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Objectives of this study were to measure both daily and periprandial plasma ghrelin concentrations of postpubertal Holstein heifers during prolonged undernutrition. Following an acclimation period, Holstein heifers [n = 10; 339.5 ± 8.6 kg of body weight (BW)] were fed ad libitum [well fed (WF); n = 5] or restricted to 50% of ad libitum intake [underfed (UF); n = 5) for 8 wk. Body condition scores (BCS) were recorded at the beginning and end of the treatment period, and weekly measurements of BW, plasma ghrelin, progesterone, and nonesterified fatty acids (NEFA) concentrations were obtained. Ovarian follicular and luteal structures were measured twice weekly via transrectal ultrasonography. Plasma ghrelin concentrations were also measured during a periprandial window bleed conducted at the end of the experiment. During the window bleed, samples were collected every 15 min between 0500 and 0900 h, with feed offered at 0700 h. Underfed heifers lost BW and BCS, whereas WF heifers gained weight and either increased or maintained BCS. Chronic underfeeding increased circulating ghrelin and NEFA concentrations. By wk 4 of the treatment period, circulating ghrelin concentrations of the UF heifers reached a plateau. Periprandial fluctuations in ghrelin concentrations were apparent as plasma ghrelin concentrations changed over time. Overall differences in periprandial plasma ghrelin concentrations were primarily due to prefeeding effects of plane of nutrition. Plasma ghrelin concentrations and change in BCS were negatively correlated such that heifers that lost the most BCS had the highest concentrations of circulating ghrelin. Two of the 5 UF heifers became anestrus by wk 3 of the treatment period. Despite being of similar age, the heifers that became anestrus had lower BW and plasma ghrelin concentrations than the UF heifers that continued to ovulate. In the current experiment, long-term undernutrition elicited ghrelin responses similar to those reported for shorter durations of nutrient restriction in cattle and other ruminants. These results demonstrate that plane of nutrition is a chronic regulator of plasma ghrelin concentrations, and that these concentrations can be experimentally manipulated in postpubertal heifers for up to 8 wk with no evidence of an adaptive response. [ABSTRACT FROM AUTHOR]

The article provides an overview of the study about the type of exercise-induced ventricular arrhythmia (EIVA) on exercise test and risk for death. It assesses whether patients with EIVA during exercise testing are at higher risk for bad outcomes, such as death. Researchers found that only those patients with right bundle-branch bloc (RBBB) abnormality EIVA are more likely to die than those without the disease. It is considered that not all EIVA is associated with bad outcomes.

