bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cover Picture: Macromol. Biosci. 2/2005
Authors: Kameda Tsunenori , Miyazawa Mitsuhiro , Ono Hiroshi , Yoshida Mitsuru 
Published: February 2005

Cover: High‐resolution 13C solid‐state NMR revealed two hydrogen bond systems in α‐chitin. The carbonyl oxygen was either intermolecularly hydrogen‐bonded to NH (blue; carbonyl 13C NMR peak at 173.5 ppm) or hydrogen‐bonded both intermolecularly to NH and intramolecularly to C(6)‐OH (red; 175.8 ppm peak). The former accounts for about 60% of the carbonyl groups and the latter for about 40%.Further details can be found in the Communication by T. Kameda,* M. Miyazawa, H. Ono, and M. Yoshida on page 103.
Supramolecular Assembly of Gold Nanoparticles Mediated by Polypseudorotaxane with Thiolated β‐Cyclodextrin
Authors: Liu Yu , Zhao Yan‐Li , Chen Yong , Wang Min 
Published: February 2005

AbstractSummary: A water‐soluble gold nanoparticle aggregate 2 was prepared by chloroauric acid and a polypseudorotaxane 1 of mono‐6‐thio‐β‐cyclodextrin with poly(propylene glycol) bis(2‐aminopropyl ether) ($\overline M _{\rm w}$ ≈ 2 000) in the presence of sodium borohydride in N,N‐dimethylformamide (DMF) solution. The investigative results indicated that the gold nanoparticle aggregate 2 might act as an efficient DNA‐cleavage reagent.A typical TEM image of gold nanoparticle aggregate 2.magnified imageA typical TEM image of gold nanoparticle aggregate 2.
Selective NMR Pulse Sequences for the Study of Solid Hydrogen‐Containing Fluoropolymers
Authors: Ando Shinji , Harris Robin K. , Hazendonk Paul , Wormald Philip 
Published: February 2005

AbstractSummary: Fluorine‐19 NMR spectra of solids have some special features, which are discussed in this article. In particular, they generally contain two abundant spin baths (protons and fluorine nuclei). This situation throws up some special operational requirements, as does the study of heterogeneous samples. The relaxation characteristics of heterogeneous systems, which are briefly described herein, frequently permit the use of specific pulse sequences to obtain subspectra for individual components. Various possible selective sequences for use in fluorinated heterogeneous organic solids are listed and their actions rationalized on the basis of molecular mobility. Semicrystalline hydrogen‐containing fluoropolymers form especially suitable systems for such operations, and in order to understand their domain structures it is essential to obtain subspectra of the amorphous and crystalline domains. Examples are given of the use of selective pulse sequences for studying fluoropolymers, especially for poly(vinylidene fluoride) (PVDF) and the copolymer P(VDF75/TrFE25) (TrFE = trifluoroethylene).DIVAM/CP spectra of the vinylidene fluoride/trifluorethylene copolymer as a function of the minipulse angle used. Top: Unfiltered spectrum. Middle: the amorphous domains. Bottom: the crystalline domains.magnified imageDIVAM/CP spectra of the vinylidene fluoride/trifluorethylene copolymer as a function of the minipulse angle used. Top: Unfiltered spectrum. Middle: the amorphous domains. Bottom: the crystalline domains.
Nerve stimulation boosts botulinum toxin action in spasticity
Authors: Frasson Emma , Priori Alberto , Ruzzante Barbara , Didonè Giuseppe , Bertolasi Laura 
Published: February 2005

