the bone grafts volume maintenance fixed either with NB‐Cn or titanium screw; (b) to assess the incorporation of onlay grafts on perforated recipient bed; and (c) the differences of expression level of tartrate‐resistant acid phosphatase (TRAP) protein involved in bone resorption.Materials and Methods: Eighteen New Zealand White rabbits were submitted to calvaria onlay grafting on both sides of the mandible. On one side, the graft was fixed with NB‐Cn, while on the other hand the bone graft was secured with an osteosynthesis screw. The computed tomography (CT) was performed just after surgery and at animals sacrifice, after 1 (n = 9) and 6 weeks (n = 9), in order to estimate the bone grafts volume along the experiments. Histological sections of the grafted areas were prepared to evaluate the healing of bone grafts and to assess the expression of TRAP protein.Results: The CT scan showed better volume maintenance of bone grafts fixed with NB‐Cn (p ≤ 0.05) compared with those fixed with screws, in both experimental times (analysis of variance). The immunohistochemical evaluation showed that the TRAP expression in a 6‐week period was significantly higher compared with the 1‐week period, without showing significant difference between the groups (Wilcoxon and Mann–Whitney). Histological analysis revealed that the NB‐Cn caused periosteum damage, but provided bone graft stabilization and incorporation similar to the control group.Conclusion: The perforation provided by screw insertion into the graft during fixation may have triggered early revascularization and remodeling to render increased volume loss compared with the experimental group. These results indicate that the NB‐Cn possesses equivalent properties to titanium screw to be used as bone fixation material in osteosynthesis.