bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructural evidence for secretion from the epithelium of ampulla ductus deferentis of the fan‐throated lizard Sitana ponticeriana Cuvier
Authors: Akbarsha M.A. , Tamilarasan V. , Kadalmani B. , Daisy P. 
Published: August 2005

AbstractAmong reptiles, an ampulla ductus deferentis has been reported only in Squamata. Fairly detailed studies are available only for two species, the lizard Calotes versicolor (Fam: Agamidae) and the snake Seminatrix pygaea (Fam: Colubridae). The light microscopic study on C. versicolor revealed the ampulla to be a prominent organ, whereas the light and transmission electron microscopic study in S. pygaea revealed it to be discernable only in histological preparations. Further, the epithelium of the ductal portion of vas deferens as well as the ampulla of C. versicolor appears to contribute to the seminal plasma and can also phagocytose dead sperm, whereas in S. pygaea neither of these roles has been established. Thus, we hypothesize that there may be variations in the anatomy, histology, and the role of the vas deferens in general, and the ampulla in particular, of the squamate reptiles. In this study, the ductus deferens of the small fan‐throated lizard Sitana ponticeriana (Fam: Agamidae) was subjected to light and transmission electron microscopic analysis. In this lizard the ampulla is more prominent than in C. versicolor. The epithelium of the ductal portion of vas deferens consists of principal cells (with features reflecting roles in endocytosis and phagocytosis of dead sperm), dark cells (which are absent in the epithelium of the ductal portion of vas deferens of snakes), and basal cells. The ampulla of S. ponticeriana is differentiated into storage and glandular portions. The epithelium of the storage portion is like that in the ductal portion of the vas deferens, whereas that of the glandular portion, consisting of dark and light principal cells and foamy cells, is tall and forms into smooth villous folds. All three cell types show evidence for a role in secretion, in all likelihood different from each other, for release into the lumen to contribute to seminal plasma. These cells do not provide evidence of a role in phagocytosis of dead sperm. It appears that within the Squamata, the ductal ampulla differs in structure as well as function. We suggest that the ductal ampulla of agamid lizards is a composite gland of the ampulla ductus deferentis and seminal vesicles of mammals. J. Morphol. © 2005 Wiley‐Liss, Inc.
Validated method for determination of bromopride in human plasma by liquid chromatography–electrospray tandem mass spectrometry: application to the bioequivalence study
Authors: Nazare P. , Massaroti P. , Duarte L. F. , Campos D. R. , Marchioretto M. A. M. , Bernasconi G. , Calafatti S. , Barros F. A. P. , Meurer E. C. , Pedrazzoli J. , Moraes L. A. B. 
Published: August 2005

AbstractA simple, sensitive and specific liquid chromatography‐tandem mass spectrometry method for the quantification of bromopride I in human plasma is presented. Sample preparation consisted of the addition of procainamide II as the internal standard, liquid‐liquid extraction in alkaline conditions using hexane‐ethyl acetate (1 : 1, v/v) as the extracting solvent, followed by centrifugation, evaporation of the solvent and sample reconstitution in acetonitrile. Both I and II (internal standard, IS) were analyzed using a C18 column and the mobile‐phase acetonitrile‐water (formic acid 0.1%). The eluted compounds were monitored using electrospray tandem mass spectrometry. The analyses were carried out by multiple reaction monitoring (MRM) using the parent‐to‐daughter combinations of m/z 344.20 > 271.00 and m/z 236.30 > 163.10. The areas of peaks from analyte and IS were used for quantification of I. The achieved limit of quantification was 1.0 ng/ml and the assay exhibited a linear dynamic range of 1–100.0 ng/ml and gave a correlation coefficient (r) of 0.995 or better. Validation results on linearity, specificity, accuracy, precision and stability, as well as application to the analysis of samples taken up to 24 h after oral administration of 10 mg of I in healthy volunteers demonstrated the applicability to bioequivalence studies. Copyright © 2005 John Wiley & Sons, Ltd.
LC–nanospray‐MS/MS analysis of hydrophobic proteins from membrane protein complexes isolated by blue‐native electrophoresis
Authors: Fandiño Anabel S. , Rais Isam , Vollmer Martin , Elgass Helmuth , Schägger Hermann , Karas Michael 
Published: August 2005

