bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Seminal Chemical Elements on the Oxidative Balance in Bovine Seminal Plasma and Spermatozoa
Authors: Tvrdá Eva , Lukáč Norbert , Schneidgenová Monika , Lukáčová Jana , Szabó Csaba , Goc Zofia , Greń Agnieszka , Massányi Peter
Published: September 2013

Mutual relationships between selected chemical elements (Na, K, Fe, Cu, Mg, and Zn), basic motility characteristics (motility and progressive motility), and markers of the oxidative balance (superoxide dismutase, catalase, glutathione, albumin, and malondialdehyde) were investigated in bovine seminal plasma and spermatozoa. Computer assisted sperm analysis was used to assess the motility parameters; mineral concentrations were determined by the voltammetric method and flame absorption spectrophotometry; antioxidants and malondialdehyde were evaluated by UV/VIS spectrophotometry. Concentrations of chemical elements in both seminal fractions were in the following descending order: Na > K > Zn > Mg > Fe > Cu. Higher amounts of all minerals and nonenzymatic antioxidants were detected in the seminal plasma (P<0.01;P<0.001), while higher MDA concentration and activity of enzymatic antioxidants were recorded in the cell lysates (P<0.01;P<0.001). Na, Fe, Cu, Mg, and Zn were positively correlated with the motility and antioxidant parameters (P<0.05;P<0.01;P<0.001). Inversely, K exhibited the positive associations with malondialdehyde (P<0.05). This study demonstrates that most chemical elements are integral components of bovine semen and are needed for the protection against oxidative stress development.
A Genetic QoS-Aware Routing Protocol for the Smart Electricity Networks
Authors: Zaballos Agustin , Vernet David , Selga Josep M.
Published: September 2013

This paper presents a QoS-aware routing protocol suitable for distribution of smart electricity grids based on heterogeneous machine to machine communications. The distribution Smart Grid needs high performance communication networks capable of handling QoS, an issue that is addressed by the present paper. The proposed algorithm is a merger between a genetic algorithm (GA) and Ticket-Based Routing (TBR), which is an on-demand routing protocol for ad hoc networks that provide quality of service. A suitable parameterization of the GA parameters is needed in order to use this protocol in the coming Smart Grid networks. The resulting routing protocol, named genetic algorithm with TBR algorithm for Smart Grids (GATAS), is an adapted intelligent evolution of the TBR. The performance of TBR has been improved by reducing the overhead of routing packets in the network and by minimizing the communication latency due to its on-demand behavior. Experimental evidence indicates that the likelihood of finding the optimum route using multiobjective dynamic metrics increases when the genetic algorithm is applied. In this paper, the main simulation results on the parameterization carried out are discussed, and the proposed attributes of the GA are described.
Enhanced Photocatalytic Degradation of Methylene Blue Using ZnFe2O4/MWCNT Composite Synthesized by Hydrothermal Method
Authors: Singhal Sonal , Sharma Rimi , Singh Charanjit , Bansal S.
Published: September 2013

Multiwalled carbon nanotubes (MWCNTs) were synthesized using arc discharge method at a magnetic field of 430 G and purified using HNO3/H2O2. Transmission electron micrographs revealed that MWCNTs had inner and outer diameter of ~2 nm and ~4 nm, respectively. Raman spectroscopy confirmed formation of MWCNTs showing G-band at 1577 cm−1. ZnFe2O4 and ZnFe2O4/MWCNT were produced using one step hydrothermal method. Powder X-ray diffraction (XRD) confirmed the formation of cubic spinel ZnFe2O4 as well as incorporation of MWCNT into ZnFe2O4. Visible light photocatalytic degradation of methylene blue (MB) was studied using pure ZnFe2O4 and ZnFe2O4/MWCNT. The results showed that ZnFe2O4/MWCNT composite had higher photocatalytic activity as compared to pure ZnFe2O4. After irradiation for 5 hours in the visible light, MB was almost 84% degraded in the presence of ZnFe2O4 photocatalyst, while 99% degradation was observed in case of ZnFe2O4/MWCNT composite. This enhancement in the photocatalytic activity of composite may be attributed to the inhibition of recombination of photogenerated charge carriers.
Lignocellulosic Fermentation of Wild Grass Employing Recombinant Hydrolytic Enzymes and Fermentative Microbes with Effective Bioethanol Recovery
Authors: Das Saprativ P. , Ghosh Arabinda , Gupta Ashutosh , Goyal Arun , Das Debasish
Published: September 2013

Simultaneous saccharification and fermentation (SSF) studies of steam exploded and alkali pretreated different leafy biomass were accomplished by recombinantClostridium thermocellumhydrolytic enzymes and fermentative microbes for bioethanol production. The recombinantC. thermocellumGH5 cellulase and GH43 hemicellulase genes expressed inEscherichia colicells were grown in repetitive batch mode, with the aim of enhancing the cell biomass production and enzyme activity. In batch mode, the cell biomass (A600 nm) ofE. colicells and enzyme activities of GH5 cellulase and GH43 hemicellulase were 1.4 and 1.6 with 2.8 and 2.2 U·mg−1, which were augmented to 2.8 and 2.9 with 5.6 and 3.8 U·mg−1in repetitive batch mode, respectively. Steam exploded wild grass (Achnatherum hymenoides) provided the best ethanol titres as compared to other biomasses. Mixed enzyme (GH5 cellulase, GH43 hemicellulase) mixed culture (Saccharomyces cerevisiae, Candida shehatae) system gave 2-fold higher ethanol titre than single enzyme (GH5 cellulase) single culture (Saccharomyces cerevisiae) system employing 1% (w/v) pretreated substrate. 5% (w/v) substrate gave 11.2 g·L−1of ethanol at shake flask level which on scaling up to 2 L bioreactor resulted in 23 g·L−1ethanol. 91.6% (v/v) ethanol was recovered by rotary evaporator with 21.2% purification efficiency.
UGT2B17 Polymorphism and Risk of Prostate Cancer: A Meta-Analysis
Authors: Kpoghomou Marce-Amara , Soatiana Joella Eldie , Kalembo Fatch W. , Bishwajit Ghose , Sheng Wei
Published: September 2013

