bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of epidermal growth factor action in human myometrial smooth muscle cells
Authors: Környei J L , Li X , Lei Z M , Rao Ch V 
Published: December 2008

Abstract
The present study investigated the mechanisms involved in the mitogenic action of epidermal growth factor (EGF) in cultured human myometrial smooth muscle cells. The cells contained EGF/transforming growth factor-α (TGF-α) receptors as well as EGF and TGF-α mRNA transcripts and the corresponding proteins. Culturing with human EGF resulted in concentration- and time-dependent increases in cell density. The maximal increase was seen at 1 nm followed by a decrease to control levels at 100 nm EGF. The EGF increased cell density from 4 to 8 days followed by a plateau coinciding with the cells reaching confluence. EGF treatment concomitantly decreased the average size of cells. TGF-α mimicked EGF and there was no synergism between the two, suggesting a common mechanism of action. Although the presence of 10% fetal bovine serum enhanced overall cell growth, it was not required for EGF and TGF-α action. The receptor antibody, which is directed against the extracellular domain and can inhibit ligand binding to the receptors, dramatically inhibited the basal cell growth and exogenous EGF reversed the antibody effect. While TGF-α antibody was only marginally effective, EGF antibody had no effect on basal cell growth. Lavendustin (a tyrosine kinase inhibitor), calphostin (a protein kinase C inhibitor), but not H-89 (a protein kinase A inhibitor), inhibited EGF action. Indomethacin, a cyclo-oxygenase inhibitor, completely inhibited, whereas nordihydroguaiaretic acid, a lipoxygenase inhibitor, slightly inhibited EGF action. While estradiol-17β modestly inhibited basal as well as EGF-stimulated myometrial smooth muscle cell density, progesterone had no effect.
In summary, mitogenic action of EGF in human myometrial smooth muscle cells does not require serum components and it involves tyrosine kinase and protein kinase C signaling and eicosanoids from the cyclo-oxygenase pathway of arachidonic acid metabolism.
Journal of Endocrinology (1995) 146, 261–270
Interleukin-1 and tumor necrosis factor-α increase insulin-like growth factor-binding protein-3 (IGFBP-3) production and IGFBP-3 protease activity in human articular chondrocytes
Authors: Olney R C , Wilson D M , Mohtai M , Fielder P J , Smith R L 
Published: December 2008

Abstract
IGF-I is the major anabolic factor for cartilage matrix production. Chondrocytes and cartilage treated with interleukin-1α (IL-1α), and chondrocytes from several models of inflammatory joint disease, exhibit reduced responsiveness to IGF-I. Since the IGF-binding proteins (IGFBPs) modulate the effects of IGF-I, we examined the effect of IL-1α and tumor necrosis factor-α (TNF-α) on IGFBP production by normal human articular chondrocytes in primary culture. Western ligand blots and immunoprecipitation of conditioned medium samples showed that articular chondrocytes produced IGFBPs-2, −3 and −4 and glycosylated IGFBP-4. Both IL-1α and TNF-α increased chondrocyte production of IGFBP-3, but did not alter IGFBP-4 production. The activity of a neutral metalloprotease with the ability to cleave IGFBP-3 was also increased by IL-1α. These data suggest that the cytokines IL-1α and TNF-α may act to reduce IGF-I access to chondrocytes by increasing production of IGFBP-3. This may be a factor in the decreased matrix production in the inflammatory arthritides.
Journal of Endocrinology (1995) 146, 279–286
Changes in calmodulin concentration and cyclic 3′,5′-nucleotide phosphodiesterase activity in skeletal muscle of hyper- and hypothyroid rats
Authors: Mano T , Iwase K , Yoshimochi I , Sawai Y , Oda N , Nishida Y , Mokuno T , Kotake M , Nakai A , Hayakawa N , Kato R , Nagasaka A , Hidaka H 
Published: December 2008

