bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new bone‐inducing biodegradable porous β‐tricalcium phosphate
Authors: Matsushita Naofumi , Terai Hidetomi , Okada Takao , Nozaki Kazutoshi , Inoue Hikaru , Miyamoto Shimpei , Takaoka Kunio 
Published: June 2004

AbstractA new type of degradable biomaterial with bone‐inducing capacity was made by combining porous β‐tricalcium phosphate (β‐TCP) with a delivery system for recombinant human bone morphogenetic protein‐2 (rhBMP‐2). The BMP delivery system consisted of a block copolymer composed of poly‐D,L‐lactic acid with random insertion of p‐dioxanone and polyethylene glycol (PLA‐DX‐PEG), a known biocompatible and biodegradable material. The efficacy of this biomaterial in terms of its bone‐inducing capacity was examined by ectopic bone formation in the dorsal muscles of the mouse. In the β‐TCP implants coated with the PLA‐DX‐PEG polymer containing more than 0.0025% (w/w) of rhBMP‐2, new ectopic bone tissues with marrow were consistently found on the surface of implants. The radiographic density of β‐TCP was diminished in a time‐dependent manner. On histological examination, numerous multinucleated osteoclasts with positive tartrate‐resistant acid‐phosphatase (TRAP) staining were noted on the surface of the β‐TCP. These experimental results indicate that β‐TCP implants coated with synthetic rhBMP‐2 delivery system might provide effective artificial bone‐graft substitutes with osteoinductive capacity and biodegradable properties. In addition, this type of biomaterial may require less rhBMP‐2 to induce significant new bone mass. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 450–458, 2004
Effect of the difference of bone turnover on peri‐titanium implant osteogenesis in ovariectomized rats
Authors: Okamura Akira , Ayukawa Yasunori , Iyama Shinji , Koyano Kiyoshi 
Published: June 2004

AbstractHigh and low bone turnover situations, both of which are typically observed as postmenopausal and senile osteoporosis, were created by ovariectomy (OVX), and then an investigation of whether or not the difference of bone turnover affected peri‐titanium (Ti) implant osteogenesis in rats was conducted. Female rats were divided into four groups. The experimental and control groups underwent OVX or sham operations at 15 or 27 weeks of age, as high or low bone turnover groups, respectively. Ti implants were inserted into the tibiae at 30 weeks, then fluorochromes were injected 10 or 20 days after the implantation for histometry. The implants were retained for 30 days and then ground sections were prepared. Afterward, the cortical bone growth rate, bone contact ratio (BCR) of the implant in both the cortical bone area and medullary canal area, and the average trabecular bone thickness around the implant were evaluated. Biochemical markers of bone turnover were also measured. Biochemical measurements indicated both increasing osteocalcin production in OVX rats and decreasing tartrate‐resistant acid phosphatase activity in the low‐turnover group. Histometrical measurements showed decreasing cortical growth and low BCR in the medullary canal of the low‐turnover group. The high‐turnover group demonstrated BCR as high as that of the control group. There was no significant difference in the average trabecular bone thickness around the implant among the groups. As a result, two types of osteoporotic situations were confirmed and it was shown that the difference of bone turnover was clearly due to the diverse osteogenesis around the Ti implant. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 497–505, 2004
The crab‐eating frog, Rana cancrivora, up‐regulates hepatic carbamoyl phosphate synthetase I activity and tissue osmolyte levels in response to increased salinity
Authors: Wright Patricia , Anderson Paul , Weng Lei , Frick Natasha , Wong Wei Peng , IP Yuen Kwong 
Published: June 2004