Objective. Recent studies on the association between uridine diphosphosglucuronosyltransferases (UGTs) 2B17 polymorphism and risk of prostate cancer (PCa) showed inconclusive results. To clarify this possible association, we conducted a meta-analysis of published studies.
Methods. We searched the published literature from PubMed, Embase, Google Scholar, and China National Knowledge Infrastructure (CNKI). According to our inclusion criteria, studies that observed the association between UGT2B17 polymorphism and PCa risk were included. The principal outcome measure was the adjusted odds ratio (OR) with 95% confidence interval (CI) for the risk of PCa associated with UGT2B17 polymorphism. Results. A total of 6 studies with 7,029 subjects (3,839 cases and 3,190 controls) were eligible for inclusion in the meta-analysis. Overall, there was a significant association between UGT2B17 polymorphism and increased risk of prostate cancer (, 95% CI 1.14–2.64, ). Similar results were found in the subgroup analyses by ethnicity and types of controls. Conclusion. This meta-analysis demonstrates that UGT2B17 polymorphism is associated with prostate cancer susceptibility, and it contributes to the increased risk of prostate cancer.
Thyroid and Aging or the Aging Thyroid? An Evidence-Based Analysis of the Literature
Authors: Aggarwal Naveen , Razvi Salman
Published: September 2013

Thyroid hormone production, metabolism, and action change with aging. The reference ranges for serum thyrotropin and thyroid hormones are derived mainly from younger populations. Thus, the prevalence of subclinical thyroid dysfunction is increased greatly in the elderly. However, it is unclear whether mild thyroid dysfunction in the elderly is associated with adverse outcomes. In this review, we discuss current evidence-based literature on thyroid function in the elderly and whether subclinical thyroid dysfunction in the elderly should be treated.
Association between Preoperative Plasma sRAGE Levels and Recovery from Cardiac Surgery
Authors: Creagh-Brown Benedict C. , Quinlan Gregory J. , Hector Lauren R. , Evans Timothy W. , Burke-Gaffney Anne
Published: September 2013

Background. The receptor for advanced glycation end products (RAGE) is an inflammation-perpetuating receptor, and soluble RAGE (sRAGE) is a marker of cellular RAGE expression. This study investigated whether raised plasma levels prior to surgery of sRAGE or S100A8/A9 (a RAGE ligand) were associated with longer duration of hospital care in patients undergoing cardiac surgery necessitating cardiopulmonary bypass.Methods. Patients (n=130) undergoing elective cardiac surgery were enrolled prospectively. Plasma sRAGE and S100A8/A9 concentrations were measured before and 2 h after surgery.Results. Preoperative plasma sRAGE increased significantly (P<0.0001) from 1.06 ng/mL (IQR, 0.72–1.76) to 1.93 ng/mL (IQR, 1.14–2.63) 2 h postoperatively. Plasma S100A8/9 was also significantly (P<0.0001) higher 2 h postoperatively (2.37 μg/mL, IQR, 1.81–3.05) compared to pre-operative levels (0.41 μg/mL, IQR, 0.2–0.65). Preoperative sRAGE, but not S100A8/A9, was positively and significantly correlated with duration of critical illness (r=0.3,P=0.0007) and length of hospital stay (LOS;r=0.31,P<0.0005). Multivariate binary logistic regression showed preoperative sRAGE to be, statistically, an independent predictor of greater than median duration of critical illness (odds ratio 16.6,P=0.014) and to be, statistically, the strongest independent predictor of hospital LOS.Conclusion. Higher preoperative plasma sRAGE levels were associated with prolonged duration of care in adults undergoing cardiac surgery requiring cardiopulmonary bypass.
Multiple Supplemental Supernumerary Premolars: Unusual Presentation in a Nonsyndrome Patient
Authors: Ramakrishna Ashwini , Rajashekarappa Kiran B.
Published: September 2013

Supplementary teeth in the dental arch are a rare occurrence. Though they are mostly reported in association with syndromes they can also present in the absence of systemic pathology. This paper reports a case with multiple supernumerary teeth along with discussion of the frequency, types, complications, and management of such occurrence.
Immunocytochemical Characterization of Alzheimer Disease Hallmarks in APP/PS1 Transgenic Mice Treated with a New Anti-Amyloid-βVaccine
Authors: Carrera Iván , Etcheverría Ignacio , Li Yi , Fernández-Novoa Lucía , Lombardi Valter , Vigo Carmen , Palacios Hector H. , Benberin Valery V. , Cacabelos Ramón , Aliev Gjumrakch
Published: September 2013

