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Sample records for hypotension marked diuresis

  1. Overdose of methyldopa, indapamide and theophylline resulting in prolonged hypotension, marked diuresis and hypokalaemia in an elderly patient.

    PubMed

    Chan, Thomas Y K; Gomersall, Charles D; Cheng, Claudia A Y; Woo, Jean

    2009-10-01

    An 89-year-old man with a history of hypertension, chronic obstructive pulmonary disease, personality disorder and previous attempts of self-poisoning attempted suicide by swallowing two mouthfuls of tablets (methyldopa 250 mg, theophylline SR 200 mg, indapamide 2.5 mg and paracetamol 500 mg). He had prolonged, severe hypotension, necessitating the use of 3000 ml of Gelofusine and almost 2 days of intravenous norepinephrine infusion. He had marked diuresis for 4.5 days, requiring continuous and bolus infusions of intravenous fluids. He had marked renal potassium loss, requiring vigorous potassium replacement therapy. Multiple-dose activated charcoal was used to enhance theophylline elimination. The plasma paracetamol level was below the treatment line. Methyldopa via its metabolite stimulates postsynaptic alpha-adrenergic receptors in cardiovascular control centres in the brain, causing a reduction in peripheral sympathetic tone and a fall in arterial blood pressure and heart rate. In overdose, it causes hypotension, bradycardia and drowsiness. The natriuretic, kaliuretic and vasodilatory effects of indapamide are exaggerated in overdose, resulting in diuresis, hypokalaemia and hypotension. Theophylline markedly increases the level of circulating catecholamines, which stimulate the vascular beta(2)-adrenergic receptors with decreased peripheral vascular resistance. Peripheral vasodilation and hypotension occur in significant theophylline poisoning. Intracellular shift of potassium results in hypokalaemia. The prescribing physicians should recognise elderly patients at a high risk of self-poisoning and avoid using drugs with a high toxicity in overdose (e.g. theophylline and methyldopa). Restricting access to hazardous drugs (in overdose) would be of paramount importance to reduce the number of severe acute poisoning cases and case-fatalities.

  2. Nociceptin/orphanin FQ (N/OFQ)-evoked bradycardia, hypotension, and diuresis are absent in N/OFQ peptide (NOP) receptor knockout mice.

    PubMed

    Burmeister, Melissa A; Ansonoff, Michael A; Pintar, John E; Kapusta, Daniel R

    2008-09-01

    Intracerebroventricular administration of the opioid-like peptide nociceptin/orphanin FQ (N/OFQ) produces bradycardia, hypotension, and diuresis in mice. We hypothesized that these responses are solely caused by selective activation of central N/OFQ peptide (NOP) receptors. To test this premise, we first examined whether i.c.v. N/OFQ produced dose-dependent diuretic and cardiovascular depressor responses in commercially available C57BL/6 mice. Next, using doses established in these studies, we examined the renal excretory and cardiovascular responses to i.c.v. N/OFQ in conscious transgenic NOP receptor knockout mice (NOP(-/-)). In metabolic studies, i.c.v. N/OFQ, but not saline vehicle, dose-dependently increased urine output (V) in NOP(+/+); this response was significant at 3 nmol (N/OFQ, V = 0.39 +/- 0.10 ml/2 h; saline, 0.08 +/- 0.05 ml/2 h). The N/OFQ-evoked diuresis was absent in littermate NOP(-/-) (N/OFQ, V = 0.06 +/- 0.06 ml/2 h; saline, 0.03 +/- 0.03 ml/2 h). There were no significant changes in urinary sodium or potassium excretion or free water clearance in either group. In telemetry studies, i.c.v. N/OFQ dose dependently lowered heart rate (HR) and mean arterial pressure (MAP). At 3 nmol N/OFQ, both HR and MAP were reduced in NOP(+/+) (peak DeltaHR = -217 +/- 31 bpm; peak DeltaMAP =-47 +/- 7 mm Hg) compared with saline (peak DeltaHR =-14 +/- 5 bpm; peak DeltaMAP = 2 +/- 3 mm Hg). These N/OFQ-evoked bradycardic and hypotensive responses were absent in NOP(-/-) (peak DeltaHR =-13 +/- 17 bpm; peak DeltaMAP =-2 +/- 4 mm Hg, respectively). Basal 24-h cardiovascular and renal excretory function were not different between NOP(-/-) and NOP(+/+) mice. These results establish that the bradycardia, hypotension and diuresis produced by centrally administered N/OFQ are mediated by selective activation of NOP receptors.

  3. Postobstructive diuresis

    PubMed Central

    Halbgewachs, Colin; Domes, Trustin

    2015-01-01

    Abstract Objective To educate primary health care professionals about the diagnosis and treatment of postobstructive diuresis (POD), a rare but potentially lethal complication associated with the relief of urinary obstructions. Sources of information The main concepts and clinical evidence reviewed in this article were derived from a literature search of PubMed and Google Scholar. Expert opinion was used to supplement recommendations in areas with little evidence. Main message Urinary retention is a frequently encountered presentation seen by all physicians. Most family physicians are comfortable treating these patients, initiating investigations, and organizing appropriate follow-up. This article reviews a rare but potentially lethal complication known as POD. Postobstructive diuresis is a polyuric response initiated by the kidneys after the relief of a substantial bladder outlet obstruction. In severe cases this condition can become pathologic, resulting in dehydration, electrolyte imbalances, and death if not adequately treated. Primary care physicians should be familiar with this potential clinical entity, especially as they are generally the first to encounter and treat these patients. Conclusion Physicians aware of POD will be able to identify patients at risk and arrange the appropriate monitoring after relieving a urinary obstruction. Early diagnosis and treatment of pathologic POD will prevent mortality. PMID:25821871

  4. A case of marked diuresis by combined dopamine and atrial natriuretic peptide administration without renal injury in acute decompensated heart failure.

    PubMed

    Kamiya, Masataka; Sato, Naoki; Akiya, Mai; Okazaki, Hirotake; Takahashi, Yasuhiro; Mizuno, Kyoichi

    2013-01-01

    Renal injury is an important factor for worsening outcome in acute decompensated heart failure (ADHF). An 81-year-old woman was admitted due to ADHF with dyspnea and mild peripheral edema. The patient was managed with intravenous administration of atrial natriuretic peptide (ANP) at a dose of 0.0125 μg/kg/minute, which did not control volume overload even at an increased dose of 0.025 μg/kg/minute. After a low dose of dopamine (DA) of 1.0 μg/kg/ minute was added, urine output increased markedly to 120 from 30 mL/hour. Furthermore, her heart rate decreased to 80-100 from 120 bpm and the congestion improved with a reduced brain natriuretic peptide level. Interestingly, the combination of ANP and DA therapy reduced serum creatinine as well as the levels of urinary liver-type fatty acid binding protein, a novel reno-tubular stress marker, by 98.9%, and an oxidative stress marker, urinary 8-hydroxydeoxyguanosine, by 88.2% from baseline levels. Thus, this ADHF patient, a nonresponder to ANP alone, improved without renal injury when administered combination therapy consisting of low doses of ANP and DA, suggesting that this combined therapy might be useful for better management of ADHF in patients without diuretic responses with ANP alone. Further prospective studies are warranted.

  5. Orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Grimm, J. J.

    1980-01-01

    Following a brief physiopathological review, orthostatic hypotension is classified into three groups: organic, functional and medication-dependent. The importance of etiological diagnosis, the use of objective tests and appropriate therapy, especially concerning the organic forms, is stressed.

  6. Hypotensive anaesthesia.

    PubMed

    Hack, H; Mitchell, V

    Hypotensive anaesthesia can be employed to improve the outcome in a variety of surgical procedures. Since there is no single agent capable of safely and effectively lowering arterial pressure in all situations, the anaesthetist may need to employ a variety of agents or techniques in order to achieve the target pressure. This article considers the currently available methods of inducing hypotension and their application to the safe conduct of anaesthesia.

  7. Urea may regulate urea transporter protein abundance during osmotic diuresis.

    PubMed

    Kim, Dongun; Klein, Janet D; Racine, Sandy; Murrell, Brian P; Sands, Jeff M

    2005-01-01

    Rats with diabetes mellitus have an increase in UT-A1 urea transporter protein abundance and absolute urea excretion, but the relative amount (percentage) of urea in total urinary solute is actually decreased due to the marked glucosuria. Urea-specific signaling pathways have been identified in mIMCD3 cells and renal medulla, suggesting the possibility that changes in the percentage or concentration of urea could be a factor that regulates UT-A1 abundance. In this study, we tested the hypothesis that an increase in a urinary solute other than urea would increase UT-A1 abundance, similar to diabetes mellitus, whereas an increase in urine urea would not. In both inner medullary base and tip, UT-A1 protein abundance increased during NaCl- or glucose-induced osmotic diuresis but not during urea-induced osmotic diuresis. Next, rats undergoing NaCl or glucose diuresis were given supplemental urea to increase the percentage of urine urea to control values. UT-A1 abundance did not increase in these urea-supplemented rats compared with control rats. Additionally, both UT-A2 and UT-B protein abundances in the outer medulla increased during urea-induced osmotic diuresis but not in NaCl or glucose diuresis. We conclude that during osmotic diuresis, UT-A1 abundance increases when the percentage of urea in total urinary solute is low and UT-A2 and UT-B abundances increase when the urea concentration in the medullary interstitium is high. These findings suggest that a reduction in urine or interstitial urea results in an increase in UT-A1 protein abundance in an attempt to restore inner medullary interstitial urea and preserve urine-concentrating ability.

  8. Orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Ninet, J.

    1981-01-01

    Basic orientation of the article, by the leader of a group of medical researchers associated with hospitals in Lyon, France, is toward definition and classification. A table divides OH (orthostatic hypotension) according to physiopathological classification into sympathicotonic and asympathicotonic types and then each of these into primary and secondary with subdivisions. The figure sketches organization and functioning of the baroreflex arc. Applications to clinical study of circulatory reflexes, listing measurement tests and the biological study of hormonal regulation listing the appropriate kinds of studies. Data are not given.

  9. Immersion diuresis without expected suppression of vasopressin

    NASA Technical Reports Server (NTRS)

    Keil, L. C.; Silver, J. E.; Wong, N.; Spaul, W. A.; Greenleaf, J. E.; Kravik, S. E.

    1984-01-01

    There is a shift of blood from the lower parts of the body to the thoracic circulation during bed rest, water immersion, and presumably during weightlessness. On earth, this central fluid shift is associated with a profound diuresis. However, the mechanism involved is not yet well understood. The present investigation is concerned with measurements regarding the plasma vasopressin, fluid, electrolyte, and plasma renin activity (PRA) responses in subjects with normal preimmersion plasma vasopressin (PVP) concentration. In the conducted experiments, PRA was suppressed significantly at 30 min of immersion and had declined by 74 percent by the end of the experiment. On the basis of previously obtained results, it appears that sodium excretion during immersion may be independent of aldosterone action. Experimental results indicate that PVP is not suppressed by water immersion in normally hydrated subjects and that other factors may be responsible for the diuresis.

  10. Effects of vasopressin administration on diuresis of water immersion in normal humans

    NASA Technical Reports Server (NTRS)

    Epstein, M.; Denunzio, A. G.; Loutzenhiser, R. D.

    1981-01-01

    The influence of vasopressin suppression on the diuresis encountered during water immersion is investigated in studies on normal humans immersed to the neck. Six hydrated male subjects were studied on two occasions while undergoing 6 h of immersion without or during the administration of aqueous vasopressin for the initial 4 h. Neck immersion is found to result in a significant increase in urinary flow rate beginning in the first hour and persisting throughout the immersion. The administration of vasopressin markedly attenuated the diuretic response throughout the period of infusion, while cessation of vasopressin administration during the final 2 h of immersion resulted in a marked offset of the antidiuresis. Results thus support the view that the suppression of antidiuretic hormone contributes to the immersion diuresis of hydrated subjects.

  11. Postexercise Hypotension: Central Mechanisms

    PubMed Central

    Chen, Chao-Yin; Bonham, Ann C.

    2010-01-01

    A single bout of exercise can lead to a postexercise decrease in blood pressure in hypertensive individuals, called postexercise hypotension. Compelling evidence suggests that the central baroreflex pathway plays a crucial role in the development of postexercise hypotension. This review focuses on the exercise-induced changes in brainstem nuclei involved in blood pressure regulation. PMID:20577060

  12. [Hypotension from endocrine origin].

    PubMed

    Vantyghem, Marie-Christine; Douillard, Claire; Balavoine, Anne-Sophie

    2012-11-01

    Hypotension is defined by a low blood pressure either permanently or only in upright posture (orthostatic hypotension). In contrast to hypertension, there is no threshold defining hypotension. The occurrence of symptoms for systolic and diastolic measurements respectively below 90 and 60 mm Hg establishes the diagnosis. Every acute hypotensive event should suggest shock, adrenal failure or an iatrogenic cause. Chronic hypotension from endocrine origin may be linked to adrenal failure from adrenal or central origin, isolated hypoaldosteronism, pseudohypoaldosteronism, pheochromocytoma, neuro-endocrine tumors (carcinoïd syndrome) or diabetic dysautonomia. Hypotension related to hypoaldosteronism associates low blood sodium and above all high blood potassium levels. They are generally classified according to their primary (hyperreninism) or secondary (hyporeninism) adrenal origin. Isolated primary hypoaldosteronisms are rare in adults (intensive care unit, selective injury of the glomerulosa area) and in children (aldosterone synthase deficiency). Isolated secondary hypoaldosteronism is related to mellitus diabetes complicated with dysautonomia, kidney failure, age, iatrogenic factors, and HIV infections. In both cases, they can be associated to glucocorticoid insufficiency from primary adrenal origin (adrenal failure of various origins with hyperreninism, among which congenital 21 hydroxylase deficiency with salt loss) or from central origin (hypopituitarism with hypo-reninism). Pseudohypoaldosteronisms are linked to congenital (type 1 pseudohypoaldosteronism) or acquired states of resistance to aldosterone. Acquired salt losses from enteric (total colectomy with ileostomy) or renal (interstitial nephropathy, Bartter and Gitelman syndromes…) origin might be responsible for hypotension and are associated with hyperreninism-hyperaldosteronism. Hypotension is a rare manifestation of pheochromocytomas, especially during surgical removal when the patient has not been

  13. What Causes Hypotension?

    MedlinePlus

    ... Intramural Research Research Resources Research Meeting Summaries Technology Transfer Clinical Trials What Are Clinical Trials? Children & Clinical ... trigger orthostatic hypotension include being out in the heat or being immobile for a long time. "Immobile" ...

  14. How Is Hypotension Diagnosed?

    MedlinePlus

    ... or low blood sugar is causing your hypotension. EKG (Electrocardiogram) An EKG is a simple test that detects and records ... whether its rhythm is steady or irregular. An EKG also shows the strength and timing of electrical ...

  15. Excess diuresis and natriuresis during acute sleep deprivation in healthy adults.

    PubMed

    Kamperis, Konstantinos; Hagstroem, Soren; Radvanska, Eva; Rittig, Soren; Djurhuus, Jens Christian

    2010-08-01

    The transition from wakefulness to sleep is associated with a pronounced decline in diuresis, a necessary physiological process that allows uninterrupted sleep. The aim of this study was to assess the effect of acute sleep deprivation (SD) on urine output and renal water, sodium, and solute handling in healthy young volunteers. Twenty young adults (10 male) were recruited for two 24-h studies under standardized dietary conditions. During one of the two admissions, subjects were deprived of sleep. Urine output, electrolyte excretions, and osmolar excretions were calculated. Activated renin, angiotensin II, aldosterone, arginine vasopressin, and atrial natriuretic peptide were measured in plasma, whereas prostaglandin E(2) and melatonin were measured in urine. SD markedly increased the diuresis and led to excess renal sodium excretion. The effect was more pronounced in men who shared significantly higher diuresis levels during SD compared with women. Renal water handling and arginine vasopressin levels remained unaltered during SD, but the circadian rhythm of the hormones of the renin-angiotensin-aldosterone system was significantly affected. Urinary melatonin and prostaglandin E(2) excretion levels were comparable between SD and baseline night. Hemodynamic changes were characterized by the attenuation of nocturnal blood pressure dipping and an increase in creatinine clearance. Acute deprivation of sleep induces natriuresis and osmotic diuresis, leading to excess nocturnal urine production, especially in men. Hemodynamic changes during SD may, through renal and hormonal processes, be responsible for these observations. Sleep architecture disturbances should be considered in clinical settings with nocturnal polyuria such as enuresis in children and nocturia in adults.

