bluuebunny/crossref_metadata_2025 huggingface dataset:
Angiopoietin-1 promotes lymphatic sprouting and hyperplasia
Authors: Tammela Tuomas , Saaristo Anne , Lohela Marja , Morisada Tohru , Tornberg Jenny , Norrmén Camilla , Oike Yuichi , Pajusola Katri , Thurston Gavin , Suda Toshio , Yla-Herttuala Seppo , Alitalo Kari
Published: March 2005

Angiopoietin 1 (Ang1), a ligand for the receptor tyrosine kinase Tie2, regulates the formation and stabilization of the blood vessel network during embryogenesis. In adults, Ang1 is associated with blood vessel stabilization and recruitment of perivascular cells, whereas Ang2 acts to counter these actions. Recent results from gene-targeted mice have shown that Ang2 is also essential for the proper patterning of lymphatic vessels and that Ang1 can be substituted for this function. In order to characterize the effects of the angiopoietins on lymphatic vessels, we employed viral vectors for overexpression of Ang1 in adult mouse tissues. We found that Ang1 activated lymphatic vessel endothelial proliferation, vessel enlargement, and generation of long endothelial cell filopodia that eventually fused, leading to new sprouts and vessel development. Cutaneous lymphatic hyperplasia was also detected in transgenic mice expressing Ang1 in the basal epidermal cells. Tie2 was expressed in the lymphatic endothelial cells and Ang1 stimulation of these cells resulted in up-regulation of vascular endothelial growth factor receptor 3 (VEGFR-3). Furthermore, a soluble form of VEGFR-3 inhibited the observed lymphatic sprouting. Our results reinforce the concept that Ang1 therapy may be useful in settings of tissue edema. (Blood. 2005;105:4642-4648)
In vitro and in vivo activity of ATP-based kinase inhibitors AP23464 and AP23848 against activation-loop mutants of Kit
Authors: Corbin Amie S. , Demehri Shadmehr , Griswold Ian J. , Wang Yihan , Metcalf Chester A. , Sundaramoorthi Raji , Shakespeare William C. , Snodgrass Joseph , Wardwell Scott , Dalgarno David , Iuliucci John , Sawyer Tomi K. , Heinrich Michael C. , Druker Brian J. , Deininger Michael W. N.
Published: March 2005

Oncogenic mutations of the Kit receptor tyrosine kinase occur in several types of malignancy. Juxtamembrane domain mutations are common in gastrointestinal stromal tumors, whereas mutations in the kinase activation loop, most commonly D816V, are seen in systemic mastocytosis and acute myelogenous leukemia. Kit activation-loop mutants are insensitive to imatinib mesylate and have been largely resistant to targeted inhibition. We determined the sensitivities of both Kit mutant classes to the adenosine triphosphate (ATP)–based inhibitors AP23464 and AP23848. In cell lines expressing activation-loop mutants, low-nM concentrations of AP23464 inhibited phosphorylation of Kit and its downstream targets Akt and signal transducer and activator of transcription 3 (STAT3). This was associated with cell-cycle arrest and apoptosis. Wild-type Kit–and juxtamembrane-mutant–expressing cell lines required considerably higher concentrations for equivalent inhibition, suggesting a therapeutic window in which cells harboring D816V Kit could be eliminated without interfering with normal cellular function. Additionally, AP23464 did not disrupt normal hematopoietic progenitor-cell growth at concentrations that inhibited activation-loop mutants of Kit. In a murine model, AP23848 inhibited activation-loop mutant Kit phosphorylation and tumor growth. Thus, AP23464 and AP23848 potently and selectively target activation-loop mutants of Kit in vitro and in vivo and could have therapeutic potential against D816V-expressing malignancies.
A murine model of ulcerative colitis: induced with sinusitis-derived superantigen and food allergen
Authors: Yang Ping-Chang , Wang Chang-Sheng , An Zi-Yuan
Published: March 2005

Background

The etiology of ulcerative colitis (UC) is to be understood. The basic pathological feature of UC is intestinal chronic inflammation. Superantigen, such as Staphylococcus enterotoxin B (SEB), is reported to compromise intestinal barrier function by increasing epithelial permeability and initiate inflammation in the intestinal mucosa. Inasmuch as anatomic position of the sinus, chronic sinusitis-derived SEB may follow the secretion and to be swallowed down to the gastrointestinal tract and induce lesions to the intestinal mucosa.

Methods

Sinus wash fluid (SWF, containing SEB) was collected from a group of patients with both chronic sinusitis (CS) and UC. A group of mice were sensitized to ovalbumin (OVA) in the presence of SWF. The sensitized mice were challenged with the specific antigen OVA. The inflammatory status of the colonic tissue was determined with histology, serology and electron microscopy. Using horseradish peroxidase (HRP) as a tracer, another group of mice was stimulated with SWF for 2 hours. The HRP activity was detected in the colonic tissue with enzymatic approaches and electron microscopy.

Results

Epithelial hyperpermeability in colonic epithelium was induced by stimulating with SWF. The HRP activity in the colonic mucosa was almost 11 times more in the SWF treated group (3.2 ± 0.6 μg/g tissue) than the control group (0.3 ± 0.1 μg/g tissue). Mice were sensitized using a mixture of SWF and OVA (serum OVA-specific IgE was detected with a highest titer as 1:64). Challenge with OVA induced extensive inflammation in the colonic mucosa by showing (1) marked degranulation in mast cells (MC, 46.3 ± 4.5%) and eosinophils (Eo, 55.7 ± 4.2%); (2) inflammatory cell infiltration (MC = 145.2 ± 11.4; Eo = 215.8 ± 12.5; mononuclear cell = 258.4 ± 15.3/mm2 tissue); (3) increased MPO activity (12.9 ± 3.2 U/g tissue) and inflammatory scores (1.8 ± 0.3); (4) mucosal surface ulcers; (5) edema in the lamina propria; (6) bacterial translocation and abscess formation in the subepithelial region.