APP/PS1 double-transgenic mouse models of Alzheimer’s disease (AD), which overexpress mutated forms of the gene for human amyloid precursor protein (APP) and presenilin 1 (PS1), have provided robust neuropathological hallmarks of AD-like pattern at early ages. This study characterizes immunocytochemical patterns of AD mouse brain as a model for human AD treated with the EB101 vaccine. In this novel vaccine, a new approach has been taken to circumvent past failures by judiciously selecting an adjuvant consisting of a physiological matrix embedded in liposomes, composed of naturally occurring phospholipids (phosphatidylcholine, phosphatidylglycerol, and cholesterol). Our findings showed that administration of amyloid-β1−42(Aβ) and sphingosine-1-phosphate emulsified in liposome complex (EB101) to APP/PS1 mice before onset of Aβdeposition (7 weeks of age) and/or at an older age (35 weeks of age) is effective in halting the progression and clearing the AD-like neuropathological hallmarks. Passive immunization with EB101 did not activate inflammatory responses from the immune system and astrocytes. Consistent with a decreased inflammatory background, the basal immunological interaction between the T cells and the affected areas (hippocampus) in the brain of treated mice was notably reduced. These results demonstrate that immunization with EB101 vaccine prevents and attenuates AD neuropathology in this type of double-transgenic mice.
Permanence and Global Attractivity of a Discrete Logistic Model with Impulses
Authors: Gao Chunyu , Guo Qingxi
Published: September 2013

By piecewise Euler method, we construct a discrete logistic equation with impulses. The constructed model is more easily implemented at computer and is a better analogue of the continuous-time dynamic system. The dynamic behaviors of the constructed model are investigated. Sufficient conditions which guarantee the permanence and the global attractivity of positive solutions of the model are obtained. Numerical simulations show the feasibility of the main results.
A Prospective Profile of Visual Field Loss following Stroke: Prevalence, Type, Rehabilitation, and Outcome
Authors: Rowe Fiona J. , Wright David , Brand Darren , Jackson Carole , Harrison Shirley , Maan Tallat , Scott Claire , Vogwell Linda , Peel Sarah , Akerman Nicola , Dodridge Caroline , Howard Claire , Shipman Tracey , Sperring Una , MacDiarmid Sonia , Freeman Cicely
Published: September 2013

Aims. To profile site of stroke/cerebrovascular accident, type and extent of field loss, treatment options, and outcome.Methods. Prospective multicentre cohort trial. Standardised referral and investigation protocol of visual parameters.Results. 915 patients were recruited with a mean age of 69 years (SD 14). 479 patients (52%) had visual field loss. 51 patients (10%) had no visual symptoms. Almost half of symptomatic patients (n=226) complained only of visual field loss: almost half (n=226) also had reading difficulty, blurred vision, diplopia, and perceptual difficulties. 31% (n=151) had visual field loss as their only visual impairment: 69% (n=328) had low vision, eye movement deficits, or visual perceptual difficulties. Occipital and parietal lobe strokes most commonly caused visual field loss. Treatment options included visual search training, visual awareness, typoscopes, substitutive prisms, low vision aids, refraction, and occlusive patches. At followup 15 patients (7.5%) had full recovery, 78 (39%) had improvement, and 104 (52%) had no recovery. Two patients (1%) had further decline of visual field. Patients with visual field loss had lower quality of life scores than stroke patients without visual impairment.Conclusions. Stroke survivors with visual field loss require assessment to accurately define type and extent of loss, diagnose coexistent visual impairments, and offer targeted treatment.
Diagnostic Consideration for Sinonasal Wegener’s Granulomatosis Clinically Mistaken for Carcinoma
Authors: La Rosa Cristina , Emmanuele Carmela , Tranchina Maria Grazia , Ippolito Massimo , Cosentino Sebastiano , Saita Vincenzo , Improta Giuseppina , Fraggetta Filippo
Published: September 2013

We report a case of Wegener’s granulomatosis clinically mistaken for carcinoma in a 21-year-old girl presenting with an ulcerated mass of the nasopharynx associated with enlarged laterocervical nodes. The lesion was clinically suspected as malignant on the basis of clinical and radiological findings (namely, computed tomography scan and positron emission tomography). However, multiple biopsies were not conclusive for malignancy showing histological change suggestive of Wegener’s granulomatosis. A serum determination of cANCA supported the diagnosis of Wegener’s granulomatosis. Clinical findings and image studies suggested an erroneous diagnosis of malignancy whereas a definitive diagnosis of Wegener’s granulomatosis was achieved only after repeated biopsies thus leading to a correct therapeutic approach. The Wegener granulomatosis must be added to the list of the differential diagnoses of the masses of the nasopharynx associated with or without enlarged laterocervical nodes.
Effect of Process Parameter Optimization in Reducing Sintering Temperature in the Synthesis and Characterization of Ba(Zn1/3Nb2/3)O3
Authors: Bajpai P. K. , Singh K. N.
Published: September 2013

Controlling the cooling rate during calcination and sintering, phase pure perovskite Ba(Zn1/3Nb2/3)O3 has been prepared by simple solid state reaction route with density >93% at relatively low sintering of 1175°C making it compatible for microwave dielectric applications. The samples are characterized by X-ray diffraction analysis and scanning electron microscopy. The X-ray diffraction shows pure perovskite phase with cubic structure. The lattice constants were obtained a = 4.1032 Å. Detailed studies of ε′ and ε′′ show that the compound exhibits dielectric anomaly at 430°C. Material shows distributed relaxation at higher temperature. Impedance analysis revealed that the impedance is mainly due to the grains. AC conduction activation energies are estimated from Arrhenius plots, and conduction mechanism is discussed.
Maternal Plasma miRNAs Expression in Preeclamptic Pregnancies
Authors: Li Hailing , Ge Qinyu , Guo Li , Lu Zuhong
Published: September 2013

