bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of androgenetic mouse embryos produced by in vitro fertilization of enucleated oocytes
Authors: Kono Tomohiro , Sotomaru Yusuke , Sato Yasuhiro , Nakahara Tatsuo
Published: February 2005

Enucleated mouse oocytes were successfully fertilized in vitro, and the resultant androgenetic eggs developed to the blastocyst stage. The proportion of enucleated oocytes fertilized in vitro was high (87–99%) at sperm concentrations ranging from 10–100 × 104/ml. At high sperm concentrations (100–1,000 × 104), 35–45% of the fertilized eggs resulted in heterozygous bispermic androgenones. The proportion of hemizygous haploid and heterozygous diploid androgenones developing to blastocysts was 11% and 43%, respectively. Hemizygous diploidization, however, showed no positive effect on development. These results clearly show that the procedure reported here is efficient and reliable for the production of androgenetic eggs. © 1993 Wiley‐Liss, Inc.
Forskolin and the meiosis inducing substance synergistically initiate meiosis in fetal male germ cells
Authors: Byskov Anne Grete , Fenger Mogens , Westergaard Lars , Andersen Claus Yding
Published: February 2005

We have shown that Meiosis Inducing Substance (MIS) and forskolin synergistically and dose dependently induce meiosis in germ cells of cultured fetal mouse testes. We used a bioassay which consists of fetal mouse testes and ovaries cultured for 6 days. In this study MIS media are spent culture media from 24 hour cultures of minced adult mouse testes. In the bioassay one gonad of each fetus is cultured either in MIS medium, in control medium with forskolin, or in MIS medium with forskolin. The other gonad serves as the control and is cultured in control medium. After culture the gonads are fixed, squashed, and DNA‐stained. In these preparations germ cells and somatic cells can be distinguished, and the number of germ cells in the different stages of meiosis is counted as is the number of somatic cells in mitosis. MIS activity is defined to be present in a medium when meiosis is induced in male germ cells during culture. We found that MIS media as well as forskolin induced meiosis in fetal male germ cells in a dose‐dependent manner. In addition, MIS media and forskolin acted synergistically by inducing meiosis. Female germ cells seem to be unaffected by the various culture media. These findings indicate that receptors for stimuli of meiotic initiation may exist in germ cells or neighbouring somatic cells. In addition to induction of meiosis, MIS media and forskolin also dose dependently increase the number of male germ cells compared to controls. This increase is correlated with induction of advanced stages of meiosis: Male germ cells seem to survive better if they are triggered to enter meiosis. Neither MIS media nor forskolin affected the growth of somatic cells. We therefore propose that MIS media has a growth factor activity with a specific effect on meiotic initiation. © 1993 Wiley‐Liss, Inc.
Pig membrana granulosa cells prevent resumption of meiosis in cattle oocytes
Authors: Kalous Jaroslav , Sutovsky Peter , Rimkevicova Zora , Shioya Yasuo , Lie Byong‐Lyul , Motlik Jan
Published: February 2005

Membrana granulosa was isolated from healthy large antral follicles of prepubertal or cyclic gilts stimulated with PMSG or PMSG and hCG. Ultrastructural observations revealed that pieces of pig membrana granulosa were associated with the basement membrane. The cattle cumulus‐enclosed oocytes (COC) were placed in the rolled pieces of the pig membrana granulosa (PMG). After 8 and 24 hr of coculture with PMG from prepubertal gilts, only 16% and 21% of oocytes underwent GVBD, respectively. PMG from PMSG‐stimulated cyclic gilts blocked the resumption of meiosis in all COC. The inhibitory effect of heterologous granulosa cells was fully reversible. When COC were initially incubated for 2 and 4 hr, subsequent culture in PMG prevented GVBD in 100% and 36% of oocytes, respectively. This suggests that functional contact between COC and PMG was established during the first 2 hr of coculture. To follow metabolic cooperation between PMG and COC, PMG was prelabeled with 3H‐uridine and cocultured with COC. Autoradiography on semithin sections revealed the intensive passage of 3H‐uridine from PMG into the cumulus layer and an oocyte. COC placed in PMG after GVBD (8 and 12 hr of an initial incubation) did not extrude the first polar body. PMG isolated from cyclic gilts after PMSG and hCG stimulation also inhibited GVBD of COC. Since nearly all COC placed in PMG isolated 10 and 12 hr after hCG remained in the GV stage after 24 hr of coculture, the hCG stimulation did not substantially diminish the meiosis inhibiting activity of PMG. During coculture, cattle cumulus cells were closely associated with the basement membrane, but no gap junctions were formed among heterologous granulosa cells. These results suggest that an inhibitory factor secreted by pig granulosa cells is not species specific and it can act in vitro without the mediation of gap junctions. © 1993 Wiley‐Liss, Inc.
Functional significance of cumulus expansion in the mouse: Roles for the preovulatory synthesis of hyaluronic acid within the cumulus mass
Authors: Chen L. , Russell P. T. , Larsen W. J.
Published: February 2005