AbstractThe crab‐eating frog Rana cancrivora is one of only a handful of amphibians worldwide that tolerate saline waters. They typically inhabit brackish water of mangrove forests of Southeast Asia, but live happily in freshwater and can be acclimated to 75% seawater (25 ppt) or higher. We report here that after transfer of juvenile R. cancrivora from freshwater (1 ppt) to brackish water (10 →20 or 20 →25 ppt; 4–8 d) there was a significant increase in the specific activity of the key hepatic ornithine urea cycle enzyme (OUC), carbamoyl phosphate synthetase I (CPSase I). At 20 ppt, plasma, liver and muscle urea levels increased by 22‐, 21‐, and 11‐fold, respectively. As well, muscle total amino acid levels were significantly elevated by 6‐fold, with the largest changes occurring in glycine and β‐alanine levels. In liver, taurine levels were 5‐fold higher in frogs acclimated to 20 ppt. There were no significant changes in urea or ammonia excretion rates to the environment. As well, the rate of urea influx (Jinurea) and efflux (Jouturea) across the ventral pelvic skin did not differ between frogs acclimated to 1 versus 20 ppt. Taken together, these findings suggest that acclimation to saline water involves the up‐regulation of hepatic urea synthesis, which in turn contributes to the dramatic rise in tissue urea levels. The lack of change in urea excretion rates, despite the large increase in tissue‐to‐water gradients further indicates that mechanisms must be in place to prevent excessive loss of urea in saline waters, but these mechanisms do not include cutaneous urea uptake. Also, amino acid accumulation may contribute to an overall rise in the osmolarity of the muscle tissue, but relative to urea, the contribution is small. J. Exp. Zool. 301A:559–568, 2004. © 2004 Wiley‐Liss, Inc.
Two fast‐type fibers in claw closer and abdominal deep muscles of the Australian freshwater crustacean, Cherax destructor, differ in Ca2+ sensitivity and troponin‐I isoforms
Authors: Koenders Annette , Lamey Tina M. , Medler Scott , West Jan M. , Mykles Donald L. 
Published: June 2004

AbstractOne type of fast fiber and two types of slow (slow‐twitch, S1 and slow‐tonic, S2) fibers are found in decapod crustacean skeletal muscles that differ in contractile properties and myofibrillar protein isoform compositions. In this study the structural characteristics, protein isoform compositions, and Ca2+‐activation properties of fast fibers in the claw closer (F1) and abdominal deep flexor (F2) muscles of Cherax destructor were analyzed. For comparison, myofibrillar protein isoform compositions of slow (long‐sarcomere) fibers from claw and abdomen were also determined; our results indicate that the slow fibers in the claw closer were the slow‐twitch (S1) type and those in the abdominal superficial flexor were primarily slow‐tonic (S2) type. F1 fibers had shorter resting sarcomere lengths (2.93 µm in unstretched fibers and 3.06 µm in stretched fibers) and smaller fiber diameter (256 µm) than F2 fibers (sarcomere lengths 3.48 µm in unstretched and 3.46 µm in stretched; 747 µm diameter). Moreover, F1 fibers showed a narrower range in sarcomere lengths than F2 fibers (2.81 to 3.28 µm vs. 2.47 to 4.05 µm in unstretched fibers). Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and immunoblotting showed that the fast fibers from claw and abdomen differed in troponin‐I composition; F1 fibers expressed two isoforms of troponin‐I (TnI1 and TnI2) in approximately equal amounts, whereas F2 fibers expressed primarily TnI3 and lower levels of TnI1. F1 fibers were more sensitive to Ca2+, as shown by higher pCa values at threshold activation (pCa10=6.50±0.07) and at 50% maximum force (pCa50=6.43±0.07) than F2 fibers (pCa10=6.12±0.04 and pCa50=5.88±0.03, respectively). F1 fibers also had a greater degree of co‐operativity in Ca2+ activation, as shown by a higher maximum slope of the force‐pCa curve (nCa=12.98±2.27 vs. 4.34±0.64). These data indicate that there is a greater fast fiber‐type diversity in crustacean muscles than was previously supposed. Moreover, the differences in activation properties suggest that the TnI isoform composition influences the Ca2+ sensitivity of the contractile mechanism. J. Exp. Zool. 301A:588–598, 2004. © 2004 Wiley‐Liss, Inc.
Effect of the two‐wall‐stitch mistake upon patency of rat femoral vein anastomosis: Preliminary observations
Authors: Pignatti Marco , Benati Donatella , Cavadas Pedro C. 
Published: June 2004

AbstractAnastomotic patency is believed to be the most important factor in microvascular surgery. The two‐wall stitch is a technical error commonly considered to cause thrombosis of the anastomosis, especially on the venous side. In order to demonstrate the real effect on vein patency of the two‐wall stitch, the authors performed a standardized mistake after correct microanastomosis on the femoral vein of 15 rats, with one stitch passing through the whole thickness of the two walls of the vein. Traditional correct anastomoses on the contralateral side were used as controls. Patency was assessed at 5, 20, and 60 min and at 24 h by the milking test, and by direct section of the vessel at 24 h. The results showed no statistically significant difference between the two techniques. Histological examination confirmed the clinical judgment about the vessel's patency, and ultrastructural microscopy evidenced only mild signs of endothelial activation. In conclusion, this study indicates that the occasional two‐wall stitch does not necessarily increase the risk of venous occlusion in anastomoses of the rat femoral vein. © 2004 Wiley‐Liss, Inc.
Reciprocal regulation of the mouse protamine genes by the orphan nuclear receptor germ cell nuclear factor and CREMτ
Authors: Hummelke Geoffrey C. , Cooney Austin J. 
Published: June 2004