Objective. Preeclampsia (PE) is a pregnancy-specific syndrome and one of the leading causes of maternal and fetal morbidity and mortality. The pathophysiological mechanisms of PE remain poorly known. Recently, circulating miRNAs are considered as potential useful noninvasive biomarkers. The aim of this study was to identify differentially expressed plasma miRNAs in preeclamptic pregnancies compared with normal pregnancies.Methods. Maternal plasma miRNA expression profiles were detected by SOLiD sequencing. Differential expressions between mPE/sPE and control group were found. Next, four differentially expressed plasma miRNAs were chosen to validate their expression in other large scale samples by real-time PCR.Results. In terms of sequencing results, we identified that 51 miRNAs were differentially expressed. Four differentially expressed plasma miRNAs (miR-141, miR-144, miR-221, and miR-29a) were selected to validate the sequencing results. RT-PCR data confirmed the reliability of sequencing results. The further statistical analysis showed that maternal plasma miR-141 and miR-29a are significantly overexpressed in mPE (P<0.05). Maternal plasma miR-144 is significantly underexpressed in mPE and sPE (P<0.05).Conclusions. Results showed that there were differentially expressed maternal plasma miRNAs in patients with preeclampsia. These plasma miRNAs might be used as notable biomarkers for diagnosis of preeclampsia.
Urinary Cytomorphology and Clinical Correlates of Prostatic Small Cell Neuroendocrine Carcinoma
Authors: Toll Adam D. , Ali Syed Z.
Published: September 2013

Background: Small cell carcinoma (SCC) of the prostate represents a rare form of prostatic carcinoma. While the tumor is often considered to arise from neuroendocrine proliferation or possibly dedifferentiation of an acinar carcinoma, the precise etiology remains uncertain. The diagnosis of prostatic SCC in urine has to date not been described. Methods: A retrospective review was performed at a tertiary-care hospital, and 3 patients with prostatic SCC in voided urinary specimens were identified. The following clinical data were collected for each case: age, gender, treatment and follow-up information, when available. Results: The patient age range was 70-86 years, all male. Two patients had known metastatic adenocarcinoma of the prostate, and 1 had recently presented with prostatic SCC. One patient with metastatic disease died shortly after diagnosis, the other was lost to follow-up. The third patient with a recent presentation has yet to have a treatment plan finalized. Conclusions: Our results highlight the importance of making this uncommon diagnosis as it may carry significant treatment and prognostic importance. Future work should hopefully clarify the role of ERG gene rearrangements in the pathogenesis of prostatic SCC, as there is a potential role here for targeted therapy.
Transcription Expression and Clinical Significance of mRNA of Vascular Endothelial Growth Factor and Endostatin in Liquid-Based Preparation Specimens from Patients with Cervical Dysplasia and Carcinoma
Authors: Wu Ming-Zhe , Zhang Yi , Wu Xin , Fu Zhi-Min , Wu Guang-Ping , Guo Ke-Jun
Published: September 2013

Objectives: The aim of this study was to assess the diagnostic usefulness of vascular endothelial growth factor (VEGF) and endostatin mRNA in cervical specimens of patients with cervical dysplasia and carcinoma. Study Design: Transcription levels of VEGF and endostatin were detected by RT-PCR in cervical liquid-based preparation specimens and compared with cytological assessments. Results: VEGF as well as endostatin mRNA expression was significantly associated with either cytological or histological diagnosis (p < 0.05). VEGF mRNA and endostatin mRNA were significantly more likely to be expressed in squamous cell carcinomas (SCC) than in cervical intraepithelial neoplasia (CIN) III (p < 0.01 and p < 0.05), and obviously also more likely to be expressed in CINII than in CINI and in CINIII than in CINII (p < 0.05). Eleven inflammation lesions gave positive results by cytology but negative results by RT-PCR for VEGF and endostatin mRNA. Twenty-four SCC lesions gave false-negative or precancerous lesion results by cytology but positive results by RT-PCR for VEGF and/or endostatin mRNA expression. Conclusion: Transcription levels of VEGF and endostatin by RT-PCR may be an adjunct to cytology screening for early detection of cervical carcinomas and may determine the progressive potentiality of individual lesions, especially in high-risk patients.
Metastases to the Pancreas Diagnosed by Fine-Needle Aspiration
Authors: Olson Matthew T. , Wakely Jr. Paul E. , Ali Syed Z.
Published: September 2013

Background: Metastatic cancer infrequently involves the pancreas. When the pancreas hosts a metastatic tumor, cytopathological evaluation of fine-needle aspirate material is a crucial part of the diagnostic process. In this study, we show two institutions' experience with cytopathological diagnosis of pancreatic metastasis. Methods: Databases of institutional experience at The Johns Hopkins Hospital and Ohio State University Medical Center were queried for cases of metastatic tumors in the pancreas that underwent fine-needle aspiration. Demographic and pathological features were compiled and the cytomorphology was reviewed. Results: Forty-two cases of tumor metastasis to the pancreas were found. Over the time of this review, 5,495 aspirates were performed, and 43% (2,389/5,495) had malignant cytological findings. Thus, the 42 cases of metastatic disease to the pancreas comprised 0.8% of all pancreas aspirates and 1.8% of the malignant ones. Renal cell carcinoma was the most common metastasis, followed by melanoma and non-small cell lung carcinoma. Among the other tumors in this series, 2 cases each of rare metastases such as the fibrolamellar variant of hepatocellular carcinoma and solitary fibrous tumor were also seen. Conclusion: The pancreas is rarely involved with metastatic disease, but when it is involved the most common tumor is renal cell carcinoma followed by melanoma and non-small cell lung cancer. Clinical history and awareness of the primary pancreatic mimickers are necessary for arriving at the correct diagnosis. As conventional pancreatic adenocarcinoma is uncommon in children and young adults, history of other tumors - even ones that usually follow an indolent course - is essential.
The Experience of a Tunisian Referral Centre in Prenatal Diagnosis of Xeroderma pigmentosum
Authors: Messaoud O. , Ben Rekaya M. , Jerbi M. , Ouertani I. , Kefi R. , Laroussi N. , Bouyacoub Y. , Benfadhel S. , Yacoub-Youssef H. , Boubaker S. , Zghal M. , Mrad R. , Amouri A. , Abdelhak S.
Published: September 2013