Conclusion

Introducing Sinusitis-derived SEB-containing SWF to the gastrointestinal tract compromised colonic mucosal barrier function increasing epithelial permeability to luminal macromolecular protein in mice. The SWF facilitated colonic mucosal sensitization to luminal antigen. Multiple challenging the sensitized colonic mucosa with specific antigen OVA induced inflammation, induced a condition similar to human ulcerative colitis.
Survivin 2α: a novel Survivin splice variant expressed in human malignancies
Authors: Caldas Hugo , Honsey Laura E , Altura Rachel A
Published: March 2005

Background

Survivin and its alternative splice forms are involved in critical cellular processes, including cell division and programmed cell death. Survivin is expressed in the majority of human cancers, but minimally in differentiated normal tissues. Expression levels correlate with tumor aggressiveness and resistance to therapy.

Results

In the present study, we identify and characterize a novel survivin isoform that we designate survivin 2α. Structurally, the transcript consists of 2 exons: exon 1 and exon 2, as well as a 3' 197 bp region of intron 2. Acquisition of a new in-frame stop codon within intron 2 results in an open reading frame of 225 nucleotides, predicting a truncated 74 amino acid protein. Survivin 2α is expressed at high levels in several malignant cell lines and primary tumors. Functional assays show that survivin 2α attenuates the anti-apoptotic activity of survivin. Subcellular localization and immunoprecipitation of survivin 2α suggests a physical interaction with survivin.

Conclusion

We characterized a novel survivin splice variant that we designated survivin 2α. We hypothesize that survivin 2α can alter the anti-apoptotic functions of survivin in malignant cells. Thus survivin 2α may be useful as a therapeutic tool in sensitizing chemoresistant tumor cells to chemotherapy.
Local coordination verses systemic disregulation: complexities in leukocyte recruitment revealed by local and systemic activation of TLR4 in vivo
Authors: Kerfoot Steven M , Kubes Paul
Published: March 2005

The recruitment of leukocytes to a tissue is a critical step in the inflammatory response. Toll-like receptor 4 (TLR4) is an important receptor involved in the initiation of inflammatory responses. Administration of the ligand for TLR4, lipopolysaccharide, is often used to model inflammation—local responses to stimuli within a specific tissue and systemic responses such as those observed during endotoxic or septic shock. Here, we review work, which demonstrates that in response to local activation of TLR4, highly coordinated and multistep processes are initiated, ultimately resulting in the leukocyte's arrival at the inflamed tissue. In contrast, systemic activation of TLR4 results in nonspecific accumulation of leukocytes within the lung capillaries and liver sinusoids through mechanisms profoundly different than those involved in local tissue recruitment. Contrary to current dogma, leukocyte accumulation in the lung is dependent on endothelial rather than leukocyte activation. Finally, we discuss recent evidence suggesting that activation of leukocytes through TLR4, although still in the circulation, effectively paralyzes inflammatory cells, rendering them incapable of appropriate trafficking to inflamed tissues.
Dual Regulatory Effects of Orexins on Sympathetic Nerve Activity Innervating Brown Adipose Tissue in Rats
Authors: Yasuda Tohru , Masaki Takayuki , Kakuma Tetsuya , Hara Masahide , Nawata Tomoko , Katsuragi Isao , Yoshimatsu Hironobu
Published: March 2005

This study examined how orexin regulates the activity of the sympathetic nerves that innervate brown adipose tissue (BAT) in rats. Infusion of orexin A at a dose of 0.3 nmol into the third cerebral ventricle decreased BAT sympathetic nerve activity, compared with the effect of PBS (P < 0.05), whereas infusion of orexin B at the same dose caused a significant increase (P < 0.05). Pretreatment with a third cerebral ventricle injection of 2.24 μmol/kg α-fluoromethylhistidine, an irreversible inhibitor of the histamine-synthesizing enzyme histidine decarboxylase, attenuated the orexin B-induced response of BAT sympathetic nerve activity, but not that induced by orexin A. These results indicate that orexins may regulate both BAT energy expenditure and thermogenesis through their dual effects on sympathetic nerve activity. In particular, orexin B regulates BAT sympathetic nerve activity via neuronal histamine in the hypothalamus.
Astrocyte-Derived Transforming Growth Factor-β Mediates the Neuroprotective Effects of 17β-Estradiol: Involvement of Nonclassical Genomic Signaling Pathways
Authors: Dhandapani Krishnan M. , Wade F. Marlene , Mahesh Virendra B. , Brann Darrell W.
Published: March 2005