AbstractGerm cell nuclear factor (GCNF) is a member of the nuclear receptor superfamily, which is expressed in the adult predominantly in the male and female germ cells. In the male, GCNF is expressed in spermatogenic cells. GCNF binds as a homodimer to direct repeat response elements of the consensus half‐site sequence, AGGTCA, with 0 bp spacing (DR0). Using this information, a search of genomic databases was performed to identify candidate GCNF responsive, spermatogenic‐specific, genes that contain DR0 sequences. The mouse protamine genes are the strongest candidates identified to date, as they are post‐meiotically expressed in round spermatids and contain DR0 elements in their proximal promoters. Previous work has shown that both recombinant and endogenous GCNF bind to DR0 elements in the mouse protamine 1 and 2 (Prm 1 and Prm 2) promoters with high affinity and specificity. The present work shows that in transient transfection assays in GC‐1 and JEG‐3 cells, co‐transfection of a GCNF‐VP16 expression plasmid with reporter plasmids containing either the wild type Prm 1 or Prm 2 promoter established that GCNF‐VP16 is able to regulate transcription from both promoters in a DR0‐dependent manner. Wild type GCNF, in contrast, acts as a repressor of basal transcription on both the Prm 1 and Prm 2 promoters in a DR0‐dependent manner. Furthermore, CREMτ activation of these promoters is also repressed by wild‐type GCNF, indicating that GCNF also acts as a repressor of activated transcription. GCNF therefore defines a novel nuclear receptor‐signaling pathway that may regulate a subset of genes involved in the terminal differentiation process of spermatogenesis, exemplified by the protamines. Mol. Reprod. Dev. 68: 394–407, 2004. © 2004 Wiley‐Liss, Inc.
Increased formation of corpora lutea in neurokinin 1‐receptor deficient mice
Authors: Löffler Sabine , Schulz Anett , Hunt Stephen P. , Spanel‐Borowski Katharina 
Published: June 2004

AbstractThere is evidence to suggest that the tachykinin‐receptor system may be involved in female reproduction. Recently, we have shown that the mRNA transcripts of the preprotachykinin‐A which encodes substance P (SP), a member of the tachykinin family, and of NK1‐R (preferred receptor of SP) are expressed in the bovine corpus luteum (CL) of early developmental stage. The question arises whether the system is expressed at the protein level and influences the ovulatory process and CL formation. For this reason, ovaries from a mouse mutant in which the NK1‐R gene had been disrupted were studied. By using RT‐PCR, mRNA expression of NK1‐R was confirmed in both the ovary and the uterus of wild‐type mice. Weaning frequency and litter size, as recorded over 6 months, were similar in both groups. However, counting of CL in serial paraffin sections revealed a significant higher number of CL in the NK1‐R deficient mice in comparison to the wild‐type group (P < 0.01). The increased formation of CL in NK1‐R deficient mice corresponded to a considerable number of CL with retained oocyte not found in ovaries of the wild‐type group. We conclude: The CL with a retained oocyte may indicate that the muscular apparatus of the preovulatory follicle plays a role in oocyte expulsion and that contractility of the follicle wall is deficient in the mutant group. Our observation may have implications for the luteinized unruptured follicle syndrome in humans. Mol. Reprod. Dev. 68: 408–414, 2004. © 2004 Wiley‐Liss, Inc.
The trafficking of prosaposin (SGP‐1) and GM2AP to the lysosomes of TM4 sertoli cells is mediated by sortilin and monomeric adaptor proteins
Authors: Hassan A. Jacob , Zeng Jibin , Ni Xiaoyan , Morales Carlos R. 
Published: June 2004

