Heat devices in nonlinear irreversible thermodynamics

We present results obtained by using nonlinear irreversible models for heat devices. In particular, we focus on the global performance characteristics, the maximum efficiency and the efficiency at maximum power regimes for heat engines, and the maximum coefficient of performance (COP) and the COP at maximum cooling power regimes for refrigerators. We analyze the key role played by the interplay between irreversibilities coming from heat leaks and internal dissipations. We also discuss the relationship between these results and those obtained by different models.

104 EXPRESSION OF ACTIVIN A AS A LOCAL REGULATOR IN THE BOVINE OVIDUCT

Activin (ACV) is known as a local regulator of several reproductive functions including follicular development and implantation in mammals. ACVA is a glycopeptide belonging to the transforming growth factor β superfamily, and is a homodimer of inhibin ßA (INHBA) subunits. Follistatin (FST), an ACV-specific binding protein, inhibits ligand-receptor binding. ACV receptor (ACVR) is a hetero-tetramer consisting of 2 kinds of protein, ACVR1 or ACVR1B and ACVR2A or ACVR2B. The oviduct provides an optimal environment for sperm capacitation, fertilization, and early embryonic development. Previous reports have demonstrated that ACVRs were expressed in bovine oocytes and embryos, and that early embryonic development is facilitated by ACVA in vitro. ACVA produced by the bovine oviduct may affect gametes and embryos as well as oviductal cells as a local regulator in cow. Bovine oviductal samples were classified into 6 stages of the oestrous cycle (day of ovulation; Days 2–3 after ovulation; Days 5–6; Days 8–12; Days 15–17; Days 19–21). We examined (1) protein expression of ACVA and FST in oviductal fluid collected from the ampulla and isthmus, (2) mRNA expression of INHBA and FST in the ampullary and isthmic oviductal tissues during the oestrous cycle, (3) the effects of oestradiol-17β (E2: 0.1, 1, 10 nM) and progesterone (P4: 1, 10, 100 nM) on mRNA expressions of INHBA and FST in cultured oviductal epithelial cells isolated from the ampulla and isthmus, and (4) mRNA expression of ACVRs in tissues and in cultured epithelial and stromal cells. The main findings were as follows: (1) Both ACVA and FST were detected throughout the oestrous cycle in the oviductal fluid of the ampulla and isthmus. (2) INHBA expression was higher in the isthmus than in the ampulla. FST expression in the ampulla was lowest at peri-ovulation, INHBA expression in the isthmus was highest on the day of ovulation and FST in the isthmus during Days 2–6 was highest. Because an increase of ACVA production and a decrease of FST production raise ACVA bioactivity, ACVA seems to be most active at peri-ovulation in both the ampulla and isthmus. (3) In the cultured isthmic oviductal epithelial cells, 10 nM E2 significantly stimulated INHBA expression, but tended to suppress FST expression. Therefore, the bioactivity of ACVA seems to be controlled by E2 during the oestrous cycle in the isthmus. (4) The expression of ACVR1B and ACVR2A was clearly detected in the tissues as well as in cultured epithelial and stromal cells. The overall findings suggest that ACVA secreted into oviductal fluid plays an important role in oviductal functions, including fertilization in the ampulla and sperm motility and viability in the isthmus. It is also suggested that ACVA acts on both epithelial and stromal cells as a local regulator of cellular functions, such as cellular proliferation and secretion in the cow.

