bluuebunny/crossref_metadata_2025 huggingface dataset:
Stabilising and destabilising modifications of cysteines in the E. coli outer membrane porin protein OmpC
Authors: Gokce Isa , Bainbridge Graeme , Lakey Jeremy H
Published: July 2002

Three sulfhydryl labels were used to modify two mutated sites, R37C and R74C in the eyelet of the outer membrane porin OmpC. Modification of R37C with the neutral groups Aldrithiol and bimane increases thermal stability but the negatively charged iodoacetate causes a decrease in thermal stability. The effects of substitution at R74C were less significant. Bimane labelling increases the voltage sensitivity and decreases the single channel conductance at R37C asymmetrically with smaller channels being recorded at cis negative voltages. Negatively charged acetate does not affect the voltage gating.
Multiple tyrosine residues in the intracellular domain of the common β subunit of the interleukin 5 receptor are involved in activation of STAT5
Authors: van Dijk Thamar B , Caldenhoven Eric , Raaijmakers Jan A.M , Lammers Jan-Willem J , Koenderman Leo , de Groot Rolf P
Published: July 2002

In contrast to the general model of cytokine‐induced JAK/STAT signaling, tyrosine phosphorylation of the IL‐5R β chain seems to be dispensable for STAT activation in cells overexpressing exogenous STAT proteins. In this study we expressed IL‐5 receptor mutants in 293 cells and studied IL‐5‐induced endogenous STAT‐dependent transcription. Our results indicate that: (a) tyrosine phosphorylation of the IL‐5R β chain is required for endogenous STAT5 activation, (b) multiple tyrosine residues are phosphorylated upon IL‐5 stimulation, including Tyr577, Tyr612, Tyr695, and Tyr750, and (c) Tyr612, Tyr695, and Tyr750 are all capable of inducing activation of STAT5, demonstrating a high level of functional redundancy within the IL‐5R β chain.
The presence of a transcription activation function in the hormone‐binding domain of androgen receptor is revealed by studies in yeast cells
Authors: Moilanen A , Rouleau N , Ikonen T , Palvimo J.J , Jänne O.A
Published: July 2002

To assess the importance of various regions of the androgen receptor (AR) in transcriptional regulation, we have compared its activation functions (AFs) in yeast and mammalian cells. The receptor's amino‐terminal region contains a major transcriptional activator (AF‐1) in both cell types, whereas AF‐2 in the ligand‐binding domain (LBD) is very weak in mammalian cells but clearly functional in the yeast. Hormone‐binding ability of LBD is mandatory for AF‐2 to operate, as illustrated by mutated LBD constructs. The activity of AF‐2 in yeast is severely attenuated when the hinge region is attached to LBD, suggesting that the former region modulates AF‐2 in vivo, probably by presenting an interface for interacting proteins.
Formation of a yeast SNARE complex is accompanied by significant structural changes
Authors: Rice Luke M , Brennwald Patrick , Brünger Axel T
Published: July 2002

The evolutionarily conserved SNARE (SNAP receptor) proteins and their complexes are key players in the docking and fusion of secretory vesicles with their target membrane. Biophysical techniques were used to characterize structural and energetic properties of the cytoplasmic domains of the yeast SNAREs Snc1 and Sso1, of the SNAP‐25‐like domain of Sec9, and of the Sso1:Sec9 and Sso1:Sec9:Snc1 complexes. Individually, all three SNAREs are monomeric; Sso1 shows significant secondary structure while Snc1 and Sec9 are largely unstructured. Ternary SNARE complex formation (K
D<50 nM) is accompanied by a more than two‐fold increase in secondary structure. This binding induced structure, the large increase in thermal stability, and the self‐association of the ternary complex represent conserved properties of SNAREs that are probably important in vesicle docking and fusion.
A reappraisal of the mechanism of the photoenzyme protochlorophyllide reductase based on studies with the heterologously expressed protein
Authors: Townley Helen E , Griffiths W.Trevor , Nugent Jonathan P
Published: July 2002

It is widely believed that protochlorophyllide reductase is a flavoenzyme effecting catalysis by a radical mechanism. Here the cyanobacterial reductase has been isolated from Escherichia coli overexpressing the Synechocystis gene. The purified enzyme, while retaining full activity, has no detectable flavine. No radical derived ESR signal was observed during catalysis or on photoexcitation under non‐catalytic conditions. Mechanistic implications of the findings are discussed.
Slow turnover of the D1 reaction center protein of photosystem II in leaves of high mountain plants
Authors: Shang William , Feierabend Jürgen
Published: July 2002

The D1 reaction center protein of photosystem II usually exhibits a rapid turnover in light. The D1 protein turnover was compared in three species of alpine plants, Homogyne alpina, Ranunculus glacialis, Soldanella alpina, and in the lowland plant Taraxacum officinale by radioactive labeling in light and subsequent chase experiments. The D1 protein of alpine plants could also be recognized by its more rapid labeling, relative to other membrane proteins. However, compared to T. officinale the turnover of the D1 protein was considerably slower in the alpine plants. The potential advantage of a slow D1 turnover for adaptation to the environmental conditions of high mountain plants is discussed.
Phosphatidylinositol transfer protein (PITPα) stimulates in vitro intra‐Golgi transport
Authors: Paul Kimberly S , Bogan Andrew A , Waters M.Gerard
Published: July 2002