Aims: Xeroderma pigmentosum (XP, OMIM 278700-278780) is one of the most severe genodermatoses and is relatively frequent in Tunisia. In the absence of any therapy and to better manage the disease, we aimed to develop a molecular tool for DNA-based prenatal diagnosis. Methods: Six consanguineous Tunisian XP families (4 XP-A and 2 XP-C) have benefited from a prenatal diagnosis. Screening for mutations was performed by direct sequencing, while maternal-foetal contamination was checked by genotyping. Results: Among the 7 prenatal diagnoses, 4 foetuses were heterozygous for the screened mutation. Exclusion of contamination by maternal cells was checked. Mutations were detected at a homozygous state in the remaining cases, and the parents decided to terminate pregnancy. Conclusion: Our study illustrates the implementation of prenatal diagnosis for better health support of XP in Tunisia.
Purification and characterization of digitalislike factors from human plasma.
Authors: Hamlyn J M , Schenden J A , Zyren J , Baczynskyj L
Published: September 2013

Increased levels of a humoral inhibitor of active sodium transport have been associated with the response to acute and chronic hypervolemia and various forms of experimental as well as human essential hypertension. In this report, we describe the purification of inhibitors of Na+, K+-adenosine triphosphatase (ATPase) from the plasma of volume-expanded individuals. Of the two amphipathic materials obtained, only one of the factors when present in high concentrations showed the slow time-dependent component of inactivation similar to that of the cardiac glycosides. Inhibition was reduced in the presence of plasma proteins and was freely reversible. Both factors inhibited potassium-dependent p-nitrophenylphosphatase activity and specific [3H]ouabain binding in a manner similar to the cardiac glycosides. In contrast to ouabain and vanadate, however, high concentrations of potassium or norepinephrine, respectively, did not affect the magnitude or kinetic characteristics of inhibition. Structural analysis by mass spectroscopy showed a mass of 444 for factor 1, whereas factor 2 was conclusively identified as lysophosphatidylcholine-gamma-palmitoyl. These factors probably inhibit Na+, K+-ATPase by a nonspecific mechanism involving reversible perturbation of lipid-enzyme interactions required for normal catalytic activity. The significance of these factors as modulators of sodium transport may be limited to pathological states associated with abnormalities in plasma protein binding or lipid metabolism. They do not appear to be directly related to the humorally mediated disturbance of cellular sodium transport in hypertension.
Endogenous cardiac glycosidelike compounds.
Authors: Kelly R A
Published: September 2013

The possibility that endogenous inhibitors of the sodium pump exist and bind to the cardiac glycoside binding site on Na+,K+-adenosine triphosphatase (ATPase) has been a source of much controversy. Although numerous hormones and inorganic ions that modulate Na+,K+-ATPase activity have been described, most of these affect the sodium pump indirectly by varying the intracellular sodium concentration or by increasing the number of enzyme units. None of these endogenous compounds has been shown conclusively to modulate sodium pump activity by binding to the cardiac glycoside binding site on Na+,K+-ATPase. However, the near-universal presence of three high-affinity binding sites on the alpha-subunit of the enzyme has engendered much speculation that endogenous ligands for these receptors must exist. In addition, none of the hormones known to indirectly affect sodium pump activity in vivo has been shown to modulate Na+,K+-ATPase activity in response to extracellular volume expansion or to play a role in the pathogenesis of hypertension or chronic renal failure, conditions in which a circulating inhibitor of Na+,K+-ATPase has been implicated. This report presents a condensed history of the search for endogenous inhibitors of Na+,K+-ATPase and describes recent advances in the field. Despite progress in identifying and characterizing compounds that could affect Na+,K+-ATPase activity in vivo, definitive proof for the existence of endogenous ligands for the cardiac glycoside binding site remains elusive.
Effect of nucleus ambiguus lesion on the development of neurogenic hypertension.
Authors: Machado B H , Brody M J
Published: September 2013

These studies evaluated the role of the nucleus ambiguus in regulating heart rate and cardiovascular activity. Three days after lesion of the nucleus ambiguus, arterial pressure and heart rate were unchanged; however, subsequent sinoaortic deafferentation produced a significantly greater increase of pressure (156 +/- 4 vs 124 +/- 6 mm Hg) compared to sham lesion. In both groups the heart rate was increased after deafferentation and the intrinsic heart rate (rate seen after autonomic blockade with atropine and propranolol) was significantly reduced. When the sequence was reversed (deafferentation before lesion), pressure (126 +/- 6 vs 126 +/- 7 mm Hg) and heart rate (334 +/- 17 and 340 +/- 16 beats/min) were not altered; however, intrinsic rate fell more. When the nucleus ambiguus was stimulated electrically, two responses emerged: increased pressure without rate changes and increased pressure with bradycardia. These data indicate that 1) lesion of the nucleus ambiguus facilitates hypertension produced by sinoaortic deafferentation unless lesioning follows deafferentation; and 2) stimulation of the nucleus ambiguus produces a pressor effect that is independent of the bradycardic response. We conclude that the nucleus ambiguus may be related to autonomic control of both heart rate and arterial pressure.
Influence of the anteroventral third ventricle region and sinoaortic denervation on the pressor response to carotid occlusion.
Authors: Menani J V , Bedran-de-Castro M T , Krieger E M
Published: September 2013