AbstractThe application of two‐dimensional electrophoresis for the identification of hydrophobic membrane proteins is principally hampered by precipitation of many of these proteins during first‐dimension, isoelectric focusing. Therefore new strategies towards the identification and characterization of membrane proteins are being developed. In this work we present a direct and rapid approach from blue‐native gels to mass spectrometry, which allows the analyses of complete complexes and prevents protein aggregation of hydrophobic regions during electrophoresis. We combine blue‐native gel electrophoresis and liquid chromatography–nanospray‐iontrap tandem mass spectrometry to analyze the composition of oxidative phosphorylation complexes I, III, IV and V from bovine‐heart mitochondria as a model system containing a number of highly hydrophobic proteins. Bands from blue‐native gels were subjected either to in‐gel or to in‐solution tryptic digestion. The obtained peptide mixtures were further analyzed by liquid chromatography–tandem mass spectrometry and the corresponding proteins were identified by database search. From a total of 86 proteins, 67 protein subunits could be identified including all highly hydrophobic components, except the ND4L and ND6 subunits of complex I. We demonstrate that liquid chromatography–tandem mass spectrometry combined to blue‐native electrophoresis is a straightforward tool for proteomic analysis of multiprotein complexes, and especially for the identification of very hydrophobic membrane protein constituents that are not accessible by common isoelectric focusing/sodium dodecyl sulphate gel electrophoresis. Copyright © 2005 John Wiley & Sons, Ltd.
Unambiguous detection of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana)
Authors: Grynbaum Marc David , Hentschel Petra , Putzbach Karsten , Rehbein Jens , Krucker Manfred , Nicholson Graeme , Albert Klaus 
Published: August 2005

AbstractHPLC atmospheric pressure chemical ionization (APCI)/MS, GC MS, HPLC diode array detection (DAD), and NMR were used for the identification of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana). Matrix solid phase dispersion was applied for the extraction of the carotenoids. This gentle and expeditious extraction technique for solid and viscous samples leads to distinct higher enrichment rates than the conventional liquid–liquid extraction. The chromatographic separation was achieved employing a C30 RP column that allows the separation of shape‐constrained geometrical isomers. A methanol/tert‐butylmethyl ether/water gradient was applied. (all‐E) Astaxanthin and the geometrical isomers were identified by HPLC APCI/MS, by coelution with isomerized authentical standard, by UV spectroscopy (DAD), and three isomers were unambiguously assigned by microcoil NMR spectroscopy. In this method, microcoils are transversally aligned to the magnetic field and have an increased sensitivity compared to the conventional double‐saddle Helmholtz coils, thus enabling the measurement on small samples. The carotenol fatty acid esters were saponified enzymatically with Lipase type VII from Candida rugosa. The fatty acids were detected by GC MS after transesterification, but also without previous derivatization by HPLC APCI/MS. C14:0, C16:0, C16:1, C18:1, C20:0, C20:5, and C22:6 were found in astaxanthin monoesters and in astaxanthin diesters. (all‐E) Astaxanthin was identified as the main isomer in six fatty acid ester fractions by NMR. Quantitation was carried out by the method of internal standard. (13‐cis) Astaxanthin (70 μg/g), 542 μg/g (all‐E) astaxanthin, 36 μg/g unidentified astaxanthin isomer, 62 μg/g (9‐cis) astaxanthin, and 7842 μg/g astaxanthin fatty acid esters were found.
Chararacterization of a monolithic immobilized trypsin microreactor with on‐line coupling to ESI‐MS
Authors: Křvenková Jana , Bilková Zuzana , Foret František 
Published: August 2005

