bluuebunny/crossref_metadata_2025 huggingface dataset:
Diadenosine polyphosphates and the control of cyclic AMP concentrations in isolated rat liver cells
Authors: Edgecombe Mandy , McLennan Alexander G. , Fisher Michael J.
Published: July 2002

Extracellular diadenosine polyphosphates (Ap
n
A), through their interactions with appropriate P2 receptors, influence a diverse range of intracellular activities. In particular, Ap4A stimulates alterations in intracellular calcium homeostasis and subsequent activation of glycogen breakdown in isolated liver cells. Here we show that, like ATP, Ap4A and other naturally occurring diadenosine polyphosphates attenuate glucagon‐stimulated accumulation of cyclic AMP in isolated rat liver cells. The characteristics of Ap4A‐ and ATP‐dependent modulation of glucagon‐stimulated cyclic AMP accumulation are similar. These results are discussed in the context of the repertoire of intracellular signalling processes modulated by extracellular nucleotides.
Transgenic replacement of type V adenylyl cyclase identifies a critical mechanism of β‐adrenergic receptor dysfunction in the Gαq overexpressing mouse
Authors: Tepe Nicole M , Liggett Stephen B
Published: July 2002

Chronic activation of Gq coupled receptors, or overexpression of Gαq, in cardiomyocytes results in hypertrophy, enhanced expression of fetal genes, decreased basal and β‐adrenergic receptor (βAR) stimulated adenylyl cyclase (AC) activities, and depressed cardiac contractility in vivo. Among several abnormalities of the βAR‐Gs‐AC pathway that occur in Gαq overexpressing transgenic mice, we have investigated whether the observed ∼45% decrease in type V AC expression and function compared to non‐transgenic (NTG) is the basis of the above phenotype. Transgenic mice were generated that overexpressed by ∼50% the rat type V AC in the heart using the α‐myosin heavy chain promoter. These mice were mated with the Gαq transgenics resulting in animals (ACV/Gαq) that had restored levels of forskolin stimulated AC activities in cardiac membranes. In addition, basal cardiac AC activities were normalized in the ACV/Gαq mice (NTG=23±4.4, Gαq=14±3.6, ACV/Gαq=29±5.3 pmol/min/mg) as were maximal isoproterenol stimulated activities (59±8.9, 34±4.6, 52±6.7 pmol/min/mg respectively). Cardiac contractility was also improved by ACV replacement, with increased fractional shortening (51±2%, 36±6%, 46±3% respectively). In contrast, hypertrophy and expression of hypertrophy associated fetal genes were not affected. Thus the observed decrease in type V AC that accompanies the development of the cardiac phenotype in the Gαq model is the dominant mechanism of dysfunctional βAR signalling and contractility. In contrast, the decrease in type V AC or βAR signalling to cAMP is not the basis of the hypertrophic response.
Solution structure of neuromedin B by 1H nuclear magnetic resonance spectroscopy
Authors: Lee Sangwon , Kim Yangmee
Published: July 2002

The solution structure of neuromedin B (NMB) was investigated using two‐dimensional nuclear magnetic resonance (NMR) spectroscopy in membrane‐mimicking environments. NMB adopts a relaxed helical conformation from Trp4 to Met10 in 50% aqueous 2,2,2‐trifluoroethanol (TFE) solution and in 150 mM SDS micelles. Sidechain atoms of the three residues, Trp4, His8 and Phe9 orient toward the same direction and these residues might play a key role on interacting with hydrophobic acyl chains of the phospholipids in the membrane. NOESY experiments performed on NMB in non‐deuterated SDS micelle show that aromatic ring protons of Trp4 and Phe9 residues are in close contact with methylene protons of SDS micelles. In addition, proton longitudinal relaxation data proved that the interactions between NMB with SDS micelle are characterized as extrinsic interaction. Trp4 and Phe9 seem to be important in interaction with receptor and this agrees with the previous studies of structure‐activity relationship (Howell, D.C. et al. (1996) Int. J. Pept. Protein Res. 48, 522–531). These conformational features might be helpful in understanding the molecular mechanism of the function of NMB and developing the efficient drugs.
A thermostable vacuolar‐type membrane pyrophosphatase from the archaeon Pyrobaculum aerophilum: implications for the origins of pyrophosphate‐energized pumps
Authors: Drozdowicz Yolanda M. , Lu Yu-Ping , Patel Vijay , Fitz-Gibbon Sorel , Miller Jeffrey H. , Rea Philip A.
Published: July 2002

Vacuolar‐type H+‐translocating pyrophosphatases (V‐PPases) have been considered to be restricted to plants, a few species of phototrophic proteobacteria and protists. Here, we describe PVP, a thermostable, sequence‐divergent V‐PPase from the facultatively aerobic hyperthermophilic archaeon Pyrobaculum aerophilum. PVP shares only 38% sequence identity with both the prototypical V‐PPase from Arabidopsis thaliana and the H+‐PPi synthase from Rhodospirillum rubrum, yet possesses most of the structural features characteristic of V‐PPases. Heterologous expression of PVP in Saccharomyces cerevisiae yields a M
r 64 000 membrane polypeptide that specifically catalyzes Mg2+‐dependent PPi hydrolysis. The existence of PVP implies that PPi‐energized H+‐translocation is phylogenetically more deeply rooted than previously thought.
Regulation of L‐arginine uptake by Ca2+ in human platelets
Authors: Giovine Marco , Signorello Maria Grazia , Pozzolini Marina , Leoncini Giuliana
Published: July 2002