Using a cell‐free assay designed to reconstitute cis‐to‐medial intra‐Golgi vesicular transport, we identified at least four crude activities in bovine brain cytosol that stimulate this assay. We have purified one of these activities to near homogeneity and have identified this M
r 36 kDa protein to be the α isoform of phosphatidylinositol transfer protein (PITPα) by N‐terminal peptide sequencing, immunoreactivity with PITP‐specific antisera, and the ability of recombinant PITPα to stimulate in vitro intra‐Golgi transport. From these data, we conclude that in vitro Golgi transport is facilitated by PITPα.
The identification, cloning and characterization of earthworm metallothionein
Authors: Stürzenbaum S.R , Kille P , Morgan A.J
Published: July 2002

Combining standard gel chromatographic techniques and novel molecular methodologies (Directed Differential Display and quantitative PCR), it has been possible to isolate and sequence two isoforms of the first true earthworm metallothionein. Both proteins are characteristically high in cysteine residues and possess no significant aromatic residues. Metal responsiveness was confirmed by determining metallothionein specific expression profiles in earthworms exposed to soils of differing heavy metal concentrations. Analysis of the derived amino acid sequence of isoform 2 identified two putative N‐glycosylation signal sequences, suggesting that the two isoforms may have different subcellular distributions and functions. Possible implications for intracellular metal trafficking are discussed.
Mapping the stereospecificity of peptidyl prolyl cis/trans isomerases
Authors: Schiene Cordelia , Reimer Ulf , Schutkowski Mike , Fischer Gunter
Published: July 2002

The stereospecificity of peptidyl prolyl cis/trans isomerases (PPIases) was studied using tetrapeptide substrate analogs in which one amino acid residue was replaced by the cognate d‐amino acid in various positions of the peptide chain. Reversed stereocenters around proline markedly increased the rate of the spontaneous trans to cis isomerization of the prolyl bond whereas cis to trans isomerizations were less sensitive. PPIases like human cyclophilin18, human FKBP12, Escherichia coli parvulin10 and the PPIase domain of E. coli trigger factor exhibited stereoselectivity demanding at the P1 to P2′ position of the substrate chain. The discriminating factor for stereoselectivity was the lack of formation of the Michaelis complexes of the diastereomeric substrates. However, d‐alanine at the P1 position preserved considerable affinity to the active site, and largely prevented activation of the catalytic machinery for all PPIases investigated.
C‐Terminal domain of β‐1,3‐glucanase H in Bacillus circulans IAM1165 has a role in binding to insoluble β‐1,3‐glucan
Authors: Yamamoto Mami , Ezure Toru , Watanabe Takeshi , Tanaka Hirosato , Aono Rikizo
Published: July 2002

The deduced amino acid sequences of 72‐kDa β‐1,3‐glucanase from Bacillus circulans WL‐12 (GlcA) and 91‐kDa enzyme from B. circulans IAM1165 (BglH) are highly homologous, except that the latter has an additional long C‐terminal region composed of 192 amino acid residues. Two mutant enzymes (BglH deprived of the C‐terminal region and GlcA with the C‐terminal region added) were constructed. The enzymes possessing the C‐terminal region bound more abundantly to pachyman (insoluble β‐1,3‐glucan) and Aspergillus oryzae cell wall than those not possessing the region. This indicates that the C‐terminal region participated in binding of the enzymes to insoluble β‐1,3‐glucan.
Enthalpy of captopril‐angiotensin I‐converting enzyme binding
Authors: Ortiz-Salmerón Emilia , Barón Carmen , Garcı́a-Fuentes Luis
Published: July 2002

High‐sensitivity titration calorimetry is used to measure changes in enthalpy, heat capacity and protonation for the binding of captopril to the angiotensin I‐converting enzyme (ACE; EC 3.4.15.1). The affinity of ACE to captopril is high and changes slightly with the pH, because the number of protons linked to binding is low. The determination of the enthalpy change at different pH values suggests that the protonated group in the captopril‐ACE complex exhibits a heat protonation of approximately −30 kJ/mol. This value agrees with the protonation of an imidazole group. The residues which may become protonated in the complex could be two histidines existing in two active sites, which are joined to the amino acids coordinated to Zn2+. Calorimetric measurements indicate that captopril binds to two sites in the monomer of ACE, this binding being enthalpically unfavorable and being dominated by a large positive entropy change. Thus, binding is favored by both electrostatic and hydrophobic interactions. The temperature dependence of the free energy of binding ΔG° is weak because of the enthalpy‐entropy compensation caused by a large heat capacity change, ΔC
p=−4.3±0.1 kJ/K/mol of monomeric ACE. The strong favorable binding entropy and the negative ΔC
p indicate both a large contribution to binding due to hydrophobic effects, which seem to originate from dehydration of the ligand‐protein interface, and slight conformational changes in the vicinity of the active sites.
Solution structure of the Eps15 homology domain of a human POB1 (partner of RalBP1)
Authors: Koshiba Seizo , Kigawa Takanori , Iwahara Junji , Kikuchi Akira , Yokoyama Shigeyuki
Published: July 2002

The solution structure of the Eps15 homology (EH) domain of a human POB1 (partner of RalBP1) has been determined by uniform 13C/15N labeling and heteronuclear multidimensional nuclear magnetic resonance spectroscopy. The POB1 EH domain consists of two EF‐hand structures, and the second one binds a calcium ion. In the calcium‐bound state, the orientation of the fourth α‐helix relative to the other helices of the POB1 EH domain is slightly different from that of calbindin, and much more different from those of calmodulin and troponin C, on the basis of their atomic coordinates.
Conformational stabilities of the rat α‐ and β‐parvalbumins
Authors: Henzl Michael T. , Graham John S.
Published: July 2002