Abstract
Hyper- and hypothyroid states occasionally induce skeletal muscle dysfunction i.e. periodic paralysis and thyroid myopathy. The etiology of these diseases remains unclear, but several findings suggest that the catecholamine-β-receptor-cAMP system or other messenger systems are disturbed in these diseases. In this context, we evaluated changes in the cyclic 3′,5′-nucleotide metabolic enzyme, cyclic 3′,5′-nucleotide phosphodiesterase (PDE) and calmodulin concentrations in skeletal muscles of hyper- and hypothyroid rats.
Activities of cyclic AMP-PDE were low in skeletal muscle both from hyper- and hypothyroid rats, and calmodulin concentration was high in hyperthyroid and low in hypothyroid rats, as compared with normal rats. DE-52 column chromatographic analysis showed that the cGMP hydrolytic activity in peak I and the cAMP hydrolytic activity in peak II were decreased in hypothyroid rats, whereas cAMP hydrolytic activity in peak III was unchanged. The cAMP hydrolytic activity in peak III was decreased in hyperthyroid rats, but the activities in peaks I and II were unchanged. These findings indicate that cAMP and calmodulin may have some role in skeletal muscle function in the hyperthyroid state, and that cAMP and calmodulin-dependent metabolism may be suppressed in the hypothyroid state.
Journal of Endocrinology (1995) 146, 287–292
Inhibin and oestradiol-17β in antral follicles of various size classes of cyclic rats
Authors: van Cappellen W A , van Leeuwen E C M , Meijs-Roelofs H M A , Kramer P , Sander H J , de Jong F H 
Published: December 2008

Abstract
On the various days of the 5-day oestrous cycle of the rat, ovarian antral follicles were dissected out and grouped in five size classes. Four follicles of the same size class were homogenized jointly in medium, after which inhibin-like bioactivity, inhibin immunoreactivity and oestradiol-17β content were measured. In general, there was a significant correlation between immunologically and biologically active inhibin levels in the different size classes; overall correlation was 0·85 (n=87, P<0·00001). In the smallest antral follicles (classes 1 and 2) inhibin bioactivity was detected only during the first three days of the cycle. With increasing follicle size, inhibin bioactivity and immunoreactivity increased, with maximal activity present in the largest, i.e. preovulatory, follicles (class 5) during the last three days of the cycle (the day of oestrus denotes day 1 of the cycle). These results indicate that only follicles which reach the antral stage at oestrus, and are known to be recruited by the periovulatory FSH peak, acquire the potency to produce biologically active inhibin. This is the cohort of follicles from which selection of ovulatory follicles will normally take place.
In contrast to inhibin, follicular oestradiol-17β concentrations were negligible until the last days of the cycle when oestradiol-17β was present in follicles larger than class 2; levels increased with increasing follicle size and a maximal level was found in preovulatory follicles at pro-oestrus.
It is concluded that (1) there is a good correlation between follicular content of inhibin-like bioactivity and inhibin immunoreactivity and (2) there are differences between patterns of follicular levels of inhibin immunoreactivity and oestradiol-17β during the ovarian cycle: follicles destined to ovulate start to produce inhibin in volume classes 1 and 2 and only thereafter also contain oestradiol-17β. Follicles entering classes 1 and 2 at dioestrus-2 and -3 or at pro-oestrus do not produce inhibin and become atretic.
Journal of Endocrinology (1995) 146, 323–330
Ovulation rate and the concentrations of gonadotrophins and metabolic hormones in ewes infused with glucose during the late luteal phase of the oestrous cycle
Authors: Downing J A , Joss J , Scaramuzzi R J 
Published: December 2008

Abstract
The positive relationship between nutrition and ovulation rate was investigated in sheep infused intravenously with glucose. Ovulation rate increased (2·0±0·0 vs 2·4 ± 0·3) when ewes were given an infusion of glucose (60–65 mm/h) for five days in the late luteal phase of the oestrous cycle. The effect of glucose was obtained without any significant change in LH secretion. The concentration of FSH in glucose-infused ewes was lower during the infusion (luteal phase) but higher during the early follicular phase. These data suggest that the change in ovulation rate occurred without increased gonadotrophin support to the follicle during the late luteal phase, which is the period of the sheep oestrous cycle during which improved nutrition increases ovulation rate. There were no changes in GH or prolactin, but changes in circulating glucose and insulin levels were detected. We conclude that insulin, because of its role in cell growth and metabolism, is involved in mediating ovulation responses to nutritional stimuli, either directly or more likely by the stimulation of insulin-mediated glucose uptake.
Journal of Endocrinology (1995) 146, 403–410
In vitro regulation of rat Sertoli cell inhibin messenger RNA levels by transforming growth factor-β1 and tumour necrosis factor α
Authors: Le Magueresse-Battistoni B , Morera A M , Benahmed M 
Published: December 2008