AbstractSpasticity leads to functional and structural changes in nerves and muscles, which alter skeletal muscle function. To evaluate whether short‐term electrical nerve stimulation (NS) improves the effect of botulinum toxin in spastic skeletal muscle, we studied changes in the amplitude of the compound muscle action potential (CMAP) recorded from the extensor digitorum brevis (EDB) muscle in response to peroneal nerve stimulation at the ankle after injection of botulinum toxin type A (BTXA) alone or combined with short‐term NS. In paraparetic patients, both EDB muscles were injected with BTXA; and NS was applied to one EDB muscle alone. All patients received a 30‐minute session of electrical NS once a day for 5 consecutive days after BTXA injection. We used two different stimulation frequencies (low‐frequency, 4 Hz; and high‐frequency, 25 Hz). EDB‐CMAP amplitudes were evaluated before BTXA injection (day 0) and changes in CMAP amplitude, expressed as a percentage (CMAP%), were measured at various time points over a 30‐day period after BTXA injection. We compared changes in the CMAP% amplitude on the stimulated and contralateral nonstimulated sides. We also studied the electromyographic activity recorded from EDB muscles over a 30‐day period. CMAP% amplitudes measured at all time points after BTXA injections were significantly reduced in both EDB muscles. On days 4, 10, and 15, the CMAP% amplitude reduction was significantly greater for the low‐frequency stimulated EDB than for the contralateral nonstimulated EDB. No significant differences in CMAP% were observed for the high‐frequency stimulated and nonstimulated EDB. After BTXA injection, spontaneous activity appeared in both EDB muscles; but it appeared earlier and involved larger areas in the stimulated than in the nonstimulated EDB. In conclusion, short‐term NS accelerates the effectiveness of intramuscular BTXA injections on the neuromuscular blockade in patients with spastic paraparesis and could induce a rapid and persistent improvement in spasticity. Its action probably arises mainly from low‐frequency NS. © 2005 Movement Disorder Society
Driving in Parkinson's disease: Mobility, accidents, and sudden onset of sleep at the wheel
Authors: Meindorfner Charlotte , Körner Yvonne , Möller Jens Carsten , Stiasny‐Kolster Karin , Oertel Wolfgang Hermann , Krüger Hans‐Peter 
Published: February 2005

AbstractOnly few studies have addressed driving ability in Parkinson's disease (PD) to date. However, studies investigating accident proneness of PD patients are urgently needed in the light of motor disability in PD and—particularly—the report of “sleep attacks” at the wheel. We sent a questionnaire about sudden onset of sleep (SOS) and driving behavior to 12,000 PD patients. Subsequently, of 6,620 complete data sets, 361 patients were interviewed by phone. A total of 82% of those 6,620 patients held a driving license, and 60% of them still participated in traffic. Of the patients holding a driving license, 15% had been involved in and 11% had caused at least one accident during the past 5 years. The risk of causing accidents was significantly increased for patients who felt moderately impaired by PD, had an increased Epworth Sleepiness Scale (ESS) score, and had experienced SOS while driving. Sleep attacks at the wheel usually occurred in easy driving situations and resulted in typical fatigue‐related accidents. Those having retired from driving had a more advanced (subjective) disease severity, higher age, more frequently female gender, an increased ESS score, and a longer disease duration. The study revealed SOS and daytime sleepiness as critical factors for traffic safety in addition to motor disabilities of PD patients. The results suggest that real sleep attacks without any prior sleepiness are rare. However, our data underline the importance of mobility for patients and the need for further studies addressing the ability to drive in PD. © 2005 Movement Disorder Society
Alanine and leucine transport in unfertilized pig oocytes and early blastocysts
Authors: Prather R. S. , Peters M. S. , Van Winkle L. J. 
Published: February 2005

AbstractAmino acid transport is facilitated by specific transporters within the plasma membrane of the cell. In mouse oocytes and cleavage‐stage conceptus Na+‐dependent L‐alanine and L‐leucine transport are nearly undetectable. Sodium‐dependent transport via system BO,+ in the mouse conceptus increases greatly between the 8‐cell and blastocyst stages. By contrast, data presented here for the pig show that L‐alanine and L‐leucine transport is mainly Na+‐dependent in the oocyte; this Na+‐dependent component of transport becomes undetectable by the blastocyst stage. The Na+‐dependent component of transport in oocytes is inhibited by BCH (2‐aminoendo‐bicyclo[2.2.1] hexane‐2‐carboxylic acid) and L‐lysine and thus could be a form of system BO,+. In both oocytes and blastocysts Na+‐independent L‐leucine transport is inhibited by BCH, which is consistent with the presence of system L. The dramatic decrease in Na+‐dependent amino acid transport activity could occur in pig conceptuses in association with the onset of RNA synthesis during the 4‐cell stage. Regardless of the precise time during development at which it occurs, however, this dramatic, developmentally regulated decrease in Na+‐dependent alanine and leucine transport activity contrasts sharply with the large increase in Na+‐dependent system BO,+ activity that occurs during preimplantation development of murine conceptuses. Elucidation of the molecular mechanisms by which these changes occur should contribute to an understanding of regulation of gene expression during early development. © 1993 Wiley‐Liss, Inc.
Roles of pH and cyclic adenosine monophosphate in the acquisition of potential for sperm motility during migration from the sea to the river in chum salmon
Authors: Morisawa Sachiko , Ishida Katsumi , Okuno Makoto , Morisawa Masaaki 
Published: February 2005