It is widely believed that β‐parvalbumin (PV) isoforms are intrinsically less stable than α‐parvalbumins, due to greater electrostatic repulsion and an abbreviated C‐terminal helix. However, when examined by differential scanning calorimetry, the apo‐form of the rat β‐PV (i.e. oncomodulin) actually displays greater thermal stability than the α‐PV. Whereas the melting temperature of the α isoform is 45.8°C at physiological pH and ionic strength, the T
m for the β isoform is more than 7° higher (53.6°C). This result suggests that factors besides net charge and C‐terminal helix length strongly influence parvalbumin conformational stability. Extension of the F helix in the β‐PV, by insertion of Ser‐109, has a modest stabilizing effect, raising the T
m by 1.1°. Truncation of the α‐PV F helix, by removal of Glu‐108, has a more profound impact, lowering the T
m by 4.0°.
The NH2‐terminal region of the active domain of sonic hedgehog is necessary for its signal transduction
Authors: Katsuura Mieko , Hosono-Sakuma Yoshiko , Wagatsuma Masako , Yanagisawa Sachiko , Okazaki Makoto , Kimura Michio
Published: July 2002

The NH2‐terminal domain of sonic hedgehog (residue 25–198) was expressed in both yeast and animal cells. The yeast‐derived NH2‐terminal domain of sonic hedgehog was less active by far than the animal cell‐derived counterpart. The yeast‐derived NH2‐terminal domain of sonic hedgehog lacked 10 amino acids from the NH2‐terminus. This cleavage of the yeast‐derived NH2‐terminal domain of sonic hedgehog might due to Kex 2. In contrast, a mutant yeast‐derived NH2‐terminal domain of sonic hedgehog (Lys‐33 to Thr) retained its NH2‐terminus and its activity was comparable to that of the animal cell‐derived NH2‐terminal domain of sonic hedgehog. The NH2‐terminal deleted NH2‐terminal domain of sonic hedgehog completely lost its activity, nevertheless it inhibited the alkaline phosphatase activity induced by the animal cell‐derived NH2‐terminal domain of sonic hedgehog in a dose‐dependent manner. These data suggest that the NH2‐terminal deleted NH2‐terminal domain of sonic hedgehog retains a receptor‐binding ability and that the NH2‐terminal peptide of the NH2‐terminal domain of sonic hedgehog is necessary for its signal transduction.
Co‐transcription of Rhizobium meliloti lysyl‐tRNA synthetase and glutamyl‐tRNA synthetase genes
Authors: Pelchat Martin , Gagnon Yves , Laberge Serge , Lapointe Jacques
Published: July 2002

An open reading frame encoding a putative polypeptide very similar to several lysyl‐tRNA synthetases was found 10 nucleotides downstream of Rhizobium meliloti gltX encoding glutamyl‐tRNA synthetase. Expression of this gene complemented a mutation in lysS of Escherichia coli and led to the overexpression of a polypeptide of the expected mass (62 kDa), thus confirming that it encodes R. meliloti lysyl‐tRNA synthetase. Reverse transcription/polymerase chain reaction was used to demonstrate that this lysS gene is co‐transcribed with gltX in R. meliloti. This is the first reported case of two immediately adjacent and co‐transcribed genes encoding aminoacyl‐tRNA synthetases.
Engineering an unnatural Nα‐anchored disulfide into BPTI by total chemical synthesis: structural and functional consequences
Authors: Bark Steven J. , Kent Stephen B.H.
Published: July 2002

A disulfide‐engineered analogue of bovine pancreatic trypsin inhibitor (BPTI), ((Nα‐(CH2)2S‐)Gly38)BPTI, has been prepared using a thioester‐mediated auxiliary functional group chemical ligation of a Nα‐ethanethiol‐containing peptide segment with a peptide‐αCOSR segment. In this study, Nα‐(ethanethiol)Gly38 replaces the native Cys38, providing the sulfhydryl group required for ligation and folding. Comparisons between ((Nα‐(CH2)2SH)Gly38)BPTI, synthetic native BPTI and reference BPTI purchased from Sigma were made using mass spectroscopy, enzyme inhibitor association constant determination (K
a) and 1H‐nuclear magnetic resonance total correlated spectroscopy (1H‐NMR TOCSY) measurements. The K
a value for ((Nα‐(CH2)2SH)Gly38)BPTI was approximately 20‐fold lower than synthetic and reference BPTI, which was attributed to perturbations in the binding loop of the protein (near Cys14). This hypothesis was confirmed by two‐dimensional (2D) 1H‐NMR TOCSY experiments. The data reported here demonstrate that total chemical synthesis by auxiliary functional group chemical ligation is a practical method for the synthesis of a novel class of biologically active protein analogues containing additional functional groups linked to the protein backbone.
Thermodynamics of target peptide recognition by calmodulin and a calmodulin analogue: implications for the role of the central linker
Authors: Moorthy Anu K. , Gopal B. , Satish P.R. , Bhattacharya Sudha , Bhattacharya Alok , Murthy M.R.N. , Surolia A.
Published: July 2002