AbstractProsaposin (SGP‐1) and GM2 activator protein (GM2AP) are soluble sphingolipid activator proteins (SAPs) that are targeted to the lysosomal compartment of Sertoli cells to aid hydrolases in the breakdown of glycosphingolipids. To reach the lysosome, most soluble proteins must interact with the mannose 6‐phosphate receptor (MPR). To be sorted from the Golgi, the MPR must bind to the Golgi associated, γ‐adaptin homologous, ARF binding proteins (GGAs), a group of monomeric adaptor proteins responsible for the recruitment of clathrin. It is well established, however, that the lysosomes of I‐cell disease (ICD) patients have near normal levels of several lysosomal proteins, including prosaposin and GM2AP. ICD results from a mutation in the phosphotransferase that adds mannose 6‐phosphate to hydrolases. Thus, prosaposin and GM2AP can traffic to lysosomes in a MPR independent manner. Previous work has demonstrated that an interaction with sphingomyelin in the Golgi membrane is necessary for the targeting of prosaposin by an unknown receptor. Using a TM4 Sertoli cell line, we tested the hypothesis that prosaposin and GM2AP are targeted to the lysosomal compartment via the sortilin receptor, which has been recently shown to have a GGA binding motif. Interestingly, dominant‐negative GGAs, unable to bind clathrin to shuttle from the Golgi, prevented the trafficking of prosaposin and GM2AP to lysosomes. A dominant negative construct of sortilin lacking the GGA binding domain retained prosaposin and GM2AP in the Golgi. In conclusion, our results showed that the trafficking of prosaposin and GM2AP to the lysosome is dependent on sortilin. Mol. Reprod. Dev. 68: 476–483, 2004. © 2004 Wiley‐Liss, Inc.
Study of the mouse sortilin gene: Effects of its transient silencing by RNA interference in TM4 sertoli cells
Authors: Zeng Jibin , Hassan A. Jacob , Morales Carlos R. 
Published: June 2004

AbstractUsing databases of the mouse genome in combination with a sequence deduced from a mouse sortilin cDNA originated in our laboratory, we found the sortilin gene to map to a region of chromosome 3. The mouse sortilin gene contains 19 short exons separated by introns of various sizes. The study elucidated the exon‐intron boundaries. Some introns extend over more than 24 kb. In the cytoplasmic domain of the translation product, we found a dileucine motif and three other motifs known to constitute the active sorting signal of the mannose 6‐phosphate receptor (M6P‐R). We also tested the hypothesis that sortilin is involved in the sorting of prosaposin (SGP‐1) to the lysosomes. Prosaposin was initially identified in Sertoli cells, found in large amounts in the lysosomal compartment and implicated in the degradation of residual bodies released by the spermatids during spermiation. Interestingly, the targeting of prosaposin to the lysosomes is independent of the M6P‐R. This investigation demonstrated that sortilin was required for the trafficking of prosaposin to the lysosomes in TM4 cells. The requirement of sortilin was shown using a siRNA probe to block the translation of sortilin mRNA. Sortilin‐deficient cells were not able to route prosaposin to the lysosomal compartment but continue to transport cathepsin B, since this hydrolase uses the M6P‐R to be routed to the lysosomes. These results indicate that sortilin appears to be involved in the lysosomal trafficking of prosaposin. Mol. Reprod. Dev. 68: 469–475, 2004. © 2004 Wiley‐Liss, Inc.
Complementary DNA cloning of rat spetex‐1, a spermatid‐expressing gene‐1, encoding a 63 kDa cytoplasmic protein of elongate spermatids
Authors: Iida Hiroshi , Ichinose Junko , Kaneko Takane , Mōri Takayuki , Shibata Yosaburo 
Published: June 2004

AbstractWe used differential display in combination with complementary DNA (cDNA) cloning approach to isolate a novel rat gene designated as spetex‐1, which had an open reading frame of 1,668‐length nucleotides encoding a protein of 556 amino acids. Spetex‐1 mRNA was highly expressed in testis, and weekly expressed in lung, intestine, and spleen. Spetex‐1 expression in the rat testes was detected first at 3 weeks in postnatal development and continued to be detected up to adulthood. A search in the databases showed that the amino acid sequence of spetex‐1 was 82% identical to that of its mouse homologue found in the databases. Both rat spetex‐1 and the mouse homologue contained Ser‐X (X = His, Arg, or Asn) repeats in the middle portion of the proteins. In situ hybridization revealed that spetex‐1 mRNA was expressed in haploid spermatids of step 7–18 within the seminiferous epithelium. Immunohistochemical analysis with confocal laser‐scanning microscopy demonstrated that spetex‐1 protein was not expressed in spermatogonia, spermatocytes, and round spermatids in adult rat testis, but was specifically detected in the residual cytoplasm of elongate spermatids of step 15–18 as well as in residual bodies engulfed by Sertoli cells. We interpreted these data as a potential role of spetex‐1 in spermatogenesis, especially in cell differentiation from late elongate spermatids to mature spermatozoa. Mol. Reprod. Dev. 68: 385–393, 2004. © 2004 Wiley‐Liss, Inc.
VEGF, bFGF, and their receptors in the endometrium of rhesus monkey during menstrual cycle and early pregnancy
Authors: Wei Peng , Chen Xin‐Lei , Song Xin‐Xin , Han Chun‐Sheng , Liu Yi‐Xun 
Published: June 2004

