Search

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jmateco.2005.12.004 Byline: Kazuya Kamiya (a), Takashi Shimizu (b) Keywords: Real indeterminacy; Matching model; Divisible money Abstract: In this paper, it is shown that real indeterminacy of stationary equilibria generically arises in most matching models with perfectly divisible fiat money. In other words, the real indeterminacy follows from the condition for stationarity of money holdings, and surprisingly it has nothing to do with the other specifications, e.g., the bargaining procedures, of the models. Author Affiliation: (a) Faculty of Economics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan (b) Faculty of Economics, Kansai University, 3-3-35 Yamate-cho, Suita-shi, Osaka 564-8680, Japan Article History: Received 4 July 2005; Accepted 8 December 2005 Article Note: (footnote) [star] This paper is a version of the manuscript originally circulated under the title 'Real Indeterminacy of Stationary Equilibria in Matching Models with Media of Exchange.'

Although Wnt signaling plays an important role in body patterning during early vertebrate embryogenesis, the mechanisms by which Wnts control the individual processes of body patterning are largely unknown. In zebrafish, wnt3a and wnt8 are expressed in overlapping domains in the blastoderm margin and later in the tailbud. The combined inhibition of Wnt3a and Wnt8 by antisense morpholino oligonucleotides led to anteriorization of the neuroectoderm, expansion of the dorsal organizer, and loss of the posterior body structure-a more severe phenotype than with inhibition of each Wnt alone--indicating a redundant role for Wnt3a and Wnt8. The ventrally expressed homeobox genes vox, vent, and ved mediated Wnt3a/Wnt8 signaling to restrict the organizer domain. Of posterior body-formation genes, expression of the caudal-related cdx1a and cdx4/kugelig, but not bmps or cyclops, was strongly reduced in the wnt3a/wnt8 morphant embryos. Like the wnt3a/wnt8 morphant embryos, cdx1a/cdx4 morphant embryos displayed complete loss of the tail structure, suggesting that Cdx1a and Cdx4 mediate Wnt-dependent posterior body formation. We also found that cdx1a and cdx4 expression is dependent on Fgf signaling, hoxa9a and hoxb7a expression was down-regulated in the wnt3a/wnt8 and cdx1a/cdx4 morphant embryos, and in embryos with defects in Fgf signaling. Fgf signaling was required for Cdx-mediated hoxa9a expression. Both the wnt3a/wnt8 and cdx1a/cdx4 morphant embryos failed to promote somitogenesis during mid-segmentation. These data indicate that the cdx genes mediate Wnt signaling and play essential roles in the morphogenesis of the posterior body in zebrafish. Keywords: Wnt; caudal-related gene; fgf; hox; Tail; Posterior body; Segmentation; Zebrafish

Ectodermal teloblastogenesis in the oligochaete annelid Tubifex is a spatiotemporally regulated process that gives rise to four bilateral pairs of ectoteloblasts (N, O, P, and Q) that assume distinct fates. Ectoteloblasts on either side of the embryo arise from an invariable sequence of asymmetric cell divisions of a proteloblast, NOPQ, which occur with a defined orientation with respect to the embryonic axes: the N teloblast is generated first and located ventralmost, and the Q teloblast, which is generated next, is located dorsalmost; finally, the O and P teloblasts are generated by almost equal division of their precursor cell, OP. Polarity ofteloblastogenesis on one side of the embryo is a mirror image of the other; this mirror symmetry of ectoteloblasts about the embryo's midline gives rise to the bilaterally symmetric organization of the ectoderm. In this study, we examined whether cellular interactions are involved in specification of polarity of asymmetric cell divisions in NOPQ cells. A set of cell transplantation experiments demonstrated that NOPQ cells are initially uncommitted in terms of division pattern and cell fates: If a left NOPQ cell is transplanted to the right side of a host embryo, it exhibits a polarity comparable to that of right NOPQ cells. The results of another set of cell transplantation experiments suggest that contact between NOPQ cells serves as an external cue for their polarization, irrespective of their position in the embryo, and that in the absence of host NOPQ cells, transplanted NOPQ cells can be polarized according to positional information residing in the host embryo. The competence of NOPQ cells to respond to external cues tapers down before their division into N and OPQ. A set of cell ablation experiments demonstrated that neighboring cells such as posteriorly located M teloblasts and anterolaterally located micromeres play a role in controlling spatial aspects of NOPQ's behavior that gives rise to their division along the dorsoventral axis. These results suggest that NOPQ cells, which do not initially have a rigidly fixed polarity, become polarized through external cues. Possible sources of signals for this polarizing induction are discussed in the light of the present results. Keywords: Asymmetric cell division; Polarity; Teloblasts; Polarizing induction; Bilateral symmetry; Clitellate armelids; Tubifex