L‐Arginine uptake and Ca2+ changes in unstirred platelets activated by thrombin, collagen and Ca2+ ionophore A23187 were evaluated. Thrombin did not affect L‐arginine uptake at short incubation times (2–15 min), but at prolonged times slowed down the amino acid transport. Collagen was ineffective. A23187 decreased the L‐arginine uptake in a dose‐dependent manner, producing the maximal inhibition at 5 μM. In FURA 2‐loaded platelets collagen did not modify Ca2+ basal level, thrombin induced a late Ca2+ rise and A23187 dose‐dependently increased cytosolic Ca2+, eliciting the highest increase at 5 μM. It is likely that L‐arginine uptake is inversely modulated by Ca2+ concentrations and is inhibited during platelet stimulation with agonists which induce cytosolic Ca2+ elevation.
Active site titration of gramicidin S synthetase 2: evidence for misactivation and editing in non‐ribosomal peptide biosynthesis
Authors: Kittelberger R. , Pavela-Vrancic M. , von Döhren H.
Published: July 2002

The catalytic competence of gramicidin S synthetase 2 (GS2) was determined by following the kinetics of PPi generation using active site titration measurements with [γ‐32P]ATP. The initial ‘burst’ of product formation can be correlated to the generation of the aminoacyl adenylate:enzyme complexes at the four amino acid activation domains and the subsequent aminoacylation of carrier domains, followed by a slow linear turnover of substrate due to breakdown of the intermediate. Simultaneous activation of all four amino acid substrates at a saturating concentration displayed a consumption of 8.3 ATP/GS2. In the presence of single amino acids, a binding stoichiometry higher than the anticipated two ATP per active site was obtained, implying misactivation at non‐cognate domains. Breakdown of acyladenylate intermediates reflects a possible corrective mechanism by which the enzyme controls the fidelity of product formation.
Biodiversity of the P450 catalytic cycle: yeast cytochrome b5/NADH cytochrome b5 reductase complex efficiently drives the entire sterol 14‐demethylation (CYP51) reaction
Authors: Lamb David C. , Kelly Diane E. , Manning Nigel J. , Kaderbhai Mustak A. , Kelly Steven L.
Published: July 2002

The widely accepted catalytic cycle of cytochromes P450 (CYP) involves the electron transfer from NADPH cytochrome P450 reductase (CPR), with a potential for second electron donation from the microsomal cytochrome b
5/NADH cytochrome b
5 reductase system. The latter system only supported CYP reactions inefficiently. Using purified proteins including Candida albicans CYP51 and yeast NADPH cytochrome P450 reductase, cytochrome b
5 and NADH cytochrome b
5 reductase, we show here that fungal CYP51 mediated sterol 14α‐demethylation can be wholly and efficiently supported by the cytochrome b
5/NADH cytochrome b
5 reductase electron transport system. This alternative catalytic cycle, where both the first and second electrons were donated via the NADH cytochrome b
5 electron transport system, can account for the continued ergosterol production seen in yeast strains containing a disruption of the gene encoding CPR.
Substitution of amino acid residue in influenza A virus hemagglutinin affects recognition of sialyl‐oligosaccharides containing N‐glycolylneuraminic acid
Authors: Masuda Hiroyuki , Suzuki Takashi , Sugiyama Yoshikuni , Horiike Goh , Murakami Kohji , Miyamoto Daisei , Jwa Hidari Kazuya I.-P. , Ito Toshihiro , Kida Hiroshi , Kiso Makoto , Fukunaga Kyoko , Ohuchi Masanobu , Toyoda Tetsuya , Ishihama Akira , Kawaoka Yoshihiro , Suzuki Yasuo
Published: July 2002

Sialic acids are essential components of cell surface receptors used by influenza viruses. To determine the molecular mechanisms of viral recognition of two major species of sialic acids, N‐acetylneuraminic acid (Neu5Ac) and N‐glycolylneuraminic acid (Neu5Gc), we tested the binding reactivity of nine human H3 influenza A viruses to sialylglycolipids containing type II sugar chain and different molecular species of terminal sialic acids. All human H3 viruses tested except A/Memphis/1/71 bound both Neu5Ac and Neu5Gc. Nucleotide sequence analysis suggests that amino acids at 143, 155, and 158 are linked to the viral recognition of Neu5Gc.
Proteolytic cleavage of protein kinase Cμ upon induction of apoptosis in U937 cells
Authors: Häussermann Sabine , Kittstein Walter , Rincke Gabriele , Johannes Franz-Josef , Marks Friedrich , Gschwendt Michael
Published: July 2002

