Search Results - (Author, Cooperation:A. M. Allen)

2012-11-30

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Brachypodium/genetics ; *Bread ; Chromosomes, Plant/genetics ; Crops, Agricultural/genetics ; DNA, Complementary/genetics ; DNA, Plant/genetics ; Evolution, Molecular ; Genes, Plant/genetics ; Genome, Plant/*genetics ; Genomics ; Multigene Family/genetics ; Oryza/genetics ; Polymorphism, Single Nucleotide/genetics ; Polyploidy ; Pseudogenes/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Triticum/classification/*genetics ; Zea mays/genetics

2018-01-26

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Geosciences

Computer Science

Medicine

Natural Sciences in General

Physics

Ecology

1365-2826

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Stimulation of the caudal ventrolateral medulla in rats and rabbits elicits secretion of vasopressin from the neurohypophysis. Inhibition of the area attenuates baroreceptor-initiated vasopressin secretion. Angiotensin II receptor binding sites and angiotensin-like immunoreactive nerve terminals are localized in the caudal ventrolateral medulla, in the region of the A1 noradrenaline-synthesizing neurons. To examine the possible functional role of angiotensin II in this region, we have microinjected angiotensin II into the A1 area in the urethane-anaesthetized rabbit. Microinjection of angiotensin II (0.1 to 100 pmol in 100 nl) stimulated vasopressin secretion (plasma vasopressin concentration increased from 24 ± 8 pg/ml to 104 ± 8 pg/ml following microinjection of 10 pmol angiotensin II) and produced a depressor response with bradycardia. The responsive area was confined to the region of the A1 cell group. AII responses were blocked by prior intramedullary injection of an angiotensin II receptor antagonist, [Sar1, Thr8] angiotensin II (2 nmol in 200 nl), which had no effect on the response to the excitatory amino-acid N-methyl-D-aspartate. Following spinal blockade of efferent sympathetic activity, microinjections of angiotensin II into the caudal ventrolateral medulla caused a similar increase in plasma vasopressin concentration without a depressor response, demonstrating that the stimulation of vasopressin release by angiotensin II was not secondary to hypotension. Microinjection of [Sar1, Thr8] angiotensin II dramatically attenuated the normal secretion of vasopressin in response to systemic haemorrhage. Following injection of vehicle into the caudal ventrolateral medulla, haemorrhage stimulated an increase in plasma vasopressin concentration from 3 ± 1 pg/ml to 335 ± 75 pg/ ml (n = 5). After microinjection of [Sar1, Thr8] angiotensin II the haemorrhage-induced change in vasopressin concentration was only 17 ± 6 pg/ml to 35 ± 7 pg/ml (n = 4). Microinjection of the N-methyl-D-aspartate receptor antagonist, DL-amino-5-phosphonovaleric acid (5 nmol, n = 4), did not alter the secretion of vasopressin in response to haemorrhage. These results in the anaesthetized rabbit suggest that angiotensin II in the caudal ventrolateral medulla may have a physiological role in baroreceptor control of vasopressin release.

Electronic Resource

1365-2826

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

This study examined the role of the diagonal band of Broca (DBB) in drinking behaviour and vasopressin release. Adult male rats were anaesthetized (pentobarbital 50 mg/kg) and received DBB injections of either ibotenic acid (0.5 µl of 5 µg/µl) or vehicle (0.5 µl of phosphate-buffered saline). Although baseline drinking and urine output were not affected, drinking to 30% polyethylene glycol (MW 8000; 1 ml/100 g s.c.) and angiotensin II (0, 1.5 and 3.0 mg/kg s.c.) were significantly increased in ibotenic acid in phosphate-buffered saline (DBBX) rats. Drinking to hypertonic saline (0.9, 4 and 6%; 1 ml/100 g), and water deprivation were not significantly affected. DBBX rats had significantly lower basal heart rates than controls but the cardiovascular responses to infusions of angiotensin II (100 ng/kg/min i.v. for 45 min) were not affected. DBBX rats had significantly higher basal vasopressin, but angiotensin-stimulated vasopressin release was not significantly different. Although the DBB is not involved in basal water intake, it is involved in dipsogenic responses to hypovolemic stimuli and possibly basal autonomic function and basal vasopressin release.

Electronic Resource

1365-2826

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Angiotensin II acts within the hypothalamic paraventricular nucleus (PVN) to help mediate a number of autonomic and endocrine responses. Evidence is sparse in regard to the particular neuronal cell groups that exhibit angiotensin II type 1 receptors within the PVN, and does not exist in relation to specified efferent neuronal populations in the nucleus. In the present experiments, retrogradely transported neuronal tracers were utilized in conjunction with immunohistochemistry using a well characterized polyclonal antibody raised against a decapeptide sequence at the carboxy terminus of the AT1 receptor, to determine whether it is preferentially distributed amongst different efferent populations within the PVN. The AT1 receptor is not associated with neurones in the PVN that project axons to the spinal cord, dorsomedial or ventrolateral medulla but coexists strongly with neurones in the anterior parvocellular division of the nucleus which direct axons to the median eminence. Such neurones often contain corticotropin releasing factor. These findings highlight the role that angiotensin II and AT1 receptors in the PVN may play in the mediation of responses to stress.

Electronic Resource

1440-1681

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

1. The distribution of angiotensin II (AII) receptor binding sites in the hypothalamus of rat, rabbit, sheep and human was determined by in vitro auto-radiography using 125I-[Sar1, IIe8]-AII as radioligand.2. High receptor binding levels were observed in the continuum of tissue comprising the anterior wall of the third ventricle, including the subfornical organ, the median pre-optic nucleus and the organum vasculosum of the lamina terminalis.3. High levels of binding sites were also found in the paraventricular and supra-optic nuclei, the median eminence and the arcuate nucleus.4. These findings demonstrate sites in the hypothalamus of rat, rabbit, sheep and human where AII could exert its known actions on fluid and electrolyte balance, pituitary hormone release and cardiovascular function.

Electronic Resource

0013-8266

History

0013-8266

History

0013-8266

History

1432-2161

Key words Spring ligament ; Plantar calcaneonavicular ligament ; Ligament tear ; Navicular subluxation ; Magnetic resonance imaging

Springer Online Journal Archives 1860-2000

Medicine

Abstract  The spring ligament is a significant contributor to the stability of the talar head and longitudinal arch of the foot, lending importance to accurate radiologic diagnosis of injury. Using MR, we diagnosed a spring ligament tear with associated navicular dorsal subluxation, confirmed intraoperatively. To our knowledge, there are no previous reports of MR diagnosis of tear of the spring ligament.

Electronic Resource