Gonadotropin‐stimulated expansion of the mouse cumulus oocyte complex (COC) in vitro, measured with a quantitative videographic method, is comparable to that observed to occur in vivo when medium is supplemented with porcine follicle stimulating hormone (pFSH), 10% fetal bovine serum (FBS), and 2.5 mM glucosamine or optimal concentrations of glutamine and glucose. In the absence of glucosamine, the volumetric expansion of COCs in vitro is never more than 25% of that occurring in its presence. The addition of 6‐diazo‐5‐oxo‐1‐norleucine (DON), an inhibitor of glucosamine synthesis to medium supplemented with glutamine and glucose, completely inhibits cumulus expansion in vitro. This system was utilized to examine the relationship between cumulus expansion and fertilization rates, and the maintenance of fertilizability in culture. Successful fertilization (as determined by development to the 2‐cell stage) was correlated with the quantity and quality of the expanded cumulus mass, and conversely, the spontaneous loss or mechanical removal of the cumulus was correlated with a loss of fertilizability following additional incubation in culture medium. In addition, the i.p. injection of DON inhibited cumulus expansion within the intact follicle and suppressed ovulation. © 1993 Wiley‐Liss, Inc.
Bovine oocyte development following different oocyte maturation and sperm capacitation procedures
Authors: Yang Xiangzhong , Jiang Shie , Foote R. H.
Published: February 2005

Various procedures have been reported for successful in vitro maturation and in vitro fertilization (IVM/IVF) of bovine follicular oocytes. Direct comparisons of these different recommended procedures have been rare. In this research, involving a total of 5,128 oocytes, a series of experiments were conducted to compare oocyte maturation, fertilization, and development in vitro with 2 maturation systems (with or without added hormones) and 3 types of sperm treatment procedures. Oocytes were collected from ovarian antral follicles (2–7 mm in diameter) within 3 hr after slaughter of cows or heifers. Those with intact or at least 4 layers of cumulus cells were selected for IVM/IVF. Oocytes were incubated for 22 hr in either Medium 199 with 7.5% fetal calf serum (M199 + FCS) alone or M199 + FCS with added hormones (M199 + FCS + H; oFSH 0.5 μg/ml, oLH 5.0 μg/ml, and E2 1.0 μg/ml) at 39°C in 5% CO2 and 95% air. For IVF, frozen‐thawed sperm were treated with either 0.1 μM calcium ionophore A23187 (A23187) for 1 min, or 10 or 100 μg/ml heparin (H10 or H100) for 15 min. Our results demonstrated the following: (1) both M199 + FCS and M199 + FCS + H supported maturation development to the metaphase II stage (90–95%, P > 0.05); (2) when oocytes were matured in M199 + FCS without added hormones, A23187 sperm treatment was superior to H10 or H100 treatment for fertilization and blastocyst development of the inseminated oocytes (P < 0.05); (3) when oocytes were matured in M199 + FCS + H, A23187 treated sperm again produced a higher fertilization rate than the H10 group (P < 0.05), but the development to the blastocyst stage was similar among all 3 sperm treatment groups (P > 0.05); (4) direct comparison of the 2 maturation systems with A23187 treated sperm resulted in no difference in all criteria measured; however, (5) when compared retrospectively, beneficial effects of added hormones are evident for blastocyst development (but not for fertilization) when sperm were treated with heparin procedures. © 1993 Wiley‐Liss, Inc.
Quantitative estimation of chimerism in mice using microsatellite markers
Authors: Delhaise Françoise , Zhao Xuyun , Bralion Valérie , Dessy Franz , Georges Michel
Published: February 2005

An embryonic stem cell line was established from SV129 mouse blastocysts and used to generate chimeric mice by injection into OF1 blastocysts; 18 out of the 30 resulting offspring appeared chimeric as judged from their coat color patterns, and 3 of the 13 males proved to be germ‐line chimeras as they transmitted the SV129 agouti phenotype to all or part of their offspring.

The degree of chimerism of these males was evaluated for different tissues using polymorphic microsatellite markers amplified by the polymerase chain reaction. It was shown that these new markers can be effectively used to quantitatively estimate levels of chimerism. The CKMM (creatine kinase, muscle) microsatellite system was used to distinguish the SV129 from the OF1 genotype. In all performed tests, the correlation between DNA ratio and signal ratio, expressed as a base 10 logarithm, was shown to exceed or equal 0.98 for known DNA ratios (SV129/OF1) ranging from 1/99 to 99/1. Linear calibration methods were used to predict the % SV129 DNA of a test sample based on the obtained signal ratio. The accuracy of the prediction was evaluated by performing repeated measurements. Differences among three repeated estimates ranged from 2 to 17% for a given sample.

Microsatellite systems should be very useful to monitor chimerism involving strains that can not be discerned with coat color or biochemical markers. This will be particularly important when ES methodology becomes available in species other than mice. © 1993 Wiley‐Liss, Inc.
Evidence for nuclear internalization of exogenous DNA into mammalian sperm cells
Authors: Francolini Maura , Lavitrano Marialuisa , Lamia Carla Lora , French Deborah , Frati Luigi , Cotelli Franco , Spadafora Corrado
Published: February 2005

Mature sperm cells have the spontaneous capacity to take up exogenous DNA. Such DNA specifically interacts with the subacrosomal segment of the sperm head corresponding to the nuclear area.