Treatment of U937 cells with various apoptosis‐inducing agents, such as TNFα and β‐D‐arabinofuranosylcytosine (ara‐C) alone or in combination with the phorbol ester 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA), bryostatin 1 or cycloheximide, causes proteolytic cleavage of protein kinase Cμ (PKCμ) between the regulatory and catalytic domain, generating a 62 kDa catalytic fragment of the kinase. The formation of this fragment is effectively suppressed by the caspase‐3 inhibitor Z‐DEVD‐FMK. In accordance with these in vivo data, treatment of recombinant PKCμ with caspase‐3 in vitro results also in the generation of a 62 kDa fragment (p62). Treatment of several aspartic acid to alanine mutants of PKCμ with caspase‐3 resulted in an unexpected finding. PKCμ is not cleaved at one of the typical cleavage sites containing the motif DXXD but at the atypical site CQND378/S379. The respective fragment (amino acids 379–912) was expressed in bacteria as a GST fusion protein (GST‐p62) and partially purified. In contrast to the intact kinase, the fragment does not respond to the activating cofactors TPA and phosphatidylserine and is thus unable to phosphorylate substrates effectively.
Non‐genomic effects of progesterone on the signaling function of G protein‐coupled receptors
Authors: Burger Katja , Fahrenholz Falk , Gimpl Gerald
Published: July 2002

Progesterone at concentrations between 10 μM and 200 μM affected the calcium signaling evoked by ligand stimulation of G protein‐coupled receptors expressed in several cell lines. At 160 μM progesterone the signaling of all receptors was completely abolished. The effect of progesterone was fast, reversible and was not prevented by cycloheximide indicating its non‐genomic nature. Overall, the action of progesterone was more cell type‐specific than receptor‐specific. Our results are in contrast to a recent report [Grazzini, E., Guillon, G., Mouillac, B. and Zingg, H.H. (1998) Nature 392, 509–512] in which a direct high‐affinity interaction between the oxytocin receptor and progesterone was suggested.
The allosteric ATP‐inhibition of cytochrome c oxidase activity is reversibly switched on by cAMP‐dependent phosphorylation
Authors: Bender Elisabeth , Kadenbach Bernhard
Published: July 2002

In previous studies the allosteric inhibition of cytochrome c oxidase at high intramitochondrial ATP/ADP‐ratios via binding of the nucleotides to the matrix domain of subunit IV was demonstrated. Here we show that the allosteric ATP‐inhibition of the isolated bovine heart enzyme is switched on by cAMP‐dependent phosphorylation with protein kinase A of subunits II (and/or III) and Vb, and switched off by subsequent incubation with protein phosphatase 1. It is suggested that after cAMP‐dependent phosphorylation of cytochrome c oxidase mitochondrial respiration is controlled by the ATP/ADP‐ratio keeping the proton motive force Δp low, and the efficiency of energy transduction high. After Ca2+‐induced dephosphorylation this control is lost, accompanied by increase of Δp, slip of proton pumping (decreased H+/e− stoichiometry), and increase of the rate of respiration and ATP‐synthesis at a decreased efficiency of energy transduction.
Requirements for alternative forms of the activator domain, P5abc, in the Tetrahymena ribozyme
Authors: Naito Yoshikazu , Shiraishi Hideaki , Inoue Tan
Published: July 2002

The role of P5abc domain of the Tetrahymena LSU self‐splicing Group I intron is to enhance the activity of the intron via tertiary interactions involving A‐rich bulge and terminal loops L5b and L5c. We constructed and examined alternative forms of the domain that accelerate the ribozymatic reaction. The results indicate that the characteristic structure of P5c subdomain plays an important role by forming L2×L5c interaction (P14) and that the region flanking P5c subdomain can be significantly mutable without much affecting the activity of the ribozyme.
Involvement of IGF2 and H19 imprinting in choriocarcinoma development
Authors: Wake Norio , Arima Takahiro , Matsuda Takao
Published: July 2002

Complete hydatidiform mole is an abnormal pregnancy characterized by grossly swollen villi in the absence of a fetus (Kajii and Ohama 1997, Wake et al., 1978, Jacobs et al., 1980). It is well known that this abnormal pregnancy product is androgenetic in origin. The entire genome of the molar conceptus is paternally derived. The majority of moles result from fertilization of an empty egg by haploid sperm. The paternally derived haploid set then duplicated without cytokinesis and restores diploidy. Invariably, this class of moles has a 46, XX karyotype and is completely homozygous for genetic markers. Fertilization of an empty egg by two sperms is responsible for the remaining case. These moles show a mixture of homozygous and heterozygous patterns of paternally derived genetic markers. Although complete mole is usually a benign process, 10 to 20 percent of cases leads to either invasive mole or choriocarcinoma. This propensity to malignancy has to associate with the genetic features shown in the mole, that imply the formation of homozygosity and the selective inheritance of paternal genome. It has been described in various human malignancies that both genetic features associate with the inactivation of tumor suppressor genes. Homozygosity would lead to the inactivation of tumor suppressor gene in the mole by a signal event occurred on sperm DNAs. In turn, paternal transmission would result in the silencing of particular tumor suppressor genes. Thus, tumor suppressor genes inactivated either by homozygosity formation or by paternal transmission would be involved in the pathogenesis of choriocarcinoma.