AbstractIn the natural process of the migration of chum salmon from the sea to the river, spermatozoa moved from the testis to the sperm duct, and the pH value of seminal plasma, concentration of cyclic adenosine monophosphate (AMP) in the sperm cells, and potential for sperm motility increased. Cyclic AMP levels and the potential for motility gradually increased when testis spermatozoa with no capacity for movement were incubated in the artificial seminal plasma of which the pH was much the same as, or higher than, the pH of natural seminal plasma from the sperm duct. Such correlation in motility, pH, and cyclic AMP suggests that the increases in seminal pH and intracellular cyclic AMP level during passage of spermatozoa from the testis to the sperm duct cause the acquisition of potential for motility. Motility of testicular spermatozoa demembranated with Triton X‐100 was very low in fish caught in the sea, while motility of spermatozoa from the posterior portion of the sperm duct was much higher in fish caught in the river. Furthermore, nondemembranated, intact spermatozoa showed a lag in the timing of the acquisition of potential for motility vs. demembranated spermatozoa: The demembranated sperm exhibited the potential earlier than the nondemembranated sperm. These data suggest that increase in activity of the motile apparatus, the axoneme, is a prerequisite, in part, for the acquisition of sperm motility, whereas the development of some function of the plasma membrane also contributes to this phenomenon. © 1993 Wiley‐Liss, Inc.
Production of cumulus expansion enabling factor by mouse oocytes grown in vitro: Preliminary characterization of the factor
Authors: Eppig John J. , Peters Antoine H. F. M. , Telfer Evelyn E. , Wigglesworth Karen 
Published: February 2005

AbstractThe objective of this study was to determine whether fully grown oocytes, obtained after isolation from preantral follicles and growth in vitro, secrete paracrine factors affecting granulosa cell development and function. If so, the relative ease in producing oocytes in this way could facilitate the identification and characterization of the factors. As a test of this idea, the ability of in vitro grown oocytes to produce a paracrine factor that is known to enable the isolated cumulus oophorus to undergo expansion in response to follicle stimulating hormone (FSH) was determined. Initial experiments compared culture systems, which differed in the orientation of the oocyte‐granulosa cell complexes from preantral follicles to an extracellular matrix, for their ability to support oocyte growth and the acquisition of competence to resume meiosis. The systems for culture on the surface of the matrix produced larger oocytes and the highest percentage of oocytes having competence to resume meiosis. Oocytes grown using this system secreted active cumulus expansion enabling factor, albeit at levels about half that of oocytes grown in vivo. A preliminary characterization of the cumulus expansion enabling factor secreted by the oocytes grown in vitro showed that activity was lost upon treatment with either heat (65°C for 15 min) or proteinase K. Activity did not pass through a membrane having a nominal molecular weight limit (NMWL) of 100 kd but did pass through a membrane having a NMWL of 300 kd. It is concluded that cumulus expansion enabling factor is secreted by oocytes grown in vitro. This factor is probably a protein or depends upon a protein for its activity. The ease in obtaining relatively large numbers of GVB‐competent oocytes using techniques for growth in vitro combined with the demonstration that these produce cumulus expansion enabling factor indicates that these protocols can be used to produce oocytes for the collection and characterization of oocyte secretory products some of which are paracrine regulators of granulosa cells. © 1993 Wiley‐Liss, Inc.
Expression of proto‐oncogenes in mouse eggs and preimplantation embryos
Authors: Pal Subrata K. , Crowell Richard , Kiessling Ann A. , Cooper Geoffrey M. 
Published: February 2005