17β-Estradiol (E2) and selective estrogen receptor modulators (SERMs), such as tamoxifen, mediate numerous effects in the brain, including neurosecretion, neuroprotection, and the induction of synaptic plasticity. Astrocytes, the most abundant cell type in the brain, influence many of these same functions and thus may represent a mediator of estrogen action. The present study examined the regulatory effect and underlying cell signaling mechanisms of E2-induced release of neurotropic growth factors from primary rat cortical astrocyte cultures. The results revealed that E2 (0.5, 1, and 10 nm) and tamoxifen (1 μm) increased both the expression and release of the neuroprotective cytokines, TGF-β1 and TGF-β2 (TGF-β), from cortical astrocytes. The stimulatory effect of E2 was attenuated by the estrogen receptor (ER) antagonist, ICI182,780, suggesting ER dependency. The effect of E2 also appeared to involve mediation by the phosphotidylinositol 3-kinase (PI3K)/Akt signaling pathway, because E2 rapidly induced Akt phosphorylation, and pharmacological or molecular inhibition of the PI3K/Akt pathway prevented E2-induced release of TGF-β. Additionally, the membrane-impermeant conjugate, E2-BSA, stimulated the release of TGF-β, suggesting the potential involvement of a membrane-bound ER. Finally, E2, tamoxifen, and E2-BSA were shown to protect neuronal-astrocyte cocultures from camptothecin-induced neuronal cell death, effects that were attenuated by ICI182,780, Akt inhibition, or TGF-β immunoneutralization. As a whole, these studies suggest that E2 induction of TGF-β release from cortical astrocytes could provide a mechanism of neuroprotection, and that E2 stimulation of TGF-β expression and release from astrocytes occurs via an ER-dependent mechanism involving mediation by the PI3K/Akt signaling pathway.
Defective Calmodulin-Mediated Nuclear Transport of the Sex-Determining Region of the Y Chromosome (SRY) in XY Sex Reversal
Authors: Sim Helena , Rimmer Kieran , Kelly Sabine , Ludbrook Louisa M. , Clayton Andrew H. A. , Harley Vincent R.
Published: March 2005

The sex-determining region of the Y chromosome (SRY) plays a key role in human sex determination, as mutations in SRY can cause XY sex reversal. Although some SRY missense mutations affect DNA binding and bending activities, it is unclear how others contribute to disease. The high mobility group domain of SRY has two nuclear localization signals (NLS). Sex-reversing mutations in the NLSs affect nuclear import in some patients, associated with defective importin-β binding to the C-terminal NLS (c-NLS), whereas in others, importin-β recognition is normal, suggesting the existence of an importin-β-independent nuclear import pathway. The SRY N-terminal NLS (n-NLS) binds calmodulin (CaM) in vitro, and here we show that this protein interaction is reduced in vivo by calmidazolium, a CaM antagonist. In calmidazolium-treated cells, the dramatic reduction in nuclear entry of SRY and an SRY-c-NLS mutant was not observed for two SRY-n-NLS mutants. Fluorescence spectroscopy studies reveal an unusual conformation of SRY.CaM complexes formed by the two n-NLS mutants. Thus, CaM may be involved directly in SRY nuclear import during gonadal development, and disruption of SRY.CaM recognition could underlie XY sex reversal. Given that the CaM-binding region of SRY is well-conserved among high mobility group box proteins, CaM-dependent nuclear import may underlie additional disease states.
Application of Fetal DNA Detection in Maternal Plasma: A Prenatal Diagnosis Unit Experience
Authors: González-González Cristina , Garcia-Hoyos Maria , Trujillo-Tiebas M. Jose , Lorda-Sanchez Isabel , de Alba Marta Rodríguez , Infantes Fernando , Gallego Jesus , Diaz-Recasens Joaquín , Ayuso Carmen , Ramos Carmen
Published: March 2005

Non-invasive prenatal diagnosis tests based on the analysis of fetal DNA in maternal plasma have potential to be a safer alternative to invasive methods. So far, different studies have shown mainly fetal sex, fetal RhD, and quantitative variations of fetal DNA during gestation with fetal chromosomal anomalies or gestations at risk for preeclampsia. The objective of our research was to evaluate the use of fetal DNA in maternal plasma for clinical application. In our study, we have established the methodology needed for the analysis of fetal DNA. Different methods were used, according to the requirements of the assay. We have used quantitative fluorescent polymerase chain reaction (QF-PCR) to perform fetal sex detection with 90% sensitivity. The same technique permitted the detection of fetal DNA from the 10th week of gestation to hours after delivery. We have successfully carried out the diagnosis of two inherited disorders, cystic fibrosis (conventional PCR and restriction analysis) and Huntington disease (QF-PCR). Ninety percent of the cases studied for fetal RhD by real-time PCR were correctly diagnosed. The detection of fetal DNA sequences is a reality and could reduce the risk of invasive techniques for certain fetal disorders in the near future.
Pallister-Killian Syndrome: Rapid Decrease of Isochromosome 12p Frequency during Amniocyte Subculturing. Conclusion for Strategy of Prenatal Cytogenetic Diagnostics
Authors: Polityko Anna D. , Goncharova Elena , Shamgina Ludmila , Drozdovskaja Natalia , Podleschuk Lubov , Abramchik Elena , Jaroshevich Eugenia , Khurs Olga , Pisarik Irina , Pribushenya Oksana , Rumyantseva Natalia , Naumchik Irina
Published: March 2005

Pallister-Killian syndrome (PKS) is characterized cytogenetically by mosaic tetrasomy of chromosome 12p. Routine prenatal diagnosis of PKS is still complicated because of the difficulties of discriminating between the supernumerary isochromosome 12p and the duplication 21q and because of the variable level of mosaicism. The frequency of cells with an extra metacentric chromosome i(12)(p10) is usually determined by tissue-limited or tissue-specific mosaicism. We demonstrated a decrease of the abnormal clone with extra i(12p) in the amniotic fluid cells of the PKS fetus during amniocyte subculturing. The rapid loss of the i(12p) in the course of amniocyte subculturing should be the focus of attention during prenatal karyotyping. This is especially necessary for cultures with slow growth, which require further interpretation of the result during cytogenetic diagnosis of PKS.
FISH Analysis of All Fetal Nucleated Cells in Maternal Whole Blood: Improved Specificity by the Use of Two Y-chromosome Probes
Authors: Mergenthaler Susanne , Babochkina Tatiana , Kiefer Vivian , Lapaire Olaf , Holzgreve Wolfgang , Hahn Sinuhe
Published: March 2005