Both the maternal and paternal genomes are necessary for normal embryonic development in mammals. Parental‐origin‐specific functional differences between two alleles, known as genomic imprinting, seem to be exploited for a regulatory mechanism crucial for the proper development of both embryonic and extraembryonic tissues. The list of imprinted genes identified is growing rapidly lately in mouse and man (DeChiara TM et al., 1991, Barlow et al., 1991, Bartolomei MS et al., 1991, Leff SE et al., 1992, Hatada I et al., 1993, Giddings SJ et al., 1994, Hayashizaki Y et al., 1994, Villar AJ et al., 1994, Guillemot F et al., 1995). Among these, IGF2 and H19 tightly linked on human chromosome 11 are of special interest because of their reciprocal imprinting and possible association with certain malignancy and congenital abnormalies. The IGF2 gene expressed from the paternally derived allele (Ohlsson et al., 1993, Giannoukalis et al., 1993), whereas the H19 gene is expressed from the maternally derived allele (Rachmilewitz et al., 1992, Zhang et al 1993, Ferguson‐Smith et al., 1993).
Topical oxatomide: an alternative approach for the treatment of vulvar lichen sclerosus
Authors: Origoni M. , Ferrari D. , Rossi M. , Gandini F. , Sideri M. , Ferrari A.
Published: July 2002

Objective: The treatment of vulvar lichen sclerosus has greatly improved in recent years, with the introduction of new pharmacological approaches and reconsideration of the traditional ones. Oxatomide is a molecule with both antihistamine and inhibiting activities for the inflammatory response, which may have potential use against this disease. Methods: We enrolled 22 patients affected by vulvar lichen sclerosus in a double‐blind, cross‐over, controlled trial. They were administered a 5% oxatomide‐based gel formulation and a placebo (petrolatum ointment) topically. At the beginning and the end of the investigation the severity and duration of symptoms, clinical appearance and tolerability were recorded. Statistical analysis of data was performed by Fisher's exact test and the Student‐NewmanKeuls test. Results: The results indicate that both regimens are significantly correlated with vulvar pruritus improvement and that 5% oxatomide gel has better anti‐itching effects compared to the placebo. Other symptoms responded poorly to the treatment. The rate of complete‐partial regression of pruritus was significantly higher (P < 0.05) in the oxatomide group than in controls, while no significant improvement was obtained neither with oxatomide or with placebo in terms of clinical appearance. Conclusions: These results, adequately confirmed, could suggest the introduction of oxatomide, in selected patients, as an alternative for the treatment of vulvar lichen sclerosus.
Pregnancy outcome beyond 41 weeks gestation
Authors: Roach V.J. , Rogers M.S.
Published: July 2002

Objective: To determine maternal and perinatal morbidity and the spontaneous labor rate beyond 41 weeks of gestation. Method: Patients with uncomplicated pregnancy were recruited at 41 weeks and screened for fetal or maternal well‐being. Following observation between 41 and 42 weeks, patients were randomized to either serial monitoring by cardiotocography and measurement of amniotic fluid index, or to immediate induction. Comparisons were made using the χ2 test. Results after 42 weeks were analyzed according to intention at randomization. Results: Morbidity was not increased before 42 weeks. After 42 weeks, the cesarean section rate and incidence of meconium below the vocal cords were increased in monitored patients. The median gestational age in patients who were monitored was 298.5 (294–321) days. In patients observed from 41 weeks, 91.6% labored spontaneously. Conclusion: It is reasonable to observe uncomplicated pregnancy until 42 weeks with adequate monitoring. After 42 weeks, induction of labor is preferred.
Recurrent abortion and moderate or strong antiphospholipid antibody production
Authors: Ogasawara M , Sasa H , Katano K , Aoyama T , Aoki K , Suzumori K
Published: July 2002

Objective: To investigate the treatment outcome for women suffering recurrent miscarriages associated with strong or moderate antiphospholipid antibody (aPL) production. Methods: Sixty‐seven pregnancies in 61 women demonstrating at least one kind of aPL with a history of recurrent miscarriages were treated with: (1) aspirin (ASA) alone; (2) prednisolone (PSL) and ASA; and (3) PSL, ASA, heparin and/or immunoglobulin (IgG). For comparison purposes the aPL‐positive patients were divided into two groups, strongly and moderately‐positive. IgG and IgM antibodies against PE and five negatively‐charged phospholipids were measured by ELISA between 1987 and 1993. β2‐glycoprotein I (β2GPI) dependent anticardiolipin antibodies were measured by ELISA since 1993. Lupus anticoagulant was measured by a diluted aPTT method since 1993. Results: Out of a total of 16 (50%) patients strongly‐positive for aPL and 47 out of 51 (92.2%) moderately‐positive demonstrated a successful outcome. The live birth rate moderate group was significantly higher than in the strongly‐positive cases (P<0.0005). In the cases exhibiting moderate aPL production, 28 out of 30 (93.3%) receiving PSL and ASA and 14 out of 15 (93.3%) treated with ASA alone successfully gave birth. None of the 14 given ASA alone suffered preterm delivery or IUGR. In contrast 12 (36.4%) and 6 (18.2%) of the 33 patients treated with the PSL combination therapy suffered from preterm delivery and IUGR, respectively. Conclusions: The live birth rate in patients strongly positive for aPL is lower than that in patients with moderate aPL production even if treatment is performed during pregnancy. However, ASA is useful to treat cases with moderate aPL so that distinction of the two groups is warranted.
Regional material properties of the human hip joint capsule ligaments
Authors: Hewitt John , Guilak Farshid , Glisson Richard , Vail T. Parker
Published: July 2002

The hip joint capsule functions to constrain translation between the femur and acetabulum while allowing rotational and planar movements. Despite the crucial role it plays in the pathogenesis of hip instability, little is known about its biomechanical properties. The goal of this study was to determine the regional material properties of the iliofemoral and ischiofemoral ligaments of the capsule.