AbstractThe preparation and characterization of a miniaturized trypsin reactor using on‐line coupling with an ESI‐TOF mass spectrometer are described. L‐1‐Tosylamido‐2‐phenylethyl chloromethyl ketone‐trypsin was covalently immobilized on poly(glycidyl methacrylate‐co‐ethylene dimethacrylate) monolith prepared in a 75 μm ID fused silica capillary resulting in a bioreactor with high local concentration of the proteolytic enzyme. Covalent immobilization of trypsin on this support was performed using the epoxide functional groups in either a one‐ or a multistep reaction. For on‐line protein digestion‐MS analysis the bioreactor was coupled with the mass spectrometer using a liquid junction microelectrospray interface. The performance of the reactor was tested using an on‐line flow through the system with flow rates of 50–300 nL/min. The resulting protein consumption was in the atto‐ to low femtomole range. Proteolytic activity was characterized in a wide range of conditions with respect to the flow rate, pH, and temperature. Complete protein digestion was achieved in less than 30 s at 25°C with the sequence coverage of 80% (cytochrome c), which is comparable to 3 h digestion in solution at 37°C. Besides the good performance at laboratory temperature, the immobilized trypsin in the bioreactor also performed well at lower pH compared to the standard in‐solution protocols.
Synthesis and Properties of Polyelectrolyte Gels with Embedded Voids
Authors: Komarova Galina A. , Starodubtsev Sergey G. , Khokhlov Alexei R. 
Published: August 2005

AbstractSummary: “Swiss‐cheese” polyelectrolyte gels, i.e., gels containing isolated voids filled with water were synthesized and studied. The gels were obtained by three‐dimensional copolymerization of neutral and charged monomers in the presence of oil/water emulsion stabilized by ionic surfactant. After removal of the surfactant and droplets of oil from the gel, the latter contains voids surrounded with charged swollen polymer network. Experiments were performed with slightly cross‐linked gels of copolymers of sodium‐2‐acrylamide‐2‐methyl‐1‐propanesulfonate with acrylamide. The gel containing voids absorbs much more anionic dyes than the control gel with the same chemical composition of the network obtained in homogeneous solution. This effect is due to strongly inhomogeneous distribution of the low molecular weight anions between the voids and the anionic matrix of the gel. The study of diffusion of the dyes in the gels with and without voids and of the kinetics of their swelling and collapse shows that the voids in the gel are isolated.Optical micrograph of polyelectrolyte gel with embedded emulsion droplets.magnified imageOptical micrograph of polyelectrolyte gel with embedded emulsion droplets.
Mass spectrometry and isotopes: A century of research and discussion
Authors: Budzikiewicz Herbert , Grigsby Ronald D. 
Published: August 2005

AbstractIn 1815, the British physician William Prout had advanced the theory that the molecular masses of elements were multiples of the mass of hydrogen. This “whole number rule” (and especially deviations from it) played an important role in the discussion whether elements could be mixtures of isotopes. F. Soddy's discovery (1910) that lead obtained by decay of uranium and of thorium differed in mass was considered a peculiarity of radioactive materials.The question of the existence of isotopes came up when the instruments developed by J.J. Thomson and by W. Wien to study cathode and canal rays by deflection in electric and magnetic fields were steadily improved. In 1913, Thomson mentioned a weak line at mass 22 accompanying the expected one at mass 20 when he analyzed the mass spectrum of neon. Subsequently Aston obtained the mass spectrum of chlorine with masses at 35 and 37. Still in 1921, Thomson objected heavily to the idea of isotopes.The isotope problem was finally settled, but more accurate mass measurements showed that even isotopic weights differed to some extent from the whole numbers. Based on earlier ideas of P. Langevin and J.‐L. Costa, F.W. Aston and A.J. Dempster developed the idea of packing fractions and mass defects due to the transformation of a portion of the matter comprising the atomic nucleus into energy.While the determination of the exact isotopic masses had improved over the years, the accurate determination of isotopic abundances remained a problem as long as photographic recording was used. Here especially A.O. Nier pioneered using dual collectors and compensation measurements. This was the prerequisite for the discovery that isotopic ratios varied somewhat in nature. M. Dole discovered the fractionation of oxygen isotopes by photosynthesis and respiration. Today 13C/12C‐ratios are employed to detect adulterations of food and in doping analysis, and 14C/13C‐ratios obtained by accelerator mass spectrometry are used for dating historical objects, just to give some examples. © 2005 Wiley Periodicals, Inc.
Prevention of levodopa‐induced dyskinesias by a selective NR1A/2B N‐methyl‐D‐aspartate receptor antagonist in parkinsonian monkeys: Implication of preproenkephalin
Authors: Morissette Marc , Dridi Mehdi , Calon Frédéric , Tahar Abdallah Hadj , Meltzer Leonard T. , Bédard Paul J. , Di Paolo Thérèse 
Published: August 2005