  16. Sleep deprivation induces excess diuresis and natriuresis in healthy children.

    PubMed

    Mahler, B; Kamperis, K; Schroeder, M; Frøkiær, J; Djurhuus, J C; Rittig, S

    2012-01-15

    Urine production is reduced at night, allowing undisturbed sleep. This study was undertaken to show the effect of sleep deprivation (SD) on urine production in healthy children. Special focus was on gender and children at an age where enuresis is still prominent. Twenty healthy children (10 girls) underwent two 24-h studies, randomly assigned to either sleep or SD on the first study night. Diet and fluid intake were standardized. Blood samples were drawn every 4 h during daytime and every 2 h at night. Urine was fractionally collected. Blood pressure and heart rate were noninvasively monitored. Blood was analyzed for plasma antidiuretic hormone (AVP), atrial natriuretic peptide (ANP), angiotensin II, aldosterone, and renin. Urine was analyzed for aquaporin-2 and PGE(2). Successful SD was achieved in all participants with a minimum of 4 h 50 min, and full-night SD was obtained in 50% of the participants. During SD, both boys and girls produced markedly larger amounts of urine than during normal sleep (477 ± 145 vs. 291 ± 86 ml, P < 0.01). SD increased urinary excretion of sodium (0.17 ± 0.05 vs. 0.10 ± 0.03 mmol·kg(-1)·h(-1)) whereas solute-free water reabsorption remained unchanged. SD induced a significant fall in nighttime plasma AVP (P < 0.01), renin (P < 0.05), angiotensin II (P < 0.001), and aldosterone (P < 0.05) whereas plasma ANP levels remained uninfluenced (P = 0.807). Nighttime blood pressure and heart rate were significantly higher during SD (mean arterial pressure: 78.5 ± 8.0 vs. 74.7 ± 8.7 mmHg, P < 0.001). SD leads to natriuresis and excess diuresis in healthy children. The underlying mechanism could be a reduced nighttime dip in blood pressure and a decrease in renin-angiotensin-aldosterone system levels during sleep deprivation.

  17. Five years of data diuresis: what have WEH learned?

    PubMed

    Sullivan, Jennifer C; Pollock, Jennifer S

    2015-11-01

    This year represents the fifth annual Data Diuresis session of the Water and Electrolyte Homeostasis (WEH) section of the American Physiological Society (APS) at the 2015 Experimental Biology meeting. As opposed to taking a single organ approach to the study of physiology, the WEH section employs an integrative approach to encompass how the different organ systems interact to regulate numerous physiological and pathophysiological processes. The goal of this minireview is to highlight the broad spectrum of research themes that were presented over the first five years of Data Diuresis. Presentation topics include (but are not limited to) oxidative stress, inflammation, obesity, pregnancy, and hypertension spanning the brain, heart and vasculature, and kidney. WEH researchers continue to impact and help drive the direction of physiological research across multiple disciplines, leaving us excited to see what the next five years of Data Diuresis will bring.

  18. Treatment of Post-SCI Hypotension

    ClinicalTrials.gov

    2016-09-27

    Spinal Cord Injury; Autonomic Dysreflexia; Orthostatic Hypotension; Baroreceptor Integrity; Sympathetic Integrity; Vagal Integrity; Hypotension; Cerebral Blood Flow; Blood Pressure; Venous Occlusion Plethysmography

  19. Hypotension in Severe Dimethoate Self-Poisoning

    PubMed Central

    Davies, James; Roberts, Darren; Eyer, Peter; Buckley, Nick; Eddleston, Michael

    2008-01-01

    Introduction Acute self-poisoning with the organophosphorus (OP) pesticide dimethoate has a human case fatality three-fold higher than poisoning with chlorpyrifos despite similar animal toxicity. The typical clinical presentation of severe dimethoate poisoning is quite distinct from that of chlorpyrifos and other OP pesticides: many patients present with hypotension that progresses to shock and death within 12–48 h post-ingestion. The pathophysiology of this syndrome is not clear. Case reports We present here three patients with proven severe dimethoate poisoning. Clinically, all had inappropriate peripheral vasodilatation and profound hypotension on presentation, which progressed despite treatment with atropine, i.v. fluids, pralidoxime chloride, and inotropes. All died 2.5–32 h post-admission. Continuous cardiac monitoring and quantification of troponin T provided little evidence for a primary cardiotoxic effect of dimethoate. Conclusion Severe dimethoate self-poisoning causes a syndrome characterized by marked hypotension with progression to distributive shock and death despite standard treatments. A lack of cardiotoxicity until just before death suggests that the mechanism is of OP-induced low systemic vascular resistance (SVR). Further invasive studies of cardiac function and SVR, and post-mortem histology, are required to better describe this syndrome and to establish the role of vasopressors and high-dose atropine in therapy. PMID:19003596

  20. Seated postural hypotension.

    PubMed

    Gorelik, Oleg; Cohen, Natan

    2015-12-01

    Most studies of postural hypotension (PH) have focused on standing PH. Less is known about PH after transition from a supine to sitting position. Moreover, seated PH has not been previously reviewed in the English literature. The aim of this review was to provide current information regarding seating-induced PH. Seventeen studies were reviewed regarding prevalence, methods of evaluation, manifestations, predisposing factors, prognosis, and management of seated PH. Prevalence ranged from 8% among community-dwelling persons to 56% in elderly hospitalized patients. Dizziness and palpitations were the most frequent symptoms. Of a variety of factors that have been identified as predisposing and contributing to seated PH, aging, bed rest, and hypertension were most important. Because seated PH is a common, easily diagnosable and frequently symptomatic condition, especially in elderly inpatients, this disorder warrants attention. Moreover, seating-induced falls in blood pressure and the associated symptoms, may be largely prevented by nonpharmacologic interventions. PMID:26515671

  1. Hypotensive Resuscitation among Trauma Patients

    PubMed Central

    Carrick, Matthew M.; Leonard, Jan; Slone, Denetta S.; Mains, Charles W.

    2016-01-01

    Hemorrhagic shock is a principal cause of death among trauma patients within the first 24 hours after injury. Optimal fluid resuscitation strategies have been examined for nearly a century, more recently with several randomized controlled trials. Hypotensive resuscitation, also called permissive hypotension, is a resuscitation strategy that uses limited fluids and blood products during the early stages of treatment for hemorrhagic shock. A lower-than-normal blood pressure is maintained until operative control of the bleeding can occur. The randomized controlled trials examining restricted fluid resuscitation have demonstrated that aggressive fluid resuscitation in the prehospital and hospital setting leads to more complications than hypotensive resuscitation, with disparate findings on the survival benefit. Since the populations studied in each randomized controlled trial are slightly different, as is the timing of intervention and targeted vitals, there is still a need for a large, multicenter trial that can examine the benefit of hypotensive resuscitation in both blunt and penetrating trauma patients.

  2. Hypotensive Resuscitation among Trauma Patients

    PubMed Central

    Carrick, Matthew M.; Leonard, Jan; Slone, Denetta S.; Mains, Charles W.

    2016-01-01

    Hemorrhagic shock is a principal cause of death among trauma patients within the first 24 hours after injury. Optimal fluid resuscitation strategies have been examined for nearly a century, more recently with several randomized controlled trials. Hypotensive resuscitation, also called permissive hypotension, is a resuscitation strategy that uses limited fluids and blood products during the early stages of treatment for hemorrhagic shock. A lower-than-normal blood pressure is maintained until operative control of the bleeding can occur. The randomized controlled trials examining restricted fluid resuscitation have demonstrated that aggressive fluid resuscitation in the prehospital and hospital setting leads to more complications than hypotensive resuscitation, with disparate findings on the survival benefit. Since the populations studied in each randomized controlled trial are slightly different, as is the timing of intervention and targeted vitals, there is still a need for a large, multicenter trial that can examine the benefit of hypotensive resuscitation in both blunt and penetrating trauma patients. PMID:27595109

  3. Hypotensive Resuscitation among Trauma Patients.

    PubMed

    Carrick, Matthew M; Leonard, Jan; Slone, Denetta S; Mains, Charles W; Bar-Or, David

    2016-01-01

    Hemorrhagic shock is a principal cause of death among trauma patients within the first 24 hours after injury. Optimal fluid resuscitation strategies have been examined for nearly a century, more recently with several randomized controlled trials. Hypotensive resuscitation, also called permissive hypotension, is a resuscitation strategy that uses limited fluids and blood products during the early stages of treatment for hemorrhagic shock. A lower-than-normal blood pressure is maintained until operative control of the bleeding can occur. The randomized controlled trials examining restricted fluid resuscitation have demonstrated that aggressive fluid resuscitation in the prehospital and hospital setting leads to more complications than hypotensive resuscitation, with disparate findings on the survival benefit. Since the populations studied in each randomized controlled trial are slightly different, as is the timing of intervention and targeted vitals, there is still a need for a large, multicenter trial that can examine the benefit of hypotensive resuscitation in both blunt and penetrating trauma patients. PMID:27595109

  4. Guidance document for structured reporting of diuresis renography.

    PubMed

    Taylor, Andrew T; Blaufox, M Donald; De Palma, Diego; Dubovsky, Eva V; Erbaş, Belkis; Eskild-Jensen, Anni; Frøkiær, Jørgen; Issa, Muta M; Piepsz, Amy; Prigent, Alain

    2012-01-01

    This Guidance Document for structured reporting of diuresis renography in adults was developed by the International Scientific Committee of Radionuclides in Nephro-urology (ISCORN; http://www.iscorn.org). ISCORN chose diuresis renography for its first structured report Guidance Document because suspected obstruction is the most common reason for referral, most radionuclide renal studies are conducted at institutions that perform fewer than 3 studies per week, and a large percentage of studies are interpreted by physicians with limited training in nuclear medicine. Ten panelists were asked to categorize specific reporting elements as essential, recommended, optional (without sufficient data to support a higher ranking), and unnecessary (does not contribute to scan interpretation or quality assurance). The final document was developed through an iterative series of comments and questionnaires with a majority vote required to place an element in a specific category. The Guidance Document recommends a reporting structure organized into indications, clinical history, study procedure, findings and impression and specifies the elements considered essential or recommended in each category. The Guidance Document is not intended to be restrictive but, rather, to provide a basic structure and rationale so that the diuresis renography report will: (1) communicate the results to the referring physician in a clear and concise manner designed to optimize patient care; (2) contain the essential elements required to evaluate and interpret the study; (3) clearly document the technical components of the study necessary for accountability, quality assurance and reimbursement; and (4) encourage clinical research by facilitating better comparison and extrapolation of results between institutions.

  5. What Are the Signs and Symptoms of Hypotension?

    MedlinePlus

    ... from the NHLBI on Twitter. What Are the Signs and Symptoms of Hypotension? Orthostatic Hypotension and Neurally Mediated Hypotension The signs and symptoms of orthostatic hypotension and neurally mediated ...

  6. Ocular hypotensive effects of medifoxamine.

    PubMed Central

    Saleh, S; Turner, P

    1992-01-01

    Medifoxamine is a novel monoamine re-uptake inhibiting antidepressive drug which preferentially inhibits dopamine reuptake. In human volunteer studies it has been found to reduce significantly intraocular pressure after single oral doses of 300-1000 mg, and to produce a small but statistically significant miosis. Its maximal ocular hypotensive action was less than that of oral timolol 20 mg. PMID:1389953

  7. Management of neurogenic orthostatic hypotension.

    PubMed

    Arbique, Debbie; Cheek, Dennis; Welliver, Mark; Vongpatanasin, Wanpen

    2014-04-01

    The burden of orthostatic hypotension (OH) on public health is a universally recognized enigmatic clinical condition that is associated with significant increases on morbidity and mortality rates, and can take a major toll on one's quality of life. Orthostatic hypotension is predictive of vascular deaths from acute myocardial infarction, strokes in the middle aged population, and increases mortality rates when associated with diabetes, hypertension, Parkinson's disease, and patients receiving renal dialysis. The consensus definition for OH is a fall in systolic blood pressure of at least 20 mm Hg and/or diastolic blood pressure of at least 10 mm Hg within 3 minutes of quiet standing. Because neurogenic OH is often accompanied by supine hypertension, the treatment program should aim toward minimizing OH and the potential fall injuries related to cerebral hypoperfusion without exacerbating nocturnal hypertension that may lead to excessive cardiovascular complications.

  8. Refractory intraoperative hypotension with elevated serum tryptase

    PubMed Central

    Larson, Kelly J.; Divekar, Rohit D.; Butterfield, Joseph H.; Schwartz, Lawrence B.; Weingarten, Toby N.

    2015-01-01

    Severe intraoperative hypotension has been reported in patients on angiotensin-converting enzyme inhibitors and angiotensin II receptor subtype 1 antagonists. We describe a patient on lisinopril who developed refractory intraoperative hypotension associated with increased serum tryptase level suggesting mast cell activation (allergic reaction). However, allergology workup ruled out an allergic etiology as well as mastocytosis, and hypotension recalcitrant to treatment was attributed to uninterrupted lisinopril therapy. Elevated serum tryptase was attributed to our patient's chronic renal insufficiency. PMID:25653920

  9. RNAi-mediated gene knockdown and in vivo diuresis assay in adult female Aedes aegypti mosquitoes.

    PubMed

    Drake, Lisa L; Price, David P; Aguirre, Sarah E; Hansen, Immo A

    2012-07-14

    This video protocol demonstrates an effective technique to knockdown a particular gene in an insect and conduct a novel bioassay to measure excretion rate. This method can be used to obtain a better understanding of the process of diuresis in insects and is especially useful in the study of diuresis in blood-feeding arthropods that are able to take up huge amounts of liquid in a single blood meal. This RNAi-mediated gene knockdown combined with an in vivo diuresis assay was developed by the Hansen lab to study the effects of RNAi-mediated knockdown of aquaporin genes on Aedes aegypti mosquito diuresis. The protocol is setup in two parts: the first demonstration illustrates how to construct a simple mosquito injection device and how to prepare and inject dsRNA into the thorax of mosquitoes for RNAi-mediated gene knockdown. The second demonstration illustrates how to determine excretion rates in mosquitoes using an in vivo bioassay.

  10. Partial blockade of neurotensin-induced hypotension in rats by nephrectomy captopril and saralasin. Possible mechanisms.

    PubMed

    Kérouac, R; St-Pierre, S; Manning, M; Rioux, F

    1983-04-01

    We have assessed the influence of acute bilateral nephrectomy, of captopril and saralasin, on the hypotensive activity of neurotensin (NT) and of various hypotensive drugs in pentobarbital-anesthetized rats. The results show that the hypotensive activity of NT and of compound 48/80 (C48/80), in contrast to that of histamine, of 5-hydroxytryptamine and of hexamethonium, is markedly reduced, especially for NT, in nephrectomized as compared to sham operated rats. The pretreatment of rats with captopril (10 mg kg-1, i.v.) or with saralasin (20 micrograms kg-1 min-1, i.v.) was found to inhibit significantly the hypotensive activity of NT and of C48/80. Adrenalectomy restored partially the hypotensive activity of NT in nephrectomized rats. The potent vasopressin antagonist [d(CH2)5 Tyr(Me)AVP] did not alter the refractoriness of nephrectomized rats to the hypotensive activity of NT. Neither nephrectomy nor saralasin were found to interfere with the ability of NT or of C48/80 to evoke an increase of plasma histamine level or of the hematocrit. The results were interpreted as an indication that NT produces part of its hypotensive effect in anesthetized rats by reducing the activity of the renin angiotensin system. The results also suggest that part of the refractoriness of nephrectomized rats to the hypotensive activity of NT could be due to the release of catecholamines from adrenal glands by NT. Endogenous vasopressin does not appear to contribute to the refractoriness of nephrectomized rats to the hypotensive action of NT.