The effect of anteroventral third ventricle (AV3V) lesion on the pressor response to occlusion of the common carotid artery was studied in freely moving rats with cuffs implanted 1 day before the tests. Short-term (6 hours) and long-term (2, 14, and 30 days) lesions greatly depressed the pressor responses to 60 seconds of common carotid occlusion. The initial peak, which depends on carotid innervation, was reduced by 55% (from 42 +/- 2 to 20 +/- 2 mm Hg), and the maintained response, which is of central origin (probably ischemic), was reduced by 32% (from 31 +/- 2 to 21 +/- 2 mm Hg). The effect of carotid or aortic denervation (or both) was also studied on control and lesioned rats. Carotid denervation produced similar extent of depression of the normal and reduced responses of the AV3V-lesioned rats 35% and 37%, respectively. Aortic denervation produced similar relative potentiation of the responses to common carotid occlusion of control and lesioned rats (72% and 66%, respectively). These data indicate the following: 1) Both short-term and long-term lesions greatly reduce the reflex and central (ischemic) components of the pressor responses to common carotid occlusion in freely moving rats; and 2) the importance of carotid innervation for development of the initial peak and the marked inhibitory effect of the aortic baroreceptor on both components are unchanged after AV3V lesion, when the depressed responses are evaluated as percent changes of the control values rather than as absolute changes.
Total plasma dopamine/norepinephrine ratio in catecholamine-secreting tumors. Its relation to hypertension.
Authors: Puyo A , Levin G , Armando I , Barontini M
Published: September 2013

We used a radioenzymatic method to determine plasma levels of free and total (free plus sulfoconjugated) norepinephrine and dopamine in 20 children with neuroblastoma (two were hypertensive), seven patients with pheochromocytoma, and 39 normotensive controls (24 children and 15 adults). No significant differences were noted between the two control groups. Patients with neuroblastoma and pheochromocytoma showed significantly higher levels of free and total norepinephrine than controls (p less than 0.01), and those with pheochromocytoma had higher levels than those with neuroblastoma (p less than 0.01). Although the differences were not statistically significant, free dopamine was higher in both groups of patients than in controls. Total dopamine was significantly higher in patients than in controls (p less than 0.01). A positive correlation was noted between levels of total norepinephrine and total dopamine in controls (r = 0.41, p less than 0.05) and in patients with neuroblastoma (r = 0.72, p less than 0.001). Such a correlation was not found in patients with pheochromocytoma. The total dopamine/total norepinephrine ratio was higher (p less than 0.005) in patients with neuroblastoma than in controls and patients with pheochromocytoma. Patients with pheochromocytoma had significantly lower ratios than the other groups (p less than 0.001). A negative correlation was found between the ratios in the different groups and either systolic (p less than 0.001) or diastolic (p less than 0.001) blood pressure. Our results not only support a role for plasma dopamine in the regulation of blood pressure but also suggest that, regardless of the actual levels of both catecholamines, a balance has to be achieved in order to maintain normal blood pressure levels.
Ganglionic immunoreactive atrial natriuretic factor in rat experimental hypertension.
Authors: Kuchel O , Debinski W , Buu N T , Cantin M , Genest J
Published: September 2013

Because previous data have suggested a dependence of ganglionic atrial natriuretic factor (ANF) content on preganglionic cholinergic input, we investigated the possibility that the increased neural activity observed in spontaneously hypertensive rats (SHR) may be reflected by ganglionic immunoreactive ANF levels. Four-week-old normotensive SHR had celiac ganglionic immunoreactive ANF values comparable to those of Wistar-Kyoto rats (WKY). When they became hypertensive, however, at 12 weeks of age, the SHR manifested higher immunoreactive ANF levels in celiac ganglia than the WKY group (25.3 +/- 2.6 vs 14.5 +/- 1.7 pg/ganglion; p less than 0.01), but there were no differences in levels in the superior cervical and nodose ganglia. The values in celiac ganglia were quadrupled on the average in hypertensive Dahl salt-sensitive rats under the influence of an 8% salt intake for 5 weeks, but no difference was noted in any of these ganglia between this group and their salt-resistant partners. The celiac and superior cervical ganglionic immunoreactive ANF content in normotensive Sprague-Dawley rats was higher with high salt than with normal salt intake. Hypertensive rats treated with deoxycorticosterone acetate (DOCA)-salt and sham-treated controls showed immunoreactive ANF concentrations in celiac ganglia similar to those detected in Dahl rats but, again, no differences were found between groups. Thus, hypertensive SHR, compared to WKY, have higher celiac ganglionic immunoreactive ANF levels, unlike Dahl salt-sensitive and DOCA-salt animals relative to their respective controls. This increase is unique to SHR (although all three models have elevated plasma immunoreactive ANF when they are hypertensive) and to the celiac ganglia.(ABSTRACT TRUNCATED AT 250 WORDS)
Secretion of N-terminal fragment of gamma-human atrial natriuretic polypeptide.
Authors: Itoh H , Nakao K , Mukoyama M , Sugawara A , Saito Y , Morii N , Yamada T , Shiono S , Arai H , Imura H
Published: September 2013