Part of the sperm‐bound foreign DNA is further internalized into nuclei. Using end‐labelled plasmid DNA we have found that 15–22% of the total sperm bound DNA is associated with nuclei as determined on isolated nuclei. On the basis of autoradiographic analysis, nuclear permeability to exogenous DNA seems to be a wide phenomenon involving the majority of the sperm nuclei. In fact, the foreign DNA, incubated with sperm cells for different lengths of time, is found in 45% (10 min) to 65% (2 hr) of the sperm nuclei.

Ultrastructural autoradiography on thin sections of mammalian spermatozoa, preincubated with end‐labelled plasmid DNA, shows that the exogenous DNA is internalized into the nucleus. This conclusion is further supported by ultrastructural autoradiographic analysis on thin sections of nuclei isolated from spermatozoa preincubated with end‐labelled DNA. © 1993 Wiley‐Liss, Inc.
Transient expression of a human β‐actin promoter/lacZ gene introduced into mouse embryos correlates with a low degree of methylation
Authors: Nilsson Erik , Lendahl Urban
Published: February 2005

We have analysed the correlation between expression and methylation for the human β‐actin promoter introduced into mouse embryos. The β‐actin promoter was fused to the reporter gene lacZ, and expression was analysed after pronuclear injection into fertilized mouse eggs. We analysed transient expression in in vitro cultured preimplantation embryos and expression after chromosomal integration in 5 independent lines of transgenic mice. The in vitro cultured preimplantation embryos expressed lacZ from the 2‐cell to the blastocyst stages, and most abundantly at the morula stage. By increasing the amount of injected DNA, a larger proportion of embryos expressed lacZ. Embryos expressing lacZ in only a subset of the blastomeres were detected at all preimplantation stages. In contrast to the transient expression after injection, we have not detected lacZ expression in any of the 5 analysed lines of transgenic mice carrying the same construct. The lack of expression in transgenic mice correlates with hypermethylation of C residues in the vast majority of CG sequences in the integrated β‐actin/lacZ construct, whereas the injected construct was completely nonmethylated. We discuss methylation and other possible reasons for the observed differences in expression between injected and integrated copies of the β‐actin/lacZ construct and for lacZ expression in only a subset of blastomeres in preimplantation embryos. © 1993 Wiley‐Liss, Inc.
Lipid globules at the midpieces of Glyptocidaris crenularis spermatozoa and their relation to energy metabolism
Authors: Mita Masatoshi , Nakamura Masaru
Published: February 2005

Spermatozoa of the sea urchin, Glyptocidaris crenularis, use endogenous triglycerides (TG), not phosphatidylcholine, to produce energy for swimming. This study was undertaken to examine ultrastructurally the location of TG available for utilization in energy metabolism in these spermatozoa. Each spermatozoon contained several lipid globules at the bottom of the midpiece. Following incubation with sea water, both the number and size of the lipid globules decreased significantly. The total volume of lipid globules in each spermatozoon was roughly halved after 1 h of incubation. Similarly, about half of the TG was metabolized during the same incubation period. Oxygen consumption by spermatozoa during the incubation indicated the oxidation of fatty acid derived from TG. Thus it appears that G. crenularis spermatozoa obtain energy through oxidation of fatty acid from TG stored in the lipid globules within their midpieces. © 1993 Wiley‐Liss, Inc.
The differential expression of lamin epitopes during mouse spermatogenesis
Authors: Moss Stuart B. , Burnham Brenda L. , Bellvé Anthony R.
Published: February 2005

The presence of lamin proteins in mouse spermatogenic cells has been examined by using an anti‐lamin AC and an anti‐lamin B antisera which recognize somatic lamins A and C, and somatic lamin B, respectively. Anti‐lamin B binds to the nuclear periphery of all cell types examined, including Sertoli cells, primitive type A spermatogonia, preleptotene, leptotene, zygotene and pachytene spermatocytes, and round spermatids. In sperm nuclei, the antigenic determinants are localized to a narrow domain of the nucleus. However, after removing the perinuclear theca, anti‐lamin B localizes to the entire nuclear periphery in a punctate pattern, suggesting that it is binding to determinants previously covered by the theca constituents. On immunoblots anti‐lamin B reacts with a ∼ 68 kD polypeptide in all germ cells and, to a lesser extent, with four additional polypeptides present only in meiotic and post‐meiotic nuclear matrices. Anti‐lamin AC also reacts with the perinuclear region of the somatic cells in the testes, in particular, those of the interstitium and also the Sertoli cells of the seminiferous epithelium. In contrast to anti‐lamin B, anti‐lamin AC does not bind to the germ cells at any stage of spermatogenesis. In addition, nuclear matrix proteins from isolated spermatogenic cells do not bind anti‐lamin AC on immunoblots, suggesting the lack of reactivity is not due to the masking of any antigenic sites. These data demonstrate that germ cells contain lamin B throughout spermatogenesis, even during meiosis and spermiogenesis when the nuclear periphery lacks a distinct fibrous lamina. © 1993 Wiley‐Liss, Inc.
Improved preservation of rat epididymal sperm for high‐resolution low‐voltage scanning electron microscopy (HR‐LVSEM)
Authors: Stoffel Michael H. , Frethem Chris , Hamilton David W. , Friess Armin E.
Published: February 2005