In contrast to many small, mountainous watersheds in temperate coastal regions, where fluvial discharge and wave energy commonly coincide, deposition and reworking of tropical flood sediment can be seasonally decoupled, and this has important implications for coral-reef ecosystems. An understanding of the interaction between tropical flood sedimentation and wave climate is essential to identifying and mitigating effects of watershed changes on coral reefs as urbanization and climate change proceed. Sedimentary facies and isotopic properties of sediment in Hanalei Bay, on the island of Kaua'i, Hawai'i, USA, were used to assess deposition and reworking of flood deposits from the Hanalei River in a case study demonstrating the potential ecosystem effects of runoff from a steep, tropical watershed. In Hanalei Bay, the youngest and thickest terrigenous sediment was consistently present near the river mouth and in a bathymetric depression that acted as at least a temporary sediment sink. During this 2 yr study, the largest flood events occurred in late winter and spring 2006; substantial terrestrial sediment delivered by those floods still remained in the bay as of June 2006 because oceanic conditions were not sufficiently energetic to transport all of the sediment offshore. Additional sediment was deposited in the bay by a summer 2006 flood that coincided with seasonal low wave energy. In most years, flood sediment accumulating in the bay and on its fringing reefs would be remobilized and advected out of the bay during winter, when the wave climate is energetic. Turbidity and sedimentation on corals resulting from late spring and summer floods during low wave energy could have a greater impact on coral-reef ecosystems than floods in other seasons, an effect that could be exacerbated if the incidence and sediment load of tropical summer floods increase due to urbanization and climate change. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to localize the mRNA and protein of ghrelin and its active receptor, growth hormone secretagogue 1A (GHS-R1A), within the reproductive tract of dairy cattle. Ghrelin is an orexigenic hormone that has been identified as a potent regulator of energy homeostasis. Recent evidence suggests that ghrelin may also serve as a metabolic signal to the reproductive tract. Ghrelin and GHS-R1A have been identified in the reproductive tract of several species, including humans, mice, and rats. However, ghrelin and GHS-R1A expression have not been described within bovine reproductive tissues. Therefore, the ampulla, isthmus, uterine body, corpus luteum, and follicles were harvested from 3 Holstein heifers (15.91 ± 0.07 mo of age) immediately following exsanguination. Duodenum and hypothalamus were collected as positive controls for ghrelin and GHS-R1A, respectively. Tissues were fixed in 10% formalin and embedded in paraffin for microscopy. Additional samples were stored at -80°C for detection of mRNA. Ghrelin and GHS-R1A mRNA and protein were observed in all tissue types within the reproductive tract of dairy heifers; however, expression appeared to be cell specific. Furthermore, ghrelin protein appeared to be localized to the cytoplasm, whereas GHS-R1A protein was found on the plasma membrane. Within the reproductive tissues, ghrelin mRNA and protein were most abundantly expressed in the ampulla of the oviduct. Concentrations of GHS-R1A were lower than those of ghrelin but differed between tissues. This is one of the first studies to provide molecular evidence for the presence of ghrelin and GHS-R1A within the entire reproductive tract. However, implications for fertility remain to be determined. [ABSTRACT FROM AUTHOR]

To investigate the impact of duration of maternal undernutrition in twin sheep pregnancies, ewes were either fed 100% (C) or 50% of their nutrient requirements from 28 to 78 d gestational age (dGA) and readjusted to 100% beginning at 79 dGA (LC) or continuously restricted from 28 to 135 dGA (LL). Weights of the fetus, empty carcass, brain, and liver were greater in the LC than LL fetuses at 135 dGA (P ≤ 0.05). Although umbilical vein (UmV) glucose concentrations did not differ, the UmV:umbilical artery (UmA) glucose gradient was smaller (0.26 ± 0.03 vs 0.38 ± 0.03 and 0.39 ± 0.04 mmol L(-1); P ≤ 0.05) in LL than C and LC fetuses, respectively. Umbilical vein concentrations of IGF-1 were less (46.7 ± 5.62 vs 74.3 ± 6.71 ng/mL; P ≤ 0.05) in LL than LC fetuses. Additionally, LL fetuses tended (P ≤ 0.10) to have lower UmA concentrations of insulin (0.24 ± 0.13 vs 0.70 ± 0.15 ng/mL) and IGF-1 (66.6 ± 7.51 vs 91.4 ± 8.97 ng/mL) than LC fetuses. Although most of the observed differences occurred between LC and LL pregnancies, LC fetuses tended (P ≤ 0.10) to have greater UmV and UmA pCO2 than C fetuses. Furthermore, the UmV:UmA O2 content gradient tended to be greater (5.02 ± 0.43 vs 3.41 ± 0.47; P ≤ 0.10) in C than LL fetuses. UmA placental lactogen also tended to be greater (46.6 ± 4.40 vs 31.1 ± 4.69 ng/mL; P ≤ 0.10) in LL than C fetuses. These data suggest that in twin pregnancies, maternal undernutrition followed by realimentation induces a different fetal outcome compared with continuous nutrient restriction, and both may differ physiologically from control fed pregnancies., (Copyright © 2015 Elsevier Inc. All rights reserved.)