To elucidate the posttranslational processing of gamma-human atrial natriuretic polypeptide (human atrial natriuretic factor-[1-126]), which is a prohormone of alpha-human atrial natriuretic polypeptide (human atrial natriuretic factor-[99-126]), and the secretion of gamma-human atrial natriuretic polypeptide-derived peptides from the heart, we established a radioimmunoassay specific for the N-terminal sequence of gamma-human atrial natriuretic polypeptide, gamma-human atrial natriuretic polypeptide-(1-25), as well as a radioimmunoassay for alpha-human atrial natriuretic polypeptide. With the aid of the radioimmunoassays for gamma-human atrial natriuretic polypeptide-(1-25) and for alpha-human atrial natriuretic polypeptide, we detected 290 +/- 35.6 pg/ml of gamma-human atrial natriuretic polypeptide-(1-25)-like immunoreactivity in plasma from healthy humans, while the simultaneously determined plasma alpha-human atrial natriuretic polypeptide-like immunoreactivity level was 20.9 +/- 2.8 pg/ml. Correlation between the two values was significant. High performance gel permeation chromatographic analysis revealed that the plasma gamma-human atrial natriuretic polypeptide-(1-25)-like immunoreactivity was composed of a component (molecular weight, 10,000) without alpha-human atrial natriuretic polypeptide-like immunoreactivity, while the plasma alpha-human atrial natriuretic polypeptide-like immunoreactivity was composed of alpha-human atrial natriuretic polypeptide with a molecular weight of 3000. In patients with heart diseases, the plasma gamma-human atrial natriuretic polypeptide-(1-25)-like immunoreactivity level showed a concomitant and graded increase, with the plasma alpha-human atrial natriuretic polypeptide-like immunoreactivity level in agreement with the severity of the disease. There were significant positive correlations between the two immunoreactivity levels and right or left atrial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
Atrial natriuretic factor immunoreactivity in human fetal lung tissue and perfusates.
Authors: Sirois P , Gutkowska J
Published: September 2013

Immunoreactive atrial natriuretic factor (ANF) was detected in human fetal homogenates and perfusates using a sensitive and specific radioimmunoassay for the 28 amino acid (C-terminal) fragment. Three peaks of ANF immunoreactive material were found in the lung homogenates. With high performance liquid chromatography, the elution characteristics of the first immunoreactive peak were the same as those of circulating human ANF. The other two peaks have not been characterized, although one had a position similar to the 126 amino acid rat prohormone (Asn 1-Ile 110-Tyr 126). The time course of release of immunoreactive ANF by perfused human fetal lungs was also studied. It is suggested that ANF may play a role in early pulmonary function.
The patient with resistant hypertension. Cations, volume, and renal factors.
Authors: Vidt D G
Published: September 2013

Hypertension that is truly resistant to modern antihypertensive therapy is uncommon. In the majority of cases, apparent resistance is more likely associated with poor patient adherence, interacting drugs, drug interactions, and inappropriate drug dosages. Sodium and fluid volume play a major role in resistant hypertension. There is considerable evidence to support the role of dietary sodium restriction in successful nonpharmacological treatment of hypertension. Salt sensitivity in humans appears to represent at least one factor determining individual susceptibility to variable salt intakes. Sodium and water retention may lead to refractoriness to many antihypertensive agents, and there is evidence to suggest that extracellular fluid volume expansion also plays a role in many hypertensive patients. While retention of sodium and water is well established early in patients with renal parenchymal disease, hypertension associated with progression of renal parenchymal disease is complicated by other factors that include interactions between hemodynamic and humoral factors, functional changes in adrenergic responses, and structural vascular disease. The role of other cations such as potassium, calcium, and magnesium in resistant hypertension has yet to be established.
Sympathetic nerves protect against stroke in stroke-prone hypertensive rats. A preliminary report.
Authors: Sadoshima S , Busija D , Brody M , Heistad D
Published: September 2013

Studies were performed to determine whether sympathetic nerves protect against stroke in hypertensive rats. The superior cervical ganglion was removed on one side in 28 stroke-prone spontaneously hypertensive rats (SHRSP) when the rats were 4 weeks old. The rats were fed Japanese rat chow and 1% saline drinking water. When the rats were 19 weeks old, systolic pressure was 206 +/- 4 mm Hg (mean +/- SE). All rats died between 19 and 23 weeks of age. Microscopic and histological examination demonstrated cerebral hemorrhage in seven rats. All the hemorrhages occurred in the denervated hemispheres. Ischemic cerebral infarctions were found in 13 rats; in 10 rats, the infarcts were only in the denervated hemisphere. Pathological changes of cerebral arteries (hyalinosis, fibrinoid changes, and thrombus formation) were observed primarily in denervated hemispheres. Wall-to-lumen ratio was less in arteries of the denervated hemisphere than in arteries of the innervated hemisphere. These preliminary observations suggest that denervation of cerebral vessels increases susceptibility to stroke and inhibits development of cerebral vascular hypertrophy in SHRSP.
Enhancement of blood pressure response to dopamine by angiotensin II.
Authors: Perez-Olea J , Quevedo M , Silva R
Published: September 2013