Various fixation protocols were used in an attempt to improve preservation of rat epididymal sperm for high‐resolution low‐voltage scanning electron microscopy (HR‐LVSEM). Wash solutions and fixatives of different composition and osmolarity were tested. Paraformaldehyde and glutaraldehyde concentrations were varied between 0.5% and 3%. Ruthenium red was tested as an additive in both primary fixation and postfixation, or in postfixation alone. HR‐LVSEM revealed various degrees of ruffing, folding, blebbing, and peeling off of the plasma membrane, as well as holes of different sizes. The plasma membrane overlying the acrosome and the connecting piece proved to be particularly sensitive to varying fixation conditions. Consistent topographical differences were revealed among the different domains over the sperm head. Most of the differences were considered to be artifacts. Their consistency, however, suggests that structural and biochemical differences exist either within the membrane or in the structures subjacent to the membrane. Primary fixation turned out to be less critical than postfixation. Preservation of a smooth plasma membrane without holes could only be achieved when primary fixation in low aldehyde concentrations, with or without ruthenium red, was followed by postfixation with OsO4 and 1,000 ppm ruthenium red. Examination of thin sections of the same material confirmed that even a considerable number of small holes are difficult to detect in transmission electron microscopy. These results show that with the recent increase in resolution of LVSEM there is need for further effort to improve sample processing. © 1993 Wiley‐Liss, Inc.
The effect of warming velocity on motility and acrosomal integrity of boar sperm as influenced by the rate of freezing and glycerol level
Authors: Fiser P. S. , Fairfull R. W. , Hansen C. , Panich P. L. , Shrestha J. N. B. , Underhill L.
Published: February 2005

The effect of thawing velocities ranging from 10°C/min to 1.800°C/min on the motility and acrosomal integrity of boar spermatozoa frozen at 1°C/min (suboptimal), 5°C/min, and 30°C/min (optimal) rate was studied with the sperm suspended for freezing in diluent containing 2, 4, or 6% of glycerol (v/v). The influence of thawing on sperm survival depends on the rate at which the sperm had been frozen. In semen frozen at a suboptimal rate of 1°C/min, the percentage of motile sperm (FMP) initially fell to 3.5–4.0% when the thawing rose to 200°C/ min, but, with further increases in thawing rate, increased and reached peak values (10.3–11.0% FMP) after thawing at 1,800°C/min. The percentage of sperm with normal apical ridge (NAR) also increased moderately with thawing rate, but the degree of improvement decreased as the glycerol level was increased. In semen frozen at 1°C/min, acrosomal integrity (NAR) was best maintained in 2% glycerol, reaching 22.9% NAR after thawing at 1,800°C/min. In semen frozen at the optimal rate of 30°C/min, the increases in thawing rates above 200°C/min substantially improved motility. Motility was generally higher in semen protected by 4 or 6% glycerol, with the peak values of 44 or 46% FMP, respectively, after thawing at 1,200°C/min. The proportion of sperm with NAR also increased with thawing rate, but as in the case of suboptimally frozen sperm it was influenced negatively by the glycerol concentration. The peak value 53% NAR was recorded in semen protected by 2% glycerol, frozen at 30°C/min, and thawed at 1,200°C/min. In view of the inverse relationship between FMP and NAR, selection of optimal conditions from among the interacting variables, freezing rate, glycerol concentration, and thawing rate requires compromising between maximal FMP and maximal NAR. Accordingly, we have adopted as optimal a protocol with a thawing rate of 1,200°C/min, a freezing rate of 30°C/min and concentrations of 3% glycerol. © 1993 Wiley‐Liss, Inc.
Fine structure of the spermatozoa of Crassostrea gigas (Mollusca, Bivalvia)
Authors: Bozzo Maria Gràcia , Ribes Enric , Sagrista Elena , Poquet Montserrat , Durfort Mercedes
Published: February 2005

We describe sperm ultrastructure and acrosome differentiation during spermiogenesis in Crassostrea gigas (Mollusca Bivalvia). The sperm cell is a uniflagellated cell of the primitive type. The head region contains a rounded or conical nucleus surmounted by small acrosome. This organelle consists of a membrane‐bound acrosomal granule, the contents of which have a homogeneous density, except in the anterior region, which is positive for PTA. The acrosome also surrounds the perforatorium, which includes oriented fibrillar elements: this is the axial body. The middle piece contains four mitochondria encircling two perpendicular centrioles. The distal centriole is provided with a system of mechanical fixation to the plasma membrane, consisting of nine fibers in radial arrangement. The tail flagellum, about 50 m̈m long, contains the usual microtubular axoneme. © 1993 Wiley‐Liss, Inc.
CDX2 co‐localizes with liver–intestine cadherin in intestinal metaplasia and adenocarcinoma of the stomach
Authors: Ko Samuel , Chu Kent‐Man , Luk John Moon‐Ching , Wong Bonnie Wing‐Yan , Yuen Siu‐Tsan , Leung Suet‐Yi , Wong John
Published: February 2005