Ten human cadaveric specimens of each ligament were tested to failure in tension. The stress at failure, strain at failure, strain energy density at failure, toe‐ and linear‐region elastic moduli, and the Poisson's ratio were measured for each ligament.

The strain to failure was greatest in the ischiofemoral ligament, while no significant difference was noted in failure stress by region or ligament. The Young's moduli of elasticity ranged from 76.1 to 285.8 MPa among the different ligaments, and were generally consistent with properties previously reported for the shoulder capsule. The elastic moduli and strain energy density at failure differed by region. No significant differences in Poisson's ratio were found by region or ligament. The average Poisson's ratio was approximately 1.4, consistent with anisotropic behavior of ligamentous tissues.

Understanding the material properties of the hip capsule may help the orthopaedic surgeon better understand normal ligament function, and thereby choose a surgical approach or strategy of repair. Furthermore, knowledge of the normal mechanical function of the hip capsule ligaments could assist in the evaluation of the success of a repair. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Neurotrophins can enhance spiral ganglion cell survival after inner hair cell loss
Authors: Miller Josef M. , Chi David H. , O'Keeffe Leonard J. , Kruszka Paul , Raphael Yehoash , Altschuler Richard A.
Published: July 2002

Following destruction of sensory cells of the organ of Corti, spiral ganglion cells (SGC) in the guinea pig degenerate. Chronic electrical stimulation via cochlear prostheses can enhance their survival, with the effect blocked by stopping the electrically elicited action potentials with tetrodotoxin. Blocking action potentials in the normal hearing ear with tetrodotoxin, however, does not cause degeneration. This suggests that in the pathological ear VIII N activity acts as a survival factor, while in the normal ear there are other survival factors that maintain SGCs. We examined neurotrophins, as survival factors in the deafened ear. Two weeks of treatment with BDNF (brain derived neurotrophic factor) administered chronically via a mini‐osmotic pump into scala tympani at 50 ng/ml, provided a statistically significant enhanced SGC survival over untreated deafened ears or deafened ears treated with artificial perilymph. Neurotrophin 3 provided some enhanced survival, but this was not statistically significant over untreated deafened ears. These observations suggest there are survival factors in the inner ear, including those coupled to direct activation of the auditory nerve fibers, that may serve to maintain the auditory nerve. These factors may be applied following deafness to maintain and enhance neural populations and to increase benefits to the profoundly deaf receiving cochlear implants.
Dopamine D3receptor agents as potential new medications for drug addiction
Authors: Le Foll B. , Schwartz J.C. , Sokoloff P.
Published: July 2002

All drugs abused by humans increase dopamine in the shell of nucleus accumbens, which implicate the neurons of this structure in their hedonic and reinforcing properties. Among the various dopamine receptor subtypes, the D1(D1R) and D3(D3R) receptors co-localise in accumbal shell neurons. Synergistic D1R/D3R interactions at this level were found on gene expression and during induction and expression of behavioral sensitisation to levodopa in rats bearing unilateral lesions of dopamine neurons. Behavioral sensitisation to abused drugs is a component of their long-term effects. Converging pharmacologic, human postmortem and genetic studies suggest the involvement of the D3R in reinforcing effects of drugs; D3R agonists reduced cocaine self-administration in rats, without disrupting the maintenance of self-administration. These data suggest the use of D3R agonists as partial substitutes to treat cocaine dependence, by affecting its reward component. However, substitution therapies maintain dependence and may be inefficient on drug craving and relapse, which are the unsolved and critical problems in the treatment of drug addiction. Recently, a highly selective and partial D3R agonist was shown to reduce cocaine-associated cue-controlled behaviour in rats, without having any primary intrinsic effects. As drug-associated cues maintain drug-seeking in animals and elicit craving and relapse in humans, such D3R agents have potential therapeutic applications.
Clinical profile and management of heart failure: rural community hospital vs. metropolitan heart center
Authors: Taubert G. , Bergmeier C. , Andresen H. , Senges J. , Potratz J.
Published: July 2002

Background:

Knowledge on clinical characteristics and prognosis of patients with heart failure originates from studies of selected populations in clinical trials or from epidemiological observations. Reports on the large numbers of patients with heart failure treated in community hospitals are sparse.

Objective:

Are there differences in patient characteristics and heart failure management between a metropolitan heart center (HC) and a rural community hospital (RCH)?

Patients and methods:

Retrospective analysis of medical charts from all patients admitted for heart failure (ICD 428.x, NYHA II–IV, EF < 45%) between May 1997 and April 1998 and discharged alive from a rural community hospital. A similar, but prospective registry was available at the HC. Follow‐up information was obtained by request at registration authorities.

Results:

Patient groups comprised 120 in RCH and 146 in HC. Mean age was 75 ± 11 and 66 ± 11 years, respectively (P < 0.001); 48% (RCH) vs. 74% (HC) of patients were male (P < 0.001). On admission the proportion of functional class IV was 69% (RCH) vs. 17% (HC) (P < 0.001). At discharge, the rate of ACE‐inhibitors was 74% (RCH) vs. 98% (HC); 11% (RCH) vs. 43% (HC) of patients received β‐blocker therapy. Ninety‐six percent of patients in HC underwent and 22% in RCH had undergone invasive diagnostics. One‐year mortality rate of patients discharged alive was 26% in RCH and 19% in HC (P ‐ n.s. after adjustment for age and gender).