AbstractEnkephalin is reported to play an important role in the pathophysiology of levodopa (LD) ‐induced dyskinesias. The present study investigated the effect of chronic treatment with a selective NR1A/2B N‐methyl‐D‐aspartate (NMDA) receptor antagonist, CI‐1041, on the expression of preproenkephalin‐A (PPE‐A) in brains of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) ‐treated monkeys in relation to the development of LD‐induced dyskinesias. Four MPTP‐monkeys received LD/benserazide alone; they all developed dyskinesias. Four other MPTP‐monkeys received LD/benserazide plus CI‐1041; only one of them developed mild dyskinesias at the end of the fourth week of treatment. Four normal monkeys and four saline‐treated MPTP monkeys were also included. MPTP‐treated monkeys had extensive and similar striatal dopamine denervation. An increase of PPE‐A mRNA levels assayed by in situ hybridization was observed in the lateral putamen (rostral and caudal) and caudate nucleus (rostral) of saline‐treated MPTP monkeys compared to controls, whereas no change or a small increase was observed in their medial parts. Striatal PPE‐A mRNA levels remained elevated in LD‐treated MPTP monkeys, whereas cotreatment with CI‐1041 brought them back to control values. These findings suggest that chronic blockade of striatal NR1A/2B NMDA receptors with CI‐1041 normalizes PPE‐A mRNA expression and prevents the development of LD‐induced dyskinesias in an animal model of Parkinson disease. © 2005 Movement Disorder Society
Entdeckung der Calcium‐Antagonisten: Ein kurzer historischer Rückblick
Authors: Goldmann Siegfried 
Published: August 2005

AbstractDer Begriff des Ca2+‐Antagonismus wurde in den sechziger Jahren von A. Fleckenstein geprägt. Er wählte diese Bezeichnung für Verbindungen, die die Kontraktion von glatten Muskelpräparaten unterbanden. Zeitgleich wurde von Bossert und Vater (Bayer AG) die Substanzklasse der 1, 4‐Dihydropyridine entdeckt, mit Nifedipin als erstem Produkt, das vor 30 Jahren als Adalat® in den Markt eingeführt wurde. Diese Substanzen erwiesen sich als die wirksamsten Ca2+‐Antagonisten.Wissenschaftlich trug die Klasse der 1, 4‐Dihydropyridine zur Charakterisierung des spannungsabhängigen Ca2+‐Kanals bei. Eine hochaffine und enantioselektive Bindestelle konnte 1980 identifiziert und die Aminosäuresequenz des Kanalproteins 1986 aufgeklärt werden. Zum größeren Verständnis für die Wirkweise des Ca2+‐Kanals trugen die 1982 entdeckten Ca2+‐Agonisten bei, die sich pharmakologisch genau entgegengesetzt zu den Antagonisten verhielten. Sie steigerten den Ca2+‐Einstrom in die glatte Muskelzelle, waren daher am Herzen positiv inotrop und an den Gefäßen konstringierend und somit blutdrucksteigernd. Ca2+‐Antagonisten binden an den inaktiven Zustand des Ca2+‐Kanals und stabilisieren ihn, wodurch der Ca2+‐Einstrom in die Zelle gesenkt wird. Ca2+‐Agonisten stabilisieren den offenen Zustand des Kanals und erhöhen so den Ca2+‐Ionenstrom in die Zelle.Mit Hilfe von so genannten Caged‐Ca2+‐Antagonisten konnte gezeigt werden, dass die Hauptmenge der für die Kontraktion wichtigen Ca2+‐Ionen aus dem Extrazellularraum und nicht aus intrazellulären Speichern stammt.
Medizinische Chemie der L‐Typ‐Calcium‐Kanalblocker: Dihydropyridine und Nicht‐Dihydropyridine
Authors: Schubert‐Zsilavecz Manfred , Stark Holger 
Published: August 2005