Current cytogenetic approaches in noninvasive prenatal diagnosis focus on fetal nucleated red blood cells in maternal blood. This practice may be too restrictive because a vast proportion of other fetal cells is ignored. Recent studies have indicated that fetal cells can be directly detected, without prior enrichment, in maternal blood samples by fluorescence in situ hybridization (FISH) analysis for chromosomes X and Y (XY-FISH). In our blinded analysis of 40 maternal blood samples, we therefore examined all fetal cells without any enrichment. Initial examinations using conventional XY-FISH indicated a low specificity of 69.4%, which could be improved to 89.5% by the use of two different Y-chromosome-specific probes (YY-FISH) with only a slight concomitant decrease in sensitivity (52.4% vs 42.9%). On average, 12–20 male fetal cells/ml of maternal blood were identified by XY- and YY-FISH, respectively.
Fetal Gender Determination and BclI Polymorphism Using Nucleated Erythrocytes in Maternal Blood
Authors: Choe Jin , Hwang Doyeong , Kim Ki-Chul , Choi Young-Min
Published: March 2005

This study demonstrated determination of fetal gender from nucleated red blood cells (NRBCs) in maternal blood and attempted to apply prenatal diagnosis of hemophilia A using BclI DNA polymorphism. Venous blood was drawn from 20 pregnant women, and NRBCs were recovered by magnetic activated cell sorting and anti-GPA (glycophorin A) immunostaining. After microdissector isolation of the NRBCs, primer extension preamplification (PEP) and nested PCR of the amelogenin gene were performed to determine fetal gender. We also performed PEP and nested PCR of BclI polymorphism to verify the validity of prenatal diagnosis of hemophilia A. DNA amplification was achieved in 107 cells (51.9%) and fetal gender determined with 65.0% accuracy. Unfortunately, we could not verify the validity within the scope of this study. However, in a larger number of cases that are informative in BclI polymorphism, we will be able to identify patients affected by hemophilia A using fetal NRBCs in maternal blood.
Evidence for High Frequency of Chromosomal Mosaicism in Spontaneous Abortions Revealed by Interphase FISH Analysis
Authors: Vorsanova Svetlana G. , Kolotii Alexei D. , Iourov Ivan Y. , Monakhov Viktor V. , Kirillova Elena A. , Soloviev Ilia V. , Yurov Yuri B.
Published: March 2005

Numerical chromosomal imbalances are a common feature of spontaneous abortions. However, the incidence of mosaic forms of chromosomal abnormalities has not been evaluated. We have applied interphase multicolor fluorescence in situ hybridization using original DNA probes for chromosomes 1, 9, 13, 14, 15, 16, 18, 21, 22, X, and Y to study chromosomal abnormalities in 148 specimens of spontaneous abortions. We have detected chromosomal abnormalities in 89/148 (60.1%) of specimens. Among them, aneuploidy was detected in 74 samples (83.1%). In the remaining samples, polyploidy was detected. The mosaic forms of chromosome abnormality, including autosomal and sex chromosomal aneuploidies and polyploidy (31 and 12 cases, respectively), were observed in 43/89 (48.3%) of specimens. The most frequent mosaic form of aneuploidy was related to chromosome X (19 cases). The frequency of mosaic forms of chromosomal abnormalities in samples with male chromosomal complement was 50% (16/32 chromosomally abnormal), and in samples with female chromosomal complement, it was 47.4% (27/57 chromosomally abnormal). The present study demonstrates that the postzygotic or mitotic errors leading to chromosomal mosaicism in spontaneous abortions are more frequent than previously suspected. Chromosomal mosaicsm may contribute significantly to both pregnancy complications and spontaneous fetal loss.
Molecular Karyotyping: Array CGH Quality Criteria for Constitutional Genetic Diagnosis
Authors: Vermeesch Joris R. , Melotte Cindy , Froyen Guy , Van Vooren Steven , Dutta Binita , Maas Nicole , Vermeulen Stefan , Menten Björn , Speleman Frank , De Moor Bart , Van Hummelen Paul , Marynen Peter , Fryns Jean-Pierre , Devriendt Koen
Published: March 2005

Array CGH (comparative genomic hybridization) enables the identification of chromosomal copy number changes. The availability of clone sets covering the human genome opens the possibility for the widespread use of array CGH for both research and diagnostic purposes. In this manuscript we report on the parameters that were critical for successful implementation of the technology, assess quality criteria, and discuss the potential benefits and pitfalls of the technology for improved pre- and postnatal constitutional genetic diagnosis. We propose to name the genome-wide array CGH “molecular karyotyping,” in analogy with conventional karyotyping that uses staining methods to visualize chromosomes.
Proteome Analysis of Maternal Serum Samples for Trisomy 21 Pregnancies Using ProteinChip Arrays and Bioinformatics
Authors: Busch Anne , Michel Susanne , Hoppe Constance , Driesch Dominik , Claussen Uwe , von Eggeling Ferdinand
Published: March 2005