The thermodynamics of interaction of two model peptides melittin and mastoparan with bovine brain calmodulin (CAM) and a smaller CAM analogue, a calcium binding protein from Entamoeba histolytica (CaBP) in 10 mM MOPS buffer (pH 7.0) was examined using isothermal titration calorimetry (ITC). These data show that CAM binds to both the peptides and the enthalpy of binding is endothermic for melittin and exothermic for mastoparan at 25°C. CaBP binds to the longer peptide melittin, but does not bind to mastoparan, the binding enthalpy being endothermic in nature. Concurrently, we also observe a larger increase in α‐helicity upon the binding of melittin to CAM when compared to CaBP. The role of hydrophobic interactions in the binding process has also been examined using 8‐anilino‐1‐naphthalene‐sulphonic acid (ANS) binding monitored by ITC. These results have been employed to rationalize the energetic consequences of the binding reaction.
Positively charged residues, the helical conformation and the structural flexibility of the leader sequence of pALDH are important for recognition by hTom20
Authors: Schleiff E. , Heard T.S. , Weiner H.
Published: July 2002

Tom20, a mitochondrial outer membrane receptor necessary for protein translocation, was found to interact specifically with mitochondrial preproteins. The interaction of proteins containing an N‐terminal matrix targeting signal was enhanced in an hydrophobic environment and the dependence of this interaction on the alpha helical conformation of the presequence was postulated. In order to test this hypothesis and to gain insights about the features of a matrix targeting signal necessary to be recognized by the receptor machinery including Tom20, the interaction of pALDH and signal sequence mutants to Tom20 in the absence and presence of a hydrophobic environment was investigated. Here we present evidence to show that in a hydrophobic environment the interaction between Tom20 and the leader sequence is strongly dependent on the positive charges within the signal sequence as well as on the flexibility of this signal.
Dynamic character of the complex of human blood coagulation factor VIIa with the extracellular domain of human tissue factor: a normal mode analysis
Authors: Soejima Kenji , Kurihara Youji , Kamiya Kenshu , Umeyama Hideaki
Published: July 2002

As an attempt to investigate the dynamic interactions between plasma serine protease, coagulation factor VIIa (VIIa) and its cofactor, tissue factor (TF), we performed normal mode analysis (NMA) of the complex of VIIa with soluble TF (the extracellular part of TF; sTF). We compared fluctuations of Cα atoms of VIIa or sTF derived from NMA in the VIIa‐sTF complex with those of VIIa or sTF in an uncomplexed condition. The atomic fluctuations of the Cα atoms of sTF complexed with VIIa did not significantly differ from those of sTF without VIIa. In contrast, the atomic fluctuations of VIIa complexed with sTF were much smaller than those of VIIa without sTF. These results suggest that domain motions of VIIa molecule alone are markedly dampened in the VIIa‐sTF complex and that the sTF molecule is relatively more rigid than the VIIa molecule. This may indicate functions of TF as a cofactor.
Maternal sickle cell anemia and neonatal isoimmunization
Authors: Narchi H , Ekuma‐Nkama E
Published: July 2002

Objective: To study the risk of alloimmunization in pregnant women with sickle cell disease (SCD) and of isoimmunization in their offspring. Method: Thirty mothers with SCD were studied and their 35 neonates (group 1) were compared with 538 infants of mothers without hemoglobinopathies (group 2). Result: Six mothers with SCD developed alloantibodies. There was no correlation with maternal age (P=0.6), parity (P=0.18) or blood transfusions (P=0.4). The risk of alloimmunization by transfusion was 20%. Six neonates were isoimmunized, a higher incidence than in group 2 (P=0.02; relative risk 3.07). Five had ABO incompatibility and only one had anti‐c isoimmunization. All had reticulocytosis, jaundice and required phototherapy, one developed anemia but none required blood transfusion. Conclusion: Although alloimmunization was common in mothers with SCD and isoimmunization in their offspring, it was rarely due to non‐ABO alloantibody. There was no significant neonatal morbidity.
Advances in perinatal medical care — from our experience
Authors: Sakamoto S. , Takeda Y. , Nakabayashi M.
Published: July 2002

In the last 30 years, maternal and perinatal mortality rates have markedly improved in Japan. These results are supported by the advanced technologies and newly developed treatments in obstetric and neonatal medicine, the evidence of which will be described through the authors' experiences. Ultrasound‐guided treatments for fetuses and pediatric surgery for extremely tiny infants have been performed with cooperation among cardiac surgeons, anesthesiologists and perinatologists. The remarkable achievements in neonatal medicine are surfactant replacement therapy, application of high frequency oscillation (HFO) respirator, nitric oxide and extracorporeal membrane oxygenation (ECMO) systems and transcutaneous blood gas monitoring. The possibility to have a safe pregnancy and delivery arose for women with severe medical complications such as diabetes mellitus (DM), heart diseases, and hemo‐dialysis, factors formerly regarded as contraindications to pregnancy. The accumulative data of these high‐risk pregnancies treated in our center are introduced. It is noted that molecular mechanisms in fetal growth have been elucidated to some extent. The insulin‐like growth factor I (IGF‐I) and IGF‐binding protein 1 (IGFBP1) system, and cytokines, are involved in the fetal growth. Newly developed treatments such as urinary trypsin inhibitor (Urinastatin) for prevention of preterm delivery and amnioinfusion to cases of preterm premature rupture of the membrane are summarized. Finally, the reference to advanced medicine and its side effects lead to broad discussions regarding the future development of perinatal medicine.
Laparoscopic loop ligatures for bladder repair during laparoscopic surgery
Authors: Yin C.S. , Li Y.‐T. , Chao T.‐C. , Yu M.‐S.
Published: July 2002