Conclusion:

Heart failure management according to current guidelines, using β‐blockers and ACE inhibitors, and invasive cardiac examination was significantly less performed in the rural community hospital than in the metropolitan heart center. Therefore, strategies to improve heart failure management according to guidelines are urgently needed.
The high‐risk HPV E6 proteins modify the activity of the eIF4E protein via the MEK/ERK and AKT/PKB pathways
Authors: Morales‐Garcia Vicente , Contreras‐Paredes Adriana , Martinez‐Abundis Eduardo , Gomez‐Crisostomo Nancy P. , Lizano Marcela , Hernandez‐Landero Fernanda , de la Cruz‐Hernandez Erick
Published: September 2020

Previous studies have proposed that the human papillomavirus (HPV) E6 oncoproteins modify the transcriptional activity of eIF4E through mechanisms dependent on p53 degradation. However, the effect of these oncoproteins on pathways regulating the activity of the eIF4E protein remains poorly understood. Hence, we investigated the mechanisms whereby E6 proteins regulate the activity of the eIF4E protein and its effect on target genes. Overexpression of E6 constructs (HPV‐6, HPV‐16, HPV‐18, and HPV52) showed that E6 oncoproteins increased phosphorylation of the eIF4E protein (Serine‐209). This result was mainly mediated by phosphorylation of the 4EBP1 protein via the PI3K/AKT pathway. Additionally, the pharmacological inhibition of eIF4E phosphorylation in cervical cancer cell lines substantially reduced the protein levels of CCND1 and ODC1, indicating that E6 of the high‐risk genotypes may modify protein synthesis of the eIF4E target genes by increasing the activity of the AKT and ERK pathways.
Big Data, Collection of (Social Media, Harvesting)
Authors: Fennell Chris
Published: September 2020

This entry covers the methodological considerations when using big data to inform social science research. Several approaches from the literature are examined which consider theoretical and information perspectives. The entry also considers and analyzes python packages that are useful in web scraping. Challenges and approaches in this research are presented by covering the development of the scripts, comparing data across datasets, and preparing data for analysis.
Ethics of Empirical Research
Authors: Ramasubramanian Srividya , Landmark Shelby
Published: September 2020

Media psychologists need to reflect on what is considered ethical research in an increasingly complex digital media and sociocultural landscape by asking questions about whose interests are served through research and the purposes that research is used for. Ethical values such as truth, equity, justice, and inclusion should govern all aspects of research topics, questions, methods, participants, instrumentation, data collection, analysis, and distribution. Ethical principles are influenced by procedural ethics, professional codes, and personal aspirational ethics. Ethical considerations for media psychologists range through informed consent, minimizing psychological harm, increasing social responsibility of researchers, greater benefit to communities that are researched, privacy and confidentiality, and authorship and citational practices. Ethical considerations relating to experimental research, computational analytics, Internet‐based data, social media data, and biophysiological data are discussed in this entry.
Experiment, Laboratory, Design of
Authors: Thorson Esther
Published: September 2020

The laboratory experiment is a powerful tool for understanding how media messages are processed because cause–effect relations can be identified. Experiments involve manipulating values on one or more independent variables, and examining correlative changes on one or more dependent variables, within environments where all other sources of effects are controlled.
Experiment, Other: Natural, Field
Authors: Batinic Bernad , Freyth Lennart , Grossi Nina Raffaela
Published: September 2020

This entry contains a definition and an overview of the different forms of experiments in media psychology. These are laboratory experiments, field experiments, quasi‐experiments, and natural experiments. Exemplary studies on mass media, such as radio, cinema, or TV, are presented and assigned to the characteristic fields of media psychology as computer‐mediated communication, mass media effects, and media selection. Starting with the Internet, new fields of media psychological research are presented. Furthermore, a state‐of‐the‐art description of modern data collection in media psychology is given—the Internet of Things and wearable technology. By combining reactive and nonreactive data, the possibilities and advantages of the new research methods in media psychology experiments are highlighted.
In‐Depth Interviews
Authors: Rutledge Pamela B. , Hogg Jerri Lynn C.
Published: September 2020

An in‐depth interview is a qualitative research technique that is used to conduct detailed interviews with a small number of participants. In contrast to other forms of qualitative research, researchers using an in‐depth interviewing approach invest a significant amount of time with each participant employing a conversational format. Interview questions are primarily open‐ended and lead to a discovery‐oriented approach. The purpose of in‐depth interviewing is to get detailed information that sheds light on an individual's perspective, experiences, feelings, and the derived meaning about a particular topic or issue. A commonly‐employed qualitative technique in the social sciences, in‐depth interviewing is most frequently used in media psychology to better understand how to approach a topic that needs further study and can be a valuable component in multi‐method research designs. As a standalone research method, in‐depth interviewing has limitations for media applications due to the lack of generalizability.
Longitudinal Data and Panel Data: Methods and Analysis
Authors: Baumgartner Susanne E.
Published: September 2020

