Performance of Tall Fescue Varieties [1984]

The objective of the tall fescue breeding program is the development of varieties characterized by superior nutritive value (including reduced contents of perloline and loline alkaloids and the fungal endophyte, Epichloe typhina, (Acremonium coenophialum), palatability, disease resistance, and adaptation through the utilization of intergeneric and interspecific hybrid derivatives of ryegtass and tall fescue species. Varieties previously released from the breeding program were Kentucky 31, Kenwell; and Kenhy. Johnstone tall fescue, developed cooperatively by the Kentucky Agricultural Experiment Station and USDA-ARS, was released March 1, 1982, as a new variety. Johnstone is characterized as having low levels of perloline alkaloid and the fungal endophyte; Acremonium coenophialum, and improved forage quality during summer. It is expected that seed of Johnstone will be available commercially during 1985, and a good supply should be available for spring and summer 1986 planting

High intensity aerobic exercise training improves deficits of cardiovascular autonomic function in a rat model of type 1 diabetes mellitus with moderate hyperglycemia

© 2016 Kenneth N. Grisé et al. Indices of cardiovascular autonomic neuropathy (CAN) in experimental models of Type 1 diabetes mellitus (T1DM) are often contrary to clinical data. Here, we investigated whether a relatable insulin-treated model of T1DM would induce deficits in cardiovascular (CV) autonomic function more reflective of clinical results and if exercise training could prevent those deficits. Sixty-four rats were divided into four groups: sedentary control (C), sedentary T1DM (D), control exercise (CX), or T1DM exercise (DX). Diabetes was induced via multiple low-dose injections of streptozotocin and blood glucose was maintained at moderate hyperglycemia (9-17 mM) through insulin supplementation. Exercise training consisted of daily treadmill running for 10 weeks. Compared to C, D had blunted baroreflex sensitivity, increased vascular sympathetic tone, increased serum neuropeptide Y (NPY), and decreased intrinsic heart rate. In contrast, DX differed from D in all measures of CAN (except NPY), including heart rate variability. These findings demonstrate that this T1DM model elicits deficits and exercise-mediated improvements to CV autonomic function which are reflective of clinical T1DM

Antiviral inflammation during early pregnancy reduces placental and fetal growth trajectories

Many viruses are detrimental to pregnancy and negatively affect fetal growth and development. What is not well understood is how virus-induced inflammation impacts fetal-placental growth and developmental trajectories, particularly when inflammation occurs in early pregnancy during nascent placental and embryo development. To address this issue, we simulated a systemic virus exposure in early pregnant rats (gestational day 8.5) by administering the viral dsRNA mimic polyinosinic:polycytidylic acid (PolyI:C). Maternal exposure to PolyI:C induced a potent antiviral response and hypoxia in the early pregnant uterus, containing the primordial placenta and embryo. Maternal PolyI:C exposure was associated with decreased expression of the maternally imprinted genes Mest, Sfrp2, and Dlk1, which encode proteins critical for placental growth. Exposure of pregnant dams to PolyI:C during early pregnancy reduced fetal growth trajectories throughout gestation, concomitant with smaller placentas, and altered placental structure at midgestation. No detectable changes in placental hemodynamics were observed, as determined by ultrasound biomicroscopy. An antiviral response was not evident in rat trophoblast stem (TS) cells following exposure to PolyI:C, or to certain PolyI:C-induced cytokines including IL-6. However, TS cells expressed high levels of type I IFNR subunits (Ifnar1 and Ifnar2) and responded to IFN-α by increasing expression of IFN-stimulated genes and decreasing expression of genes associated with the TS stem state, including Mest. IFN-α also impaired the differentiation capacity of TS cells. These results suggest that an antiviral inflammatory response in the conceptus during early pregnancy impacts TS cell developmental potential and causes latent placental development and reduced fetal growth

Antiviral inflammation during early pregnancy reduces placental and fetal growth trajectories