A surface-enhanced laser desorption/ionization time of flight (SELDI-TOF)-based ProteinChip System was used as a tool for rapid discovery and identification of protein patterns in serum that discriminate between trisomy 21 and unaffected pregnancies. We analyzed 24 serum samples from women carrying a trisomy 21 pregnancy and 32 with an unaffected pregnancy, ranging from 10.0 to 14.0 weeks of gestation. The resulting protein profiles were submitted to a clustering algorithm, a rule extraction, a rating, and a rule base construction step. For the generated combined rule base, the specificity and sensitivity for the prediction of a trisomy 21 pregnancy reach 97% and 91%, respectively.
Analysis of Cell-free Fetal DNA in Plasma and Serum of Pregnant Women
Authors: Zolotukhina T.V. , Shilova N.V. , Voskoboeva E. Yu
Published: March 2005

Sixty blood samples from pregnant women during gestational weeks 9–28 were investigated. Cell-free fetal DNA was extracted from maternal plasma or serum to be detected by nested PCR for determination of fetal gender. The SRY gene as a marker for fetal Y chromosome was detected in 34/36 women carrying a male fetus. In 3/24 women carrying female fetuses, the SRY sequence was also detected. Overall, fetal sex was correctly predicted in 91.7% of the cases. Therefore, the new, non-invasive method of prenatal diagnosis of fetal gender for women at risk of producing children with X-linked disorders is reliable, secure, and can substantially reduce invasive prenatal tests.
Three Cases with Enlarged Acrocentric p-arms and Two Cases with Cryptic Partial Trisomies
Authors: Starke Heike , Mrasek Kristin , Liehr Thomas
Published: March 2005

In three cases, banding analysis revealed a normal karyotype except for an enlarged short arm of one chromosome 13 or 15. To clarify whether this enlargement was due to a heteromorphism or to a cryptic chromosomal trisomy, so-called cenM-FISH probe sets containing a microdissection-derived probe specific for the acrocentric human p-arms were applied. The results enabled us to confirm in one case and to exclude in two cases that the enlargement on the suspect chromosome was due to a p-arm polymorphism. M-FISH and/or microdissection were used to resolve the nature of the rearrangements, i.e., partial trisomies 6 and 19.
Trophoblasts Isolated from the Maternal Circulation: In Vitro Expansion and Potential Application in Non-invasive Prenatal Diagnosis
Authors: Guetta Esther , Gutstein-Abo Liat , Barkai Gad
Published: March 2005

Prenatal diagnosis based on rare fetal cells in maternal blood is currently not a feasible option. An effort was made to improve cell yields by targeting trophoblast cells. After sorting, the HLA-G-positive cell fraction was analyzed directly or after culture. In situ hybridization technology was applied to prove fetal cell source in samples from women carrying a male fetus and to predict gender in samples without previous knowledge of fetal sex. In vitro culture led to a significant increase in fetal cells and accurate gender prediction in 93% of these samples. This approach might be useful for non-invasive prenatal diagnosis.
Recent Advances in Fetal Nucleic Acids in Maternal Plasma
Authors: Dennis Lo Y.M.
Published: March 2005

The discovery of cell-free fetal DNA in maternal plasma in 1997 has opened up new possibilities for noninvasive prenatal diagnosis. Circulating fetal DNA molecules have been detected in maternal plasma from the first trimester onwards and can be robustly detected using a variety of molecular methods. This approach has been used for the prenatal investigation of sex-linked diseases, fetal RhD status, and prenatal exclusion of β-thalassemia major. Recently, fetal RNA has also been found in maternal plasma. Such fetal RNA has been shown to originate from the placenta and to be remarkably stable. The use of microarray-based approaches has made it feasible to rapidly generate new circulating RNA markers. It is hoped that further developments in this field will make the routine and widespread practice of noninvasive nucleic acid-based prenatal diagnosis for common pregnancy-associated disorders feasible in the near future.
Cyclic changes of the ovarian surface epithelium in the rat
Authors: Gaytán M , Sánchez M A , Morales C , Bellido C , Millán Y , Martín de las Mulas J , Sánchez-Criado J E , Gaytán F
Published: March 2005

The ovarian surface epithelium (OSE) plays pivotal roles during ovulation and postovulatory wound repair. In this paper we describe the proliferative activity of the OSE through the estrous cycle in adult cycling rats, by immunohistochemical detection of DNA-incorporated bromodeoxyuridine (BrdU). Immunohistochemical detection of estrogen receptor α (ERα) and progesterone receptor was also performed. The cycle of the OSE consists of a proliferative phase (that lasts for two consecutive estrous cycles) and a quiescent phase of variable duration. Cyclic changes in the OSE were related to the underlying ovarian structure. OSE areas covering growing follicles entered into the proliferative phase during the transition from proestrus to estrus, with the appearance of fast-growing class 1 follicles, destined to ovulate at the end of the current estrous cycle. A labeling index (after pulse-labeling BrdU treatment) of about 7% was maintained throughout the estrous cycle in parallel to follicle growth. Cumulative BrdU-labeling (after daily BrdU treatment) indicated that about 1/3 of the total OSE cell proliferation was related to follicle growth. Following ovulation, OSE cells covering newly-formed corpora lutea showed a labeling index of about 50% that decreased through metestrus and diestrus (about 13% and 3%, respectively), returning to basal levels by proestrus. Cumulative BrdU-labeling indicated that about 2/3 of the total proliferative activity was related to ovulation repair/luteinization. The remaining OSE covering ovarian stroma or structurally regressing corpora lutea of previous cycles showed negligible BrdU labeling. The equivalent proliferative activity found in the OSE covering newly-formed corpora lutea in indomethacin-treated rats lacking rupture of the OSE at the apex, demonstrated that ovulation-triggered proliferation was not dependent on the loss of integrity of the OSE at the ovulation site. OSE cells expressed ERα throughout the cycle, but no differential expression was found between proliferating and quiescent OSE areas. On the contrary, OSE cells did not express PR at any time of the cycle. These data indicate the existence of a cycle of the OSE, related to the cyclic changes in the underlying ovarian structure and strongly suggest that the proliferative activity of the OSE is regulated by local microenvironmental rather than by systemic factors.
Short-term nutritional supplementation of ewes in low body condition affects follicle development due to an increase in glucose and metabolic hormones
Authors: Viñoles C , Forsberg M , Martin G B , Cajarville C , Repetto J , Meikle A
Published: March 2005