In this paper, we report a case where a bladder perforation occurred during a laparoscopically assisted vaginal hysterectomy and was repaired by laparoscopic loop ligatures. This is the first case report of using the laparoscopic loop ligatures to close the bladder perforations. The loop ligature is an easy and quick procedure, which can be performed by most surgeons who take the time to learn the endoscopic suturing techniques.
Some ethical and legal issues in assisted reproductive technology
Authors: Dickens B.M. , Cook R.J.
Published: July 2002

The potential and actual applications of reproductive technologies have been reviewed by many governmental committees, and laws have been enacted in several countries to accommodate, limit and regulate their use. Regulatory systems have nevertheless left some legal and ethical issues unresolved, and have caused other issues to arise. Issues that regulatory systems leave unresolved, or that systems have created, include disposal of embryos that remain after patients' treatments are concluded, and multiple implantation and pregnancy. This may result in risks to maternal, embryonic and neonatal life and health, and the contentious relief that may be achieved by selective reduction of multiple pregnancies. A further concern arises when clinics must (or choose to) publicize their success rates, and they compete for favorable statistics by questionable patient selection criteria and treatment priorities.
A comparative study on the structural relationships of manufacturing practices, lead time and productivity in Japan and Korea
Authors: Rho Boo‐Ho , Yu Yung‐Mok
Published: July 2002

This study focuses on analyzing how the factory productivity and lead time can be linked together with manufacturing practices in different countries, especially in Japan and Korea. A structural relationship model with five exogenous manufacturing practice constructs (design and engineering changes, production planning, materials management, process and process technologies, and quality) and two endogenous manufacturing performance constructs (lead time and productivity) has been proposed and empirically tested with mail‐surveyed data sets collected in these two countries. As a result, the overall fitness of the proposed model showed a significant structural relationship in both countries. Two exogenous constructs, process and process technologies and materials management, appeared to have significant effect on length of the lead time in both countries. Process and process technologies also showed a direct significant relationship with productivity in both countries. But other manufacturing practices had different cause‐and‐effect relationship with lead time and/or productivity depending on the countries. No other constructs were found to have any significant relationship with lead time in Japan. But the Japanese sample showed that process and process technologies, lead time and quality had a significant effect on productivity. Production planning and quality performance also seemed to significantly affect the length of lead time in Korea. But no significant relationship could be found between productivity and lead time or between productivity and quality in Korea.
Levels of dopamine and noradrenaline in the developing retina — effect of light deprivation
Authors: Shelke Rajani R.J. , Lakshmana Madepalli K. , Ramamohan Y. , Raju Trichur R.
Published: July 2002

The effect of light deprivation on the levels of dopamine and noradrenaline was studied in the developing rat retina. These transmitters were estimated in three groups of rats: (i) cycling light reared; (ii) dark reared since birth; and (iii) dark reared since birth, but exposed to cycling light for 1 day prior to the estimation of catecholamines. Our results show that (1) there is a progressive decrease in the levels of dopamine and noradrenaline in the cycling light and dark reared rats during postnatal development; (2) dark rearing further reduces the content of dopamine and noradrenaline; and (3) restoration of physiological (light) stimulus in the dark‐reared rats during the early postnatal period results in the recovery of noradrenaline to a greater extent than that of dopamine. This study demonstrates a progressive decrease in the plasticity of dopaminergic system during retinal development, while such a decrease is not apparent in the noradrenergic system.
Lectin characterization of the olfactory system inbrachiopterygian fish
Authors: Franceschini Valeria , Lazzari Maurizio , Ciani Franco
Published: July 2002

Lectin binding was performed on the olfactory system of Polypterus and Erpetoichthys, the living genera of the subclass of Brachiopterygii. The lectin histochemicalpatterns and the Western‐blot analysis indicate that the receptor cells of the olfactory mucosa arecharacterized by high density of specific glycoconjugate residues. The presence of glycoproteins,whose terminal sugars are detected by lectin binding, might be related to the reception of an odorstimulus and its transduction into a nervous signal or to the histogenesis of the olfactory system.© 1999 ISDN. Published by Elsevier Science Ltd. All rights reserved
Prolactin secretion in response to haloperidol challenge in delusional (psychotic) and non-delusional depression
Authors: Lykouras L , Markianos M , Hatzimanolis J , Oulis P , Christodoulou G.N
Published: July 2002

Certain studies on measures related to central neurotransmitter activity have demonstrated that in delusional (psychotic) depression there is a dopaminergic dysregulation which distinguishes it from non-psychotic depression. A neuroendocrinologic method to check the degree of DA receptor responsivity is by measuring the prolactin responses to acute intramuscular administration of haloperidol. We studied this possibility by applying the haloperidol test in seven delusional and ten non-delusional depressed patients. All patients met DSM-IV criteria for a major depressive episode, single or recurrent, with or without psychotic features. After a three-week washout period, 5 mg of haloperidol were injected i.m. and blood samples were taken at 0, 30, 60, 90 and 120 minutes. In both trials, significant time effects were observed (elevated prolactin levels, F = 11.36, P = 0.000). However, the prolactin responses to haloperidol did not differ significantly between the two patient groups (F = 0.12, P = 0.97). These data do not show a difference in D2 receptor responsivity, at least at the hypothalamus-pituitary level, between psychotic and non-psychotic depression.
Associations between cortical slow potentials and clinical rating scales in panic disorder: a 1.5- year follow-up study
Authors: Dengler W. , Wiedemann G. , Pauli P.
Published: July 2002