  11. Retrospective study to characterize post-obstructive diuresis in cats with urethral obstruction.

    PubMed

    Francis, Brenda J; Wells, Raegan J; Rao, Sangeeta; Hackett, Timothy B

    2010-08-01

    Urethral obstruction is a common medical emergency in cats. Frequency of post-obstruction diuresis in cats following resolution of urethral obstruction is unknown. The objective of this study was to document frequency and associated clinical features of post-obstruction diuresis in cats. The records of 32 cats undergoing 33 admissions to the Colorado State University Veterinary Hospital for urethral obstruction were reviewed. Signalment, admission blood values, fluid therapy, and urine output were recorded. Diuresis was defined as urine output greater than 2ml/kg/h. Post-obstructive diuresis occurred in 46% (13/28) of cats within the first 6h of treatment. Occurrence of post-obstructive diuresis was statistically more likely in cats with venous pH<7.35 on admission. Urine production following resolution of urethral obstruction should be monitored so that fluid therapy can be adjusted to the individual patient, as many cats will have a higher fluid requirement secondary to post-obstruction diuresis.

  12. A dynamic paracellular pathway serves diuresis in mosquito Malpighian tubules.

    PubMed

    Beyenbach, Klaus W

    2012-07-01

    Female mosquitoes gorge on vertebrate blood, a rich nutrient source for developing eggs, but gorging meals increase the risk of predation. Mosquitoes are quick to reduce the flight payload with a potent diuresis. Diuretic peptides of the insect kinin family induce a tenfold reduction in the paracellular resistance of Malpighian tubules and increase the paracellular permeation of Cl(-), the counterion of the transepithelial secretion of Na(+) and K(+). As a result, the transepithelial secretion of NaCl and KCl and water increases. Insect kinins signal the opening of the paracellular pathway via G protein-coupled receptors and the elevation of intracellular [Ca(2+)], which leads to the reorganization of the cytoskeleton associated with the septate junction (SJ). The reorganization may affect the septate junctional proteins that control the barrier and permselectivity properties of the paracellular pathway. The proteins involved in the embryonic formation of the SJ and in epithelial polarization are largely known for ectodermal epithelia, but the proteins that form and mediate the dynamic functions of the SJ in Malpighian tubules remain to be determined.

  13. Renal melatonin excretion in sheep is enhanced by water diuresis.

    PubMed

    Valtonen, M; Laitinen, J T; Eriksson, L

    1993-09-01

    Diurnal variation in blood melatonin levels and renal melatonin excretion was monitored in five ewes by blood sampling and quantitative urine collection at 2-h intervals. A typical secretory pattern of melatonin was seen both in blood and urine levels and in the renal excretion of melatonin. Serum melatonin levels increased from daytime values of approximately 200 pmol/l to a mean of 800 pmol/l during darkness. Urine flow rate and urine osmolality did not show any clear diurnal rhythm. To examine whether urine flow rate affects renal melatonin excretion at night, urine was collected in three consecutive 30-min fractions, and blood was sampled in the middle of each urine collection period when the sheep were in normal water balance or after hydration. Hydration increased urine flow rate over sixfold and decreased urine osmolality well below plasma osmolality. Glomerular filtration rate, measured as creatinine clearance, did not change. Serum melatonin concentrations did not differ between hydrated and non-hydrated sheep. However, urinary melatonin excretion was 1.1 +/- 0.3 (S.E.M.) pmol/min at midnight in normal water balance, and significantly higher (2.6 +/- 0.4 pmol/min) in the hydrated state. In this study, the validity of urinary melatonin determinations as an indicator of pineal function was confirmed in normal water balance. In addition, our results suggest that a high tubular fluid load during diuresis increases urinary melatonin excretion because of decreased tubular reabsorption.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Hemodilution, vasopressin suppression, and diuresis during water immersion in man

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Keil, L. C.; Shvartz, E.

    1981-01-01

    The possible role of hemodilution in the early stages of water immersion in the suppression of antidiuretic hormone (vasopressin) and subsequent diuresis in man is investigated. Parameters characterizing hemodilution as well as water balance and intercompartmental fluid levels were measured before, during and after the immersion of ten subjects in a semireclining position in tap water up to their necks at 34.6 C for 8 hr. Results indicate that hemodilution and the suppression of vasopressin and plasma renin activity were present by the second hour of immersion, with the early hemodilution due to a slight increase in plasma volume with no change in plasma sodium or osmotic contents, even though urine volume and osmotic excretion rates increased significantly. Hyponatremia, hyposmotemia and plasma renin activity suppression are observed to continue to the end of immersion, resulting in final decreases of 15.6% in plasma volume, 18.8% in extracellular volume, 19.6% in interstitial volume and 10.7% in red cell volume. Findings suggest the transfer of hypotonic fluid into the vascular system, which contributes to vasopressin suppression observed during immersion.

  15. Orthostatic hypotension: epidemiology, pathophysiology and management

    NASA Technical Reports Server (NTRS)

    Jacob, G.; Robertson, D.

    1995-01-01

    Orthostatic hypotension is characterized by low upright blood pressure levels and symptoms of cerebral hypoperfusion. Whereas orthostatic hypotension is heterogeneous, correct pathophysiologic diagnosis is important because of therapeutic and prognostic considerations. Although therapy is not usually curative, it can be extraordinarily beneficial if it is individually tailored. Management of the Shy-Drager syndrome (multiple-system atrophy) remains a formidable challenge.

  16. A rare cause of postoperative hypotension.

    PubMed

    Salinas, Pedro D; Toth, Laura N; Manning, Harold L

    2015-05-01

    A 62-year-old woman presented with a 3-month history of abdominal distension and decreased exercise tolerance. A chest radiograph showed a probable left pleural effusion (Fig 1). A CT scan of the abdomen revealed a solid ovarian mass with omental caking and a large volume of ascites; there was also confirmation of a left pleural effusion. Three days before surgery a CT pulmonary angiogram (CTPA) showed no evidence of pulmonary thromboembolism (PTE). The patient had some improvement in her symptoms after paracentesis and thoracentesis with drainage of 2,000 mL and 250 mL of fluid, respectively. She underwent total abdominal hysterectomy, bilateral oophorectomy, and partial sigmoid resection with an estimated blood loss of 850 mL. During the operation, she received 5 L of crystalloid and required phenylephrine at 40 to 80 μg/min to maintain a mean arterial pressure > 65 mm Hg. She was extubated after surgery, but immediately after extubation, she became markedly hypotensive and hypoxemic with a BP of 50/20 mm Hg and an oxygen saturation of 70%. An ECG showed T-wave inversions from V1 to V5 and an S1Q3T3 pattern (Fig 2). A bedside echocardiogram showed an enlarged right ventricle (RV), septal dyskinesia, and obliteration of the left ventricle, all consistent with systolic and diastolic RV overload (Fig 3). PMID:25940260

  17. Droxidopa in neurogenic orthostatic hypotension.

    PubMed

    Kaufmann, Horacio; Norcliffe-Kaufmann, Lucy; Palma, Jose-Alberto

    2015-01-01

    Neurogenic orthostatic hypotension (nOH) is a fall in blood pressure (BP) on standing due to reduced norepinephrine release from sympathetic nerve terminals. nOH is a feature of several neurological disorders that affect the autonomic nervous system, most notably Parkinson disease (PD), multiple system atrophy (MSA), pure autonomic failure (PAF), and other autonomic neuropathies. Droxidopa, an orally active synthetic amino acid that is converted to norepinephrine by the enzyme aromatic L-amino acid decarboxylase (dopa-decarboxylase), was recently approved by the FDA for the short-term treatment of nOH. It is presumed to raise BP by acting at the neurovascular junction to increase vascular tone. This article summarizes the pharmacological properties of droxidopa, its mechanism of action, and the efficacy and safety results of clinical trials. PMID:26092297

  18. Droxidopa in neurogenic orthostatic hypotension

    PubMed Central

    Kaufmann, Horacio; Norcliffe-Kaufmann, Lucy; Palma, Jose-Alberto

    2015-01-01

    Neurogenic orthostatic hypotension (nOH) is a fall in blood pressure on standing due to reduced norepinephrine release from sympathetic nerve terminals. nOH is a feature of several neurological disorders that affect the autonomic nervous system, most notably Parkinson disease (PD), multiple system atrophy, pure autonomic failure and other autonomic neuropathies. Droxidopa, an orally active synthetic amino acid that is converted to norepinephrine by the enzyme aromatic L-amino acid decarboxylase (dopa-decarboxylase), was recently approved by the FDA for the short-term treatment of nOH. It is presumed to raise blood pressure by acting at the neurovascular junction to increase vascular tone. This review summarizes the pharmacological properties of droxidopa, its mechanism of action, and the efficacy and safety results of clinical trials. PMID:26092297

  19. Orthognathic surgery with or without induced hypotension.

    PubMed

    Carlos, E; Monnazzi, M S; Castiglia, Y M M; Gabrielli, M F R; Passeri, L A; Guimarães, N C

    2014-05-01

    This study involved a retrospective evaluation of patients subjected to surgery for dentofacial deformities treated without induced controlled hypotension (group I, n=50) and a prospective evaluation of patients who were subjected to surgery under hypotensive general anaesthesia (group II, n=50). No statistical differences were found between the study groups with regard to the duration of surgery. However, there were statistically significant differences in the need for blood transfusion and the occurrence of bradycardia during the maxillary down-fracture. Hypotensive anaesthesia decreased the need for a blood transfusion and the occurrence of bradycardia, and is therefore considered highly beneficial for patients undergoing orthognathic surgery.

  20. Sympathoinhibition and hypotension in carotid sinus hypersensitivity

    NASA Technical Reports Server (NTRS)

    Smith, M. L.; Ellenbogen, K. A.; Eckberg, D. L.

    1992-01-01

    Carotid sinus reflex hypersensitivity is a known cause of syncope in humans. The condition is characterized by cardioinhibition and vasodepression, each to varying degrees. The extent and importance of sympathoinhibition has not been determined in patients with carotid sinus hypersensitivity. This study reports on the extent of sympathoinhibition measured directly directly during carotid massage with and without atrioventricular sequential pacing, in a patient with symptomatic carotid sinus reflex hypersensitivity. Carotid massage elicited asystole, hypotension and complete inhibition of muscle sympathetic nerve activity. Carotid massage during atrioventricular pacing produced similar sympathoinhibition, but with minimal hypotension. Therefore, sympathoinhibition did not contribute importantly to the hypotension during carotid massage in the supine position in this patient. Further investigations are required to elucidate the relation of sympathoinhibition to hypotension in patients with carotid sinus hypersensitivity in the upright position.

  1. [Orthostatic hypotension in the elderly].

    PubMed

    Ferrer-Gila, Teresa; Rízea, Cristian

    2013-03-16

    Orthostatic hypotension (OH) is defined as a decrease in systolic blood pressure of 20 mmHg, or a decrease in diastolic blood pressure of 10 mmHg within three minutes of standing. It results from an inadequate response to postural changes in blood pressure. Common symptoms include dizziness, light-headedness, blurred vision, weakness, fatigue, nausea, palpitations, sweating, head and neck ache, slow cognitive performance and transient loss of conscientiousness. OH is a common problem among elderly patients and its aetiology is diverse, including autonomic nervous system dysfunction, cardiac problems, medication side effects, ageing changes or transitory deregulation of blood volume. The instrumental diagnosis can be easily accomplished by the tilt-table test, with continuous monitoring of blood pressure and cardiac parameters. It is a non-invasive technique and needs minimal collaboration from the patient. In our experience, when reviewing 327 patients, aged over 40 years and examined because of clinical suspicion of OH, the prevalence thereof was 51% whereas if focused in subjects older than 70, OH was proven in 90% of the cases. The older the patients, the more frequently they presented general deterioration, neurological or cardiac problems as well as pharmacological side effects. Ruling out neurological or cardiac malfunction can drastically improve the prognosis with possible reversibility of symptoms. Some nonpharmacological and pharmacological approaches to improve management of OH and life quality are described for guidance.

  2. Coordinated response of renal medullary enzymes regulating net sorbitol production in diuresis and antidiuresis.

    PubMed

    Sands, J M; Schrader, D C

    1990-07-01

    The renal response to changes in hydration includes variation in intracellular sorbitol, a major inner medullary osmolyte. To examine the mechanism for changes in net sorbitol production, we measured activities of enzymes regulating sorbitol production (aldose reductase) and degradation (sorbitol dehydrogenase) in untreated, water diuretic, and antidiuretic (water restriction and/or vasopressin administration) rats. Collecting duct segments dissected from collagenase-treated kidneys of Sprague-Dawley rats were divided into outer medullary and three distinct inner medullary regions. Aldose reductase activity increased during antidiuresis and decreased during diuresis. In contrast, sorbitol dehydrogenase activity was very low during antidiuresis and increased during diuresis. These changes in enzyme activity were found after 3 days, but not after 1 day, of water diuresis/antidiuresis. Enzyme activity changed only in the deepest 50% of the inner medullary collecting duct. Thus, there is coordinated regulation of aldose reductase and sorbitol dehydrogenase activities so that (a) during water diuresis, aldose reductase activity decreases while sorbitol dehydrogenase activity increases; and (b) during antidiuresis (water restriction and/or vasopressin administration), aldose reductase activity increases while sorbitol dehydrogenase activity remains low. We conclude that long-term osmoregulation in response to physiologic stimuli involves both aldose reductase and sorbitol dehydrogenase activities in rat terminal inner medullary collecting duct segments.

  3. Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats

    PubMed Central

    Cheema-Dhadli, Surinder; Chong, Chee Keong; Kim, Namhee; Kamel, Kamel S

    2010-01-01

    When the concentration of sodium (Na+) in arterial plasma (PNa) declines sufficiently to inhibit the release of vasopressin, water will be excreted promptly when the vast majority of aquaporin 2 water channels (AQP2) have been removed from luminal membranes of late distal nephron segments. In this setting, the volume of filtrate delivered distally sets the upper limit on the magnitude of the water diuresis. Since there is an unknown volume of water reabsorbed in the late distal nephron, our objective was to provide a quantitative assessment of this parameter. Accordingly, rats were given a large oral water load, while minimizing non-osmotic stimuli for the release of vasopressin. The composition of plasma and urine were measured. The renal papilla was excised during the water diuresis to assess the osmotic driving force for water reabsorption in the inner medullary collecting duct. During water diuresis, the concentration of creatinine in the urine was 13-fold higher than in plasma, which implies that ~8% of filtered water was excreted. The papillary interstitial osmolality was 600 mOsm/L > the urine osmolality. Since 17% of filtered water is delivered to the earliest distal convoluted tubule micropuncture site, we conclude that half of the water delivered to the late distal nephron is reabsorbed downstream during water diuresis. The enormous osmotic driving force for the reabsorption of water in the inner medullary collecting duct may play a role in this reabsorption of water. Possible clinical implications are illustrated in the discussion of a case example. PMID:21468191

  4. Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats.

    PubMed

    Cheema-Dhadli, Surinder; Chong, Chee Keong; Kim, Namhee; Kamel, Kamel S; Halperin, Mitchell L

    2010-06-01

    When the concentration of sodium (Na(+)) in arterial plasma (P(Na)) declines sufficiently to inhibit the release of vasopressin, water will be excreted promptly when the vast majority of aquaporin 2 water channels (AQP2) have been removed from luminal membranes of late distal nephron segments. In this setting, the volume of filtrate delivered distally sets the upper limit on the magnitude of the water diuresis. Since there is an unknown volume of water reabsorbed in the late distal nephron, our objective was to provide a quantitative assessment of this parameter. Accordingly, rats were given a large oral water load, while minimizing non-osmotic stimuli for the release of vasopressin. The composition of plasma and urine were measured. The renal papilla was excised during the water diuresis to assess the osmotic driving force for water reabsorption in the inner medullary collecting duct. During water diuresis, the concentration of creatinine in the urine was 13-fold higher than in plasma, which implies that ~8% of filtered water was excreted. The papillary interstitial osmolality was 600 mOsm/L > the urine osmolality. Since 17% of filtered water is delivered to the earliest distal convoluted tubule micropuncture site, we conclude that half of the water delivered to the late distal nephron is reabsorbed downstream during water diuresis. The enormous osmotic driving force for the reabsorption of water in the inner medullary collecting duct may play a role in this reabsorption of water. Possible clinical implications are illustrated in the discussion of a case example. PMID:21468191

  5. Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats.