This study tested whether the effects of a short period of nutritional supplementation given to ewes during the luteal phase on follicle development and ovulation rate is associated with an increase in circulating concentrations of FSH, glucose or metabolic hormones. Oestrus was synchronised with two prostaglandin injections given 9 days apart and the supplement consisted of corn grain and soybean meal. Corriedale ewes with low body condition were randomly assigned to 2 groups: the control group (C; n = 10) received a maintenance diet while the short-term supplemented group (STS; n = 10) received double the maintenance diet over days 9 to 14 of the oestrous cycle (day 0 = ovulation). Ovaries were examined daily by ultrasound and blood was sampled three times a day during the inter-ovulatory interval for measuring reproductive and metabolic hormones. On days 9, 11 and 14 of the oestrous cycle, half of the ewes from each group (n = 5) were bled intensively to determine the concentrations of glucose, insulin, IGF-I and leptin. Plasma FSH, progesterone, oestradiol and androstenedione concentrations were similar among groups. Dietary supplementation increased plasma insulin concentrations from the first to the sixth day of supplementation and increased glucose concentrations on the third day, compared with control ewes. Plasma leptin concentrations were higher in STS ewes from the second to the fifth day of supplementation. The pattern of IGF-I concentrations was similar among groups. In STS ewes, the nutritional treatment prolonged the lifespan of the last non-ovulatory follicle, so fewer follicular waves developed during the cycle. In STS ewes, increased concentrations of glucose, insulin and leptin one day before ovulatory wave emergence were associated with increased numbers of follicles growing from 2 to 3 mm and with stimulation of the dominant follicle to grow for a longer period. We suggest that the mechanism by which short-term nutritional supplementation affects follicle development does not involve an increase in FSH concentrations, but may involve responses to increased concentrations of glucose, insulin and leptin, acting directly at the ovarian level. This effect is acute, since concentrations of all three substances decrease after reaching peak values on the third day of supplementation. The status of follicle development at the time of maximum concentrations of glucose and metabolic hormones may be one of the factors that determines whether ovulation rate increases or not.
The Number of Mutations Selected During Adaptation in a Laboratory Population of Saccharomyces cerevisiae
Authors: Zeyl Clifford
Published: March 2005

There is currently limited empirical and theoretical support for the prevailing view that adaptation typically results from the fixation of many mutations, each with small phenotypic effects. Recent theoretical work suggests that, on the contrary, most of the phenotypic change during an episode of adaptation can result from the selection of a few mutations with relatively large effects. I studied the genetics of adaptation by populations of budding yeast to a culture regime of daily hundredfold dilution and transfer in a glucose-limited minimal liquid medium. A single haploid genotype isolated after 2000 generations showed a 76% fitness increase over its ancestor. This evolved haploid was crossed with its ancestor, and tetrad dissections were used to isolate a complete series of six meiotic tetrads. The Castle-Wright estimator of the number of loci at which adaptive mutations had been selected, modified to account for linkage and variation among mutations in the size of their effect, is 4.4. The estimate for a second haploid genotype, isolated from a separate population and with a fitness gain of 60%, was 2.7 loci. Backcrosses to the ancestor with the first evolved genotype support the inference that adaptation resulted primarily from two to five mutations. These backcrosses also indicated that deleterious mutations had hitchhiked with adaptive mutations in this evolved genotype.
Evidence That Spt10 and Spt21 of Saccharomyces cerevisiae Play Distinct Roles in Vivo and Functionally Interact With MCB-Binding Factor, SCB-Binding Factor and Snf1
Authors: Hess David , Winston Fred
Published: March 2005

Mutations in SPT10 and SPT21 of Saccharomyces cerevisiae have been previously shown to cause two prominent mutant phenotypes: (1) defects in transcription of particular histone genes and (2) suppression of Ty and δ-insertion mutations (Spt− phenotype). The requirement for Spt10 and Spt21 for transcription of particular histone genes suggested that they may interact with two factors previously shown to be present at histone loci, SBF (Swi4 and Swi6) and MBF (Mbp1 and Swi6). Therefore, we have studied swi4Δ, mbp1Δ, and swi6Δ mutants with respect to histone gene transcription and for interactions with spt10Δ and spt21Δ. Our results suggest that MBF and SBF play only modest roles in activation of histone gene transcription. In addition, we were surprised to find that swi4Δ, mbp1Δ, and swi6Δ mutations suppress the spt21Δ Spt− phenotype, but not the spt21Δ defect in histone gene transcription. In contrast, both swi4Δ and mbp1Δ cause lethality when combined with spt10Δ. To learn more about mutations that can suppress the spt21Δ Spt− phenotype, we performed a genetic screen and identified spt21Δ suppressors in seven additional genes. Three of these spt21Δ suppressors also cause lethality when combined with spt10Δ. Analysis of one spt21Δ suppressor, reg1, led to the finding that hyperactivation of Snf1 kinase, as caused by reg1Δ, suppresses the Spt− phenotype of spt21Δ. Taken together, these genetic interactions suggest distinct roles for Spt21 and Spt10 in vivo that are sensitive to multiple perturbations in transcription networks.
Metal coatings on SiC nanowires by plasma-enhanced chemical vapor deposition
Authors: LaLonde Aaron D. , Norton M. Grant , McIlroy David N. , Zhang Daqing , Padmanabhan Radhakrishnan , Alkhateeb Abdullah , Han Hongmei , Lane Nicholas , Holman Zachery
Published: March 2005