AbstractNach der ersten Beschreibung einer physiologischen Bedeutung von Calciumionen an kardialen Geweben im Jahre 1883 von Ringer haben sich die Kenntnisse um die Regulation dieses wichtigen Regulators enorm erweitert. Die hier vorgestellten Calcium‐Kanalblocker sind alle Vasodilatatoren, aber dies in einem unterschiedlichen Ausmaß. Während die Nicht‐DHPs aufgrund ihrer vaskulären und kardialen Effekte antihypertensive, antiarrhythmische und antianginöse Wirkungen aufweisen, sind bei den DPHs im Gegensatz zu ihrer starken Senkung des koronaren und peripheren Widerstands die Wirkungen auf die Schrittmacherfunktionen (AV‐Überleitung) und die Dehnungsantwort am Herzen (Kontraktilität) kaum ausgeprägt. Dies zeigt, dass nicht alle Calcium‐Kanalblocker gleich sind und eine patientenorientierte erkrankungsangepasste Arzneimittelauswahl erfolgen muss.
Pharmakologie der Calcium‐Antagonisten: Wirkstoffe am Typ‐L‐Calciumkanal
Authors: Knorr Andreas 
Published: August 2005

AbstractCa2+‐Antagonisten sind eine chemisch und pharmakologisch sehr divergente Wirkstoffklasse. Die hauptsächlich therapierelevanten 1, 4‐Dihydropyridine, Phenykalkylamine und Benzothiazepine binden an drei unterschiedlichen Bindungsorten an der die Kanalpore bildenden α1c‐Untereinheit des Typ‐L‐Ca2+‐Kanals. Die Interaktionen mit dem Ca2+‐Kanal sind gut charakterisiert. Die Stoffklassen unterscheiden sich in ihrer Gewebespezifität und damit in ihrer Wirkcharakteristik: 1, 4‐Dihydropyridine sind vornehmlich peripher vasodilatierend, die Vertreter der beiden anderen haben eine stärkere kardiodepressive Wirkung. Die größte Wirkstoffgruppe, die 1, 4‐Dihydropyridine, finden die breiteste Anwendung in der Behandlung des Bluthochdrucks. Verapamil wird vor allem für die Therapie der supraventrikulären Arrhythmien eingesetzt. Weitere Einsatzgebiete sind die Behandlung der stabilen Angina pectoris und subarachnoidale Blutungen (nur Nimodipin).
Stellenwert von Nimodipin in der Demenztherapie: Calcium‐Hypothese der Demenz
Authors: Eckert Anne 
Published: August 2005

AbstractDie Calcium‐Hypothese der Demenz bildet die Rationale für den therapeutischen Einsatz des Calcium‐Antagonisten Nimodipin zur Behandlung von Demenzerkrankungen. Die Datenlage zur klinischen Wirksamkeit von Nimodipin zur Behandlung dementieller Syndrome wird in der Literatur allerdings kontrovers diskutiert, wenngleich eine kleine Zahl klinischer Studien eine Überlegenheit von Nimodipin gegenüber Plazebo hauptsächlich bei vaskulärer Demenz nachweisen konnte.
Therapie nach aneurysmatischer Subarachnoidalblutung: Einsatzgebiet für Calcium‐Antagonisten
Authors: Nemec Karin , Greif Robert 
Published: August 2005