AbstractThe expression of several protooncogenes has been investigated in mouse eggs and preimplantation embryos using reverse transcription coupled to amplification of cDNAs by the polymerase chain reaction (RT‐PCR). The genes chosen for analysis included both cytoplasmic (c‐raf‐1, rasH, rasK, and rasN) and nuclear (c‐fos and c‐myc) proto‐oncogenes encoding proteins involved in the transduction of signals from protein‐tyrosine kinase growth factor receptors. Transcripts of the cytoplasmic proto‐oncogenes were detected both as maternal and embryonic mRNAs at levels (ca. 1,000 copies per egg or embryo) approximately comparable to their levels of transcription in somatic cells. Transcripts of c‐fos and c‐myc were also detected in both eggs and embryos, although at more variable levels: Maternal transcripts were present at very low levels (ca. 1–10 copies per egg) in growing oocytes and ovulated eggs; embryonic transcription of c‐myc increased, reaching mRNA levels of approximately 100–1,000 copies per embryo in four‐cell embryos, mórula, and blastocysts; in contrast the transcription of c‐fos remained at low, barely detectable levels throughout preimplantation development. Although the significance of the low levels of c‐fos mRNA is unclear, these results indicate that preimplantation embryos possess the basic intracellular signaling apparatus required to respond to polypeptide growth factors. © 1993 Wiley‐Liss, Inc.
Inositol tri‐phosphate in human and ascidian spermatozoa
Authors: Tosti Elisabetta , Palumbo Anna , Dale Brian 
Published: February 2005

AbstractUsing a specific protein binding assay we have shown that a spermatozoon of the ascidian Ciona intestinalis contains 1.58 ± 0.74 × 10−19 moles of inositol 1,4,5‐tri‐phosphate (InsP3), while a human spermatozoon contains 6.4 ± 0.14 × 10−19 moles. Induction of the acrosome reaction (AR) in both species, by exposure to the calcium ionophore A23187, does not significantly alter levels of InsP3, suggesting that phosphatidylinositol (PI) turnover is not necessary for the calcium ionophore induced AR. Furthermore, PI turnover in ascidian spermatozoa appears to be insensitive to lithium and phorbol ester. The high intracellular concentration of InsP3 in spermatozoa, corresponding to 50–200 μM, suggests it may play a role in egg activation. © 1993 Wiley‐Liss, Inc.
Zona‐free sperm penetration assay and inducers of the acrosome reaction: A model for sperm microinjection under the zona pellucida
Authors: Tarín Juan J. , Trounson Alan O. 
Published: February 2005

AbstractIn order to minimize the percentage of false‐negative results in the zona‐free sperm penetration assay (SPA), a wide range of substances and/or physical agents capable of inducing the acrosome reaction (AR) have been incorporated in the incubation medium. These agents can also be used for treatment of severe male infertility using the technique of sperm microinjection under the zona pellucida (SMUZ). In the present review, the percentages of acrosome‐reacted spermatozoa induced by several physiological, biochemical or physical agents published in the literature are compared in order to find the most efficient method(s) of inducing the AR In human sperm as a previous requirement for optimizing the technique of SMUZ. A working estimate of the level of efficiency of a given AR inducer is calculated by adding up its range score in each of three different arrangements from the highest to the lowest value of percentages of AR and differences in percentages of AR and penetration indexes between treated and control groups in SPA. The agents able to induce the AR by nonphysiological (electropermeabilization, lysophosphatidyl choline, and freezing‐thawing) have better positions in this hierarchical system than those ones which require the active participation of sperm membrane receptors or second messenger systems (progesterone, zona pellucida, and stimulators of protein kinase A). Electropermeabilization appears to be the most efficient AR inducer. However, more possibilities need to be explored to enhance the relatively low percentages of acrosome‐reacted spermatozoa shown by infertile men. © 1993 Wiley‐Liss, Inc.
Gene transfer in bovine blastocysts using replication‐defective retroviral vectors packaged with gibbon ape leukemia virus envelopes
Authors: Kim Teoan , Leibfried‐Rutledge Mary L. , First Neal L. 
Published: February 2005