Longitudinal studies allow the investigation of dynamic processes of media use and effects. The most frequently used longitudinal design in media psychological research is the panel design. Panel studies are typically survey based and assess the same behaviors, attitudes, or emotions at least twice among the same participants. Panel studies are time intensive and expensive. Potential problems such as panel mortality, consistency of measures over time, and panel conditioning effects need to be considered when designing longitudinal studies. Although longitudinal studies are frequently used to assess causal relationships, researchers need to be aware of the limitations in drawing causal claims from panel data. There are a variety of statistical methods available for examining longitudinal data. When choosing the best method, researchers need to take into account the nested structure of the data, as well as the theoretical question they want to answer. Cross‐lagged panel models and latent growth models are frequently used statistical methods for longitudinal data in media effects research.
Measurement of Attitudes
Authors: Coenen Lennert
Published: September 2020

As the attitude concept is integral to many theories across the social sciences the measurement of attitudes has long been an important topic of research. Over the years, a variety of different attitude measurement techniques have been developed, all of which rely on their own theoretical rationale and methodological characteristics. Generally speaking, these testing procedures can be categorized into one of three fundamentally different families: direct, indirect, and physiological. Media psychologists should be aware of the theoretical and methodological differences between these families of attitude measurement, acknowledge their strengths and weaknesses, and deal with the theoretical complexities associated with relying on a particular approach.
Observational Methods
Authors: Courtright John A.
Published: September 2020

There are two approaches to observing human communication behavior: the unitize and categorize approach and the observe and record approach. Four fundamental types of units are presented: thoughts, grammatical units, time, and turns at talk. Similarly, the three basic requirements of a good category system are described: finite number of categories, mutual exclusivity, and exhaustiveness. In the discussion of the observe and record approach, five dimensions of communication behavior are presented and discussed. These are frequency, latency, intensity, pattern, and duration. Finally, three different reliability coefficients are described: Guetzkow's
U
for unitizing reliability, Cohen's kappa for categorizing, and intraclass correlation coefficients for assessing the reliability of the observe and record approach.
Publication Bias
Authors: Carpenter Christopher J.
Published: September 2020

Publication bias occurs when studies are conducted but do not enter the scientific record in the form of academic journal articles or other publications that other researchers can access. It is unclear how often this problem occurs in media psychology. Several methods have been proposed to detect publication bias in a research literature when conducting meta‐analyses. Shifts in publishing norms may reduce any publication bias that may exist.
Question Wording and Item Formulation
Authors: Holbert R. Lance , Koshy Abraham
Published: September 2020

Social and behavioral scientists rarely indulge in asking a single question about a given phenomenon of interest. As a result, the ordering of the items being presented to a subject of observation becomes a detail requiring attention. Also, as communication scholars, we know words matter. The systematic, empirical study of question wording and item formulation has been ongoing for more than three quarters of a century. Researchers have long focused on ways to increase clarity of presentation as a means of boosting the reliability and validity of measurement. With the global reach of empirical communication research, comparative research is on the rise and with this important development wide range of item formulation (e.g., translation equivalencies) issues have taken shape. Researchers are also faced with many challenges as they operationalize their variable concepts, including whether to use single‐ or multiple‐item measurement. If multiple‐item measurement is used, then there are specific criteria by which to judge indices versus scales. In addition, researchers have available a wide range of different types of item formation. There is the use of open‐ versus closed‐ended questions, and with closed‐ended questions there are many different types (e.g., Likert, semantic differential, multiple choice). All of these topics should be given consideration by media psychologists and are covered in this entry.
Sampling, Random
Authors: Meltzer Christine E.
Published: September 2020

A random sample is a subset of individuals randomly chosen from a larger population. Each individual has the same probability of being chosen at any stage during the sampling process. Only such a probability sampling allows for the use of inferential statistic to make estimations from the sample to the whole population. Depending on whether there is a full list of individuals of the population or not, how much information is available from the target population, and whether it is homogeneous or heterogeneous, the researcher can apply several different strategies to achieve a random sample. The most common strategies are introduced in this entry.
Secondary Task Reaction Time
Authors: Bracken Cheryl Campanella , DiRusso Carlina
Published: September 2020

This entry provides an overview of secondary task reaction time (STRT). The methodology relies on the theory of limited capacity of human processing. The method measures allocation of resource use through employment of a primary and secondary task and the amount of time (e.g., response time) it takes an individual to respond to the presentation of the secondary task. Examples of research topics examined using STRT, as well as how to calculate reaction time, are detailed.
Structural Equation Modeling
Authors: McNallie Jenna
Published: September 2020

Structural equation modeling (SEM) is a set of multivariate techniques developed to analyze complex theoretical models consisting of observed and/or latent variables. General processes associated with the development and analysis of measurement and structural (latent) models are described. Current debates regarding best practices for sample size and model fit indices are identified. The flexibility of SEM in testing multiple mediators along with the potential to compare multiple groups can pose some problems for current software. Phantom modeling is described as a potential solution for those issues.
Unobtrusive Measures for Media Research
Authors: Araujo Theo , Neijens Peter
Published: September 2020

Unobtrusive measuresare measures that—unlike self‐reports—do not intrude on or interfere with the context of the research. Observation, physical traces, and archives and documents are the three main categories of nondigital unobtrusive data. Digital unobtrusive measures can be collected online or offline, at aggregate or individual levels. Merits of unobtrusive measures are that they are not influenced by the research situation, make it possible to reach hard to get respondents, and allow for data collection from older or longer time periods. Digital unobtrusive data come in great numbers and give a detailed picture of user behavior. Limitations of unobtrusive measures include issues of validity, privacy, and representativity.
Validation
Authors: De Grove Frederik
Published: September 2020