105 EFFECT OF LYSOPHOSPHATIDIC ACID ON PROSTAGLANDIN PRODUCTION IN THE BOVINE OVIDUCT

The oviduct is an essential organ for successful pregnancy in mammals. The transport of gametes and early embryos is mainly induced by contraction and relaxation of smooth muscle. The contraction and relaxation of bovine oviductal smooth muscle are induced by prostaglandin (PG) F2α and PGE2, respectively. Lysophosphatidic acid (LPA), a type of phospholipid, is involved in various physiological actions such as promoting inflammation and cellular proliferation in various organs. LPA acts through at least 6 G protein-coupled receptors. Both LPA and LPA receptors are expressed in endometrium and, moreover, LPA affects PG production by the endometrium in cow. Based on the above findings, we hypothesised that LPA is locally involved in PG production by oviductal cells to promote motility of oviductal smooth muscle in cow. Oviductal samples ipsilateral to a corpus luteum or a dominant follicle at peri-ovulation (0–6 and 19–21 days after ovulation) were collected in abattoir. Messenger RNA expression of LPA receptors (LPAR1–6) and LPA-producing enzymes (ATX, PLA1α, PLA1β) was examined in ampullary and isthmic tissues. Expression in cultured epithelial and stromal cells isolated from the bovine oviduct were also examined to determine the cells possessing LPA receptors and LPA-producing enzymes. In addition, the effect of LPA (0.1, 1, 10 μM) on the expression of cyclooxygenase (COX)-1 and COX-2 (PG-synthesising enzymes) and on PGE2 and PGF2α production by cultured epithelial and stromal cells was investigated. The significant differences (P < 0.05) were determined by Student's t-test for 2 groups, and by one-way ANOVA followed by Tukey's multiple comparison test for more than 3 groups. LPAR1–6, ATX, PLA1α, and PLA1β were expressed in both ampullary and isthmic tissues as well as in both cultured epithelial and stromal cells. The expression of LPAR1–3 was significantly lower in the isthmic tissues than in the ampullary tissues, whereas the expression of LPAR4–6 was significantly higher in the isthmic tissues than in the ampullary tissues. The expression of COX-2 was significantly stimulated by 10 μM LPA in cultured isthmic stromal cells. In addition, LPA significantly stimulated both PGE2 and PGF2α production by cultured isthmic stromal cells. In the isthmus of the oviduct, LPA produced by epithelial and stromal cells may stimulate the expression of COX-2 in the stromal cells, followed by increased PG production. Because the mRNA expression of LPAR4–6 is higher in the isthmus than in the ampulla, those effects of LPA might be mediated by activation of LPAR4–6. The overall findings suggest that LPA is one of the regulating factors for transport of gametes and early embryos by controlling the motility of smooth muscle in the bovine oviduct.

Structural Study of Amorphous Co-Ferrite Film by Anomalous X-Ray Scattering

The structure of amorphous Co-ferrite film grown on a glass substrate was studied by anomalous X-ray scattering (AXS). Co atoms cannot be distinguished from Fe atoms with the usual X-ray diffraction technique. Therefore the AXS method at the Fe and Co K-absorption edges was adopted. In the previous AXS studies only the lower energy side of the absorption edges was adopted. In the previous AXS studies only the lower energy side of the absorption edge was used. In the present case, the lower energy side of the Co K-absorption edge corresponds to the higher energy side of the Fe K-absorption edge. Therefore, in order to overcome this inconvenience, the scattering was measured on both sides of the absorption edge, thus enabling the independent determination of the oxygen coordination numbers around Co and Fe in the ferrite film from the environmental RDFs estimated from the energy differential profiles by coupling with the linear least squares technique.

Three-dimensional surface figure measurement of high-accuracy spherical mirror with nanoprofiler using normal vector tracing method