Abstract
In the present study, we examined the in vitro regulation of 20-day-old rat Sertoli cell inhibin α- and βB-subunits mRNA levels by transforming growth factor-β1 (TGF-β1) and tumour necrosis factor α (TNFα), two factors produced in the testis. Addition of TGF-β1 to highly purified cultured Sertoli cells resulted in a time- and dose-dependent enhancement in the α-subunit mRNA levels (ED50=2·4 pm; maximal increase of 2·6-fold after 48 h of treatment), without affecting the βB-subunit mRNA levels. Similarly, activin A up-regulated the α-but did not modulate the βB-subunit mRNA levels. By contrast, TNFα decreased in a time- and dose-dependent fashion the mRNA levels of the two inhibin subunits α and βB (IC50=29 pm for both subunits; maximal decrease of 4·4- and of 4-fold after 72 and 24 h of treatment for respectively the α- and βB-subunits). The effects of TGF-β1 and TNFα on inhibin mRNA levels occurred within a dose range that might be expected under physiological conditions. In addition, TGF-β1-treated Sertoli cells responded to FSH or dibutyryl cyclic AMP ((Bu)2cAMP) by a further and significant additive increase of the α-subunit mRNA levels. TNFα-treated Sertoli cells responded significantly to FSH and to (Bu)2cAMP, thus attenuating the inhibitory action of TNFα on the α-inhibin mRNA levels. Together, the present findings emphasize the ability of some local growth factors to modulate the effects of FSH on Sertoli cell function.
Journal of Endocrinology (1995) 146, 501–508
Similarities between hamster pancreatic islet beta (HIT) cell vasopressin receptors and V1b receptors
Authors: Richardson S B , Laya T , VanOoy M 
Published: December 2008

Abstract
Vasopressin (VP) elicits almost identical insulin-stimulatory dose responses in isolated mouse islets and hamster β (HIT) cells. We have further pharmacologically characterized HIT cell VP receptors by comparing the potencies of a series of VP agonists including the novel V1b agonist, desamino(d-3-(3′-pyridyl)-Ala2,Arg8)VP (d(d-3-Pal)VP), in stimulating insulin secretion and inositol phosphate (IP) production. The relative orders of potency of VP analogues were parallel in both respects: desamino-Arg-VP (dAVP)>Arg-vasotocin (AVT)= VP>oxytocin (OXY)>desamino-d-Arg-VP (ddAVP)> d(d-3-Pal)VP. dAVP, the most potent agonist tested, behaved as a V1 but non-V1a agonist. The potency of d(d-3-Pal)VP relative to VP was 1:134 in stimulating insulin secretion and 1:40 with respect to IP production. In HIT cell monolayers, the relative order of affinity of analogues in competition for binding with [3 H]AVP was: dAVP>AVT=VP>V1a antagonist>OXY>ddAVP>V2 antagonist=d(d-3-Pal)VP, in parallel with their biological activity. The relative orders of potency and affinity parallel those reported for corticotrophic V1b receptors. Binding studies with hamster liver membranes indicate that the hepatic VP receptor belongs to the V1a class. We conclude that VP activates phospholipase C and interacts with functional VP receptors of the V1 type, which do not belong to the V1a subclass and which are similar to V1b receptors.
Journal of Endocrinology (1995) 147, 59–65
Synergism of GH and IGF-I in stimulation of sulphate uptake by teleostean branchial cartilage in vitro
Authors: Cheng C M , Chen T T 
Published: December 2008