AbstractA number of cytokines and growth factors are known to modulate proliferation and differentiation of human endometrium. In this study, the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and VEGF receptors, fms‐like tyrosine kinase (Flt1) and kinase insert domain‐containing region (KDR), and bFGF receptor 1 (Flg) were examined in the endometrium of rhesus monkey on Day 5, 10, 16, 20, 25 of menstrual cycle and on Day 19 of early pregnancy. Western blot analysis showed the specificity of the anti‐human antibodies with the monkey tissue. The expression of mRNA and protein of VEGF was correlated with that of its receptor KDR, which was detected in epithelial, vascular, and myometrial cells. The localization of bFGF and its receptor Flg was similar to that of VEGF, except that the Flg was absent in the endothelial cells. Strong expression of VEGF and bFGF in the glandular epithelial cells was observed in the proliferative phase, declined in the secretory phase during the cycle. Stronger staining of these factors was also observed in the decidual cells of the pregnant uterus, as compared with the stromal cells of cycling uterus. No expression of Flt1 was detected in the tissue examined in this study. These data suggest that VEGF, bFGF, and their receptors play important roles in epithelial and stromal development, angiogenesis, and blood vessel function in the endometrium during the menstrual cycle and early pregnancy of the rhesus monkey. Mol. Reprod. Dev. 68: 456–462, 2004. © 2004 Wiley‐Liss, Inc.
CASK is in the mammalian sperm head and is processed during epididymal maturation
Authors: Burkin Heather R. , Zhao Longmei , Miller David J. 
Published: June 2004

AbstractUpon adhesion to the zona pellucida or egg extracellular matrix, sperm undergo regulated exocytosis of the acrosomal vesicle. CASK is an adaptor protein that has been implicated in coupling neuronal cell adhesion to regulated exocytosis. In neurons, this scaffolding molecule is associated with several types of transmembrane receptor complexes and connects cell adhesion molecules with ion channels, the actin cytoskeleton, and the cell's exocytotic machinery. We hypothesized CASK might also be an important link between zona pellucida binding and the sperm acrosome reaction. RT‐PCR experiments indicated CASK is transcribed in mouse testis. The full size (120 kDa) CASK protein was present in testis from mouse and pig. Immunoblots of mature porcine and murine sperm revealed that the 120 kDa molecule was much less abundant than in testis but the antibody also recognized a group of smaller proteins migrating at 55–65 kDa. Immunofluorescence experiments indicated both the full length and smaller CASK immunoreactive products were found only in the acrosomal region of spermatids and mature sperm and not in other testicular cell types. CASK immunofluorescence was lost following the acrosome reaction. During epididymal maturation, the abundance of the full size CASK decreased and the CASK fragments increased. These results suggest that CASK may be proteolytically processed during epididymal maturation. Because sperm acquire the ability to bind the zona pellucida, acrosome react, and fertilize eggs during epididymal maturation, CASK processing may play a role in the acquisition of these functions. Mol. Reprod. Dev. 68: 500–506, 2004. © 2004 Wiley‐Liss, Inc.
Production of transgenic chimeric rabbits and transmission of the transgene through the germline
Authors: Bodó Szilárd , Gócza Elen , Révay Tamás , Hiripi László , Carstea Bogdan , Kovács András , Bodrogi Lilla , Bösze Zsuzsanna 
Published: June 2004

AbstractHere we report that improved reproductive technologies combined with an efficient microinjection method and in vitro cultivation medium enabled us to create germ line chimeric rabbits. To follow the fate of the chimeric embryo a blastomere marked with the human blood coagulation factor VIII (hFVIII) transgene was microinjected into a morula stage wild type embryo. The degree of chimerism in different tissues was estimated by real‐time PCR and was found to be in the range of 0.1–42%. Among the four chimeric animals, one was identified as a chromosomal intersex and two were germline chimeras. Mol. Reprod. Dev. 68: 435–440, 2004. © 2004 Wiley‐Liss, Inc.