We identified a zebrafish homologue of Dickkopf-1 (Dkk1), which was previously identified in Xenopus as a Wnt inhibitor with potent head-inducing activity. Zebrafish dkk1 is expressed in the dorsal marginal blastoderm and also in the dorsal yolk syncytial layer after mid-blastula transition. At later blastula stages, the expression expands to the entire blastoderm margin. During gastrulation, dkk1-expressing cells are confined to the embryonic shield and later to the anterior axial mesendoderm, prospective prechordal plate. Embryos, in which dkk1 was ectopically expressed, exhibited enlarged forebrain, eyes, and axial rnesendoderm such as prechordal plate and notochord, dkk1 expression in the dorso.anterior mesendoderm during gastrulation was prominently reduced in zebrafish mutants bozozok (boz), squint (sqt), and one-eyed pinhead (oep), which all display abnormalities in the formation and function of the Spemann organizer and axial mesendoderm, dkk1 expression was normal in these embryos during the blastula period, indicating that zygotic functions of these genes are required for maintenance but not establishment of dkk1 expression. Overexpression of dkk1 suppressed defects in the development of forebrain, eyes, and notochord in boz mutants. Overexpression of dkk1 promoted anterior neuroectoderm development in the embryos injected with antivin RNA, which lack most of the mesoderm and endoderm, suggesting that Dkk1 can affect regionalization of neuroectoderm independently of dorso-anterior mesendoderm. These data indicate that Dkk1, expressed in dorsal mesendoderm, functions in the formation of both the anterior nervous system and the axial mesendoderm in zebrafish.

The first cleavage in the Tubifex egg is unequal and involves a monastral mitotic apparatus (MA), which remains at the egg's center from metaphase through telophase. The monastral form of the MA is thought to arise due to the involvement of a single maternal centrosome in the MA assembly (R. Ishii and T. Shimizu, Dev. Growth Differ. 37, 687-701, 1995). To investigate the mechanisms that generate asymmetry in this division, we have examined the cleavage patterns in eggs that are manipulated to inherit two centrosomes during the first mitosis. When eggs are prevented from extruding polar bodies, centrosomes located at both poles of the first meiotic spindle persist into the first mitosis without showing any sign of duplication and generate astral spindle poles. Eggs that inherit these centrosomes exhibit two types of MA configurations, viz., an amphiastral MA and twin monastral MAs. We found that eggs with amphiastral MAs undergo bipolar equal divisions, while those with twin MAs divide into three cells simultaneously (tripolar divisions). The amphiastral MAs are located at the egg's center and their astral poles are organized symmetrically, suggesting that Tubifex eggs are unable to generate asymmetry in the amphiastral MAs during the first mitosis. These results suggest that inheritance of a single centrosome during the first mitosis is critical for Tubifex eggs to undergo unequal cleavage. We propose that the cortical mechanisms for MA asymmetry are lacking in the Tubifex egg during the first mitosis.

Tubifex eggs contain two configurations of actin cytoskeleton (AC): a cortical thin shell of densely packed actin filaments and an endoplasmic loose network of actin filaments. Here we show that microinjection of botulinum C3 exoenzyme (ADP-ribosyltransferase) into Tubifex eggs disrupts the cortical AC, but not the endoplasmic AC. C3 exclusively ADP-ribosylates a 24-kDa protein in the Tubifex egg, suggesting the involvement of this protein in the regulation of the cortical AC. Among the actin-dependent processes that occur during maturation divisions and the first cell cycle, only outward migration of ooplasm (viz., early stage of the first step of ooplasmic segregation) occurs in C3-injected eggs, although migrating ooplasm is organized into patches rather than a continuous layer as observed in intact eggs. This ooplasmic movement is inhibited by cytochalasin D treatments. These results suggest that the endoplasmic AC is able to move ooplasm centrifugally in the absence of the cortical AC. In contrast, poleward movement of subcortical ooplasm along the egg surface (viz., the second step of ooplasmic segregation) is completely abolished in C3-injected eggs, even though the endoplasmic AC is present in the subcortical ooplasm.