    PubMed

    Cheema-Dhadli, Surinder; Chong, Chee Keong; Kim, Namhee; Kamel, Kamel S; Halperin, Mitchell L

    2010-06-01

    When the concentration of sodium (Na(+)) in arterial plasma (P(Na)) declines sufficiently to inhibit the release of vasopressin, water will be excreted promptly when the vast majority of aquaporin 2 water channels (AQP2) have been removed from luminal membranes of late distal nephron segments. In this setting, the volume of filtrate delivered distally sets the upper limit on the magnitude of the water diuresis. Since there is an unknown volume of water reabsorbed in the late distal nephron, our objective was to provide a quantitative assessment of this parameter. Accordingly, rats were given a large oral water load, while minimizing non-osmotic stimuli for the release of vasopressin. The composition of plasma and urine were measured. The renal papilla was excised during the water diuresis to assess the osmotic driving force for water reabsorption in the inner medullary collecting duct. During water diuresis, the concentration of creatinine in the urine was 13-fold higher than in plasma, which implies that ~8% of filtered water was excreted. The papillary interstitial osmolality was 600 mOsm/L > the urine osmolality. Since 17% of filtered water is delivered to the earliest distal convoluted tubule micropuncture site, we conclude that half of the water delivered to the late distal nephron is reabsorbed downstream during water diuresis. The enormous osmotic driving force for the reabsorption of water in the inner medullary collecting duct may play a role in this reabsorption of water. Possible clinical implications are illustrated in the discussion of a case example.

  6. Hyperprolactinemia due to spontaneous intracranial hypotension.

    PubMed

    Schievink, Wouter I; Nuño, Miriam; Rozen, Todd D; Maya, M Marcel; Mamelak, Adam N; Carmichael, John; Bonert, Vivien S

    2015-05-01

    OBJECT Spontaneous intracranial hypotension is an increasingly recognized cause of headaches. Pituitary enlargement and brain sagging are common findings on MRI in patients with this disorder. The authors therefore investigated pituitary function in patients with spontaneous intracranial hypotension. METHODS Pituitary hormones were measured in a group of 42 consecutive patients with spontaneous intracranial hypotension. For patients with hyperprolactinemia, prolactin levels also were measured following treatment. Magnetic resonance imaging was performed prior to and following treatment. RESULTS The study group consisted of 27 women and 15 men with a mean age at onset of symptoms of 52.2 ± 10.7 years (mean ± SD; range 17-72 years). Hyperprolactinemia was detected in 10 patients (24%), ranging from 16 ng/ml to 96.6 ng/ml in men (normal range 3-14.7 ng/ml) and from 31.3 ng/ml to 102.5 ng/ml in women (normal range 3.8-23.2 ng/ml). In a multivariate analysis, only brain sagging on MRI was associated with hyperprolactinemia. Brain sagging was present in 60% of patients with hyperprolactinemia and in 19% of patients with normal prolactin levels (p = 0.02). Following successful treatment of the spontaneous intracranial hypotension, hyperprolactinemia resolved, along with normalization of brain MRI findings in all 10 patients. CONCLUSIONS Spontaneous intracranial hypotension is a previously undescribed cause of hyperprolactinemia. Brain sagging causing distortion of the pituitary stalk (stalk effect) may be responsible for the hyperprolactinemia. PMID:25380110

  7. Cardiac morphology and function in patients with and without residual diuresis on hemodialysis.

    PubMed

    Araujo, Salustiano; Lemes, Helton P; Cunha, Danny A; Queiroz, Vinicius S; Nascimento, Daniela D; Ferreira Filho, Sebastião Rodrigues

    2011-03-01

    In patients with chronic renal failure on hemodialysis, left ventricular hypertrophy is related to the increase in total peripheral vascular resistance and volume overload. The presence of residual diuresis enables greater control of the volemia of these. We evaluated the morpho-functional changes of the left ventricle in patients with chronic kidney disease on hemodyalisis treatment with and without residual diuresis. A total of 31 non diabetic patients were studied and they were divided into two groups: with residual diuresis (RD+) (n = 17) and without residual diuresis (RD-) (n = 14). In both groups, RD+ vs. RD-, using data from a Doppler echocardiogram differences were found, respectively, in the cardiac index (3.9 ± 0.2 vs. 3.0 ± 0.2 L/min/m²; p = 0.0056), systolic index (54 ± 2.9 vs. 45 ± 3.3 mL/b/m²; p = 0.04), end diastolic volume (141 ± 6.7 vs. 112 ± 7.6 mL; p = 0.008), end diastolic diameter (52 ± 0.7 vs. 48 ± 1.1 mm; p = 0.0072) and total peripheral resistance index (1121 ± 56 vs. 1529 ± 111 dyne.sec.cm-5; p = 0.001). RD+ had lower relative wall thickness than RD- (0.38 ± 0.01 vs. 0.45 ± 0.01; p = 0.0008). The ejection fraction and the left ventricular mass index were similar in both groups. The urinary 24-hour volume correlated with the relative wall thickness (r = -0.42; p = 0.0186) and with peripheral resistance index (r = -0.48; p = 0.0059). In conclusion, there were distinct ventricular geometric patterns and different functional performances between RD+ and RD- groups. The presence of residual diuresis can be responsible by these modifications in systolic function.

  8. Caffeine-induced diuresis and natriuresis is independent of renal tubular NHE3.

    PubMed

    Fenton, Robert A; Poulsen, Søren B; de la Mora Chavez, Samantha; Soleimani, Manoocher; Busslinger, Meinrad; Dominguez Rieg, Jessica A; Rieg, Timo

    2015-06-15

    Caffeine is one of the most widely consumed behavioral substances. We have previously shown that caffeine- and theophylline-induced inhibition of renal reabsorption causes diuresis and natriuresis, an effect that requires functional adenosine A1 receptors. In this study, we tested the hypothesis that blocking the Gi protein-coupled adenosine A1 receptor via the nonselective adenosine receptor antagonist caffeine changes Na(+)/H(+) exchanger isoform 3 (NHE3) localization and phosphorylation, resulting in diuresis and natriuresis. We generated tubulus-specific NHE3 knockout mice (Pax8-Cre), where NHE3 abundance in the S1, S2, and S3 segments of the proximal tubule was completely absent or severely reduced (>85%) in the thick ascending limb. Consumption of fluid and food, as well as glomerular filtration rate, were comparable in control or tubulus-specific NHE3 knockout mice under basal conditions, while urinary pH was significantly more alkaline without evidence for metabolic acidosis. Caffeine self-administration increased total fluid and food intake comparably between genotypes, without significant differences in consumption of caffeinated solution. Acute caffeine application via oral gavage elicited a diuresis and natriuresis that was comparable between control and tubulus-specific NHE3 knockout mice. The diuretic and natriuretic response was independent of changes in total NHE3 expression, phosphorylation of serine-552 and serine-605, or apical plasma membrane NHE3 localization. Although caffeine had no clear effect on localization of the basolateral Na(+)/bicarbonate cotransporter NBCe1, pretreatment with DIDS inhibited caffeine-induced diuresis and natriuresis. In summary, NHE3 is not required for caffeine-induced diuresis and natriuresis.

  9. Genetics and molecular biology of hypotension

    NASA Technical Reports Server (NTRS)

    Robertson, D.

    1994-01-01

    Major strides in the molecular biology of essential hypertension are currently underway. This has tended to obscure the fact that a number of inherited disorders associated with low blood pressure exist and that these diseases may have milder and underrecognized phenotypes that contribute importantly to blood pressure variation in the general population. This review highlights some of the gene products that, if abnormal, could cause hypotension in some individuals. Diseases due to abnormalities in the catecholamine enzymes are discussed in detail. It is likely that genetic abnormalities with hypotensive phenotypes will be as interesting and diverse as those that give rise to hypertensive disorders.

  10. Orthostatic Hypotension (Low Blood Pressure) and Parkinson's Disease

    MedlinePlus

    ... Order Free Materials Today Orthostatic Hypotension (Low Blood Pressure) Callers to the Parkinson’s Disease Foundation (PDF) National ... known as orthostatic hypotension (OH), or low blood pressure. If you have experienced it, you may already ...

  11. Multiple System Atrophy with Orthostatic Hypotension (Shy-Drager Syndrome)

    MedlinePlus

    ... Enhancing Diversity Find People About NINDS NINDS Multiple System Atrophy with Orthostatic Hypotension Information Page Synonym(s): Shy- ... being done? Clinical Trials Organizations What is Multiple System Atrophy with Orthostatic Hypotension? Multiple system atrophy with ...

  12. Genetic AVP deficiency abolishes cold-induced diuresis but does not attenuate cold-induced hypertension.

    PubMed

    Sun, Zhongjie

    2006-06-01

    Chronic cold exposure causes hypertension and diuresis. The aim of this study was to determine whether vasopressin (AVP) plays a role in cold-induced hypertension and diuresis. Two groups of Long-Evans (LE) and two groups of homozygous AVP-deficient Brattleboro (VD) rats were used. Blood pressure (BP) was not different among the four groups during a 2-wk control period at room temperature (25 degrees C, warm). After the control period, one LE group and one VD group were exposed to cold (5 degrees C); the remaining groups were kept at room temperature. BP and body weight were measured weekly during exposure to cold. Food intake, water intake, urine output, and urine osmolality were measured during weeks 1, 3, and 5 of cold exposure. At the end of week 5, all animals were killed and blood was collected for measurement of plasma AVP. Kidneys were removed for measurement of renal medulla V2 receptor mRNA and aquaporin-2 (AQP-2) protein expression. BP of LE and VD rats increased significantly by week 2 of cold exposure and reached a high level by week 5. BP elevations developed at approximately the same rate and to the same degree in LE and VD rats. AVP deficiency significantly increased urine output and solute-free water clearance and decreased urine osmolality. Chronic cold exposure increased urine output and solute-free water clearance and decreased urine osmolality in LE rats, indicating that cold exposure caused diuresis in LE rats. Cold exposure failed to affect these parameters in VD rats, suggesting that the AVP system is responsible for cold-induced diuresis. Cold exposure did not alter plasma AVP in LE rats. Renal medulla V2 receptor mRNA and AQP-2 protein expression levels were decreased significantly in the cold-exposed LE rats, suggesting that cold exposure inhibited renal V2 receptors and AVP-inducible AQP-2 water channels. We conclude that 1) AVP may not be involved in the pathogenesis of cold-induced hypertension, 2) the AVP system plays a critical role

  13. Does training-induced orthostatic hypotension result from reduced carotid baroreflex responsiveness?

    NASA Technical Reports Server (NTRS)

    Pawelczyk, James A.; Raven, Peter B.

    1994-01-01

    As manned space travel has steadily increased in duration and sophistication, the answer to a simple, relevant question remains elusive. Does endurance exercise training - high intensity rhythmic activity, performed regularly for extended periods of time - alter the disposition to, or severity of, postflight orthostatic hypotension? Research results continue to provide different views; however, data are difficult to compare because of the following factors that vary between investigations: the type of orthostatic stress imposed (+Gz, lower body negative pressure (LBNP), head-up tilt); pretest perturbations used (exercise, heat exposure, head-down tilting, bed rest, water immersion, hypohydration, pharmacologically-induced diuresis); the length of the training program used in longitudinal investigations (days versus weeks versus months); the criteria used to define fitness; and the criteria used to define orthostatic tolerance. Generally, research results indicate that individuals engaged in aerobic exercise activities for a period of years have been reported to have reduced orthostatic tolerance compared to untrained control subjects, while the results of shorter term longitudinal studies remain equivocal. Such conclusions suggest that chronic athletic training programs reduce orthostatic tolerance, whereas relatively brief (days to weeks) training programs do not affect orthostatic tolerance to any significant degree (increase or decrease). A primary objective was established to identify the alterations in blood pressure control that contribute to training-induced orthostatic hypotension (TIOH). Although any aspect of blood pressure regulation is suspect, current research has been focused on the baroreceptor system. Reductions in carotid baroreflex responsiveness have been documented in exercise-trained rabbits, reportedly due to an inhibitory influence from cardiac afferent, presumably vagal, nerve fibers that is abolished with intrapericardiac denervation. The

  14. Evaluation of Polyuria: The Roles of Solute Loading and Water Diuresis.

    PubMed

    Bhasin, Bhavna; Velez, Juan Carlos Q

    2016-03-01

    Polyuria, defined as daily urine output in excess of 3.0 to 3.5L/d, can occur due to solute or water diuresis. Solute-induced polyuria can be seen in hospitalized patients after a high solute load from exogenous protein administration or following relief of urinary obstruction. Similar clinical scenarios are rarely encountered in the outpatient setting. We describe a case of polyuria due to high solute ingestion and excessive water intake leading to a mixed picture of solute and water diuresis. Restriction of the daily solute load and water intake resulted in complete resolution of polyuria. Determination of the daily excreted urinary osmoles may yield important clues to the cause of polyuria and should be included in the routine workup of polyuria.

  15. Forced diuresis with the RenalGuard system: impact on contrast induced acute kidney injury.

    PubMed

    Solomon, Richard

    2014-01-01

    Kidney injury following the administration of iodinated contrast media occurs particularly in patients with reduced kidney and cardiac function and when large doses of contrast are used. There is little compelling evidence that vasodilators and anti-oxidants prevent this injury. Most prevention trials have employed intravenous volume loading as a central strategy. However, the success of this approach depends upon maintaining euvolemia while producing a vigorous diuresis. A novel strategy for maintaining euvolemia and inducing a vigorous diuresis has been developed using the RenalGuard system. In this review; the mechanism of protective action is reviewed. The trials of the RenalGuard device are reviewed and future uses of the device are discussed.

  16. Diagnosis of upper urinary tract obstruction in children: comparison of diuresis renography and pressure flow studies

    SciTech Connect

    Gonzalez, R.; Chiou, R.

    1985-04-01

    A report is given of the use of diuresis renography and pressure flow studies to diagnose urinary tract obstruction in 41 collecting systems of 33 children. If differential pressures between the renal pelvis and the bladder in excess of 22 cm. water at a flow rate of 10 ml. per minute is accepted as evidence of obstruction and below 15 cm. water is accepted as normal the interpretation of the renogram showing O'Reilly's pattern IIIa as evidence of stasis without obstruction was correct in 74 per cent of the cases. Likewise, the interpretation of O'Reilly's renogram pattern IIIb as showing partial obstruction was correct in only 40 per cent of the cases. Thus, the authors urge caution in the use of the diuresis renogram to diagnose or to rule out upper urinary tract obstruction.