AbstractWith this work we demonstrate that murine leukemia virus (MLV)‐based replication‐defective retroviral vectors encapsidated with Gibbon ape leukemia virus (GaLV) envelopes are significantly more infectious to bovine embryonic trachea (EBTr) cells than vectors encapsidated with murine xenotropic envelope proteins. In a test of internal promoter activity in an MLV retroviral vector, the rat β‐actin promoter was shown to be better than the herpes simplex virus type 1 thymidine kinase (TK) and human cytomegalovirus (CMV) immediate early promoters for the expression of an E. coli β‐galactosidase marker gene in bovine target cells. By co‐culture of bovine blastocysts and virus‐producing cells, or by culture of embryos in the medium harvested from virus‐producing cells, we transferred the E. coli β‐galactosidase gene into trophoblasts and also into inner cell mass (ICM) cells of a bovine embryo through the infection of the MLV‐based replication‐defective retroviruses encapsidated with GaLV envelope proteins. The infection was confirmed by the expression of the E. coli β‐galactosidase gene under a β‐actin internal promoter. In addition, co‐culture of ICM cells with virus‐producing cells resulted in differentiation of ICM cells into embryoid bodies expressing the marker genes. © 1993 Wiley‐Liss, Inc.
Quantitative analysis of protein synthesis in mouse embryos. II: Differentiation of endoderm, mesoderm, and ectoderm
Authors: Latham Keith E. , Beddington Rosa S. P. , Solter Davor , Garrels James I. 
Published: February 2005

AbstractThe changes in protein synthesis that occur during differentiation of the primitive germ layers were examined by high‐resolution, two‐dimensional gel electrophoresis of proteins synthesized in 6.5 and 7.5 days postcoitum (d.p.c.) mouse embryos. For 6.5 d.p.c. embryos, protein synthesis patterns were compared between whole extraembryonic and embryonic regions and between embryonic visceral endoderm and embryonic ectoderm. For 7.5 d.p.c. embryos, comparisons were made between extraembryonic and embryonic regions and between isolated embryonic endoderm, mesoderm, and ectoderm. Each of the isolated 7.5 d.p.c. germ layers was divided into anterior and posterior fragments in order to evaluate possible regional differences in gene expression along the anterior–posterior axis. Comparisons of protein synthesis patterns revealed the greatest difference between isolated endoderm and ectoderm, indicating that by as early as 6.5 d.p.c. patterns of gene expression differ significantly between these tissues. The greatest similarities were found between ectoderm and whole embryonic regions and between endoderm and whole extraembryonic regions, which most likely reflects the overall cellular compositions of the embryonic and extraembryonic regions. Based on their patterns of synthesis, four groups of proteins were identified that were preferentially synthesized in either endoderm or ectoderm. These provide useful markers for studying differentiation in these tissues. One other protein, migrating at the position expected for vimentin, was synthesized at an elevated rate in isolated mesoderm. We also observed differences in rates of synthesis of α‐tubulin and tropomyosin‐5 indicative of potential differences in cytoskeletal composition among the germ layers beyond those previously described. The difference in overall protein synthesis patterns between anterior and posterior regions was greatest in the embryonic endoderm, indicating that differentiation along the anterior–posterior axis may be initiated sooner or may proceed more rapidly in the endoderm than in the other germ layers. These data provide the first quantitative evaluation of the degree to which differentiation of the three primitive germ layers affects protein synthesis patterns and reveal potentially useful markers of endoderm and ectoderm differentiation. © 1993 Wiley‐Liss, Inc.
Rat Sertoli cell extracellular matrix regulates glycosaminoglycan synthesis by peritubular myoid cells in vitro
Authors: Raychoudhury Samir S. , Blackshaw Alan W. , Irving Michael G. 
Published: February 2005

AbstractWe have previously reported metabolic cooperation between Sertoli and peritubular myoid cells in terms of synthesis of one of the main testicular extracellular matrix (ECM) constituents, glycosaminoglycans (GAG). This study concerns Sertoli cell ECM‐peritubular myoid cell interactions in terms of GAG synthesis. We have examined the responses of hormones and other regulatory agents such as a combination of follicle‐stimulating hormone (FSH), insulin, retinol, and testosterone (FIRT) on peritubular myoid cells, and tested if Sertoli cell ECM or serum factor substitute for the stimulation by FIRT. Testicular peritubular myoid cells cultured on Sertoli cell ECM showed significant increases in the levels of cell‐ and ECM‐associated GAG over that when cultured on uncoated plastic. This indicates a specific cell‐substratum interaction between Sertoli cell ECM and peritubular myoid cells in the testis in terms of GAG synthesis. Moreover, in terms of cell‐associated GAG synthesis, peritubular myoid cells cultured on Sertoli cell ECM or on plastic in the presence of serum substituted for the stimulatory response of FIRT on peritubular myoid cells cultured on uncoated plastic. The data are discussed in relation to the possible role of cell‐substratum interaction in maintaining peritubular myoid cell functions. © 1993 Wiley‐Liss, Inc.