CDX2 and liver–intestine (LI)‐cadherin are intestine‐specific markers and both are physiologically expressed in the small intestine and colon. Recent studies have demonstrated that CDX2 regulates LI‐cadherin gene (CDH17) expression in colorectal cancer. The present study investigated the relationship of CDX2 and LI‐cadherin expression in gastric cancer. One hundred and nine pairs of tumour and non‐cancerous gastric mucosa were collected from gastrectomy specimens. Protein expression levels of CDX2 and LI‐cadherin were determined by immunohistochemical staining. Semi‐quantitative RT‐PCR showed that the mRNAs of both CDX2 and CDH17 were highly expressed in tumour compared with non‐cancerous mucosa. Overexpression of CDX2 was significantly associated with CDH17 in gastric adenocarcinoma. Furthermore, the expression of CDX2 and LI‐cadherin proteins was strongly coupled in intestinal metaplasia. In conclusion, overexpression of CDH17 is significantly associated with CDX2. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Simultaneous detection of HER2/neu gene amplification and protein overexpression in paraffin‐embedded breast cancer
Authors: Lottner Christian , Schwarz Stephan , Diermeier Simone , Hartmann Arndt , Knuechel Ruth , Hofstaedter Ferdinand , Brockhoff Gero
Published: February 2005

The determination of HER2/neu status in breast carcinomas has become essential for the selection of breast cancer patients for Herceptin therapy. Herceptin treatment is used in patients with metastatic breast carcinoma with HER2/neu protein overexpression detected by immunohistochemistry (IHC) or gene amplification analysed by fluorescence in situ hybridization (FISH). A multiparametric fluorescent approach based on the simultaneous detection of HER2/neu gene amplification and protein expression was established to increase the accuracy, and to improve the reproducibility, of HER2/neu diagnostics. Based on four paraffin‐embedded breast cancer cell lines, a combined fluorescent immunostaining (FIHC) and FISH method was developed by using the PathVysion HER2 DNA Probe Kit (VYSIS) and the polyclonal antibody from the HercepTest (DAKO). Diagnostic applicability was documented on 215 formalin‐fixed primary breast carcinomas. Criteria for immunofluorescence quantification were chosen by analogy with the FDA‐approved HercepTest scoring, ranging from 0 to 3+. There was 97.7% concordance between conventional IHC and fluorescence IHC. The FISH data resulting from the multiparametric approach did not differ from conventional FISH. Breast carcinomas with HER2/neu protein overexpression and simultaneous gene amplification were detected with 100% sensitivity. In addition, five of the 215 cases (2.3%) had HER2/neu gene amplification without protein overexpression. The main advantage of this novel approach is that polysomy, aneuploidy, gene amplification, and protein content can be analysed simultaneously in the same cell. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Defect‐selective etching of SiC
Authors: Weyher J. L. , Lazar S. , Borysiuk J. , Pernot J.
Published: February 2005

Two methods of defect‐selective etching of SiC are described: (i) orthodox etching in molten KOH–NaOH eutectic with 10% of MgO powder (E + M etch) and (ii) electroless photo‐etching in aqueous KOH solutions (PEC method). The first etch shows similar effectiveness in revealing different type of dislocations, micropipes and stacking faults, as the commonly used molten KOH. The second approach is new for studying defects in SiC and is most suitable for revealing stacking faults both on the disoriented (0001) basal planes and on the ($1 \bar1 00$) cleavage surfaces. Cross‐calibration of both techniques and examples of calibration of PEC etch features by TEM are shown. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Forward‐bias degradation in 4H–SiC p+nn+ diodes: Influence of the mesa etching
Authors: Camara N. , Thuaire A. , Bano E. , Zekentes K.
Published: February 2005

We have investigated the appearance of defects in silicon carbide p+nn+ 4H–SiC diodes by observing the forward‐bias‐induced light emission through the substrate. The spatial intensity distribution, the temporal evolution and the spectral content of the electroluminescence (EL) signal have been measured in order to detect, identify and understand the defect formation during forward‐bias application. It was found that mesa etching is a main cause for the formation of extended defects. Reduction of mesa‐etching‐induced defects is the subject of our investigations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Processing of novel SiC and group III‐nitride based micro‐ and nanomechanical devices
Authors: Foerster Ch. , Cimalla V. , Brueckner K. , Lebedev V. , Stephan R. , Hein M. , Ambacher O.
Published: February 2005

Micromechanical 3C‐SiC‐ and AlN‐resonator beams with resonant frequencies between 20 kHz and 5 MHz have been realized. The 200 nm thin epitaxial SiC and group III‐nitrides layers were grown on silicon (100) and (111) oriented substrates, respectively. Subsequent the beams were dry‐etched by an electron cyclotron resonance (ECR) plasma technique. This new developed plasma based process allows anisotropic as well as isotropic etching for all materials involved. The created freestanding resonator bars have dimensions in the µm to sub‐µm range. The operation principle based on a magneto motive actuation and a thin conductive metal layer on top of the resonator realizes the detection. We present a measurement setup for the electrical characterization of the bars and show coupled beams, to isolate the sensor signal from the excitation signal. Furthermore, we realized beams with a separate read‐out unit (capacitive) as well as resonator structures with separate actuation (piezoelectric) to solve the problems of the superimposition of actuation and detection. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The expression level of GCNF affects fate choice during neural differentiation of PCC7 cells
Authors: Koziollek‐Drechsler Ingrid , Sattler Ulrike , Zechel Christina
Published: February 2005