Analyses of mitotic cycles in early Tubifex embryos whose DNA replication was inhibited by aphidicolin revealed that Tubifex embryos have a feedback route which couples the completion of DNA replication to the initiation of mitosis. Bigger blastomeres of early Tubifex embryos lack the replication feedback system which is functional in smaller blastomeres. Inverse correlation was evident between the vulnerability to unreplicated DNA of blastomeres and the quantity of pole plasma they obtain.

The factors responsible for cleavage asynchrony in the Tubifex embryo, in which the AB-cell divides much later than the CD-cell, were examined. Chromosome cycle studies revealed that AB-cells underwent M-phase five minutes after the CD-cell and that its prometaphase portion lasted 25 minutes longer. The length of the AB nucleus' prometaphase was reduced significantly only after the mitotic spindles of AB and CD nuclei, in a common cytoplasm, were united at one pole. Asters did not play any role in AB-cell mitotic spindle assembly. Results suggest that cleavage asynchrony in the embryo is caused by both cytoplasmic and nucleus-associated factors.

Herein, we report a case of 61-year-old male with congestive heart failure (HF) due to severe aortic regurgitation (AR) caused by ruptured aortic valve aneurysm (VA). Aortic valve replacement (AVR) was performed after improvement of HF symptoms. Pathological examination of resected aortic VA showed neutrophil infiltration. Although he did not have typical clinical features associated with infective endocarditis (IE) such as fever, leukocytosis, or positive blood culture, we misdiagnosed this case as "concealed IE". However, we reconsidered the etiology because prosthetic aortic valve detachment occurred only one year after AVR. When considering causes except IE for perforated aortic VA and early prosthetic valve detachment, Behçet's disease (BD) was more likely based on the clinical course, echocardiography, and pathological findings in this case. The inflammatory process of BD is associated with aortic valvulitis/aortitis, leading to a possible cause of aortic regurgitation due to aortic VA or early prosthetic valve detachment. The diagnosis of BD was challenging in this case because he did not have predominant clinical findings, including recurrent oral ulcer which is a mandatory criterion for the diagnosis by the International Study Group, however, cardiac involvement may have been the initial presentation of BD. < Leaning objective: Aortic valve aneurysm and its rupture are rare and most cases are caused by infective endocarditis (IE). However, if there is no typical clinical feature of IE including fever, leukocytosis, or positive blood culture in such case, Behçet's disease BD should be considered even if there are no predominant clinical findings including recurrent oral ulcer. Appropriate immunosuppressive therapy and modification of surgical techniques for the possible cardiac involvement may improve prognosis in patients with BD.> [ABSTRACT FROM AUTHOR]

Background: Plasma albumin (ALB) redox state reflects protein nutritional status, but how it differs from other protein nutrition biomarkers remains to be fully elucidated.Objective: This study aimed to delineate the characteristics of plasma ALB redox state as a protein nutrition biomarker.Methods: Adult male Wistar rats were maintained on an AIN-93 M [14% casein, control (CT)] diet or an AIN-93 M-based 5% casein [low protein (LP)] diet ad libitum for 4 wk. Plasma samples were repeatedly obtained from the same rats at weeks 0-4, ALB redox state was determined by HPLC, and the concentrations of conventional protein nutrition biomarkers, ALB and transthyretin (TTR), were compared between the groups by Student t test. Body mass, relative muscle masses, plasma proteome, and plasma lipids at week 4 were also compared.Results: Plasma ALB redox state shifted to a more oxidized state in the LP diet group compared with the CT diet group at weeks 1-4. The LP diet group also showed significantly lower plasma ALB concentrations at weeks 1 and 2 (13% and 11% lower, respectively) and significantly lower TTR concentration at week 1 (21% lower) compared with the CT diet group, but these concentrations did not differ significantly at weeks 3 and 4. After 4 wk, body mass and relative soleus and gastrocnemius muscle masses did not differ, but the relative plantaris muscle mass tended to be 4% lower (1.75 compared with 1.68 g/kg body mass) in the LP diet group compared with the CT group (P = 0.06). The LP diet group also had a significantly lower HDL particle number than the CT group (30% lower).Conclusions: A more oxidized plasma ALB redox state and lower plasma HDL particle number reflect LP diet ingestion in adult rats, which did not exhibit changes of plasma ALB and TTR concentrations. [ABSTRACT FROM AUTHOR]