In a previous study of 15 panic patients, we demonstrated that body-related (somatic) word stimuli elicited an enhanced positive cortical slow wave compared to non-somatic word stimuli. Healthy controls did not show this difference. The present paper reports on psychometric ratings in relation to cortical slow waves in these patients. Patients were clinically reexamined after about 1.5 years. Although no significant correlations between neurophysiology and psychometric measures could be found at the onset of the study, there was a significant correlation between improvement over the follow-up period and neurophysiology. A decline in the Hamilton Anxiety Scale (HAMA), which proved to be the best estimate for improvement, was associated with the relative magnitude of the positive slow wave elicited by somatic stimuli. Our findings support cognitive models of panic disorder, which stress that abnormal processing of bodily symptoms is relevant for the development and/or maintenance of the disorder.
An Evidence‐Based Approach To Male Circumcision: What Do We Know?
Authors: Updegrove Kimberly K.
Published: July 2002

Midwives care for women throughout their childbearing years, guiding them through decisions made about themselves and their newborn children. The decision to circumcise a male infant depends on a number of factors, including medical, social, cultural, and religious considerations. Data surrounding medical benefits and risks of this surgery are inconsistent and, therefore, confusing. However, substantial data exist to support the conclusions that uncircumcised males have greater incidences of urinary tract infections, especially in the first 6 months of life when complications are greatest, greater incidences of ulcerative sexually transmitted infections, and increased transmission of human immunodeficiency virus. This article reviews available research on the medical benefits and risks of infant circumcision. Informed consent is essential for all parents who must make this decision.
THE 1999 ACC TASK ANALYSIS OF NURSE‐MIDWIFERY/MIDWIFERY PRACTICE PHASE I: THE INSTRUMENT DEVELOPMENT STUDY
Authors: Fullerton Judith T. , Johnson Peter , Oshio Sachiko
Published: July 2002

The national certification examination (NCE) in nurse‐midwifery and midwifery is developed, administered, and evaluated by the ACNM Certification Council (ACC). The blueprint for the NCE is based upon a comprehensive list of tasks that describe the knowledge, skills, and abilities expected of the midwifery practitioner at entry into the profession. In 1999, the ACC initiated the third in a series of task analysis studies to ensure the currency and relevance of the task list. This study was considered particularly timely, given that the professional organization, the American College of Nurse‐Midwives, had approved pathways to midwifery for individuals whose first degree was not in nursing (the certified midwife) and also had expanded the core competencies for midwifery practice to include responsibilities in the domain of primary care. This manuscript reports the results of the pilot study, in which the specific list of tasks was developed. Three hundred and six ACNM members responded to a preliminary list of tasks, indicating their opinion about whether each specific task was relevant to entry‐level midwifery practice. The task list finally derived consists of 219 tasks and 177 clinical conditions, dispersed among seven domains of practice (antepartum, intrapartum, newborn, postpartum, well‐woman/gynecology, primary care/health assessment, and professional issues.) The task list represents a comprehensive profile of entry‐level practice for nurse‐midwives and midwives certified by the ACC.
Self‐Reporting Gold Nanourchins for Tumor‐Targeted Chemo‐Photothermal Therapy Integrated with Multimodal Imaging
Authors: Zhang Beilu , Wang Jinping , Sun Jingyu , Wang Yuhao , Chou Tsengming , Zhang Qiang , Shah Harshal R. , Ren Lei , Wang Hongjun
Published: July 2020

In search of facile yet efficient therapeutic and imaging nanoagents for cancer treatment, versatile self‐reporting gold nanourchins (AuNUs) featuring synergic chemo‐photothermal therapies and multimodal imaging are fabricated. AuNUs are synthesized using a surfactant‐free approach, and then functionalized with a Raman reporter 4‐mercaptophenylboronic acid (4‐MPBA) and dopamine to form adenosine triphosphate (ATP)‐cleavable boronate ester bonds prior to further immobilization with hyaluronic acid (HA) for cancer targeting. Controlled release of an anticancer drug, doxorubicin (DOX), loaded in the interstices of AuNUs, is achieved upon exposure to the overproduced hyaluronidase (HAase) in a tumor microenvironment. The spiny exterior of AuNUs enables their optophysical conversion of near‐infrared (NIR) light (808 nm) to heat for photothermal therapy and IR imaging. The surface enhanced Raman scattering (SERS) of AuNUs also allows sensitive and reliable Raman mapping of their cellular uptake in vitro, and intratumoral accumulation in vivo, complementary to conventional photoacoustic imaging (PAI). With a demonstrated ability to eradicate tumors and enable multimodal imaging, AuNUs exemplify ongoing efforts in design and utility of multifunctional nanoplatforms.
A Fully Phase‐Modulated Metasurface as An Energy‐Controllable Circular Polarization Router
Authors: Yuan Yueyi , Sun Shang , Chen Yang , Zhang Kuang , Ding Xumin , Ratni Badreddine , Wu Qun , Burokur Shah Nawaz , Qiu Cheng‐Wei
Published: July 2020