Coating of nanowires is being investigated to broaden potential uses for future applications. Coatings of Ni and Pt nanoparticles have been synthesized on silicon carbide nanowires by plasma enhanced chemical vapor deposition. Coatings with high particle densities with average particle diameters of 2.76 and 3.28 nm for Pt and Ni, respectively, were formed with narrow size distributions. Plasma enhanced chemical vapor deposition appears to be an efficient method for production of metal coatings on nanowires.
Porous Al2O3/Al catalyst supports fabricated by an Al(OH)3/Al mixture and the effect of agglomerates
Authors: Deng Zhen-Yan , Tanaka Yoshihisa , Sakka Yoshio , Kagawa Yutaka
Published: March 2005

Porous Al2O3/Al catalyst supports were fabricated using a mixture of Al(OH)3 and Al powders, followed by pressureless sintering at a temperature of 600 °C in vacuum. Different pressures were used to prepare green compacts. High compaction pressure led to a high surface area and good mechanical and electrical properties for the sintered specimens. However, when the Al content in the sintered specimen exceeded a definite value, high compaction pressure decreased the surface area abruptly. Scanning electron microscopy observations revealed that agglomeration in the starting mixture has a significant effect on the microstructure of the sintered specimens. High compaction pressure greatly eliminated the agglomerates and led to a uniform microstructure for the sintered specimens. However, when the Al content in the starting mixture was too high, Al particles in the compacts prepared by the high pressure were largely sintered due to the high compact density so that most of the pores were closed. The present study indicates that a suitable compaction pressure is critical to obtaining superior Al2O3/Al supports.
An unusual way to luminescent terbium molecular-level hybrid materials: Modified methyl benzoic acid covalently bonded with silica as a bridge
Authors: Wang Qianming , Yan Bing
Published: March 2005

The syntheses of modified ortho or meta methylbenzoic acid by (3-aminopropyl)triethoxysilane and the preparation of their corresponding organic–inorganic molecular-based hybrid material with the two components equipped with covalent bonds are described. The organic part is a derivative of methyl benzoic acid, which is used to coordinate to Tb3+ and further introduced into silica matrices by Si–O bonds after hydrolysis and polycondensation processes. The Judd–Ofelt theory proves that covalency increases along with increasing reciprocal energy difference between the 4fN and 4fN−15d1 configurations. Ultraviolet absorption, phosphorescence spectra, and luminescence spectra were applied to characterize the photophysical properties of the obtained hybrid material, and the above spectroscopic data reveal that the triplet energy of modified methyl benzoic acid matches with the emissive energy level of Tb3+. In this way, the intramolecular energy transfer process took place within these molecular-based hybrids, and strong green emission of Tb3+ was obtained.
Catalytic synthesis and characterization of spindle-type α–Fe2O3 particles
Authors: Zhang Xiuli , Liu Hui , Wei Yu
Published: March 2005

Catalytic synthesis of spindle-type hematite particles was studied for the first time under the conditions of boiling reflux and pH values ranging from 4 to 7, using Fe2(SO4)3 and NaOH as raw material, a trace amount of FeSO4 as the catalyst, and NaH2PO4 as the growth-regulating agent. The final products were characterized by x-ray diffraction, high-resolution electron microscopy, scanning electron microscopy, and Fourier transform infrared techniques. Primarily, the catalytic effect of ferrous ion on the conversion of ferric hydroxide was investigated. It was found that the addition of a trace amount of ferrous ion promoted fast conversion of ferric hydroxide and remarkably accelerated the transformation process to hematite. The reaction conditions affecting the conversion rate and morphologies in the presence of trace amount of ferrous ion were investigated. The final particles prepared had the characteristics of controlled size, a narrow particle size distribution, and good reproducibility.
Structural investigation of diamond nanoplatelets grown by microwave plasma-enhanced chemical vapor deposition
Authors: Chen Hou-Guang , Chang Li
Published: March 2005

We report a unique morphology of diamond nanoplatelets synthesized by microwave plasma chemical vapor deposition on Ni coated polycrystalline diamond substrates. The diamond nanoplatelets were as thin as approximately 30 nm. Electron microscopy showed that the diamond nanoplatelets appear in a shape consisting of trapezoid and parallelogram tabular crystallites. Furthermore, the diamond nanoplatelets were single crystalline, as shown by electron diffraction. The edges of nanoplatelets were along the 〈110〉 direction with both the top and bottom tabular surfaces parallel to the {111} plane. Transmission electron microscopy revealed that the twinned planes are parallel to the platelet and side-face structure in ridge shape is bounded by {100} and {111} planes. Lateral growth of diamond nanoplatelet is believed to result from twin and ridge face structure. An oriented thin graphite layer was observed on some diamond nanoplatelets.
Simultaneous spark plasma synthesis and consolidation of WC/Co composites
Authors: Locci Antonio Mario , Orrù Roberto , Cao Giacomo
Published: March 2005