The interaction of dopamine and angiotensin II (AII) on blood pressure and heart rate was studied in rats. The influence of reserpine pretreatment and vagotomy was also studied. Inbred rats anesthetized with urethane received intravenous (i.v.) doses of 50, 100, 200, or 400 micron g (per 100 g body weight) of dopamine HCI, before and after a single i.v. dose of 0.025 micron g of AII. The same doses of dopamine were tested in vagotomized rats and in rats pretreated with reserpine. The effect of dopamine alone on blood pressure was biphasic, since 16 of 38 rats showed an early fall followed by a later rise. The early fall decreased significantly with the dose and was absent with the highest dose tested (400 micron g). The late rise was observed in all experiments, and it increased significantly with the dose. Parallel to hypotension, a decrease of heart rate was observed, but both phenomena appeared not to be linked by a sauce-effect relationship. Vagotomy prevented both hypotension and bradycardia induced by dopamine. Angiotensin II inhibited the early fall and increased the late rise of blood pressure induced by dopamine but had no effect on the bradycardia. Reserpine retreatment prevented the hypotensive and enhanced the hypertensive response to dopamine, and in this situation dopamine induced cardiac arrhythmia. The interaction between dopamine and AII is inhibited by pretreatment with reserpine. The early hypotensive phase and bradycardia caused by dopamine appeared to be the consequence of a vagal reflex.
Catecholamines and serotonin in the area postrema of normal and sodium-depleted dogs.
Authors: Brosnihan K B , Ferrario C M , Saavedra J M , Speth R C
Published: September 2013

Sodium depletion, a maneuver that is accompanied by a 14-fold elevation of plasma renin activity (PRA), alters the norepinephrine concentration of the canine area postrema (AP), a circumventricular organ of the 4th ventricle known to be sensitive to circulating angiotensin II. The norepinephrine concentration of the AP after 3 weeks of sodium depletion decreased by 43%, whereas the concentration of epinephrine and dopamine and the activity of phenylethanolamine-N-methyltransferase (PNMT) did not change. In the pyramidal tract (PT) and choroid plexus (CP) catecholamines were present in significantly lower amounts than in the AP; their concentrations were unaffected by sodium depletion in the PT, but in the CP the norepinephrine concentration was reduced. Serotonin was present in the AP but its concentration was unaltered by sodium depletion. These findings provide evidence that sodium depletion produced an alteration in the concentration of norepinephrine of the area postrema without any change in the concentration of epinephrine, dopamine or serotonin.
Sympathetic nervous system response to graded exercise: effect of beta-blockade.
Authors: Barontini M B , Feldstein C A , Armando M I , Marchezotti A , Levin G M , Vilches A , Olivieri A , Burucua J E
Published: September 2013

This study compares the sympathetic nervous system response to graded exercise in normotensive and essential hypertensive subjects with and without beta-adrenergic blockade. Blood pressure (BP), heart rate, and plasma norepinephrine (NE), epinephrine (E), and dopamine (DA) were measured just before starting the exercise (Pre-Ex), in the submaximal exercise (Sub-max),and after 8 minutes rest (Post-Ex). On placebo, Sub-max induced in both normotensives and hypertensives a similar increase in NE and E plasma levels. Plasma DA remained unchanged. Propranolol in controls and propranolol or mepindolol in hypertensives didn't modify significantly: 1) Pre-Ex plasma levels of E, NE, and DA; 2) response at Sub-max in controls; 3) plasma E and DA in hypertensive patients. In hypertensives on beta-blockade, submaximal exercise elicited a greater increase in plasma NE. Values for plasma NE in patients on propranolol were 1135 +/- 229 pg/ml higher than those obtained in the same patients on placebo (p less than 0.001). On mepindolol, the plasma NE increment was higher than that on placebo (p less than 0.05), but lower than that on propranolol (p less than 0.01). In controls, propranolol did not significantly modify BP at Pre-Ex or its response to exercise, whereas systolic and diastolic BP were significantly lower at Pre-Ex, Sub-max, and Post-Ex in hypertensives. On beta-blockade, heart rate decrease in Pre-Ex, Sub-max, and Post-Ex were not different in controls and hypertensives. The differences found on beta blockade would indicate that the effects of beta blockers are not identical in normotensive and hypertensive subjects.
Left ventricular hypertrophy in rats with renovascular hypertension. Alterations in cardiac function and adrenergic responses.
Authors: Saragoça M A , Tarazi R C
Published: September 2013

Performance of the hypertrophied left ventricle was studied by determination of the inotropic response to different stimuli in renal hypertensive rats (two-kidney, one clip Goldblatt, RHR, n = 13) and matched sham-operated controls (NR, n = 11). A model was developed to determine maximal pressure development (transient aortic ligation), maximal pumping ability (rapid transfusion, 2 ml/30 sec), and responses to beta stimulation (isoproterenol, 0.01 to 0.10 micron g/kg/min), using dP/dt/P40 as a load-independent index of contractility. With rapid blood transfusion, RHR developed a higher ventricular systolic pressure (211.5 +/- 10.1 mm Hg vs 194.0 +/- 9.3 (SE), p less than 0.001) but at the expense of higher end-diastolic pressure (LVEDP) (12.2 +/- 1.1 mm Hg vs 7.7 +/- 1.0, p less than 0.02). The maximal response of dP/dt/P40 to isoproterenol was diminished in RHR (29.5 +/- 3.2 sec-1 vs 49.6 +/- 5.2, p less than 0.01) whereas the maximal developed pressure (MDP) was greater in RHR than in NR (239.2 +/- 7.5 mm Hg vs 197.0 +/- 3.9, p les than 0.001). A positive correlation was found between MDP and ventricular weight (r = 0.846, p less than 0.001) in contrast with the negative correlation found between ventricular weight and maximal dP/dt/P40 response to isoproterenol (r = 0.677, p less than 0.001). Thus, cardiac hypertrophy in RHR allowed higher developed ventricular pressures but at the expense of higher LVEDP; at the same time, however, the ability to increase contractility in response to beta adrenergic stimulation was decreased. The contrast in results obtained using different tests of cardiac function indicates the need for a multifactorial approach. It also suggests a subtle transformation in this hypertrophy of the pattern of cardiac adaptation to the increased load.