The nuclear receptor GCNF (NR6A1) is required for embryonic survival and development, and regulation of fertility. We used a transgenic approach to investigate its role in neural differentiation. As model we chose the embryonal carcinoma cell line PCC7, which reproducibly differentiates into a tissue‐like pattern of neuronal and non‐neuronal cells after exposure to retinoic acid (RA). The differentiation pattern of gcnf sense and antisense clones consistently indicated that the expression level of GCNF positively correlated with the development of the neuronal fate. Moreover, antisense clones failed to down‐regulate expression of the key regulator of differentiation Oct4 during the initial stages of neural differentiation. This data proposes that GCNF might promote the neuronal fate by mechanisms that involve repression of Oct4.
Aluminium-induced bone disease in uremic Rats: Effect of deferoxamine
Authors: Jablonski Greg , Klem Knut H. , Danielsen Carl Ch. , Mosekilde Lis , Gordeladze Jan O.
Published: February 2005

We have previously established a rat model of chronic uremia, which is suitable to investigate the effect of various treatment modalities on renal osteodystrophy [1]. After four months subsequent to 5/6 nephrectomy, some animals were treated by gavage for 9 weeks with tap water (controls), or with aluminium (Al-citrate) 3 × 25 mg/week/kg b.wt ± subsequent deferoxamine (DFO) 3 × 50 mg/ week/kg b.wt. for 4 weeks. At termination of the study, serum clinical chemistry, femoral chemical composition and mechanical properties, calvarial parathyroid hormone (PTH)-elicited adenylate cyclase (AC) and phospholipase C (PLC) activities, cross-sectional femoral area, as well as bone histomorphometry, were analyzed. Animals given Al displayed moderately enhanced serum Al and bone Al accumulation, however, DFO-treatment did not fully alleviate bone Al retainment. A small increase in serum PTH was seen in all animals rendered uremic. Furthermore, a marked fall in serum alkaline phosphatase (ALP) below normal controls was observed in Al ± DFO-treated animals compared with uremic controls. The uremic condition led to reduced femoral ratios of hydroxyproline (HYP) over Ca2+ and phosphate (Pi), while Al-intoxication alone enhanced femoral Hyp contents above values seen for normal controls. The protracted ureamia caused a deterioration of long bone resilience and brittleness, however, Al ± DFO-treatment seemed to normalize the latter. Contrastingly, Al ± DFO-gavage enhanced time to fracture. Uremic rats intoxicated with Al showed a complete loss of calvarial PTH-sensitive AC and PLC activities. DFO-treatment normalized PTH-elicited PLC, while PTH-susceptible AC remained super-normal. Al apparently exerts a long term down-regulation of both PTH-sensitive signaling systems as evidenced by studies of rat UMR 106 osteosarcoma cells in culture. The uremic condition enhanced endosteal bone resorption as shown by femoral shaft dimension analysis, while AI ± DFO-treatment insignificantly reversed the condition. Finally, histomorphometrical analyses showed that DFO-administration tended to normalize aberrant trabecular bone volume, while rectifying both bone resorption and degree of mineralization. In conclusion, we assert that Al-intoxication hampers both processes (i.e. formation and resorption) of bone turnover, and that DFO-treatment to a certain extent prevents the uremia- and Al-induced bone disease in rats.
Identification and phylogenetic classification of eleven putative P-type calcium transport ATPase genes in the yeastsSaccharomyces cerevisiaeandSchizosaccharomyces pombe
Authors: Catty P. , Goffeau A.
Published: February 2005

Calcium is an essential second messenger in yeast metabolism and physiology. So far, only four genes coding for calcium translocating ATPases had been discovered in yeast. The recent completion of the yeast Saccharomyces cerevisiae genome allowed us to identify six new putative Ca++-ATPases encoding genes. Protein sequence homology analysis and phylogenetic classification of all putative Ca++-ATPase gene products from the yeasts Saccharomyces cerevisiae and Schizosacchraomyces pombe reveal three clusters of homologous proteins. Two of them comprises seven proteins which might belong to a new class of P-type ATPases of unknown subcellular location and of unknown physiological function.
Heterologous expression of sarcoplasmic reticulum Ca2+-ATPase
Authors: Reis Eduardo M. R. , Slayman Carolyn W. , Verjovski-Almeida Sergio
Published: February 2005

In recent years, expression of rabbit sarcoplasmic reticulum (SR) Ca2+-ATPase in heterologous systems has been a widely used strategy to study altered enzymes generated by site-directed mutagenesis. Various eukaryotic expression systems have been tested, all of them yielding comparable amounts of recombinant protein. However, the relatively low yield of recombinant protein obtained so far suggests that novel purification techniques will be required to allow further characterization of this enzyme based on direct ligand-binding measurements.
The targeting of the plasma membrane calcium pump in the cell
Authors: Guerini Danilo , Carafoli Ernesto
Published: February 2005

The information on the structural determinants that control the cellular distribution of P-type pumps is very scarce. However, recent experiments on the membrane targeting of the plasma membrane Ca2+ pump (PMCA) have provided interesting leads on the problem: they will be discussed in this succinct review. A general introduction on the biochemical properties of the PMCA pump will preface the discussion of the specific findings on the role of three distinct regions of the molecule in the targeting process.
A fully abstract semantics of classes for Object-Z
Authors: Smith Graeme
Published: February 2005

This paper presents a fully abstract semantics of classes for the object oriented formal specification language Object-Z. Such a semantics includes no unnecessary syntactic details and, hence, describes a class in terms of the external behaviour of its objects only. The semantics, based on an extension of existing process models, defines a notion of behavioural equivalence which is stronger than that of CSP and weaker than that of CCS.
Psychosocial functioning of mothers with chronic pain: a comparison to pain‐free controls
Authors: Evans Subhadra , Shipton Edward A. , Keenan Thomas R.
Published: February 2005