Abstract
The combined effects of teleostean GH and human IGF-I in the regulation of teleost branchial cartilage growth were examined. Ceratobranchial cartilages were dissected from the common carp (Cyprinus carpio) and maintained in a defined culture medium supplemented with recombinant striped bass GH (sbGH), human IGF-I (hIGF-I) or both, and the uptake of [35S]sulphate by cartilage explants was measured. sbGH alone in the culture medium did not exhibit a significant stimulatory effect on the uptake of [35S]sulphate when compared with the controls. However, with hIGF-I in the culture medium, as low as 1 ng/ml, the stimulatory effect of sbGH was apparent and dose-dependent. The synergism of sbGH and hIGF-I was observed at the concentrations of 1 and 10 ng IGF/I/ml tested. At a constant hIGF-I concentration (10 ng/ml), a maximum stimulatory effect was detected with 3 μg recombinant sbGH/ml, at which point a 2·3-fold increase in sulphation activity was obtained when compared with the treatment with hIGF-I alone. A similar dose-dependent stimulatory effect was observed when native common carp and bonito GHs were tested using this assay system. These results suggest that the synergistic effect of sbGH and hIGF-I on sulphation activity is a common biological function of teleost GH, thus ruling out the possibility of experimental artifacts resulting from utilization of heterologous GH. Furthermore, experiments were conducted to test whether the synergism between sbGH and hIGF-I occurred between sbGH and insulin. Results showed that although bovine insulin was less effective than hIGF-I on the stimulation of [35S]sulphate uptake, the synergistic effects of sbGH with hIGF-I and sbGH with insulin were similar at the concentrations tested. The concept of a 'dual effector' mechanism for GH action in teleosts is supported by these findings.
Journal of Endocrinology (1995) 147, 67–73
Glucagon improves insulin secretion from pig islets in vitro
Authors: Bertuzzi F , Berra C , Socci C , Davalli A M , Calori G , Freschi M , Piemonti L , De Nittis P , Pozza G , Pontiroli A E 
Published: December 2008

Abstract
It has been shown that peripheral glucagon secreting cells (A-cells) are lost during most of the isolation procedures employed for pig islets. Loss of A-cells decreases intra-islet glucagon levels and cAMP levels in B-cells and might reduce glucose-induced insulin release. This study was designed to test this hypothesis, by evaluating the effects of culture of porcine islets with exogenous glucagon on insulin secretion and on insulin and cAMP content in islets. Islets were isolated from adult 2-year old Large White pigs using an automated method. The number of A-cells was calculated by immunostaining for glucagon in islets before and after isolation and a significant decrease in A-cells was observed. After an overnight culture, islets were cultured for 48 h in a standard medium (CMRL 1066, 10% foetal calf serum, 1% antibiotics, 1% glutamine) alone or in the presence of glucagon at two different concentrations (1·0 and 10·0 μm); exposure to glucagon was either continuous or alternated with periods of incubation in CMRL 1066 alone. After the 48-h culture in standard medium, the islet glucagon response to arginine was almost negligible and significantly lower than that observed in human islets. After culture, islet insulin response to glucose, and islet insulin and cAMP content were evaluated; continuous exposure to glucagon did not produce any significant effect on either insulin secretion or insulin and cAMP content; in contrast, discontinuous exposure to glucagon induced a significant improvement in insulin release, proportional to glucagon concentrations (integrated insulin release: −13·8 ±20·12 pg/islet/20 min in control islets, 111·0±50·73 and 144·7± 47·54 pg/islet/20 min in islets exposed to 1·0 and 10·0 μg glucagon respectively; n=10, P=0·01). Intracellular insulin and cAMP content of islets cultured in different culture media were not different. In conclusion, discontinuous exposure of isolated pig islets to exogenous glucagon induced a significant increase in glucose-induced insulin release which was not associated with an increase in cAMP content. The fact that even in the presence of glucagon the secretory activity of pig islets was lower than the reported activity of human or rat islets suggests that glucagon is only one of the factors involved in the poor insulin responsiveness of pig islets.
Journal of Endocrinology (1995) 147, 87–93
Endothelin-1 and endothelin receptors are present in the sheep uterus and conceptus at implantation
Authors: Riley S C , Findlay J K , Salamonsen L A 
Published: December 2008