Background: Several types of oligosaccharides are used in infant formula to improve the gut microbiota of formula-fed infants. We previously reported that a combination of 3 oligosaccharides (lactulose, raffinose, and galacto-oligosaccharides; LRG) and Bifidobacterium breve effectively increased B. breve numbers, acetate, and the expression of several immune- and gut hormone-related mRNAs in neonatal mice gut.Objective: We investigated whether changes in neonatal gut microbiota alter gut immune and endocrine development.Methods: We first compared postnatal day (PD) 14 with PD21 in C57BL/6J male mouse pups to identify the physiologic immune and endocrine changes during development. In a separate study, we administered phosphate-buffered saline (control group; CON), B. breve M-16V (M-16V), or M-16V + LRG to male mouse pups from PD6 to PD13, and analyzed the gut microbiota and immune and endocrine parameters on PD14 to evaluate whether M-16V + LRG accelerates gut immune and endocrine development.Results: The proportion of regulatory T (Treg) cells in the CD4+ cells of large intestinal lamina propria lymphocytes (LPLs) was significantly increased (63% higher) at PD21 compared with PD14. The serum glucagon-like peptide (GLP)-1 tended to be lower (P = 0.0515) and that of GLP-2 was significantly lower (58% lower) at PD21 than at PD14. M-16V + LRG significantly increased the Treg proportion in large intestinal LPL CD4+ cells (20% and 29% higher compared with CON and M-16V, respectively) at PD14. M-16V + LRG also caused significant changes in expression of large intestinal mRNAs that are consistent with developmental progression, and increased serum concentrations of GLP-1 (207% and 311% higher compared with CON and M-16V, respectively) and GLP-2 (57% and 97% higher compared with CON and M-16V, respectively) at PD14.Conclusions: Neonatal administration of M-16V + LRG alters the gut microbiota and enhances gut immune and endocrine development in suckling mice. [ABSTRACT FROM AUTHOR]

The zebrafish homeobox gene dharma/bozozok (boz) is required for the formation and/or function of the Nieuwkoop center and the subsequent induction of the Spemann organizer, dharma is expressed soon after the midblastula transition in the dorsal blastomeres and the dorsal yolk syncytial layer (YSL). We found that the expression of dharma was upregulated or ectopically induced by misexpression of a Wnt protein and cytoplasmic components of the Wnt signaling pathway and downregulated by the expression of dominant-negative Tcf3. A 1.4-kbp fragment of the dharma promoter region contains consensus sequences for Tcf/Lef binding sites. This promoter region recapitulated the Wnt-dependent and dorsal dharma expression pattern when it was fused to luciferase or GFP. Deletion and point mutant analyses revealed that the Tcf/Lef binding sites were required to drive this expression pattern. These data established that dharma/boz functions between the dorsal determinants-mediated Wnt signals and the formation of the Nieuwkoop center. [C] 2001 Academic Press Key Words: dharma; bozozok; Wnt signal; Nieuwkoop center; [Beta]-catenin; Tcf; Lef.

In the embryos of the oligochaete annelid Tubifex, segments VII and VIII specifically express mesodermal alkaline phophatase (ALP) activity in the ventrolateral region. In this study, we examined whether this segment-specific expression of ALP activity depends on external cues. Cell lineage analyses show that the ALP-expressing cells originate from/VI teloblasts. Furthermore, a set of teloblast-ablation experiments demonstrated that the seventh and eighth primary in blast cells (m7 and m8) produced from M teloblasts give rise to ALP-expressing cells in segments VII and VIII, respectively, and that primary m blast cells other than m7 and m8 lack the ability to generate ALP-expressing progeny cells. The results of another set of blastomere-ablation, experiments suggest that ALP-expressing cells emerge independently of interactions with surrounding tissues. Teloblast-transplantation experiments demonstrated that m8 can generate ALP-expressing cells in an ectopical position, suggesting that it is unlikely that ALP activity emerges in response to the positional cues residing in the embryo. These results suggest that m7 and m8 are exclusively specified as precursors of ALP-expressing cells at the time of their birth from M teloblasts. We propose that segmental identities in primary m blast cells of the Tubifex embryo are determined according to the genealogical position in the M lineage and that the M teloblast possesses a developmental program through which the sequence of blast cell identities is determined. [C] 2000 Academic Press Key Words: oligochaete embryo; mesoderm; alkaline phosphatase; segmental specificity.