The single-step synthesis and densification of the WC–6Co cemented carbide starting from elemental powders was obtained by the spark plasma sintering (SPS) technique. The operating conditions that guarantee the complete conversion of the reactants to the desired full dense material have been identified. Specifically, under the application of 800 A and a mechanical pressure of 40 MPa for about 200 s, a product with relative density higher than 99%, hardness of 14.97 ± 0.35 GPa, and 12.5 ± 1.0 MPa m0.5 fracture toughness was obtained. A kinetic investigation of the SPS process was also performed. It revealed that an intermediate phase, i.e., W2C, is the first carbide formed during the carburization process. It was observed that the synthesis and sintering stages take place simultaneously. It was also found that as the applied pulsed current intensity was augmented, the synthesis/sintering time required decreased significantly.
New method for the production of bulk amorphous materials of Nd–Fe–B alloys
Authors: Saito Tetsuji , Takeishi Hiroyuku , Nakayama Noboru
Published: March 2005

We report a new compression shearing method for the production of bulk amorphous materials. In this study, amorphous Nd–Fe–B melt-spun ribbons were successfully consolidated into bulk form at room temperature by the compression shearing method. X-ray diffraction and transmission electron microscopy studies revealed that the amorphous structure was well maintained in the bulk materials. The resultant bulk materials exhibited the same magnetic properties as the original amorphous Nd–Fe–B materials.
A Comparison of Elastomer Marks and Fin Clips as Marking Techniques for Walleye
Authors: Thompson James M. , Hirethota Pradeep S. , Eggold Bradley T.
Published: March 2005

Two marking techniques, fin removal and visible implant elastomer, were evaluated in walleye Sander vitreus. Although fin-clipping is widely practiced, research results have been ambiguous as to whether the technique is harmful to fish over the long term. We attempted to determine over a 7-year period whether elastomer marking might have significant benefits to growth and survival of walleye when compared with fish given a single fin clip. We also evaluated the long-term detection rates of elastomer marks as well as their cost-effectiveness. Each year for 5 years we marked and stocked an average of 8,000 extended-growth walleye fingerlings in the lower Milwaukee River, Wisconsin, as part of a project to reintroduce walleyes to the Milwaukee River estuary. One-half were given a single fin clip and one-half were given an elastomer mark. Fin clips and elastomer colors were changed each year. Fish were recaptured the following year by means of electrofishing gear. We found no significant differences in survival or growth rates between the differentially marked fish. We also found that tag detection in recaptured fish over the long term was 82.5% for fish originally marked with elastomer. The cost associated with elastomer marking was US$0.40 per mark while the cost of fin clipping was $0.03 per mark. We concluded that a single fin clip was the more desirable technique for marking walleyes.
Prolonged insulin treatment inhibits GH signaling via STAT3 and STAT1
Authors: Xu Jie , Ji Shaonin , Venable Derwei Y , Franklin John L , Messina Joseph L
Published: March 2005

Growth hormone (GH) and insulin are important regulators of cellular and whole body metabolism as well as somatic growth and body composition. Studies have indicated complex feedback effects of GH on insulin action and of insulin on GH signaling pathways. Previous studies in our laboratory have shown that GH induction of signal transducers and activators of transcription (STAT)5B tyrosine phosphorylation is inhibited by prolonged insulin treatment, probably via downregulation of GHR. Here, we find that in rat H4IIE hepatoma cells GH-induced tyrosine phosphorylation of two other STATs (STAT3 and STAT1) was also greatly reduced following prolonged insulin pretreatment compared with that induced by GH alone. In the present work, total STAT5B and STAT1 protein levels were not altered by prolonged insulin treatment. However, prolonged insulin treatment (16 h; 10 or 100 nM) resulted in a 30–40% reduction of total STAT3 protein, with little change at 0.1 and 1.0 nM insulin. Thus, there is a selective reduction of total STAT3 protein levels by insulin, but only at high concentration of insulin. Basal tyrosine phosphorylated (PY)-STAT3 was also significantly reduced by prolonged insulin treatment, and to a greater extent than total STAT3 protein levels. The inhibitory effect of insulin on total STAT3 protein and basal PY-STAT3 levels was dependent on activation of the MEK-ERK pathway, rather than the PI3K pathway. In contrast, the MEK-ERK pathway did not play a major role in insulin’s inhibition of GH-induced PY-STAT3 and PY-STAT1. The present studies indicate that prolonged hyperinsulinemia, such as that found in some obese patients or patients with Type 2 diabetes mellitus, may have profound effects on GH signaling via STAT3 and STAT1.
Synergistic activity of activin A and basic fibroblast growth factor on tyrosine hydroxylase expression through Smad3 and ERK1/ERK2 MAPK signaling pathways
Authors: Bao Y L , Tsuchida K , Liu B , Kurisaki A , Matsuzaki T , Sugino H
Published: March 2005

Activin has previously been shown to act as a nerve cell survival factor and to have neurotrophic effects on neurons. However, the role of activin in regulating neurotransmitter expression in the central nervous system and the exact mechanisms involved in this process are poorly understood. In the present study, we report that activin A and basic fibroblast growth factor (bFGF) synergistically increased the protein level of tyrosine hydroxylase (TH), and also greatly increased the TH mRNA level, in both mouse E14 striatal primary cell cultures and the hippocampal neuronal cell line HT22. Activin A and bFGF cooperatively stimulated nuclear translocation of Smad3 and specifically activated ERK1/2, but not p38 or JNK. Interestingly, a specific inhibitor for MEK, U0126, efficiently blocked the induction of TH promoter activity by activin A and bFGF, indicating that activin A collaborated with bFGF signaling to induce the TH gene through selective activation of ERK-type MAP kinase in mouse striatal and HT22 cells. These data suggest that activin A may act in concert with bFGF for the development of TH-positive neurons.