Geometric metasurfaces primarily follow the physical mechanism of Pancharatnam–Berry (PB) phases, empowering wavefront control of cross‐polarized reflective/transmissive light components. However, inherently accompanying the cross‐polarized components, the copolarized output components have not been attempted in parallel in existing works. Here, a general method is proposed to construct phase‐modulated metasurfaces for implementing functionalities separately in co‐ and cross‐polarized output fields under circularly polarized (CP) incidence, which is impossible to achieve with solely a geometric phase. By introducing a propagation phase as an additional degree of freedom, the electromagnetic (EM) energy carried by co‐ and cross‐polarized transmitted fields can be fully phase‐modulated with independent wavefronts. Under one CP incidence, a metasurface for separate functionalities with controllable energy repartition is verified by simulations and proof‐of‐principle microwave experiments. A variety of applications can be readily expected in spin‐selective optics, spin‐Hall metasurfaces, and multitasked metasurfaces operating in both reflective and transmissive modes.
Exploring Eye‐tracking Technology as an Assessment Tool for Point‐of‐care Ultrasound Training
Authors: Lee Wei Feng , Chenkin Jordan
Published: July 2020

Objectives

Eye‐tracking technology has emerged as a potentially useful learner assessment tool in several medical specialties. In the fields of general surgery and anesthesiology, it has been shown to reliably differentiate between different levels of expertise in procedural skills. In the field of radiology, it has been shown to be a valid assessment tool for diagnostic test interpretation. Current methods of competency assessment in point‐of‐care ultrasound (POCUS) remain a challenge, because they require significant direct observation time by an instructor. The purpose of this study was to determine if eye‐tracking technology can accurately distinguish between novice and experts in the interpretation of POCUS clips, specifically of the focused assessment using sonography in trauma (FAST) scan.

Methods

A convenience sample of medical students, residents, and emergency physicians from a single academic emergency department were invited to participate. Participants included both novices and experts in POCUS. Each participant completed a baseline questionnaire and viewed 16 video clips of a FAST ultrasound examination while their gaze patterns were recorded by a commercially available eye‐tracking device. The primary outcome was total gaze time on the area of interest (AOI). Secondary outcomes included total time to fixation, mean number of fixations, and mean duration of first fixation on the AOI.

Results

Fifteen novices and 15 experts completed this study. For total gaze time on the AOI, experts fixated their gaze significantly longer than novices (75.8 ± 16.2 seconds vs. 56.6 ± 12.8 seconds, p = 0.001). Similarly, experts were significantly faster to fixate on the AOI and had a higher fixation count on the AOI (8.5 ± 4.0 seconds vs. 15.1 ± 6.8 seconds, p = 0.003; and 170 ± 30 vs. 143 ± 28 seconds, p = 0.016). There were no differences on the mean duration of first fixation on the AOI (0.42 ± 0.12 seconds vs. 0.39 ± 0.09 seconds, p = 0.467).

Conclusion

Eye‐tracking technology shows the potential to differentiate between experts and novices by their gaze patterns on video clips of FAST examinations. The total gaze time on the AOI may be a useful metric to help in the assessment of competency in POCUS image interpretation. In addition, the evaluation of gaze patterns may help educators identify causes of interpretation errors. Future studies are needed to further validate these metrics in a larger cohort.
Creeping bentgrass summer decline as influenced by climatic conditions and cultural practices
Authors: Miller Grady L. , Brotherton Mark A.
Published: July 2020

Despite its popularity as a putting surface in North Carolina, creeping bentgrass (Agrostsis stolonifera L.) is highly susceptible to summer bentgrass decline (SBD) during hot summer months. Cultural practices have been shown to help alleviate the pressure of SBD. The objectives of this study were to detail the impacts of N fertility, soil water content, and hollow‐ and solid‐tine cultivation on creeping bentgrass quality. Cultural treatments included four N rates (97, 195, 293, and 391 kg ha−1 yr−1), four hollow‐tine core cultivation programs (6.4 mm diam. tines two times yr−1, 9.5 mm diam. tines two and three times yr−1, and a non‐cored control), two soil water content levels (low and high), and two summer solid‐tine spiking cultivation treatments (spiked and not spiked). Visual turfgrass quality was measured. A N rate greater than 195 kg ha−1 was needed to maintain acceptable turfgrass quality. High soil water content consistently provided better summer turfgrass quality compared to low soil water content conditions. Nitrogen fertility and soil water content interacted where higher levels of both resulted in the best quality ratings. Hollow‐core cultivation reduced turfgrass quality at the lower N rates; whereas, solid‐tine spiking had no effect on turfgrass quality. Although weather plays a large role in SBD in North Carolina, results from this study show that cultural practices can influence its severity.
Characterization of variability in blazar light curves
Authors: Singh Krishna K. , Meintjes Peter J.
Published: July 2020

Blazars represent the dominant population of the extragalactic γ‐ray sources in the universe. These sources exhibit some characteristic properties such as strong and nonthermal continuum emission over the entire electromagnetic spectrum, from radio to Tera electron Volts (TeV) γ‐rays, with rapid variability on all timescales. The emission at radio and optical wavelengths is highly polarized with significant variation. The fastest variability in the blazar emission is observed during the flaring activity, which is an important observational property of blazars. In this paper, we describe various methods to characterize the temporal variability in the multiwavelength light curves of blazars. We also provide a detailed description of the set of statistical parameters that are used to quantify the level of variability present in the time series. Implications of the information derived from the variability study to probe the physics of blazars using multiwavelength observations are also discussed.
Simultaneous determination of citalopram and tadalafil by the second derivative synchronous fluorescence method in biological fluids; application of Box–Behnken optimization design
Authors: Abdel‐Raoof Ahmed M. , Hasan Mohamed A. , Madkour Ahmed W. , Abdel‐Fattah Ashraf , Eissa Maya S.
Published: July 2020