"Transactivation" of epidermal growth factor receptors (EGFRs) in response to activation of many G protein-coupled receptors (GPCRs) involves autocrine/paracrine shedding of heparin-binding EGF (HB-EGF). HB-EGF shedding involves proteolytic cleavage of a membrane-anchored precursor by incompletely characterized matrix metalloproteases. In COS-7 cells, alpha(2A)-adrenergic receptors (ARs) stimulate ERK phosphorylation via two distinct pathways, a transactivation pathway that involves the release of HB-EGF and the EGFR and an alternate pathway that is independent of both HB-EGF and the EGFR. We have developed a mixed culture system to study the mechanism of GPCR-mediated HB-EGF shedding in COS-7 cells. In this system, alpha(2A)AR expressing "donor" cells are co-cultured with "acceptor" cells lacking the alpha(2A)AR. Each population expresses a uniquely epitope-tagged ERK2 protein, allowing the selective measurement of ERK activation in the donor and acceptor cells. Stimulation with the alpha(2)AR selective agonist UK14304 rapidly increases ERK2 phosphorylation in both the donor and the acceptor cells. The acceptor cell response is sensitive to inhibitors of both the EGFR and HB-EGF, indicating that it results from the release of HB-EGF from the alpha(2A)AR-expressing donor cells. Experiments with various chemical inhibitors and dominant inhibitory mutants demonstrate that EGFR-dependent activation of the ERK cascade after alpha(2A)AR stimulation requires Gbetagamma subunits upstream and dynamin-dependent endocytosis downstream of HB-EGF shedding and EGFR activation, whereas Src kinase activity is required both for the release of HB-EGF and for HB-EGF-mediated ERK2 phosphorylation.

Using both confocal immunofluorescence microscopy and biochemical approaches, we have examined the role of beta-arrestins in the activation and targeting of extracellular signal-regulated kinase 2 (ERK2) following stimulation of angiotensin II type 1a receptors (AT1aR). In HEK-293 cells expressing hemagglutinin-tagged AT1aR, angiotensin stimulation triggered beta-arrestin-2 binding to the receptor and internalization of AT1aR-beta-arrestin complexes. Using red fluorescent protein-tagged ERK2 to track the subcellular distribution of ERK2, we found that angiotensin treatment caused the redistribution of activated ERK2 into endosomal vesicles that also contained AT1aR-beta-arrestin complexes. This targeting of ERK2 reflects the formation of multiprotein complexes containing AT1aR, beta-arrestin-2, and the component kinases of the ERK cascade, cRaf-1, MEK1, and ERK2. Myc-tagged cRaf-1, MEK1, and green fluorescent protein-tagged ERK2 coprecipitated with Flag-tagged beta-arrestin-2 from transfected COS-7 cells. Coprecipitation of cRaf-1 with beta-arrestin-2 was independent of MEK1 and ERK2, whereas the coprecipitation of MEK1 and ERK2 with beta-arrestin-2 was significantly enhanced in the presence of overexpressed cRaf-1, suggesting that binding of cRaf-1 to beta-arrestin facilitates the assembly of a cRaf-1, MEK1, ERK2 complex. The phosphorylation of ERK2 in beta-arrestin complexes was markedly enhanced by coexpression of cRaf-1, and this effect is blocked by expression of a catalytically inactive dominant inhibitory mutant of MEK1. Stimulation with angiotensin increased the binding of both cRaf-1 and ERK2 to beta-arrestin-2, and the association of beta-arrestin-2, cRaf-1, and ERK2 with AT1aR. These data suggest that beta-arrestins function both as scaffolds to enhance cRaf-1 and MEK-dependent activation of ERK2, and as targeting proteins that direct activated ERK to specific subcellular locations.