Processing technology using an extreme ultraviolet light source, e.g., next-generation lithography, requires next-generation high-accuracy mirrors. As it will be difficult to attain the degree of precision required by next-generation high-accuracy mirrors such as aspherical mirrors through conventional processing methods, rapid progress in nanomeasurement technologies will be needed to produce such mirrors. Because the measuring methods used for the surface figure measurement of next-generation mirrors will require high precision, we have developed a novel nanoprofiler that can measure the figures of high-accuracy mirrors without the use of a reference surface. Because the accuracy of the proposed method is not limited by the accuracy of a reference surface, the measurement of free-form mirrors is expected to be realized. By using an algorithm to process normal vectors and their coordinate values at the measurement point obtained by a nanoprofiler, our measurement method can reconstruct three-dimensional shapes. First, we measured the surface of a concave spherical mirror with a 1000-mm radius of curvature using the proposed method, and the measurement repeatability is evaluated as 0.6 nm. Sub-nanometer repeatability is realized, and an increase in the repeatability would be expected by improving the dynamic stiffness of the nanoprofiler. The uncertainty of the measurement using the present apparatus is estimated to be approximately 10 nm by numerical simulation. Further, the uncertainty of a Fizeau interferometer is also approximately 10 nm. The results obtained using the proposed method are compared with those obtained using a Fizeau interferometer. The resulting profiles are consistent within the range of each uncertainty over the middle portions of the mirror.

Influence of prostaglandin F₂α analogues on the secretory function of bovine luteal cells and ovarian arterial contractility in vitro

Although prostaglandin (PG) F2α analogues are routinely used for oestrus synchronisation in cattle, their effects on the function of the bovine corpus luteum (CL), and on ovarian arterial contractility, may not reflect the physiological effects of endogenous PGF2α. In the first of two related experiments, the effects of different analogues of PGF2α (aPGF2α) on the secretory function and apoptosis of cultured bovine cells of the CL were assessed. Enzymatically-isolated bovine luteal cells (from between days 8 and 12 of the oestrous cycle), were stimulated for 24h with naturally-occurring PGF2α or aPGF2α (dinoprost, cloprostenol or luprostiol). Secretion of progesterone (P4) was determined and cellular [Ca(2+)]i mobilisation, as well as cell viability and apoptosis were measured. Naturally-occurring PGF2α and dinoprost stimulated P4 secretion (P<0.05), whereas cloprostenol and luprostiol did not influence P4 synthesis. The greatest cytotoxic and pro-apoptotic effects were observed in the luprostiol-treated cells, at 37.3% and 202%, respectively (P<0.001). The greatest effect on [Ca(2+)]i mobilisation in luteal cells was observed post-luprostiol treatment (200%; P<0.001). In a second experiment, the influence of naturally-occurring PGF2α and aPGF2α on ovarian arterial contraction in vitro, were examined. No differences in the effects of dinoprost or naturally-occurring PGF2α were found across the studied parameters. The effects of cloprostenol and luprostiol on luteal cell death, in addition to their effects on ovarian arterial contractility, were much greater than those produced by treatment with naturally-occurring PGF2α.

Lipopolysaccharides, cytokines, and nitric oxide affect secretion of prostaglandins and leukotrienes by bovine mammary gland epithelial cells

The aims of this study were to determine the effects of lipopolysaccharides (LPS), tumor necrosis factor (TNF), interleukin 1 alpha (IL-1α), nitric oxide donor (NONOate), or the combination of TNF + IL-1α + NONOate on the following: (i) secretion of prostaglandin (PG)-F(2α), PGE(2), leukotriene (LT)-B(4), and LTC(4) by epithelial cells of the teat cavity and lactiferous sinus of bovine mammary gland; (ii) messenger RNA (mRNA) transcription of enzymes responsible for arachidonic acid (AA) metabolism (prostaglandin-endoperoxide synthase 2 [PTGS2], prostaglandin E synthase [PTGES], prostaglandin F synthase [PGFS], and arachidonate 5-lipooxygenase [ALOX5]); and (iii) proliferation of the cells. The cells were stimulated for 24 h. Prostaglandins and LT were measured by enzyme immunoassay, mRNA transcription of enzymes was determined by real-time reverse transcription polymerase chain reaction, and the cell viability was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide. All factors increased PG secretion, but the highest stimulation was observed after TNF and IL-1α (P < 0.001). Tumor necrosis factor, NONOate, and TNF + IL-1α + NONOate increased LTB(4) production (P < 0.01), whereas LTC(4) was increased by LPS, TNF, and IL-1α (P < 0.01). Lipopolysaccharides, TNF, IL-1α, and the reagents combination increased PTGS2, PTGES, and PGFS mRNA transcription (P < 0.01), whereas ALOX5 mRNA transcription was increased only by TNF (P < 0.001). Lipopolysaccharides, TNF, IL-1α, NONOate, and the combination of reagents increased the cell number (P < 0.001). Mediators of acute-clinical Escherichia coli mastitis locally modulate PG and LT secretion by the epithelial cells of the teat cavity and lactiferous sinus, which might be a useful first line of defense for the bovine mammary gland. Moreover, the modulation of PG and LT secretion and the changing ratio of luteotropic (PGE(2), LTB(4)) to luteolytic (PGF(2α), LTC(4)) metabolites may contribute to disorders in reproductive functions.