This study compared the functioning of mothers experiencing chronic pain and control mothers on a range of psychosocial variables. Participants included 39 mothers with chronic pain conditions ranging from migraine and arthritis to chronic neck and back pain and 35 control mothers with out chronic pain. Analyses indicated that mothers with chronic pain experienced more physical, psychological and social difficulties when compared to controls. More difficulties were reported in completing day‐to‐day parenting tasks in mothers with chronic pain. Consistent with the biopsychosocial model of chronic pain, psychosocial variables accounted for approximately half of the variance in chronic pain mothers' physical functioning scores. The importance of psychological variables in the experience of chronic pain, the potential reduction in parenting efficacy and the risk that these influences hold for children are discussed.
Neuroanatomic observations of the brain in autism: a review and future directions
Authors: Bauman Margaret L. , Kemper Thomas L.
Published: February 2005

Infantile autism is a behaviorally defined disorder associated with characteristic cognitive, language and behavioral features. Several postmortem studies have highlighted areas of anatomic abnormality in the autistic brain. Consistent findings have been observed in the limbic system, cerebellum and related inferior olive. In the limbic system, the hippocampus, amygdala and entorhinal cortex have shown small cell size and increased cell packing density at all ages, suggesting a pattern consistent with development curtailment. Findings in the cerebellum have included significantly reduced numbers of Purkinje cells, primarily in the posterior inferior regions of the hemispheres. A different pattern of change has been noted in the vertical limb of the diagonal band of broca, cerebellar nuclei and inferior olive with plentiful and abnormally enlarged neurons in the brains of young autistic subjects, and in adult autistic brains, small, pale neurons that are reduced in number. These findings combined with reported age‐related changes in brain weight and volume, have raised the possibility that the neuropathology of autism may represent an on‐going process.
Helicobacter pylori infection and platelet counts during pregnancy
Authors: Fukui O. , Shimoya K. , Shimizu T. , Fukuda H. , Wasada K. , Murata Y.
Published: February 2005

Objective

To investigate whether there is any correlation between Helicobacter pylori infection and platelet counts during pregnancy.

Methods

One hundred and twenty pregnant women without any complications were evaluated. Platelet counts were determined during pregnancy and postpartum. H. pylori infection was assessed by the detection of serum antibodies at the 3rd day postpartum. Statistically significant differences of platelet count between H. pylori‐positive and ‐negative patients were determined.

Results

H. pylori infection was found in 29 of 120 (24.2%). Platelet counts in the 3rd trimester were 22.7±4.7×103/μl in H. pylori‐positive group and 22.8±5.6×103/μl in negative group (p=0.98). Platelet count in the 3rd trimester in positive and negative patients were 93±17% and 94±20%, respectively, of that of the 1st trimester (p=0.92). The incidence of hyperemesis gravidarum in both groups was not significant (p=0.28).

Conclusion

A correlation between H. pylori infection and thrombocytopenia during pregnancy was not found in this study.
The contribution of music to quality of life in older people: an Australian qualitative study
Authors: HAYS TERRENCE , MINICHIELLO VICTOR
Published: February 2005

This study examines the personal meaning and importance of music in the lives of older people, paying particular attention to the ways in which music contributes to self-identity and the quality of life. The data derive from qualitative interviews with a sample of older Australians aged 65 years and over who live in rural and urban settings. The findings reveal that music provides people with ways of understanding and developing their self-identity, of connecting with other people, of maintaining wellbeing and of experiencing and expressing spirituality, and that it provides strong associations with and memories of a person's life. Specifically, the results show how music is used as a source of entertainment as well as a forum to share and interact with others. Music was described as a personal experience to which people assigned meaning and emotions. The informants also described how music allowed them to engage in imaginative play and to escape from some of the hardships experienced in later life. The results reveal that music promotes quality of life by contributing to positive self-esteem, by helping people feel competent and independent, and by lessening feelings of isolation and loneliness. The paper argues that music can be used to maintain and promote a better quality of life for older people.
Minding the money: a growing responsibility for informal carers
Authors: TILSE CHERYL , SETTERLUND DEBORAH , WILSON JILL , ROSENMAN LINDA
Published: February 2005

Managing the assets of older people is a common and potentially complex task of informal care with legal, financial, cultural, political and family dimensions. Older people are increasingly recognised as having significant assets, but the family, the state, service providers and the market have competing interests in their use. Increased policy interest in self-provision and user-charges for services underline the importance of asset management in protecting the current and future health, care and accommodation choices of older people. Although ‘minding the money’ has generally been included as an informal care-giving task, there is limited recognition of either its growing importance and complexity or of care-givers' involvement. The focus of both policy and practice have been primarily on substitute decision-making and abuse. This paper reports an Australian national survey and semi-structured interviews that have explored the prevalence of non-professional involvement in asset management. The findings reveal the nature and extent of involvement, the tasks that informal carers take on, the management processes that they use, and that ‘minding the money’ is a common informal care task and mostly undertaken in the private sphere using some risky practices. Assisting informal care-givers with asset management and protecting older people from financial risks and abuse require various strategic policy and practice responses that extend beyond substitute decision-making legislation. Policies and programmes are required: to increase the awareness of the tasks, tensions and practices surrounding asset management; to improve the financial literacy of older people, their informal care-givers and service providers; to ensure access to information, advice and support services; and to develop better accountability practices.
A time of one's own? Female recollections of youth in Denmark at the turn of the twentieth century
Authors: SØLAND BIRGITTE
Published: February 2005