Many viruses are detrimental to pregnancy and negatively affect fetal growth and development. What is not well understood is how virus-induced inflammation impacts fetal-placental growth and developmental trajectories, particularly when inflammation occurs in early pregnancy during nascent placental and embryo development. To address this issue, we simulated a systemic virus exposure in early pregnant rats (gestational day 8.5) by administering the viral dsRNA mimic polyinosinic:polycytidylic acid (PolyI:C). Maternal exposure to PolyI:C induced a potent antiviral response and hypoxia in the early pregnant uterus, containing the primordial placenta and embryo. Maternal PolyI:C exposure was associated with decreased expression of the maternally imprinted genes Mest, Sfrp2, and Dlk1, which encode proteins critical for placental growth. Exposure of pregnant dams to PolyI:C during early pregnancy reduced fetal growth trajectories throughout gestation, concomitant with smaller placentas, and altered placental structure at midgestation. No detectable changes in placental hemodynamics were observed, as determined by ultrasound biomicroscopy. An antiviral response was not evident in rat trophoblast stem (TS) cells following exposure to PolyI:C, or to certain PolyI:C-induced cytokines including IL-6. However, TS cells expressed high levels of type I IFNR subunits (Ifnar1 and Ifnar2) and responded to IFN-α by increasing expression of IFN-stimulated genes and decreasing expression of genes associated with the TS stem state, including Mest. IFN-α also impaired the differentiation capacity of TS cells. These results suggest that an antiviral inflammatory response in the conceptus during early pregnancy impacts TS cell developmental potential and causes latent placental development and reduced fetal growth

Agronomic and Animal Performance of Different Tall Fescue Varieties

The objective of the tall fescue breeding program is the development of varieties characterized by superior nutritive value (including reduced contents of perloline and loline alkaloids and minimal infestation of the fungal endophyte, Acremonium coenophialum), palatability, disease resistance, and adaptation through the utilization of intergeneric and interspecific hybrid derivatives of ryegrass and tall fescue species. Kentucky 31, Kenwell, and Kenhy were previously released from this breeding program. Johnstone tall fescue, developed cooperatively by the Kentucky Agricultural Experiment Station and USDA-ARS, was released March 1, 1982 as a new variety. Johnstone is characterized as having low levels of perloline alkaloid and the fungal endophyte (Acremonium coenophialum) and improved forage quality during summer. It is expected that seed of Johnstone will be available commercially during 1985, and a good supply be available for /\u27 spring and summer 1986 plantings

1986 Update of Agronomic and Animal Performance of Different Tall Fescue Varieties

The objective of the tall fescue breeding program at the University of Kentucky is the development of varieties characterized by superior nutritive value (including reduced levels of perloline and loline alkaloids), minimal infestation of the fungal endophyte, Acremonium coenophialum), higher palatability, improved disease resistance, and wider adaptation through the derivation of intergeneric and interspecific hybrids of ryegrass and tall fescue species. Kentucky 31, Kenwell, and Kenhy were varieties released from this breeding program. Johnstone tall fescue, developed cooperatively by the Kentucky Agricultural Experiment Station and USDA-ARS, is the most recently released variety. It is characterized as having low levels of perloline alkaloid and the fungal endophyte (Acremonium coenophialum) and improved forage quality during summer. Ample Johnstone seed should be available to meet demand during 1986

Evidence of bidirectional flow in the sciatic vasa nervorum.

The purpose of this study was to determine whether bidirectional flow exists in the sciatic vasa nervorum. Images obtained using high-frequency color Doppler ultrasound in duplex imaging mode (Vevo 2100) were studied retroactively. In Fig. 1 (left panel; rat 1), the color Doppler signal and flow-velocity waveforms are indicative of pulsatile flow traveling towards (B) and away (C) from the probe. In the right panel (Fig. 1; rat 2), there appears to be three distinct vessels, reflective of non-pulsatile negative flow (D), and pulsatile positive (E) and negative (F) flows. These data confirm the presence of bidirectional arterial flow in the sciatic vasa nervorum. Investigating bidirectional flow in the intact whole nerve may be helpful in elucidating novel features of nerve blood flow control in healthy and diseased states

A dynamic neonatal heart phantom for ultrafast color Doppler echocardiography evaluation

© 2019 SPIE. New high-frame-rate ultrasound imaging techniques are being developed to image tissue motion and blood flow with high sensitivity and at high temporal resolution. An emerging application for these new techniques is diagnosing inutero and neonatal cardiac disease. We have developed a morphologically and hemodynamically accurate neonatal heart phantom to provide a high-fidelity physical model for laboratory testing of ultrafast color Doppler echocardiography methods. This paper summarizes the design and functionality of the simulator by measuring pressure gradients across the mitral valve at a physiologic heart-rate range and stroke volume and by evaluating valve function using 2D transesophageal echocardiography (TEE) and Doppler images. The phantom achieved normal physiological pressures across the mitral valve ranging from 42 to 87 mmHg in systole and 2.4 to 4.2 mmHg in diastole at heartrates of 100, 125 and 150 beats per minute (bpm), with a realistic neonatal stroke volume of 7 ml. 2D ultrasound images were obtained at 60 bpm