Abstract
Previous studies have demonstrated that endothelin is present in the ovine endometrium and increases at around the expected time of implantation. To characterize further uterine endothelin at the time of establishment of pregnancy in sheep, endothelin was measured by radioimmunoassay in uterine flushings obtained during the oestrous cycle and in pregnant ewes up to the time of implantation (day 16). During the oestrous cycle, the highest amounts of endothelin were present in uterine flushings on day 14 (1·1 ±0·2 ng endothelin/uterus). During early pregnancy, basal levels of endothelin (0·5–0·6 ng endothelin/uterus) were present in uterine flushings for the first 10 days and then increased on day 14 to levels similar to those found at the equivalent stage of the oestrous cycle. On days 15 and 16 of pregnancy, endothelin content in the uterine lumen increased to significantly (P<0·05) higher concentrations (2·9±0·4 ng endothelin/uterus) when compared with the non-fertile cycle. The principal isoform present in flushings at the time of implantation was endothelin-1, as determined by reverse-phase HPLC. Endothelin was released principally by purified endometrial epithelial cells in culture, with barely detectable amounts released by endometrial stromal cells or conceptus tissue, which is consistent with the epithelium being the principal source of endothelin in the uterine lumen. Endothelin binding sites were present in endometrium and myometrium, as demonstrated by specific binding of 125I-labelled endothelin-1, which was saturable and displaced by endothelin-1. Both endothelinA and B sub-types of receptors were present as demonstrated by the biphasic displacement of 125I-labelled endothelin-1 binding by the specific endothelinB agonist BQ3020. These were localised principally on luminal and glandular epithelium and in the vasculature of the endometrium and myometrium as shown by autoradiography. Endothelin receptors were also present on the conceptus obtained at the time of implantation. In the day 20 conceptus, endothelin immunostaining was localised principally in the heart, in trophoblast in uninucleate but not in binucleate cells, and in fetal membranes. This immunostaining of the conceptus may represent binding to receptor sites. It is concluded that endothelin-1 is present in the uterine lumen and may play an important role in the paracrine regulation of the conceptus and endometrium at the time of rapid embryo development, implantation and early placentation.
Journal of Endocrinology (1995) 147, 235–244
Bokor—A New Look at Sand Production in a Mature Field
Authors: Kasim Abdullah , Wijnands Frank , Subbiah Surej 
Published: December 2008

Summary
Although the stacked reservoirs of the Bokor field, offshore Sarawak, Malaysia, are prone to sand production, the field development team did not opt a priori for gravel packs in every well. While such completions can indeed eliminate sanding risk, the team also wanted to consider the impact of the completion on the production rate of a well. The optimum completion not only excludes sand, but it also maximizes hydrocarbon production.
The team carried out a geomechanics and sand-production study, using readily available data. The paper gives an insight in the physics of sand production and how this process can be modeled geomechanically. It shows how the model is used to select feasible completions and quantify sand-free production rates over the life of the reservoir.
One important outcome was that screenless completions were possible in the deeper reservoirs by optimizing perforation orientations. Apart from other advantages of screenless completions, this leads to significant potential increases in sand-free production rates.
An integrated sand-management process brought together geomechanics, petrophysics, and reservoir and completion engineering to truly optimize completions.
Strain-Based Design of Tubulars for Extreme-Service Wells
Authors: Nowinka J. , Kaiser T. , Lepper B. 
Published: December 2008

Summary
This paper presents a framework for a strain-based design of tubular strings in extreme-temperature or high-pressure/ high-temperature (HP/HT) wells. The relevant concepts are illustrated by examples from analytical and experimental investigation of a casing material considered for use in thermally stimulated wells operated by Shell Canada Limited (Shell) in western Canada. Much of this framework is also relevant to other applications where deformation-driven loading mechanisms are present.
Strain-based design uses material capacity beyond its elastic range to overcome a number of economic and technical hurdles encountered in conventional load-based designs. It has been used successfully in field applications where plastic deformations occur (e.g., thermal wells and pipelines). However, current industry standards for material selection have their origins in load-based design. More sophisticated material-characterization tools are required for strain-based designs, in which post-yield material properties govern much of the system response.
This paper describes the application of strain-based concepts to the design of casing strings under combined loading where some load components are deformation controlled. The paper emphasizes the need to address strain localization, high-strain cyclic plastic loading, strain-rate-dependent strength, and associated stress-relaxation effects.
Strain-based design is most effective if relevant and reliable post-yield material properties are available. Experimental investigation of a candidate material considered for Shell Canada's thermal wells consisted of a series of custom-designed coupon-scale tests. The tests were conducted to acquire data describing the post-yield material response to monotonic and cyclic loading at temperatures ranging from 20 to 350°C.
Conclusions of this paper summarize findings of the executed material-evaluation program, outline options to minimize strain-localization impacts, and provide recommendations for strain-based designs of well-completion tubulars. Following these recommendations should result in higher reliability and more cost-effective wells in completion programs using strain-based strategies for designs of extreme service wells.