The decades around the turn of the twentieth century mark a critical transitional moment in the history of European girlhood. These decades witnessed a significant expansion in educational opportunities for girls and young women, while a broad range of new jobs provided previously unknown options in the labour market. Based on 1,100 unpublished memoirswritten by Danish women, this article explores how these changes affected the lives and experiences of three successive generations of women who came of age from the 1880s to the 1930s.
Introduction: Young women in Europe in the era of ‘first-wave’ feminisms: analyses of generation and gender
Authors: MAYNES MARY JO
Published: February 2005

During the course of the nineteenth century, the parameters defining ‘youth’, marking its beginning and its end, were becoming more precise and more institutionally defined for both girls and boys in Europe. More than any other phenomenon or institution, elementary schooling (and leaving school) contributed to a certain ‘normalization’ of the life cycle for young people. By the end of the nineteenth century, most girls as well as boys attended school at least intermittently until at least age 12 or 13; at school-leaving a new phase of life began. Throughout much of Europe a select minority of middle-class and upper-class young women joined their brothers at universities, as higher education became first a possibility and then a routine for them in the last decades of the nineteenth and the first decades of the twentieth century.
Value Commitments and the Balanced Life
Authors: TIBERIUS VALERIE
Published: February 2005

According to critics such as Bernard Williams, traditional ethical theories render it impossible to lead good and meaningful lives because they emphasize moral duty or the promotion of external values at the expense of the personal commitments that make our lives worth living from our own perspective. Responses to this criticism have not addressed the fundamental question about the proper relationship between a person's commitments to moral values and her commitments to non-moral or personal values. In this article, I suggest that we think about this relationship by reflecting on the way that a prudentially virtuous person who has commitments to both moral and non-moral values would regard these commitments. I argue that people with the virtue of balance do have reasons to act in accordance with their moral commitments, but that whether or not these reasons are overriding depends on the type of commitment in question.
Inegalitarian Biocentric Consequentialism, the Minimax Implication and Multidimensional Value Theory: A Brief Proposal for a New Direction in Environmental Ethics
Authors: CARTER ALAN
Published: February 2005

Perhaps the most impressive environmental ethic developed to date in any detail is Robin Attfield's biocentric consequentialism. Indeed, on first study, it appears sufficiently impressive that, before presenting any alternative theoretical approach, one would first need to establish why one should not simply embrace Attfield's. After outlining a seemingly decisive flaw in his theory, and then criticizing his response to it, this article adumbrates a very different theoretical basis for an environmental ethic: namely, a value-pluralist one. In so doing, it seeks to give due weight to anthropocentric, zoocentric, biocentric and ecocentric considerations, and argues that the various values involved require trading off. This can be accomplished by employing multidimensional indifference curves. Moreover, after considering a three-dimensional indifference plane superimposed upon a three-dimensional possibility frontier, it becomes apparent that a moral-pluralist environmental ethic is, contrary to widespread assumptions, capable, in principle at least, of providing determinate answers to moral questions.
Biocentric Consequentialism and Value-Pluralism: A Response to Alan Carter
Authors: ATTFIELD ROBIN
Published: February 2005

My theory of biocentric consequentialism is first shown not to be significantly inegalitarian, despite not advocating treating all creatures equally. I then respond to Carter's objections concerning population, species extinctions, the supposed minimax implication, endangered interests, autonomy and thought-experiments. Biocentric consequentialism is capable of supporting a sustainable human population at a level compatible with preserving most non-human species, as opposed to catastrophic population increases or catastrophic decimation. Nor is it undermined by the mere conceivable possibility of counter-intuitive implications. While Carter shows that value-pluralism need not be riddled with contradictions, his version still introduces some, and faces further problems. Thus consequentialist theories may be needed to sift our values, at least if our values are commensurable. Carter's apparent suggestion that monistic theories such as biocentric consequentialism can never be harnessed to rich theories of value and must each myopically give undue prominence to a single value is questioned.
Gamma ray flashes due to plasma processes in the atmosphere: Role of whistler waves
Authors: Milikh G. M. , Guzdar P. N. , Sharma A. S.
Published: February 2005

A proposed mechanism for the generation of gamma ray flashes in the atmosphere, observed on Compton Gamma Ray Observatory satellite, is a runaway discharge mediated by whistler waves. In this model the relativistic electrons produced by a cosmic ray shower during a thunderstorm lead to a runaway discharge, which is maintained by the interaction with whistler waves and the relativistic electrons propagate up in ducts produced by the self‐focusing of these waves. The paper presents a detailed study of the instability which develops in the lower stratosphere when a beam of hot magnetized electrons interacts with whistler waves. It was shown that the growth rate of such instability depends on the number density of hot electrons and on their collision rate, and it peaks at about 25 km. The instability develops under the conditions for runaway breakdown, similar to those leading to the generation of strong narrow bipolar pulses, which indicates a possible correlation between these two phenomena.