  17. Evaluation of Polyuria: The Roles of Solute Loading and Water Diuresis.

    PubMed

    Bhasin, Bhavna; Velez, Juan Carlos Q

    2016-03-01

    Polyuria, defined as daily urine output in excess of 3.0 to 3.5L/d, can occur due to solute or water diuresis. Solute-induced polyuria can be seen in hospitalized patients after a high solute load from exogenous protein administration or following relief of urinary obstruction. Similar clinical scenarios are rarely encountered in the outpatient setting. We describe a case of polyuria due to high solute ingestion and excessive water intake leading to a mixed picture of solute and water diuresis. Restriction of the daily solute load and water intake resulted in complete resolution of polyuria. Determination of the daily excreted urinary osmoles may yield important clues to the cause of polyuria and should be included in the routine workup of polyuria. PMID:26687922

  18. Myocardial contractile function and intradialytic hypotension.

    PubMed

    Owen, Paul J; Priestman, William S; Sigrist, Mhairi K; Lambie, Stewart H; John, Stephen G; Chesterton, Lindsay J; McIntyre, Christopher W

    2009-07-01

    Dialysis-induced hypotension remains a significant problem in hemodialysis (HD) patients. Numerous factors result in dysregulation of blood pressure control and impaired myocardial reserve in response to HD-induced cardiovascular stress. Episodic intradialytic hypotension may be involved in the pathogenesis of evolving myocardial injury. We performed an initial pilot investigation of cardiovascular functional response to pharmacological cardiovascular stress in hypotension-resistant (HR) and hypotension-prone (HP) HD patients. We studied 10 matched chronic HD patients (5 HP, 5 HR). Dobutamine-atropine stress (DAS) was performed on a nondialysis short interval day, with noninvasive pulse-wave analysis using the Finometer to continuously measure hemodynamic variables. Baroreflex sensitivity was assessed at rest and during DAS. Baseline hemodynamic variables were not significantly different. The groups had differing hemodynamic responses to DAS. The Mean arterial pressure was unchanged in the HR group but decreased in HP patients (-13.6 +/- 3.5 mmHg; P<0.001). This was associated with failure to significantly increase cardiac output in the HP group (cf. increase in cardiac output in the HR group of +33.4 +/- 6%; P<0.05), and a reduced response in total peripheral resistance (HP -10.3 +/- 6.8%, HR -22.7 +/- 2.9%, P=NS). Baroreflex sensitivity was not significantly different between groups at baseline or within groups with increasing levels of DAS; however, the mean baroreflex sensitivity was higher in HR cf. HP subjects throughout pharmacological stress (P<0.05). Hypotension-prone patients appear to have an impaired cardiovascular response to DAS. The most significant abnormality is an impaired myocardial contractile reserve. Early identification of these patients would allow utilization of therapeutic strategies to improve intradialytic tolerability, potentially abrogating aggravation of myocardial injury.

  19. Hypotension and Environmental Noise: A Replication Study

    PubMed Central

    Lercher, Peter; Widmann, Ulrich; Thudium, Jürg

    2014-01-01

    Up to now, traffic noise effect studies focused on hypertension as health outcome. Hypotension has not been considered as a potential health outcome although in experiments some people also responded to noise with decreases of blood pressure. Currently, the characteristics of these persons are not known and whether this down regulation of blood pressure is an experimental artifact, selection, or can also be observed in population studies is unanswered. In a cross-sectional replication study, we randomly sampled participants (age 20–75, N = 807) from circular areas (radius = 500 m) around 31 noise measurement sites from four noise exposure strata (35–44, 45–54, 55–64, >64 Leq, dBA). Repeated blood pressure measurements were available for a smaller sample (N = 570). Standardized information on socio-demographics, housing, life style and health was obtained by door to door visits including anthropometric measurements. Noise and air pollution exposure was assigned by GIS based on both calculation and measurements. Reported hypotension or hypotension medication past year was the main outcome studied. Exposure-effect relationships were modeled with multiple non-linear logistic regression techniques using separate noise estimations for total, highway and rail exposure. Reported hypotension was significantly associated with rail and total noise exposure and strongly modified by weather sensitivity. Reported hypotension medication showed associations of similar size with rail and total noise exposure without effect modification by weather sensitivity. The size of the associations in the smaller sample with BMI as additional covariate was similar. Other important cofactors (sex, age, BMI, health) and moderators (weather sensitivity, adjacent main roads and associated annoyance) need to be considered as indispensible part of the observed relationship. This study confirms a potential new noise effect pathway and discusses potential patho-physiological routes of actions

  20. Antagonistic effects of atipamezole and yohimbine on xylazine-induced diuresis in healthy dogs.

    PubMed

    Talukder, Hasanuzzaman; Hikasa, Yoshiaki; Matsuu, Aya; Kawamura, Hiroe

    2009-05-01

    The aim of this study was to investigate and compare the antagonistic effects of atipamezole and yohimbine on xylazine-induced diuresis in healthy dogs. Five healthy male beagles were assigned to each of the 8 treatment groups in a randomized design at 1-week intervals in the same dog. One group was not medicated. The dogs in the other groups received 2 mg/kg xylazine intramuscularly (IM) and a treatment of saline (control), 50, 100 or 300 microg/kg of each atipamezole or yohimbine IM 0.5 hr later. Urine and blood samples were collected 11 times over the course of 24 hr. Urine volume, pH, specific gravity and creatinine values; osmolality, electrolyte and arginine vasopressin (AVP) values in both urine and plasma; and plasma atrial natriuretic peptide (ANP) concentration were measured. Both atipamezole and yohimbine antagonized xylazine-induced diuresis. The reversal effect of yohimbine was more potent, but not dose-dependent at the tested doses, in contrast with atipamezole. Both atipamezole and yohimbine exhibited similar potency in reversing the decreases in urine specific gravity, osmolality, creatinine, sodium and chloride concentrations and the increase in the plasma potassium concentration induced by xylazine. Both also inhibited xylazine-induced diuresis without significantly altering the hormonal profile in the dogs. A higher dose of atipamezole tended to increase the plasma ANP concentration. This may not be due only to actions mediated by alpha(2)-adrenoceptors. Both drugs can be used as antagonistic agents against xylazine-induced diuresis in healthy dogs.

  1. Effect of water temperature on diuresis-natriuresis: AVP, ANP, and urodilatin during immersion in men

    NASA Technical Reports Server (NTRS)

    Nakamitsu, S.; Sagawa, S.; Miki, K.; Wada, F.; Nagaya, K.; Keil, L. C.; Drummer, C.; Gerzer, R.; Greenleaf, J. E.; Hong, S. K.

    1994-01-01

    Effects of water temperature on diuresis, natriuresis, and associated endocrine responses during head-out immersion were studied in eight men during four 5-h experimental conditions: air control at 28 C and immersion at 34.5 C (thermoneutral (Tnt)), 36 C (above Tnt (aTnt)), and 32 C (below Tnt (bTnt). Esophageal temperature decreased by approximately 0.4 C in bTnt and increased by approximately 0.5 C in aTnt. Cardiac output increased by approximately 80% in aTnt and approximately 40% in bTnt while thoracic impedance, an index of central blood pooling, decreased by 7.5 ohms in bTnt (NS vs. Tnt) and 8.8 ohms in aTnt. Total peripheral resistance decreased at all temperatures (50% in aTnt, 20% in bTnt). Urine flow and Na(+) excretion increased by sixfold in bTnt and Tnt but by only threefold in aTnt. Creatinine clearance was unchanged while osmolal clearance (but not free water clearance) increased two-fold with all immersions. Plasma atrial natriuretic peptide (ANP), urinary urodilatin, and urinary guanosine 3',5'-cyclic monophosphate increased while plasma renin activity, aldosterone, and arginine vasopressin (AVP) decreased similarly at all temperatures. bTnt did not potentiate diuresis by selective attenuation of AVP. The overall natriuretic response exhibited a higher correlation with urodilatin than with ANP. Because diuresis and natriuresis were significantly attenuated in aTnt where central blood pooling was greater, we conclude that mechanisms other than the atrial stretch receptor reflex, i.e., urodilatin and effective arterial blood volume, may play more predominant roles in the mechanism of immersion-induced diuresis and natriuresis.

  2. Osmotic diuresis-induced hypernatremia: better explained by solute-free water clearance or electrolyte-free water clearance?

    PubMed

    Popli, Subhash; Tzamaloukas, Antonios H; Ing, Todd S

    2014-01-01

    Hypernatremia may result from inadequate water intake, excessive water loss or a combination of the two. Osmotic diuresis leads to losses of both solute and water. The relationship between solute and water losses determines the resulting changes in serum osmolality and sodium concentration. Total solute loss is routinely higher than loss of water in osmotic diuresis. Theoretically, then, decreases in serum osmolality (and serum sodium concentration) should follow. In clinical situations of osmotic diuresis, however, reduction in osmolality can take place, but not reduction in serum sodium concentration. It is of note that serum sodium concentration changes are related to urinary losses of sodium and potassium but not to the loss of total solute. In osmotic diuresis, the combined loss of sodium and potassium per liter of urine is lower than the concurrent serum sodium level. Consequently, hypernatremia can ensue. A patient who presented with osmotic diuresis and hypernatremia is described here. In this patient, we have shown that electrolyte-free water clearance is a better index of the effect of osmotic diuresis on serum sodium concentration than the classic solute-free water clearance.

  3. Diuresis by intravenous administration of xanthurenic acid in rats, and inhibition by probenecid.

    PubMed

    Uwai, Yuichi; Nakashima, Yuta; Honjo, Emi; Kawasaki, Tatsuya; Nabekura, Tomohiro

    2014-01-01

    The conjugates with sulfate and glucoside of xanthurenic acid, a tryptophan metabolite, were reported to show natriuresis. Sulfotransferase for xanthurenic acid works in the renal proximal tubule to produce the sulfate of xanthurenic acid as well as the liver, and we recently found that xanthurenic acid is a substrate of renal organic anion transporter OAT1. The purpose of this study was to examine relationship between the transport by OAT1 and diuresis related with xanthurenic acid. Drug transport experiment using Xenopus laevis oocytes represented that probenecid inhibited xanthurenic acid uptake by rat OAT1 (rOAT1). Although no diuresis was recognized by the intravenous injection of xanthurenic acid as a bolus in rats, the addition of its infusion exhibited natriuresis. Simultaneous administration of probenecid significantly decreased the urine volume and excreted amounts of sodium into urine. These findings showed the diuresis by the xanthurenic acid administration, and it was probenecid-sensitive. The rOAT1-mediated transport of xanthurenic acid might, at least in part, contribute to its diuretic effect.

  4. Antagonistic effects of atipamezole, yohimbine and prazosin on medetomidine-induced diuresis in healthy cats.

    PubMed

    Murahata, Yusuke; Yamamoto, Asami; Miki, Yuya; Hikasa, Yoshiaki

    2014-03-01

    This study aimed to investigate and compare the antagonistic effects of atipamezole, yohimbine and prazosin on medetomidine-induced diuresis in healthy cats. Five cats were repeatedly used in each of the 9 groups. One group was not medicated. Cats in the other groups received 40 µg/kg medetomidine intramuscularly and saline (as the control), 160 µg/kg prazosin, or 40, 160 or 480 µg/kg atipamezole or yohimbine intravenously 0.5 hr later. Volume, pH and specific gravity of urine; plasma arginine vasopressin (AVP) level; and creatinine, osmolality and electrolyte levels in both urine and plasma were measured. Both atipamezole and yohimbine, but not prazosin, antagonized medetomidine-induced diuresis. The antidiuretic effect of atipamezole was more potent than that of yohimbine, but was not dose dependent, in contrast to the effect of yohimbine at the tested doses. Both atipamezole and yohimbine reversed medetomidine-induced decreases in both urine specific gravity and osmolality and increases in plasma osmolality and free-water clearance. Antidiuresis of either atipamezole or yohimbine was not related to the area under the curve for AVP level, although the highest dose of both atipamezole and yohimbine initially and temporarily increased plasma AVP levels, suggesting that this may partly influence the antidiuretic effects of both agents. The diuretic effect of medetomidine in cats may be mediated by α2-adrenoceptors, but not α1-adrenoceptors. Atipamezole and yohimbine can be used as antagonistic agents against medetomidine-induced diuresis in healthy cats.

  5. Thienoquinolins exert diuresis by strongly inhibiting UT-A urea transporters.

    PubMed

    Ren, Huiwen; Wang, Yanhua; Xing, Yongning; Ran, Jianhua; Liu, Ming; Lei, Tianluo; Zhou, Hong; Li, Runtao; Sands, Jeff M; Yang, Baoxue

    2014-12-15

    Urea transporters (UT) play an important role in the urine concentration mechanism by mediating intrarenal urea recycling, suggesting that UT inhibitors could have therapeutic use as a novel class of diuretic. Recently, we found a thienoquinolin UT inhibitor, PU-14, that exhibited diuretic activity. The purpose of this study was to identify more potent UT inhibitors that strongly inhibit UT-A isoforms in the inner medullary collecting duct (IMCD). Efficient thienoquinolin UT inhibitors were identified by structure-activity relationship analysis. Urea transport inhibition activity was assayed in perfused rat terminal IMCDs. Diuretic activity of the compound was determined in rats and mice using metabolic cages. The results show that the compound PU-48 exhibited potent UT-A inhibition activity. The inhibition was 69.5% with an IC50 of 0.32 μM. PU-48 significantly inhibited urea transport in perfused rat terminal IMCDs. PU-48 caused significant diuresis in UT-B null mice, which indicates that UT-A is the target of PU-48. The diuresis caused by PU-48 did not change blood Na(+), K(+), or Cl(-) levels or nonurea solute excretion in rats and mice. No toxicity was detected in cells or animals treated with PU-48. The results indicate that thienoquinolin UT inhibitors induce a diuresis by inhibiting UT-A in the IMCD. This suggests that they may have the potential to be developed as a novel class of diuretics with fewer side effects than classical diuretics.

  6. Thienoquinolins exert diuresis by strongly inhibiting UT-A urea transporters

    PubMed Central

    Ren, Huiwen; Wang, Yanhua; Xing, Yongning; Ran, Jianhua; Liu, Ming; Lei, Tianluo; Zhou, Hong; Li, Runtao; Sands, Jeff M.

    2014-01-01

    Urea transporters (UT) play an important role in the urine concentration mechanism by mediating intrarenal urea recycling, suggesting that UT inhibitors could have therapeutic use as a novel class of diuretic. Recently, we found a thienoquinolin UT inhibitor, PU-14, that exhibited diuretic activity. The purpose of this study was to identify more potent UT inhibitors that strongly inhibit UT-A isoforms in the inner medullary collecting duct (IMCD). Efficient thienoquinolin UT inhibitors were identified by structure-activity relationship analysis. Urea transport inhibition activity was assayed in perfused rat terminal IMCDs. Diuretic activity of the compound was determined in rats and mice using metabolic cages. The results show that the compound PU-48 exhibited potent UT-A inhibition activity. The inhibition was 69.5% with an IC50 of 0.32 μM. PU-48 significantly inhibited urea transport in perfused rat terminal IMCDs. PU-48 caused significant diuresis in UT-B null mice, which indicates that UT-A is the target of PU-48. The diuresis caused by PU-48 did not change blood Na+, K+, or Cl− levels or nonurea solute excretion in rats and mice. No toxicity was detected in cells or animals treated with PU-48. The results indicate that thienoquinolin UT inhibitors induce a diuresis by inhibiting UT-A in the IMCD. This suggests that they may have the potential to be developed as a novel class of diuretics with fewer side effects than classical diuretics. PMID:25298523

  7. Antagonistic effects of atipamezole, yohimbine and prazosin on medetomidine-induced diuresis in healthy cats.

    PubMed

    Murahata, Yusuke; Yamamoto, Asami; Miki, Yuya; Hikasa, Yoshiaki

    2014-03-01

    This study aimed to investigate and compare the antagonistic effects of atipamezole, yohimbine and prazosin on medetomidine-induced diuresis in healthy cats. Five cats were repeatedly used in each of the 9 groups. One group was not medicated. Cats in the other groups received 40 µg/kg medetomidine intramuscularly and saline (as the control), 160 µg/kg prazosin, or 40, 160 or 480 µg/kg atipamezole or yohimbine intravenously 0.5 hr later. Volume, pH and specific gravity of urine; plasma arginine vasopressin (AVP) level; and creatinine, osmolality and electrolyte levels in both urine and plasma were measured. Both atipamezole and yohimbine, but not prazosin, antagonized medetomidine-induced diuresis. The antidiuretic effect of atipamezole was more potent than that of yohimbine, but was not dose dependent, in contrast to the effect of yohimbine at the tested doses. Both atipamezole and yohimbine reversed medetomidine-induced decreases in both urine specific gravity and osmolality and increases in plasma osmolality and free-water clearance. Antidiuresis of either atipamezole or yohimbine was not related to the area under the curve for AVP level, although the highest dose of both atipamezole and yohimbine initially and temporarily increased plasma AVP levels, suggesting that this may partly influence the antidiuretic effects of both agents. The diuretic effect of medetomidine in cats may be mediated by α2-adrenoceptors, but not α1-adrenoceptors. Atipamezole and yohimbine can be used as antagonistic agents against medetomidine-induced diuresis in healthy cats. PMID:24107430

  8. Filum ependymoma mimicking spontaneous intracranial hypotension.

    PubMed

    Schievink, Wouter I; Akopov, Sergey E

    2005-05-01

    A 34-year-old man with a 2-week history of orthostatic headaches and a "dry tap" at lumbar puncture was found to have a lumbar intradural mass on magnetic resonance imaging (MRI) examination. A myxopapillary ependymoma was resected and the patient's headache completely resolved. The combination of spontaneous orthostatic headaches and a "dry tap" at the time of lumbar puncture does not always indicate the presence of a spontaneous cerebrospinal fluid (CSF) leak and intracranial hypotension. PMID:15953283

  9. Attending Rounds: A Patient with Intradialytic Hypotension

    PubMed Central

    2014-01-01

    Intradialytic hypotension is the most common adverse event that occurs during the hemodialysis procedure. Despite advances in machine technology, it remains a difficult management issue. The pathophysiology of intradialytic hypotension and measures to reduce its frequency are discussed. An accurate assessment of dry weight is crucial in all patients on dialysis and especially those patients prone to intradialytic hypotension. The presence of edema and hypertension has recently been shown to be a poor predictor of volume overload. Noninvasive methods to assess volume status, such as whole body and segmental bioimpedance, hold promise to more accurately assess fluid status. Reducing salt intake is key to limiting interdialytic weight gain. A common problem is that patients are often told to restrict fluid but not salt intake. Lowering the dialysate temperature, prohibiting food ingestion during hemodialysis, and midodrine administration are beneficial. Sodium modeling in the absence of ultrafiltration modeling should be abandoned. There is not enough data on the efficacy of l-carnitine to warrant its routine use. PMID:24385517

  10. Effect of canagliflozin on blood pressure and adverse events related to osmotic diuresis and reduced intravascular volume in patients with type 2 diabetes mellitus.