This is the first study focusing solely on that determination of tadalafil in the presence of citalopram as an antidepressant drug. The determination in biological fluids of a co‐administered antidepressant drug and a sexual stimulation drug is a very critical and important step for psychotic and ischaemic heart disease patients, especially in cases of emergency and this requires therapeutic drug monitoring. A sensitive, efficient and rapid assay was selected satisfactorily and applied for simultaneous determination of citalopram and tadalafil either in their pure forms, in tablet dosage forms or in spiked human plasma. There was a large overlap for both drugs, forming the broad band found in conventional fluorescence spectra and their related synchronous fluorescence intensity. Therefore, the development of a highly sensitive second derivative synchronous fluorescence method was demonstrated that removed this overlap. The proposed method depended on measuring the amplitudes of the second derivative of synchronous fluorescence intensity at suitable wavelengths of 301 nm and 367 nm for citalopram and tadalafil at Δλ = 60 nm, respectively. Box–Behnken design as a response surface methodology was used to fit models and create an optimization process encompassing a set of factors and resulting in an optimum response value specifically designed for this method. Under optimum conditions, the linear dynamic ranges for citalopram and tadalafil estimation were 20–900 and 5–400 ng ml−1 with detection limits of 5.40 and 1.43 ng ml−1, respectively.
Pyrazines: Synthesis and Industrial Application of these Valuable Flavor and Fragrance Compounds
Authors: Mortzfeld Frederik B. , Hashem Chiam , Vranková Kvetoslava , Winkler Margit , Rudroff Florian
Published: July 2020

Alkyl pyrazines—other than being extracted from various natural sources such as coffee beans, cocoa beans, and vegetables—can be synthesized by chemical methods or by certain microorganisms. The importance of pyrazines for the food industry is expected to grow in the upcoming years due to the higher demand for convenience products. The roasty, nutty, and earthy smell is reminiscent of coffee and cocoa, depending on substitution and concentration of pyrazines. The growing awareness of people about the ingredients and the origin of their daily food has strongly influenced the market with labels like “organic” and “natural.” Many flavor ingredients prepared by biotechnological methods have conquered the market recently and are destined to replace the ineffective (0.01% pyrazine kg−1 biomass) extraction from plants or animal sources. This review focuses on the achievements and challenges in pyrazine synthesis. The major part deals with an overview of methods such as the extraction of natural products, the chemical and biocatalytic synthesis, and fermentation by microorganisms. The different types of production are decisive for the declaration and value of the final product and span from 200–3500 US$ kg−1 for the synthetically produced or the naturally extracted 2,5‐dimethylpyrazine, respectively.
Factors associated with mammography use: A side‐by‐side comparison of results from two national surveys
Authors: Li Lihua , Ji Jiayi , Besculides Melanie , Bickell Nina , Margolies Laurie R. , Jandorf Lina , Taioli Emanuela , Mazumdar Madhu , Liu Bian
Published: July 2020

Background

Mammography use is affected by multiple factors that may change as public health interventions are implemented. We examined two nationally representative, population‐based surveys to seek consensus and identify inconsistencies in factors associated with mammography use in the entirety of the US population, and by black and white subgroups.

Methods

Self‐reported mammography use in the past year was extracted for 12 639 and 169 116 women aged 40‐74 years from the 2016 National Health Interview Survey (NHIS) and the 2016 Behavioral Risk Factor Surveillance System (BRFSS), respectively. We applied a random forest algorithm to identify the risk factors of mammography use and used a subset of them in multivariable survey logistic regressions to examine their associations with mammography use, reporting predictive margins and effect sizes.

Results

The weighted prevalence of past year mammography use was comparable across surveys: 54.31% overall, 54.50% in white, and 61.57% in black in NHIS and 53.24% overall, 56.97% in white, and 62.11% in black in BRFSS. Overall, mammography use was positively associated with black race, older age, higher income, and having health insurance, while negatively associated with having three or more children at home and residing in the Western region of the US. Overweight and moderate obesity were significantly associated with increased mammography use among black women (NHIS), while severe obesity was significantly associated with decreased mammography use among white women (BRFSS).

Conclusion

We found higher mammography use among black women than white women, a change in the historical trend. We also identified high parity as a risk factor for mammography use, which suggests a potential subpopulation to target with interventions aimed at increasing mammography use.
Lung cyst and multinodular thyroid goiter: Keys to DICER1 syndrome diagnosis in a 16‐year‐old female
Authors: Tutor James D. , Miller Stephen F. , Al Zubeidi Hiba , Sheyn Anthony , Zhang Jie , Williams Regan , McGee Rose B.
Published: July 2020

Pulmonary cysts and neoplasms, especially congenital or occurring at a young age, should be thoroughly investigated. Evaluation for DICER1 mutations should be performed if there is a family history of this syndrome, the lung cyst/neoplasm is a pleuropulmonary blastoma, or other clinical manifestations of this syndrome are present or develop.
A case of gastric cardia telangiectasias and primary biliary cirrhosis with hemorrhage
Authors: Guo Jinsheng
Published: July 2020

In patients presenting with persistent anemia and gastric cardia telangiectasias, a potential etiology of portal hypertension due to chronic liver disease, especially primary biliary cirrhosis, should be considered. Drugs for treating specific liver disease and lowering portal hypertension are effective strategies to prevent hemorrhage.