Validation refers to the process through which the validity of a measurement instrument is assessed. Instruments are typically used to measure latent constructs. It involves evaluating content, predictive, and construct validity. Content validity asks the question to what extent the items in the instrument cover the content domain of the construct. Predictive validity seeks to validate an instrument by looking at correlations between the construct and a criterion. Finally, construct validity lies at the heart of the validation process and looks at the structural properties of the construct itself and in relation to others. This is typically done through confirmatory factor analysis. These three aspects of validation are complementary. Each one allows for collecting evidence against or in favor of the validity of an instrument. While validation ideally starts at the beginning of the scale development effort, it continues for as long as the instrument is used in research on the topic.
Excitation Transfer Theory
Authors: Cummins R. Glenn
Published: September 2020

Excitation transfer theory posits that residual emotional arousal or stimulation from an initial event can linger to impact subsequent emotional response to a subsequent stimulus. The effect of this transfer is typically observed in the form of elevated or exaggerated response to the second event, which could variably take the form of interpersonal aggression, interpersonal attraction, or subjective evaluations of media content. It has been applied in a variety of contexts, including news, advertising and persuasive messaging, and media entertainment.
Presence
Authors: Green Melanie C. , McAllister Cass A.
Published: September 2020

Presence refers to the feeling of “being there” in a mediated or virtual environment; more formally, presence is the perceptual illusion of nonmediation. Individuals who experience presence may feel as if they are located in or connected with others in the medium as if it were real life. People may experience different types of presence, including social presence, spatial presence, and self‐presence. Social presence refers to a sense of interacting with another entity (person or virtual reality character), fostering feelings of togetherness. Spatial presence positions individuals within the mediated environment as though they were actually there. Finally, self‐presence occurs when an individual assumes the role of the character or avatar as if it were themselves. Although the term presence is most frequently used for virtual reality and video games, presence or immersion can be experienced across a wide variety of mediums such as books and movies.
Media Multitasking
Authors: Tchernev John M.
Published: September 2020

The past few years have seen a meteoric rise in the amount that people media multitask—that is, engage in more than one task at a time, at least one of which is mediated. Researchers of media multitasking (also sometimes referred to as “dual tasking”) as a general phenomenon must first confront the term's inherent vagueness. For example, different types of multitasking can be identified by focusing on different dimensions of the construct, such as task modality, task relatedness, and the level of user choice, among others. Likewise, a range of theoretical backgrounds have been used to guide media multitasking research, with the uses and gratifications perspective and limited capacity models of human cognition being among the most frequently cited. Overall, a substantial body of research has shown that media multitasking has negative effects, particularly on cognitive performance and recall. The effects of media multitasking in other areas are less well understood, and much remains to be explored by future research.
Vividness and Salience
Authors: Riddle Karyn
Published: September 2020

Vivid stimuli are those presented with high‐quality contextual details. Scholars from psychology and communication have theorized about potential effects of exposure to vivid stimuli, and have generated a body of empirical research revealing several consistent (and, sometimes, inconsistent) patterns of findings. This entry reviews this research, relating it to a similar concept, salience.
Cognitive Biases and Heuristics
Authors: Shapiro Michael A.
Published: September 2020

Growing in part out of insights about heuristics and biases, the notion that people sometimes make decisions using mental shortcuts that require little mental effort or capacity and sometimes are more consciously thoughtful (Type 1 and Type 2 processing) has dominated much of social psychology for 50 years. While much of the early research in this area was dominated by investigations of errors apparently caused by mental shortcuts, current investigators note that both types of processing can lead to productive decisions as well as errors. The dual processing notion has been challenged by several theories of a single dimension of processing and by criticisms of the assumed clustering of processing features. However, the dual processing paradigm is likely to continue to be influential in a wide variety of studies in social psychology and media psychology.
Exemplification
Authors: Andsager Julie L.
Published: September 2020

Exemplification refers to message construction in terms of the use of examples, statistics and data, or both. The subsequent effects on individuals' knowledge levels (cognitive effects), emotionally‐based responses (affective effects), attitudes, and message effectiveness have been the primary interest of scholars. Exemplars may occur in news and entertainment media, in persuasive messages, in fiction, and in interpersonal communication. Media effects research focuses on the first two categories. The term
exemplar
encompasses individuals, objects, or events. Facts and figures comprise base‐rate information. The bulk of media effects research suggests that exemplars tend to have more effect on individuals than base‐rate information, in large part because they are more concrete than abstract. Effects on individual perceptions are often mediated, however, by individual differences in involvement, numeracy levels, congruity or similarity with an exemplar, and so forth. Exemplification theory posits that individual message consumers employ three decision‐making tools in evaluating the effects of such messages on themselves: a representativeness heuristic, a quantification heuristic, and an availability heuristic. The first describes the tendency of individuals to presume that a given exemplar accurately represents a larger group of individuals, objects, or events. Quantification heuristics relate to message consumers' estimations of the magnitude of an issue and how subgroups are distributed within the larger group. The availability heuristic refers to the probability that a recent or frequent exposure to an exemplar will affect message processing because these place it at the top of the mind.