    PubMed

    Weir, Matthew R; Januszewicz, Andrzej; Gilbert, Richard E; Vijapurkar, Ujjwala; Kline, Irina; Fung, Albert; Meininger, Gary

    2014-12-01

    ] and polyuria [increased urine frequency]) vs placebo (6.7%, 5.6%, and 0.8%). The incidence of intravascular volume reduction-related AEs (eg, orthostatic hypotension and postural dizziness) was low across groups (1.2%, 1.3%, and 1.1%). In summary, canagliflozin was associated with reduced BP in patients with T2DM across a range of baseline BPs, with increased incidence of AEs related to osmotic diuresis but not intravascular volume reduction.

  11. Effects of Anesthetics on the Renal Sympathetic Response to Anaphylactic Hypotension in Rats

    PubMed Central

    Wang, Mofei; Kuda, Yuhichi; Kurata, Yasutaka; Shibamoto, Toshishige

    2014-01-01

    -anesthetized rats. RSNA was increased markedly in conscious rats during anaphylactic hypotension. Anesthetics attenuated this antigen-induced renal sympathoexcitation through the suppression of baroreceptor function. PMID:25423366

  12. Medial prefrontal cortex acetylcholine injection-induced hypotension: the role of hindlimb vasodilation

    NASA Technical Reports Server (NTRS)

    Crippa, G. E.; Lewis, S. J.; Johnson, A. K.; Correa, F. M.

    2000-01-01

    The injection of acetylcholine (ACh) into the cingulate region of the medial prefrontal cortex (MPFC) causes a marked fall in arterial blood pressure which is not accompanied by changes in heart rate. The purpose of the present study was to investigate the hemodynamic basis for this stimulus-induced hypotension in Sprague-Dawley rats. The study was designed to determine whether a change in the vascular resistance of hindlimb, renal or mesenteric vascular beds contributes to the fall in arterial pressure in response to ACh injection into the cingulate cortex. Miniature pulsed-Doppler flow probes were used to measure changes in regional blood flow and vascular resistance. The results indicated that the hypotensive response was largely due to a consistent and marked vasodilation in the hindlimb vascular bed. On this basis, an additional experiment was then undertaken to determine the mechanisms that contribute to hindlimb vasodilation. The effect of interrupting the autonomic innervation of one leg on the hindlimb vasodilator response was tested. Unilateral transection of the lumbar sympathetic chain attenuated the cingulate ACh-induced vasodilation in the ipsilateral, but not in the contralateral hindlimb. These results suggest that the hypotensive response to cingulate cortex-ACh injection is caused by skeletal muscle vasodilation mediated by a sympathetic chain-related vasodilator system.

  13. Hypotensive responses to common daily activities in institutionalized elderly. A potential risk for recurrent falls.

    PubMed

    Jonsson, P V; Lipsitz, L A; Kelley, M; Koestner, J

    1990-07-01

    Transient hypotension may be one of many factors contributing to the high prevalence of falls among elderly people. To determine the frequency and magnitude of hypotensive responses to common daily activities, and their potential relationship to falls in the elderly, we examined blood pressure (BP) and heart rate during a standardized series of activities in 38 institutionalized recurrent fallers (age, 87 +/- 6 years), 20 institutionalized nonfallers (age, 85 +/- 5 years), and 10 healthy young control subjects (age, 24 +/- 3 years). The coefficient of variation for systolic BP during all activities was higher in elderly subjects (fallers, 14% +/- 5%; nonfallers, 12% +/- 3%) than in young control subjects (8% +/- 1%). In contrast, the coefficient of variation for heart rate during all activities was higher in young subjects than in the elderly subjects. Elderly subjects had marked BP reduction following meals and nitroglycerin, which was significantly greater in fallers than in nonfallers, independent of the cause of the fall. Thus, institutionalized elderly have marked BP variability and hypotensive responses to meals and nitroglycerin. A decline in BP during common preload-reducing stresses may predispose some elderly people to falls.

  14. Antagonistic effects of atipamezole, yohimbine, and prazosin on xylazine-induced diuresis in clinically normal cats.

    PubMed

    Murahata, Yusuke; Miki, Yuya; Hikasa, Yoshiaki

    2014-10-01

    This study aimed to investigate and compare the antagonistic effects of atipamezole, yohimbine, and prazosin on xylazine-induced diuresis in clinically normal cats. Five cats were repeatedly used in each of the 9 groups. One group was not medicated. Cats in the other groups received 2 mg/kg BW xylazine intramuscularly, and saline (as the control); 160 μg/kg BW prazosin; or 40, 160, or 480 μg/kg BW atipamezole or yohimbine intravenously 0.5 h later. Urine and blood samples were collected 10 times over 8 h. Urine volume, pH, and specific gravity; plasma arginine vasopressin (AVP) concentration; and creatinine, osmolality, and electrolyte values in both urine and plasma were measured. Both atipamezole and yohimbine antagonized xylazine-induced diuresis, but prazosin did not. The antidiuretic effect of atipamezole was more potent than that of yohimbine but not dose-dependent, in contrast to the effect of yohimbine at the tested doses. Both atipamezole and yohimbine reversed xylazine-induced decreases in both urine specific gravity and osmolality, and the increase in free water clearance. Glomerular filtration rate, osmolar clearance, and plasma electrolyte concentrations were not significantly altered. Antidiuresis of either atipamezole or yohimbine was not related to the area under the curve for AVP concentration, although the highest dose of both atipamezole and yohimbine increased plasma AVP concentration initially and temporarily, suggesting that this may in part influence antidiuretic effects of both agents. The diuretic effect of xylazine in cats may be mediated by α2-adrenoceptors but not α1-adrenoceptors. Atipamezole and yohimbine can be used as antagonistic agents against xylazine-induced diuresis in clinically normal cats.

  15. Function of cGMP-dependent protein kinase II in volume load-induced diuresis.

    PubMed

    Schramm, Andrea; Schinner, Elisabeth; Huettner, Johannes P; Kees, Frieder; Tauber, Philipp; Hofmann, Franz; Schlossmann, Jens

    2014-10-01

    Atrial natriuretic peptide (ANP)/cGMPs cause diuresis and natriuresis. Their downstream effectors beyond cGMP remain unclear. To elucidate a probable function of cGMP-dependent protein kinase II (cGKII), we investigated renal parameters in different conditions (basal, salt diets, starving, water load) using a genetically modified mouse model (cGKII-KO), but did not detect any striking differences between WT and cGKII-KO. Thus, cGKII is proposed to play only a marginal role in the adjustment of renal concentration ability to varying salt loads without water restriction or starving conditions. When WT mice were subjected to a volume load (performed by application of a 10-mM glucose solution (3% of BW) via feeding needle), they exhibited a potent diuresis. In contrast, urine volume was decreased significantly in cGKII-KO. We showed that AQP2 plasma membrane (PM) abundance was reduced for about 50% in WT upon volume load, therefore, this might be a main cause for the enhanced diuresis. In contrast, cGKII-KO mice almost completely failed to decrease AQP2-PM distribution. This significant difference between both genotypes is not induced by an altered p-Ser256-AQP2 phosphorylation, as phosphorylation at this site decreases similarly in WT and KO. Furthermore, sodium excretion was lowered in cGKII-KO mice during volume load. In summary, cGKII is only involved to a minor extent in the regulation of basal renal concentration ability. By contrast, cGKII-KO mice are not able to handle an acute volume load. Our results suggest that membrane insertion of AQP2 is inhibited by cGMP/cGKII.

  16. Antagonistic effects of atipamezole, yohimbine, and prazosin on xylazine-induced diuresis in clinically normal cats.

    PubMed

    Murahata, Yusuke; Miki, Yuya; Hikasa, Yoshiaki

    2014-10-01

    This study aimed to investigate and compare the antagonistic effects of atipamezole, yohimbine, and prazosin on xylazine-induced diuresis in clinically normal cats. Five cats were repeatedly used in each of the 9 groups. One group was not medicated. Cats in the other groups received 2 mg/kg BW xylazine intramuscularly, and saline (as the control); 160 μg/kg BW prazosin; or 40, 160, or 480 μg/kg BW atipamezole or yohimbine intravenously 0.5 h later. Urine and blood samples were collected 10 times over 8 h. Urine volume, pH, and specific gravity; plasma arginine vasopressin (AVP) concentration; and creatinine, osmolality, and electrolyte values in both urine and plasma were measured. Both atipamezole and yohimbine antagonized xylazine-induced diuresis, but prazosin did not. The antidiuretic effect of atipamezole was more potent than that of yohimbine but not dose-dependent, in contrast to the effect of yohimbine at the tested doses. Both atipamezole and yohimbine reversed xylazine-induced decreases in both urine specific gravity and osmolality, and the increase in free water clearance. Glomerular filtration rate, osmolar clearance, and plasma electrolyte concentrations were not significantly altered. Antidiuresis of either atipamezole or yohimbine was not related to the area under the curve for AVP concentration, although the highest dose of both atipamezole and yohimbine increased plasma AVP concentration initially and temporarily, suggesting that this may in part influence antidiuretic effects of both agents. The diuretic effect of xylazine in cats may be mediated by α2-adrenoceptors but not α1-adrenoceptors. Atipamezole and yohimbine can be used as antagonistic agents against xylazine-induced diuresis in clinically normal cats. PMID:25356000

  17. Alanine increases blood pressure during hypotension

    NASA Technical Reports Server (NTRS)

    Conlay, L. A.; Maher, T. J.; Wurtman, R. J.

    1990-01-01

    The effect of L-alanine administration on blood pressure (BP) during haemorrhagic shock was investigated using anesthetized rats whose left carotid arteries were cannulated for BP measurement, blood removal, and drug administration. It was found that L-alanine, in doses of 10, 25, 50, 100, and 200 mg/kg, increased the systolic BP of hypotensive rats by 38 to 80 percent (while 100 mg/kg pyruvate increased BP by only 9.4 mmhg, not significantly different from saline). The results suggest that L-alanine might influence cardiovascular function.

  18. Orthostatic hypotension of prolonged weightlessness: clinical models.

    PubMed

    Robertson, D; Biaggioni, I; Mosqueda-Garcia, R; Robertson, R M

    1992-07-01

    Orthostatic intolerance on return from space is a widely known consequence of space travel. Development of countermeasures against this problem is a major priority of the field of space physiology and medicine. The bedrest model is widely used in the investigation of this phenomenon, and has provided important data, but questions remain. In this article, we suggest that the disorders that produce chronic orthostatic hypotension have significant potential as models of microgravity-induced orthostatic intolerance. Understanding the pathophysiology of these syndromes may be useful to those involved in improving the operational aspects of manned space flight; four such syndromes and their possible relevance to space flight are described.

  19. Orthostatic hypotension. Causes, evaluation, and management.

    PubMed Central

    Hollister, A S

    1992-01-01

    Chronic orthostatic hypotension is caused by a variety of disorders. Frequently patients withdraw from social interactions, are prone to adverse drug reactions and inappropriate diagnoses, and are bed-bound by the time of diagnosis. Applying basic principles of cardiovascular physiology and pharmacology usually permits these patients to lead active lives and to live longer. Much of the management is based on common sense and knowledge of the basic pathophysiology of the disorder and depends on thorough patient education and close monitoring of blood pressure in many of the activities of daily living. PMID:1475949

  20. Osmotic diuresis

    MedlinePlus

    ... the presence of certain substances in the fluid filtered by the kidneys. This fluid eventually becomes urine. These substances cause additional water to come into the urine, increasing its amount.

  1. Traumatic rhabdomyolysis from severe beating--experience of volume diuresis in 200 patients.

    PubMed

    Knottenbelt, J D

    1994-08-01

    Fluid loading with balanced salt solution (BSS) was carried out in 200 patients with extensive soft tissue injuries from severe beatings. Urinary volume and dipstick specific gravity testing were used to monitor renal function with administration of furosemide for persistent oliguria. Acute intrinsic renal failure (AIRF) occurred in 21 patients (10.5%) and five patients died (2.5%); two of hyperkalemia, two of sepsis and one of multiple organ failure. Significantly increased rates of AIRF and death were associated with injury-admission intervals of more than 12 hours, severe metabolic acidosis, low initial hemoglobin, heavy pigmenturia, and high serum creatine kinase (CK) levels. An increased serum creatinine/BUN ratio was noted in four of the five patients who died. An average of 7.5 L fluids was needed in non-AIRF patients to achieve adequate diuresis with a mean positive fluid balance of 4.7 L. No patient without pigmenturia developed AIRF. Balanced salt solution volume diuresis supplemented with furosemide as necessary appears to be safe and effective in preventing AIRF in soft tissue injuries sustained in beatings. PMID:8064919

  2. Disabling postural hypotension complicating diabetic autonomic neuropathy.

    PubMed

    Stevens, M J; Edmonds, M E; Mathias, C J; Watkins, P J

    1991-11-01

    A 35-year-old Type 1 diabetic man with severe disabling postural hypotension was studied for physiological abnormalities, precipitating factors, and effect of current treatment. A 24-h blood pressure profile indicated a diurnal variation in systolic blood pressure with the lowest values recorded between 0100 and 0600 h, during which the patient often lost consciousness on standing (mean standing systolic pressure 78 mmHg at night vs 105 mmHg in the afternoon, p less than 0.001). Food induced a profound fall in systolic pressure, both while supine and while standing erect. The systolic pressure fall during euglycaemia was 49 mmHg vs 3 mmHg during hypoglycaemia. Plasma noradrenaline and adrenaline levels were low during euglycaemia, but increased during hypoglycaemia. Therapeutic manoeuvres aimed at increasing heart rate (by atrial tachypacing) and reducing the peripheral pooling of blood (vasoconstricting drugs and gravity suit), together with the somatostatin analogue octreotide, proved ineffective. These observations demonstrate the phenomenon of post-prandial exacerbation of postural hypotension in a Type 1 diabetic patient, and indicate that despite failure of conventional methods of treatment, hypoglycaemia increased plasma catecholamines and was effective in abolishing the blood pressure fall on standing.