beta-Arrestins, originally discovered in the context of heterotrimeric guanine nucleotide binding protein-coupled receptor (GPCR) desensitization, also function in internalization and signaling of these receptors. We identified c-Jun amino-terminal kinase 3 (JNK3) as a binding partner of beta-arrestin 2 using a yeast two-hybrid screen and by coimmunoprecipitation from mouse brain extracts or cotransfected COS-7 cells. The upstream JNK activators apoptosis signal-regulating kinase 1 (ASK1) and mitogen-activated protein kinase (MAPK) kinase 4 were also found in complex with beta-arrestin 2. Cellular transfection of beta-arrestin 2 caused cytosolic retention of JNK3 and enhanced JNK3 phosphorylation stimulated by ASK1. Moreover, stimulation of the angiotensin II type 1A receptor activated JNK3 and triggered the colocalization of beta-arrestin 2 and active JNK3 to intracellular vesicles. Thus, beta-arrestin 2 acts as a scaffold protein, which brings the spatial distribution and activity of this MAPK module under the control of a GPCR.

RAFT1 (rapamycin and FKBP12 target 1; also called FRAP or mTOR) is a member of the ATM (ataxia telangiectasia mutated)-related family of proteins and functions as the in vivo mediator of the effects of the immunosuppressant rapamycin and as an important regulator of messenger RNA translation. In mammalian cells RAFT1 interacted with gephyrin, a widely expressed protein necessary for the clustering of glycine receptors at the cell membrane of neurons. RAFT1 mutants that could not associate with gephyrin failed to signal to downstream molecules, including the p70 ribosomal S6 kinase and the eIF-4E binding protein, 4E-BP1. The interaction with gephyrin ascribes a function to the large amino-terminal region of an ATM-related protein and reveals a role in signal transduction for the clustering protein gephyrin.

When the omentum of the dog is floated in a suspension of insoluble nickel silicate in physiological saline under circumstances precluding the possibility of lymphatic drainage, the liver removed after at least 1 hour contains nickel which must have been brought to it by way of the blood capillaries in particulate form. The blood capillaries are, therefore, a pathway for absorption of solid material but are not important in this respect.

1. The normal lymph pressure in the legs of anesthetized dogs is not measurable. 2. The maximum pressure of lymph in the quiescent leg under conditions of sterile inflammation is around 120 cm. of lymph. 3. Venous pressure rises immediately in a region subjected to sterile inflammation and then slowly returns to normal. The rise in lymph pressure follows the rise in venous pressure. 4. Changes in lymph flow, lymph pressure, and protein concentration of the lymph occur when the part producing lymph is subjected to external temperatures between 50 degrees and 60 degrees C.

1. Physiological salt solution is absorbed from the pericardial cavity of medium-sized rabbits at a rate of approximately 1.3 cc. per hour. This absorption is via the subepicardial blood capillaries. 2. Rabbit serum and horse serum are absorbed extremely slowly-an indication of the low-grade lymphatic drainage of the pericardial sac. 3. Graphite particles of bacterial dimensions are also removed very slowly. Such particles enter lymphatics only after phagocytosis. The lymphatics in the basal part of the pericardium are the principal source of drainage. Subepicardial lymphatics are entered with difficulty from the pericardial cavity.

Experiments are described which show that in rabbits infected intravenously with virulent Type III pneumococci, these organisms are found not only in the thoracic duct lymph, as previously reported, but also in lymph from the cervical and leg lymphatics. The nonmotile bacteria must have crossed both vascular and lymphatic endothelium in reaching the lymph. Intracellular transportation by phagocytes is apparently not the means by which this is effected. The intravenous and intraperitoneal injection of large amounts of homologous type-specific antibody fails even after many hours to terminate or permanently reduce the pneumococcal infection of the lymph. The failure of antiserum to sterilize the lymph is discussed.

In anesthetized dogs the popliteal lymph node alone, and the popliteal and iliac lymph nodes in series, have been perfused with solutions containing dog erythrocytes and streptococci. The perfusions have been carried out under conditions of lymph flow and pressure within the limits of those occurring in the actively moving dog, or after a severe degree of inflammatory swelling has developed. Figures for filtration are given, with protocols of typical experiments. They indicate that normal lymph nodes possess a high degree of filtering efficiency-an efficiency so great as to make it fairly certain that in a part kept at rest early in an infection, practically no microorganisms would escape the nodes in the line of drainage.