In ovarian cystic follicles, molecular changes in the growing follicle may have a local action and contribute to anovulation and cystic formation. One of the candidate molecules that affect the steroid and gonadotropin signaling systems of cystic follicles is lipopolysaccharide (LPS), a cell wall component of gram-negative bacteria. To examine the molecular characteristics of bovine cystic follicles, we analyzed LPS concentration in follicular fluid of cystic follicles, and the expression of LPS receptors and steroidogenesis-related genes in granulosa and theca cells. Cystic follicles were categorized as estradiol (E2)-active (EACF) and E2-inactive cystic follicle (EICF). Overall, LPS concentration in follicular fluid of EACF and EICF was higher compared with healthy preovulatory follicles (POF). Expression of luteinizing hormone receptor ( LHR ) in granulosa and thecal cells was decreased in EACF and EICF compared with POF. Expression of CYP19 in granulosa cells of EACF and EICF was lower than POF. High expression of StAR in granulosa and thecal cells was observed in EICF. In granulosa cells, the expression of TLR4 and TLR2 mRNA was higher in EICF than other follicles. By contrast, higher expression of TLR2 in thecal cells was observed in EICF. Thus, high LPS concentration in follicular fluid of cystic follicles may be associated with the regulation of expression of steroidogenesis-related genes in granulosa and theca cells. These finding revealed the molecular characteristics of bovine ovarian cysts and possible involvement of LPS in the pathology of cystic follicle diseases. [ABSTRACT FROM AUTHOR]

Objective: To clarify the clinical utility of urinary DNA methylation for detection of intravesical recurrence of non-muscle invasive BCa (NMIBC), we performed a 2-center prospective study.Patients and Methods: A series of 207 self-voided urine samples were prospectively collected from 132 patients with NMIBC who had undergone transurethral resection of BCa. Methylation of miRNA genes (miR-9-3, miR-124-2, miR-124-3, and miR-137) was analyzed using bisulfite pyrosequencing. The primary end point was detection of intravesical recurrence; the secondary end point was prediction of late recurrence. The number of methylated genes (M-score) or quantitative level of methylation were compared with outcomes.Results: Twenty-six urine specimens were collected on the same day intravesical recurrence was detected, and 14 were collected from patients whose recurrences were found during the subsequent follow-up period (0-632 days, mean, 342.2 days). For detection of current recurrence, M-scores achieved 61.5% sensitivity and 74.0% specificity, and the area under the ROC curve was 0.71. Regarding prediction of late recurrence, patients with a high M-score (≥3) showed worse recurrence-free survival (P <.01). Multivariate analysis revealed that high M-scores were independently associated with current (P = .028) and late recurrence (P = .026). Elevated levels of urinary DNA methylation were also strongly associated with recurrence and radical cystectomy.Conclusion: Our data suggest that urinary methylation of miRNA genes may be a useful marker for detecting and predicting BCa recurrence. [ABSTRACT FROM AUTHOR]

In postpartum dairy cows, lipopolysaccharide (LPS) derived from gram-negative bacteria such as Escherichia coli causes uterine inflammation resulting in low fertility. The aim of this study was to determine the effect of LPS on the developmental competence of bovine oocytes in vitro. LPS perturbed the nuclear maturation of bovine oocytes by inhibiting meiotic progression. Although LPS did not affect the copy number of mitochondrial DNA, it decreased mitochondrial membrane potential in matured oocytes. LPS inhibited mitochondrial redistribution throughout the cytoplasm. Oocytes matured under LPS treatment showed decreased development to the blastocyst stage. Moreover, the trophoblast cell number of blastocysts was significantly lower when the oocytes were matured in the presence of LPS. Our findings suggest that LPS might impair the nuclear and cytoplasmic maturation of oocytes and obstruct subsequent embryonic development in dairy cows. [ABSTRACT FROM AUTHOR]