  3. Marking Time

    ERIC Educational Resources Information Center

    Foster, Colin

    2011-01-01

    Teachers say that they would gladly teach a day in the classroom if at the end of the day they could leave and have no marking. There is a common staffroom perception that mathematics teachers have it easy when it comes to marking. In arts subjects, setting an essay can be a fairly straightforward matter--a one-line question may suffice--but…

  4. Association of Mortality Risk with Various Definitions of Intradialytic Hypotension

    PubMed Central

    Xue, Hui; Lynch, Katherine E.; Curhan, Gary C.; Brunelli, Steven M.

    2015-01-01

    Intradialytic hypotension is a serious and frequent complication of hemodialysis; however, there is no evidence-based consensus definition of intradialytic hypotension. As a result, coherent evaluation of the effects of intradialytic hypotension is difficult. We analyzed data from 1409 patients in the HEMO Study and 10,392 patients from a single large dialysis organization to investigate the associations of commonly used intradialytic hypotension definitions and mortality. Intradialytic hypotension definitions were selected a priori on the basis of literature review. For each definition, patients were characterized as having intradialytic hypotension if they met the corresponding definition in at least 30% of baseline exposure period treatments or characterized as control otherwise. Overall and within subgroups of patients with predialysis systolic BP<120 or 120–159 mmHg, an absolute nadir systolic BP<90 mmHg was most potently associated with mortality. Within the subgroup of patients with predialysis BP≥160 mmHg, nadir BP<100 mmHg was most potently associated with mortality. Intradialytic hypotension definitions that considered symptoms, interventions, and decreases in BP during dialysis were not associated with outcome, and when added to nadir BP, symptom and intervention criteria did not accentuate associations with mortality. Our results suggest that nadir-based definitions best capture the association between intradialytic hypotension and mortality. PMID:25270068

  5. Predictors of dexmedetomidine-associated hypotension in critically ill patients

    PubMed Central

    Gerlach, Anthony T.; Blais, Danielle M.; Jones, G. Morgan; Burcham, Pamela K.; Stawicki, Stanislaw P.; Cook, Charles H.; Murphy, Claire V.

    2016-01-01

    Background: Dexmedetomidine is commonly used for sedation in the Intensive Care Unit (ICU), and its use may be associated with hypotension. We sought to determine predictors of dexmedetomidine-associated hypotension. Methods: Retrospective, single-center study of 283 ICU patients in four adults ICUs over a 12 month period. Univariate analyses were performed to determine factors associated with dexmedetomidine-related hypotension. Risk factors significant at the 0.20 level in the univariate analysis were considered for inclusion into a step-wise multiple logistical regression model. Results: Hypotension occurred in 121 (42.8%) patients with a median mean arterial pressure (MAP) nadir of 54 mmHg. Univariate analyses showed an association between hypotension and age (P = 0.03), Acute Physiology and Chronic Health Evaluation II (APACHE II) score (P = 0.02), baseline MAP (<0.001), admission to the cardiothoracic ICU (P = 0.05), history of coronary artery disease (P = 0.02), and postcardiac surgery (P = 0.0009). Admission to the medical ICU was associated with a decrease in development in hypotension (P = 0.03). There was a trend for hypotension with weight (P = 0.09) and history of congestive heart failure (P = 0.12) Only MAP prior to initiation (odds ratio [OR] 0.97, 95% confidence interval [95% CI] 0.95–0.99; P < 0.0001), APACHE II scores (OR 1.06, 95% CI 1.01–1.12; P = 0.017), and history of coronary artery disease (OR 0.48, 95% CI 0.26–0.90, P = 0.022) were independently associated with hypotension by multivariable analysis. Conclusions: Dexmedetomidine-associated hypotension is common. Preexisting low blood pressure, history of coronary artery disease, and higher acuity were identified as independent risk factors for dexmedetomidine-associated hypotension. PMID:27722111

  6. Hypotension and shock in the preterm neonate.

    PubMed

    Schmaltz, Chris

    2009-08-01

    While the methods of establishing and maintaining organ perfusion differ from one clinician to the next, the underlying physiological rationale remains constant. The gestalt for correcting circulatory compromise is generally performed in a stepwise manner; first ensuring that the vasculature is filled, then administering medications to tighten the vasculature, and lastly, compensating for an immature vasculature. This stepwise approach is reflected in the pharmacological interventions of providing fluid boluses (filling the pump), giving catecholamines (tightening the pump), and starting hydrocortisone (compensating for an immature pump). While the stepwise management approach may be familiar to some nurses, it is important to understand the evidence-based rationale that supports clinical decisions. This article will outline physiology unique to the neonate, clarify terminology that surrounds hypotension and shock, and explore various methods for the treatment of circulatory compromise in the preterm neonate. PMID:19696569

  7. Hypotension and shock in the preterm neonate.

    PubMed

    Schmaltz, Chris

    2009-08-01

    While the methods of establishing and maintaining organ perfusion differ from one clinician to the next, the underlying physiological rationale remains constant. The gestalt for correcting circulatory compromise is generally performed in a stepwise manner; first ensuring that the vasculature is filled, then administering medications to tighten the vasculature, and lastly, compensating for an immature vasculature. This stepwise approach is reflected in the pharmacological interventions of providing fluid boluses (filling the pump), giving catecholamines (tightening the pump), and starting hydrocortisone (compensating for an immature pump). While the stepwise management approach may be familiar to some nurses, it is important to understand the evidence-based rationale that supports clinical decisions. This article will outline physiology unique to the neonate, clarify terminology that surrounds hypotension and shock, and explore various methods for the treatment of circulatory compromise in the preterm neonate.

  8. Dynamic data during hypotensive episode improves mortality predictions among patients with sepsis and hypotension

    PubMed Central

    Mayaud, Louis; Lai, Peggy S.; Clifford, Gari D.; Tarassenko, Lionel; Celi, Leo Anthony G.; Annane, Djillali

    2012-01-01

    Objective To determine if a prediction rule for hospital mortality using dynamic variables in response to treatment of hypotension in patients with sepsis performs better than current models Design Retrospective cohort study Setting All intensive care units at a tertiary care hospital Patients Adult patients admitted to intensive care units between 2001 and 2007 of whom 2,113 met inclusion criteria and had sufficient data Interventions None Measurements and Main Results We developed a prediction algorithm for hospital mortality in patients with sepsis and hypotension requiring medical intervention using data from the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC-II database). We extracted 189 candidate variables, including treatments, physiologic variables and laboratory values collected before, during and after a hypotensive episode. Thirty predictors were identified using a genetic algorithm on a training set (n=1500), and validated with a logistic regression model on an independent validation set (n=613). The final prediction algorithm used included dynamic information and had good discrimination (AUC = 82.0%) and calibration (Hosmer-Lemeshow C statistic = 10.43, p=0.06). This model was compared to APACHE IV using reclassification indices and was found to be superior with a NRI of 0.19 (p<0.001) and an IDI of 0.09 (p<0.001). Conclusions Hospital mortality predictions based on dynamic variables surrounding a hypotensive event is a new approach to predicting prognosis. A model using these variables has good discrimination and calibration, and offers additional predictive prognostic information beyond established ones. PMID:23385106

  9. Effects of bradykinin B2 receptor antagonism on the hypotensive effects of ACE inhibition.

    PubMed Central

    Bouaziz, H; Joulin, Y; Safar, M; Benetos, A

    1994-01-01

    1. The aim of this study was to determine the participation of endogenous bradykinin (BK) in the antihypertensive effects of the angiotensin converting enzyme inhibitor (ACEI), perindoprilat, in the spontaneously hypertensive rat (SHR) on different salt diets. 2. Conscious SHRs receiving either a low or a high NaCl diet were used in order to evaluate the respective roles of angiotensin II suppression and bradykinin stimulation in the acute hypotensive effects of perindoprilat. Two different B2 receptor antagonists (B 4146 and Hoe 140) were used after bolus administration of 7 mg kg-1 of the ACEI, perindoprilat. In separate animals, Hoe 140 was administered before the injection of perindoprilat. In other experiments, the effects of Hoe 140 on the hypotensive effects of the calcium antagonist, nicardipine, were tested. 3. The different NaCl diets had no effect on baseline blood pressure. Hoe 140 injection before ACE inhibition did not modify blood pressure. Perindoprilat caused more marked hypotension in the low salt-fed rats than in the high salt animals (P < 0.01). Administration of Hoe 140 or B4146 after perindoprilat significantly reduced the antihypertensive effects of perindoprilat in the different groups, but this effect was more pronounced in high salt-fed rats. However, in SHRs receiving Hoe 140 before perindoprilat, the antihypertensive effect of perindoprilat was completely abolished in both high or low salt diet rats. In separate experiments we confirmed that Hoe 140 did not affect the hypotensive efficacy of the calcium antagonist, nicardipine. 4. Our study shows that inhibition of endogenous bradykinin degradation participates in the acute antihypertensive effects of perindoprilat in SHRs. The role of bradykinin is more pronounced following exposure to a high salt diet i.e., when the renin-angiotensin system is suppressed.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7858859

  10. Stretch Marks

    MedlinePlus

    ... changes that can go with bodybuilding. People who use steroid-containing skin creams or ointments (such as hydrocortisone) for more than a few weeks may also get stretch marks. So might people who have to ... surgeon. These doctors may use one of many types of treatments — from actual ...

  11. Gastrin and D1 dopamine receptor interact to induce natriuresis and diuresis.

    PubMed

    Chen, Yue; Asico, Laureano D; Zheng, Shuo; Villar, Van Anthony M; He, Duofen; Zhou, Lin; Zeng, Chunyu; Jose, Pedro A

    2013-11-01

    Oral NaCl produces a greater natriuresis and diuresis than the intravenous infusion of the same amount of NaCl. Gastrin is the major gastrointestinal hormone taken up by renal proximal tubule (RPT) cells. We hypothesized that renal gastrin and dopamine receptors interact to synergistically increase sodium excretion, an impaired interaction of which may be involved in the pathogenesis of hypertension. In Wistar-Kyoto rats, infusion of gastrin induced natriuresis and diuresis, which was abrogated in the presence of a gastrin (cholecystokinin B receptor [CCKBR]; CI-988) or a D1-like receptor antagonist (SCH23390). Similarly, the natriuretic and diuretic effects of fenoldopam, a D1-like receptor agonist, were blocked by SCH23390, as well as by CI-988. However, the natriuretic effects of gastrin and fenoldopam were not observed in spontaneously hypertensive rats. The gastrin/D1-like receptor interaction was also confirmed in RPT cells. In RPT cells from Wistar-Kyoto but not spontaneously hypertensive rats, stimulation of either D1-like receptor or gastrin receptor inhibited Na(+)-K(+)-ATPase activity, an effect that was blocked in the presence of SCH23390 or CI-988. In RPT cells from Wistar-Kyoto and spontaneously hypertensive rats, CCKBR and D1 receptor coimmunoprecipitated, which was increased after stimulation of either D1 receptor or CCKBR in RPT cells from Wistar-Kyoto rats; stimulation of one receptor increased the RPT cell membrane expression of the other receptor, effects that were not observed in spontaneously hypertensive rats. These data suggest that there is a synergism between CCKBR and D1-like receptors to increase sodium excretion. An aberrant interaction between the renal CCK BR and D1-like receptors (eg, D1 receptor) may play a role in the pathogenesis of hypertension.

  12. Chronic intrarenal insulin replacement reverses diabetes mellitus-induced natriuresis and diuresis.

    PubMed

    Manhiani, M Marlina; Duggan, A Daniel; Wilson, Hunter; Brands, Michael W

    2012-02-01

    We showed recently that sustained natriuresis in type 1 diabetic dogs was attributed to the decrease in insulin rather than the hyperglycemia alone. The sodium-retaining action of insulin appeared to require hyperglycemia, and it completely reversed the diabetic natriuresis and diuresis. This study tested whether the sodium-retaining effect was attributed to direct intrarenal actions of insulin. Alloxan-treated dogs (D; n=7) were maintained normoglycemic using 24-h/d IV insulin replacement. After control measurements, IV insulin was decreased to begin a 6-day diabetic period. Blood glucose increased from 84±6 mg/dL to an average of 428 mg/dL on days 5 and 6, sodium excretion increased from 74±8 to 98±7 meq/d over the 6 days, and urine volume increased from 1645±83 to 2198±170 mL/d. Dir dogs (n=7) were subjected to the same diabetic regimen, but, in addition, insulin was infused continuously into the renal artery at 0.3 mU/kg per minute during the 6-day period. This did not affect plasma insulin. Blood glucose increased from 94±10 mg/dL to an average of 380 mg/dL on days 5 and 6, but sodium excretion averaged 76±5 and 69±8 meq/d during control and diabetes mellitus, respectively. The diuresis also was prevented. Glomerular filtration rate increased only in Dir dogs, and there was no change in mean arterial pressure in either group. This intrarenal insulin infusion had no effect on sodium or volume excretion in normal dogs. Intrarenal insulin replacement in diabetic dogs caused a sustained increase in tubular reabsorption that completely reversed diabetic natriuresis. Insulin plus glucose may work to prevent salt wasting in uncontrolled type 2 diabetes mellitus.

  13. [Case of ischemic heart disease resulting from persistent diuresis after giant ovarian tumor resection].

    PubMed

    Sata, Naho; Satoh, Masaaki; Seo, Norimasa

    2010-02-01

    A patient with a giant ovarian tumor weighing about 7 kg was successfully removed by operation. However, her ECG demonstrated ischemic changes after the operation. We report a case of ischemic heart disease due to persistent diuresis after giant ovarian tumor resection. A 75-year-old, 56.5 kg, 143.5 cm woman was admitted to our hospital for ovarian tumor resection. The preoperative ECG showed normal sinus rhythm and no ischemic changes. Both general anesthesia and epidural anesthesia were planed. An epidural catheter was inserted at T12-L1. Anesthesia was induced with propofol 100 mg, fentanyl 100 microg and vecuronium 8 mg under 100% oxygen inhalation. General anesthesia was maintained with sevoflurane while epidural anesthesia was achieved using 0.375% ropivacaine 6 ml. During the operation, blood pressure was 90-110/70-80 mmHg, with SaO2, 100% and heart rate, 70-80 beats x min(-1). The content of tumor was suctioned for 30 minutes. Surgery was successfully finished without any other incidence. After extubation, her ECG changed to atrial fibrillation from normal sinus rhythm and showed ST-T depression. And then her systolic blood pressure became 80 mmHg or below, but we found continued diuresis at about 10 ml x kg(-1) x hr(-1) for over 2 hr. The total of 7 unit vasopressin was intermittently given for vasoconstriction and antidiuresis. Her hemodynamic was immediately restored, and ECG turned to normal ST-T. The patient had uneventful postoperative recovery.

  14. Enalapril and pressure-diuresis in hypertensive rats transgenic for mouse renin gene.

    PubMed

    Springate, J; Van Liew, J; Ganten, D

    1997-01-01

    The recent development of a transgenic rat strain bearing the mouse ren-2 renin gene [TGR(mRen2)27] has provided a new monogenetic model of hypertension. Other hypertensive rat strains are characterized by a blunted pressure-diuresis-natriuresis response such that higher renal perfusion pressures are required to excrete normal amounts of water and sodium. Dysfunction of the renin-angiotensin and nitric oxide systems may cause in this abnormality. This study examined the effect of enalapril on the pressure-natriuresis response and urinary nitric oxide metabolite excretion in 6-month-old TGR(mRen2)27 rats. The slope of the line relating renal perfusion pressure and urine flow rate in TGR (0.08+/-0.01 microl x min(-1) x g kidney weight(-1) mm Hg[-1]) was significantly lower than that in control rats (0.15+/-0.01 microl x min(-1) x g kidney weight(-1) mm Hg[-1]). Pressure-natriuresis responses were also shifted to higher pressure levels in TGR. Treatment with enalapril for 3 months lowered the mean arterial pressure from 94+/-2 to 84+/-4 mm Hg in control rats and from 146+/-3 to 89+/-3 mm Hg in TGR. The slopes of lines relating renal perfusion pressure and urine flow rate as well as sodium excretion were significantly increased by enalapril in control and transgenic animals. Urinary nitric oxide metabolite excretion rose similarly with increasing renal perfusion pressure in both control and TGR rats and was not affected by enalapril. These results confirm that older TGR rats have a blunted pressure-diuresis-natriuresis response that can be corrected by inhibition of the renin-angiotensin system and suggest that their production of nitric oxide is normal.