Histological changes in bovine endometrium during the estrous cycle

Endometrial biopsy specimens were obtained from 46 normally cyclic heifers at known stages of their estrous period to show precise characteristic changes. These tissues were embedded in paraffin, sectioned, and stained with hematoxylin and eosin. The following histological changes were observed during the estrous cycle. Metrorrhagia was observed on Days 0 to 1 (estrus = Day 0). Mitoses in glandular epithelium occurred on Day 5. Basal vacuolation in the surface epithelium occurred on Days 5 to 6. Leukocyte invaded the functional layer on Day 7. Stromal mitoses were observed on Days 9 to 12. The results indicate that clincians need to be aware that histological evaluation is important for the diagnosis of endometrial function and that biopsy is useful for this purpose.

Glucose requirement at different developmental stages of in vitro fertilized bovine embryos cultured in semi-defined medium

Three experiments were conducted in which 2-cell bovine embryos were prepared from oocytes, obtained from abattoir ovaries, by in-vitro maturation for 22 to 24 hours, followed by exposure to spermatozoa for 8 hours and culture for 40 hours within the cumulus. The cumulus cells were then removed, and the cleaved embryos were cultured for a further 120 hours or longer, in the presence or absence of glucose, pyruvate and lactate. Very few embryos developed in the complete absence of energy substrates. Lactate and pyruvate, alone or combined, supported development to the 8-cell stage, but pyruvate was required to support development to the morula stage (Experiment 1). When present throughout culture or when added at 48 or 96 hours postinsemination, 5.56 mM glucose was detrimental to development (Experiments 1 and 2). However, when added at 120 hours postinsemination, 5.56 mM glucose improved development to the blastocyst and expanded blastocyst stages, compared with no glucose or 11.12 mM glucose (Experiment 3).

Efficacy and safety of bipolar electrode grasping forceps for laparoscopic myomectomy in uterine cervical myoma

INTRODUCTION

Myomectomy for cervical myoma is problematic because cervical myomas are very close to neighboring structures, such as the ureters, uterine artery, bladder and rectum. There are a few reports on laparoscopic myomectomy for cervical myomas to avoid blood loss, such as occlusion of iliac arteries and clipping of the uterine artery. We evaluated the efficacy and safety of bipolar electrode grasping forceps for laparoscopic myomectomy in uterine cervical myoma.

METHODS

From November 2006 to May 2009, eight women with uterine cervical myoma underwent laparoscopic myomectomy. We employed electrode grasping forceps with a combination of two tenaculums for separating and securing hemostatsis.

RESULTS

Seven of eight cases were successfully treated by laparoscopic myomectomy, but one patient, with a large 900-g myoma was converted to the laparotomy as a result of blood loss (1800 mL). Among the other seven cases, the average weight of the myoma was 132 g (range, 16-310 g) and the operating time was 176 min. (range, 125-255 min). No complications occurred. Of the four cases who wanted to become pregnant postoperatively, two became pregnant and delivered by Caesarean section.

CONCLUSION

These findings indicate that bipolar electrode grasping forceps using two tenaculums for traction of the myoma are useful for laparoscopic myomectomy in cervical myomas.