Summary To investigate the effects of n -3 polyunsaturated fatty acids on stearoyl-CoA desaturase (SCD) activity, we treated 10 obese children (mean age: 12.9 years) with cod liver oil once daily for 12 weeks. The effects of cod liver oil supplementation on SCD activity, as estimated by the palmitoleate/palmitate ratio, depended on the docosahexaenoic acid (DHA) contents at baseline. Baseline DHA contents were negatively correlated with baseline SCD activity. After the treatment, baseline DHA contents were found to be significantly associated with the reduction of SCD activity. Cod liver oil supplementation may be a complementary treatment for obese children with low baseline contents of DHA. [ABSTRACT FROM AUTHOR]

Tubifex eggs undergo a drastic reorganization of the cortical actin cytoskeleton during metaphase of the second meiosis. At the end of the first meiosis, the egg cortex displays only scattered actin filaments and tiny dots of F-actin; during the following 90 rain, cortical F-actin gradually increases in amount, becomes organized into foci that are interlinked by actin bundles, and generates a geodesic dome-like organization. In this study, we have characterized this reorganization of the cortical actin cytoskeleton. In living eggs injected with rhodamine-phalloidin at the beginning of the second meiosis, cortical actin assembly (i.e., formation of actin foci and bundles) proceeds normally, but labeled F-actin is not found to be included significantly in the formed cortical actin network, suggesting that the increase in cortical F-actin is not simply ascribable to the recruitment of preexisting actin filaments. Cortical actin assembly can be induced precociously not only by calcium ionophore A23187 but also by a phorbol ester PMA, an agonist of protein kinase C (PKC). Conversely, the formation of actin foci and bundles is inhibited by PKC antagonists, although cortical F-actin increases to some extent in the presence of these inhibitors. Similar inhibition of the cortical reorganization is elicited in eggs whose intracellular free calcium level ([[[Ca.sup.2+]].sub.i]) has been clamped low by microinjection of a calcium chelator BAPTA. The treatment of BAPTA-injected eggs with PMA results in the formation of actin foci and bundles. An experiment with eggs injected with fluo-3 shows that [[[Ca.sup.2+]].sub.i] increases during metaphase of the second meiosis. These results suggest that the reorganization of cortical actin during metaphase of the second meiosis requires activation of PKC, which depends on increases in [[[Ca.sup.2+]].sub.i].

Abstract: Background: Dysregulation of microRNAs (miRNAs) has been implicated in bladder cancer (BCa), although the mechanism is not fully understood. Objective: We aimed to explore the involvement of epigenetic alteration of miRNA expression in BCa. Design, setting, and participants: Two BCa cell lines (T24 and UM-UC-3) were treated with 5-aza-2′-deoxycytidine (5-aza-dC) and 4-phenylbutyric acid (PBA), after which their miRNA expression profiles were analyzed using a TaqMan array (Life Technologies, Carlsbad, CA, USA). Bisulfite pyrosequencing was used to assess miRNA gene methylation in 5 cancer cell lines, 83 primary tumors, and 120 preoperative and 47 postoperative urine samples. Outcome measurements and statistical analysis: Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of the miRNA gene panel. Results and limitations: Of 664 miRNAs examined, 146 were upregulated by 5-aza-dC plus PBA. CpG islands were identified in the proximal upstream of 23 miRNA genes, and 12 of those were hypermethylated in cell lines. Among them, miR-137, miR-124-2, miR-124-3, and miR-9-3 were frequently and tumor-specifically methylated in primary cancers (miR-137: 68.7%; miR-124-2: 50.6%; miR-124-3: 65.1%; miR-9-3: 45.8%). Methylation of the same four miRNAs in urine specimens enabled BCa detection with 81% sensitivity and 89% specificity; the area under the ROC curve was 0.916. Ectopic expression of silenced miRNAs in BCa cells suppressed growth and cell invasion. Conclusions: Our results indicate that epigenetic silencing of miRNA genes may be involved in the development of BCa and that methylation of miRNA genes could be a useful biomarker for cancer detection. [Copyright &y& Elsevier]