AbstractDie Wirkstoffklasse der Calcium‐Antagonisten ist seit ihrer Markteinführung aus der Therapie kardiovaskulärer Erkrankungen nicht mehr wegzudenken. Obwohl ihre klinische Bedeutung in den letzten Jahren im Sinken begriffen war und eine Neubewertung stattgefunden hat, gibt es für einige Indikationen keinen Ersatz für die Anwendung von CalciumAntagonisten. Dazu gehören die Prophylaxe und Therapie ischämischer neurologischer Defizite infolge zerebraler Vasospasmen nach aneurysmatischer Subarachnoidalblutung (SAB).
Pharmazeutische Betreuung der Patienten in der Apotheke: Therapie mit Calcium‐Antagonisten
Authors: Diers Karsten 
Published: August 2005

AbstractPatienten, die mit einer Verordnung über Calcium‐Antagonisten in die Apotheke kommen, sind in den meisten Fällen entweder Hypertoniker oder leiden unter einer koronaren Herzkrankheit. Im Falle der Hypertonie ist die Krankheits‐ und Therapieeinsicht der Patienten gering, zudem sind sie nicht selten schlecht versorgt und therapiert. Das Auftreten von unerwünschten Arzneimittelwirkungen ist der Hauptgrund für Non‐Compliance bei Hypertonikern. Calcium‐Antagonisten nehmen hier vor allem wegen des Auftretens peripher Ödeme und Flush im Vergleich zu anderen Antihypertensiva eine Spitzenstellung ein. Die Pharmazeutische Betreuung hat als Hauptaufgabe, dieses Problem zu lösen. Neben der umfassenden Beratung des Patienten über seine Erkrankung und der zur Verfügung stehenden Therapiemöglichkeiten in Zusammenarbeit mit dem behandelnden Arzt sollte in der Apotheke mittels des Arzneidossiers eine Non‐Compliance detektiert, die Gründe hierfür identifiziert und mit Patient und Arzt gemeinsam nach Wegen zur Lösung gesucht werden. Hierzu ist die stärkere Einbindung des Patienten in die Therapie, das gemeinsame Festlegen von Therapiezielen und die eigenständige Überprüfung durch den Patienten Grundvoraussetzung.
Heilungschancen durch embryonale Stammzellen?
Authors: Zündorf Ilse , Dingermann Theo 
Published: August 2005

AbstractMitte Mai ging es durch die Medien und Woo Suk Hwang wurde plötzlich zum bekanntesten Südkoreaner: Er hatte 11 maßgeschneiderte embryonale Stammzelllinien für sowohl männliche als auch weibliche Patienten unterschiedlichen Alters und mit verschiedenen Erkrankungen durch Kerntransfer generiert.
Plasma protein profiling: Unique and stable features of individuals
Authors: Nelsestuen Gary L. , Zhang Yan , Martinez Michael B. , Key Nigel S. , Jilma Bernd , Verneris Michael , Sinaiko Alan , Kasthuri Raj S. 
Published: August 2005

AbstractCarefully controlled ZipTip extraction of diluted human plasma or serum was combined with MALDI‐TOF‐MS to produce highly reproducible protein profiles. Components detected included apolipoproteins CI, CII and CIII as well as transthyretin and several isoforms of each protein that are created by glycosylation or other modification and by proteolytic processing. Profiles of healthy individuals all contained the same 15 components. Others were found in plasma from individuals with disease. Profiles were analyzed by peak ratios within the same spectrum. Reproducibility for multiple assays was generally 4 to 10%. Within the healthy population, a given peak ratio occurred with a range of about fourfold. However, peak ratios of multiple samples from the same individual showed a much lower range, typically ±10%. In fact, each individual displayed a personal protein profile that changed very little over time. Because of the stability of protein profiles over time within individuals, these results suggest further studies may discover that certain profile characteristics or changes in an individual's profile may be a sign of current or future disease, even when the altered profile remains within the range for healthy individuals.