Abstract: The present study investigated the effects of bovine granulosa cell monolayers (BGML) and canine granulosa cell monolayers (CGML) on nuclear maturation of canine oocytes with and without cumulus cells. Cumulus-oocyte complexes (COCs) or cumulus-free oocytes were cultured in Dulbecco''s Modified Eagle''s Medium (DMEM, control group), DMEM with BGML (BGML group), or DMEM with CGML (CGML group) for 72 h at 38.5 °C in 5% CO2, 5% O2, and 90% N2. All media were supplemented with 10% of FCS, 50 ng/mL of EGF, 2 μg/mL of estradiol-17β, 0.1 IU/mL of hCG, 0.1 IU/mL of FSH, 0.25 mM of pyruvic acid, 100 μM of β-mercaptoethanol, 100 IU/mL of penicillin, and 100 μg/mL of streptomycin. In cumulus-enclosed oocytes retrieved from ovaries at estrus and/or diestrus, the highest percentage of M-II oocytes (P < 0.05) was present in the BGML group (27.0%) compared with the CGML group (7.9%) and the control group (3.5%). In cumulus-free oocytes collected from ovaries at estrus and/or diestrus, the proportions of M-II oocytes co-cultured with the CGML were low (3.0%) and similar (P > 0.05) to proportions achieved with control (3.0%). However, the presence of BGML improved (P < 0.05) the ability of denuded oocytes to develop into M-II (10.2%). The BGML group had the highest overall meiotic resumption (P < 0.05), and least oocyte degeneration (P < 0.05) among experimental groups. In conclusion, BGML had a positive impact on the in vitro maturation system, as well as meiotic resumption of canine oocytes. [Copyright &y& Elsevier]

Abstract: In the mammalian ovary, the microvasculature in the thecal layer of follicles is associated with follicular development. Apelin and its receptor, APJ, are expressed in the tissues and organs which include the vasculature. The aims of the present study were to examine the mRNA expression of apelin and the APJ receptor in granulosa cells and theca tissue of bovine follicles and the effects of steroid hormone and gonadotrophins on the expression of these genes in cultured granulosa cells and theca cells. The expression of apelin mRNA was not found in the granulosa cells of bovine follicles. The expression of the APJ gene was increased in granulosa cells of estrogen-inactive dominant follicles. The expression of apelin mRNA increased in theca tissues of estrogen-inactive dominant follicles. APJ expression in theca tissues increased with follicle growth. Progesterone stimulated the expression of APJ mRNA in the cultured granulosa cells. FSH stimulated the expression of APJ mRNA in the cultured granulosa cells. LH induced the expression of apelin and APJ receptor mRNAs in cultured theca cells. Taken together, our data indicate that the APJ receptor in granulosa cells and both apelin and the APJ receptor in theca tissues are expressed in bovine ovary, that APJ in granulosa cells may be involved in the appearance of the cell apoptosis, and that LH stimulates the expression of apelin and APJ genes in theca cells. [Copyright &y& Elsevier]

We investigated whether bovine milk constituents influenced glucagon-like peptide (GLP)-2 secretion and intestinal growth in suckling rats. Male Sprague-Dawley rats (14 d old) received i.g. infusions of a milk protein fraction, a lactose solution, or the cream fraction of milk. The serum concentration of GLP-2, but not GLP-1, markedly increased in rats administered milk protein compared with those given the lactose solution or the cream fraction from 60 to 120 min after administration. In another experiment, both casein (CN) and whey protein isolate stimulated GLP-2 secretion at 120 min after administration, but soy protein and ovalbumin did not. Stimulation of GLP-2 secretion by several milk proteins was similar, including α-CN, α-lactalbumin (α-La), and β-lactoglobulin, in a separate experiment. A hydrolysate of α-La obtained by incubation with protease A extracted from Aspergillus oryzae (LaHPA) caused almost twice the GLP-2 release due to intact α-La acid other α-La hydrolysates. Free amino acid concentrations and molecular size distributions did not differ among α-La hydrolysates, including LaHPA. In rat pups reared with milk formulae containing α-La or LaH PA, LaH PA significantly promoted small intestinal elongation and increased the number of crypt epithelial cells compared with a formula containing intact α-La. LaHPA administration also increased the maltase:lactase activity ratio, a marker of maturation of the intestinal mucosa. In conclusion, milk proteins stimulate GLP-2 secretion and contribute to growth and maturation of the small intestine in suckling rats. [ABSTRACT FROM AUTHOR]