  15. Discovery of novel selective hypotensive vasopressin peptides that exhibit little or no functional interactions with known oxytocin/vasopressin receptors

    PubMed Central

    Chan, W Y; Wo, N C; Stoev, S; Cheng, L L; Manning, M

    1998-01-01

    Arginine-vasopressin (VP) has both vasoconstricting and vasodilating action. We report here the discovery of four novel selective hypotensive VP analogues: d(CH2)5[D-Tyr(Et)2,Arg3,Val4]AVP; d(CH2)5[D-Tyr(Et)2,Lys3,Val4]AVP and their iodinatable Tyr-NH29 analogues.Bioassays in rats for activities characteristic of neurohypophysial peptides showed that the four VP peptides possessed little or no V1a, V2 or oxytocin (OT) receptor agonistic or antagonistic activities.In anaesthetized rats, these peptides (0.05–0.10 mg kg−1 i.v.) elicited a marked fall in arterial blood pressure.Blockade of cholinoceptors, adrenoceptors and bradykinin B2 receptors, and inhibition of prostaglandin synthesis had little effect on their vasodepressor action.Classical V1a, V2 and OT receptor antagonists did not block the vasodepressor response.L-NAME, 0.2 mg kg−1 min−1, markedly suppressed the hypotensive response to ACh but not the vasodepressor response to the hypotensive VP peptides. However, the duration of the vasodepressor response was shortened. Very high doses of L-NAME attenuated both the vasodepressor response and the duration of action.These findings indicate that the vasodepressor action of these VP peptides is independent of the peripheral autonomic, bradykinin and PG systems and is not mediated by the known classical OT/VP receptors. NO does not appear to have an important role in their vasodepressor action.The discovery of these novel VP peptides could lead to the development of new tools for the investigation of the complex cardiovascular actions of VP and the introduction of a new class of hypotensive agents. The two iodinatable hypotensive VP peptides could be radiolabelled as potential markers for the localization of the receptor system involved. PMID:9831918

  16. Evaluation of the contribution of mast cell mediators to the hypotensive activity of various peptides in rats.

    PubMed

    Kérouac, R; Fournier, A; Barabé, J; St-Pierre, S; Rioux, F

    1983-04-01

    We have tested the effects of intravenous injections of substance P (SP), bradykinin (BK), somatostatin (SS) and vasoactive intestinal peptide (VIP) on the blood pressure, histaminemia and hematocrit in pentobarbital-anesthetized rats. The four peptides elicited a decrease of the mean arterial blood pressure which varied both in amplitude and in duration depending both on the peptide and on the doses utilized. The hypotensive effects of SP and VIP were more persistent than those caused by BK or SS. Only SP evoked an increase of histaminemia. Both SP and BK caused an increase of hematocrit. The change of hematocrit was more prominent and of longer duration after Sp than after BK. Pretreatment of rats with the antiinflammatory drug dexamethasone inhibited markedly the changes of blood pressure, histaminemia and hematocrit caused by SP. The hypotensive effects of BK, SS and VIP as well as the transient change of hematocrit evoked by BK were not affected by dexamethasone. The results suggest that part of the hypotensive activity and changes of hematocrit evoked by SP in rats is due to the release and action of histamine and possibly of other vasoactive substances, of mast cell origin. The results also indicate that mast cell mediators, particularly histamine, are unlikely to be instrumental in the hypotensive activity of BK, SS or VIP in rats.

  17. Bed Rest and Orthostatic-Hypotensive Intolerance

    NASA Technical Reports Server (NTRS)

    Schneider, Suzanne M.

    2000-01-01

    Orthostatic tolerance may be defined as the ability of humans to maintain cerebral perfusion and consciousness upon movement from a supine or sitting position to the upright posture; for example, subjects can stand suddenly or be tilted to the head-up body position. Similar but not identical physiological responses can be induced by positive G(sub Z) (head to foot) acceleration or exposure to lower body negative pressure (LBNP). The objective is to suddenly shift blood to the lower body to determine how effectively cardiovascular and neural-hormonal compensatory responses react to maintain blood pressure. In the most precise method for measuring tolerance, individuals would be stressed until they faint (syncope). However, the potential consequences and discomforts of such a test usually prohibit such a procedure so that few investigators actually induce syncope. In a more common approach, subjects are exposed to a given level of stress, for example, head-up tilt for 15 min, and any increases in heart rate or decreases in blood pressure are interpreted as indicators of progress toward syncope. Presumably, the greater the perturbation of heart rate and blood pressure, the closer to "tolerance," i.e., point of unconsciousness. Another more appropriate approach is to induce a progressively increasing hypotensive stress until pre-determined physiological responses or pre-syncopal symptoms appear. The physiological criteria may include a sudden drop in systolic blood pressure (greater than 25 mm/min), a sudden drop in heart rate (greater than 15 beats/min), or a systolic blood pressure less than 70 mmHg. The most common pre-syncopal symptoms include lightheadedness, stomach awareness or distress, feelings of warmth, tingly skin, and light to profuse sweating. Usually a combination of physiological responses and symptoms occurs such that, on different days, the tolerance time to the same orthostatic protocol is reproducible for a given individual. The assumption is that

  18. Cognitive performance in hypotensive persons with spinal cord injury

    PubMed Central

    Jegede, Adejoke B.; Rosado-Rivera, Dwindally; Bauman, William A.; Cardozo, Christopher P.; Sano, Mary; Moyer, Jeremy M.; Brooks, Monifa; Wecht, Jill Maria

    2010-01-01

    Background Due to sympathetic de-centralization, individuals with spinal cord injury (SCI), especially those with tetraplegia, often present with hypotension, worsened with upright posture. Several investigations in the non-SCI population have noted a relationship between chronic hypotension and deficits in memory, attention and processing speed and delayed reaction times. Objective To determine cognitive function in persons with SCI who were normotensive or hypotensive over a 24-h observation period while maintaining their routine activities. Methods Subjects included 20 individuals with chronic SCI (2–39 years), 13 with tetraplegia (C4–8) and 7 with paraplegia (T2–11). Individuals with hypotension were defined as having a mean 24-h systolic blood pressure (SBP) below 110 mmHg for males and 100 mmHg for females, and having spent ≥50% of the total time below these gender-specific thresholds. The cognitive battery used included assessment of memory (CVLT), attention and processing speed (Digit Span, Stroop word and color and Oral Trails A), language (COWAT) and executive function (Oral Trails B and Stroop color–word). Results Demographic parameters did not differ among the hypotensive and normotensive groups; the proportion of individuals with tetraplegia (82%) was higher in the hypotensive group. Memory was significantly impaired (P<0.05) and there was a trend toward slowed attention and processing speed (P<0.06) in the hypotensive compared to the normotensive group. Interpretation These preliminary data suggest that chronic hypotension in persons with SCI is associated with deficits in memory and possibly attention and processing speed, as previously reported in the non-SCI population. PMID:19842013

  19. Polar Markings

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02155 Polar Markings

    These bright and dark markings occurred near the end of summer in the south polar region. The dark material is likely dust that has been freed of frost cover.

    Image information: VIS instrument. Latitude -76.3N, Longitude 84.9E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. Clinical implications of delayed orthostatic hypotension

    PubMed Central

    Freeman, Roy

    2015-01-01

    Objective: To define the long-term outcome of delayed orthostatic hypotension (OH). Hypothesis: Delayed OH is an early and milder form of OH that progresses over time. Methods: We reviewed the medical records of 230 previously reported patients who completed autonomic testing at our center from January 1, 2002, through December 31, 2003. All available information on clinical diagnosis, mortality, medication use, and autonomic testing were extracted and included in the reported outcomes. Standard criteria were used to define OH and delayed OH. Results: Forty-eight individuals with delayed OH, 42 individuals with OH, and 75 controls had complete follow-up data. Fifty-four percent of individuals with delayed OH progressed to OH. Thirty-one percent of individuals with delayed OH developed an α-synucleinopathy. The 10-year mortality rate in individuals with delayed OH was 29%, in individuals with baseline OH was 64%, and in controls was 9%. The 10-year mortality of individuals who progressed to OH was 50%. Progression to OH was associated with developing an α-synucleinopathy, baseline diabetes, and abnormal baseline autonomic test results. Conclusion: Delayed OH frequently progresses to OH with a high associated mortality. PMID:26400576

  1. Standing worsens cognitive functions in patients with neurogenic orthostatic hypotension.

    PubMed

    Poda, R; Guaraldi, P; Solieri, L; Calandra-Buonaura, G; Marano, G; Gallassi, R; Cortelli, P

    2012-04-01

    In previous studies, addressing the association between orthostatic hypotension and cognitive decline, patients underwent neuropsychological evaluation in sitting position, and blood pressure values and cognition were not measured concurrently. Furthermore, no studies assessed the acute effects of orthostatic hypotension on cognitive performances. The aim of our study was to evaluate the effect of a documented fall in systolic blood pressure (SBP) of at least 20 mmHg on a battery of cognitive tests in patients with neurogenic orthostatic hypotension. Ten consecutive patients with neurogenic orthostatic hypotension, normal brain imaging, and a normal Mini Mental State Examination in supine position were enrolled in the study. Patients underwent a detailed neuropsychological assessment (Brief Mental Deterioration battery and computerized tests) over two test sessions: the first while tilted to an angle able to cause a fall of at least 20 mmHg in SBP; the second while supine, after 30 min of rest. Parallel forms of the tests were presented on each testing session. Patients scored significantly worse in the visual search test, analogies test, immediate visual memory, and the measure of global cognitive functioning of Brief Mental Deterioration battery during the orthostatic challenge compared to the supine position. Orthostatic hypotension was associated with a significant worsening of cognitive performances, affecting both global cognitive functioning and specific tasks, mainly exploring executive functions. The assessment of cognitive function in patients with neurogenic orthostatic hypotension should be performed considering the body's position of the subject.

  2. Postexercise Hypotension After Continuous, Aerobic Interval, and Sprint Interval Exercise.

    PubMed

    Angadi, Siddhartha S; Bhammar, Dharini M; Gaesser, Glenn A

    2015-10-01

    We examined the effects of 3 exercise bouts, differing markedly in intensity, on postexercise hypotension (PEH). Eleven young adults (age: 24.6 ± 3.7 years) completed 4 randomly assigned experimental conditions: (a) control, (b) 30-minute steady-state exercise (SSE) at 75-80% maximum heart rate (HRmax), (4) aerobic interval exercise (AIE): four 4-minute bouts at 90-95% HRmax, separated by 3 minutes of active recovery, and (d) sprint interval exercise (SIE): six 30-second Wingate sprints, separated by 4 minutes of active recovery. Exercise was performed on a cycle ergometer. Blood pressure (BP) was measured before exercise and every 15-minute postexercise for 3 hours. Linear mixed models were used to compare BP between trials. During the 3-hour postexercise, systolic BP (SBP) was lower (p < 0.001) after AIE (118 ± 10 mm Hg), SSE (121 ± 10 mm Hg), and SIE (121 ± 11 mm Hg) compared with control (124 ± 8 mm Hg). Diastolic BP (DBP) was also lower (p < 0.001) after AIE (66 ± 7 mm Hg), SSE (69 ± 6 mm Hg), and SIE (68 ± 8 mm Hg) compared with control (71 ± 7 mm Hg). Only AIE resulted in sustained (>2 hours) PEH, with SBP (120 ± 9 mm Hg) and DBP (68 ± 7 mm Hg) during the third-hour postexercise being lower (p ≤ 0.05) than control (124 ± 8 and 70 ± 7 mm Hg). Although all exercise bouts produced similar reductions in BP at 1-hour postexercise, the duration of PEH was greatest after AIE.

  3. Effect of hemorrhage on cardiac output, vasopressin, aldosterone, and diuresis during immersion in men

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Simanonok, K.; Bernauer, E. M.; Wade, C. E.; Keil, L. C.

    1992-01-01

    The purpose of this research was to test the hypotesis that a reduction in blood volume would attenuate or eliminate immersion-induced increases in cardiac output (Q(sub co)) and urine excretion, and to investigate accompanying vasoactive and fluid-electrolyte hormonal responses. Eight men (19-23 yr) were supine during a 2-hr control period in air, and then sat for 5-hr test periods in air at 20 C (dry control, DC); water at 34.5 C (wet control, WC); and water (34.5 C) after hemorrhage (WH) of 14.8 plus or minus 0.3 percent of their blood volume. Blood volume was -11.6 plus or minus 0.6 percent at immersion (time 0). Mean (bar-X hrs 1-5) Q(sub co) was unchanged in WC (5.3 plus or minus 0.01 l/min) and in WH (4.5 plus or minus 0.1 l/min), but decreased (P less than 0.05) in DC to 3.6 plus or minus 0.1 l/min. Mean urine excretion rates were 1.0 plus or minus 0.2 ml/min for DC and 1.1 plus or minus 0.2 ml/min for WH; both were lower (P less than 0.05) than that for WC of 2.0 plus or minus 0.4 ml/min. Plasma (Na+) and (Osm) were unchanged in all experiments. Mean plasma vasopressin (PVP) (bar-X hrs 1-5) was 1.1 plus or minus 0.1 pg/ml in WC, and higher (P less than 0.05) in DC (2.1 plus or minus 0.2 pg/ml)and WH (2.1 plus or minus 0.1 pg/ml); it was unchanged during air and water test periods. Thus, hemorrhage attenuated the immersion-induced increase in Q(sub co), eliminated the WC diuresis, maintained plasma renin activity and PVP at DC levels and did not change immersion-induced aldosterone suppression; the osmotic diuresis during control immersion is apparently not due to either aldosterone suppression or vasopressin suppression.

  4. Pilot Study: Colostomy and Urine Collection Protocol for Investigating Potential Inciting Causes of Hen Diuresis Syndrome.

    PubMed

    Jones, Kelli; Turner, Bradley; Brandão, João; Hubbard, Sue Ann; Magee, Danny; Baughman, Brittany; Wills, Robert; Tully, Thomas

    2015-06-01

    Hen diuresis syndrome has emerged over the past 5 yr as a significant cause of mortality in the U.S. broiler breeder industry. The condition affects hens in production and is characterized by transient muscle weakness in the vent region, transient diuresis, and often urate deposits on the skin below the vent. Affected hens are often seen straining to lay an egg, which suggests oviduct contraction is also impaired. Related hen mortality, often reaching 1% or more a week, is believed to be primarily the result of male aggression of the vent region (Turner et al., "Investigating Causes of Excessive Urate Production in Broiler Breeder Hens Associated with Peritonitis and Cannibalism Mortality," Oral Presentation at The American Association of Avian Pathologists Annual Meeting, p. 139, 2010). The exact association between the cause of mortality and this syndrome is unknown, but it may be the consequence of transient partial to full oviduct prolapse, which predisposes or stimulates cannibalism and aggression. Based on unpublished work done prior to this study (Turner et al., ibid.), the evidence suggests the underlying problem is metabolic. We feel that urine collection and analysis is an essential component to understanding this condition. This study serves as a pilot study for future investigations that attempt to identify the nature and cause of the metabolic disturbance through paired urine and serum collection and analysis. For the purpose of this study, a small sample of 10 affected and 10 unaffected birds was used for sample collection. In order to collect pure urine, the birds were surgically colostomized. Colostomy did prove to be a useful means of collecting urine free of feces, and for the purposes of our study it yielded adequate urine samples for analysis. There were statistically relevant urine values observed. Affected birds had a higher presence of blood in the urine, a lower uric acid excretion rate (mg/hr), higher concentration (mEq/L) of urine Na+, and

  5. Theory of hydrokinetic clearance of bacteria from the urinary bladder. II. Effects of "bound" organisms and diuresis.

    PubMed

    Mackintosh, I P; Watson, B W; O'Grady, F

    1975-05-01

    When patients with urinary infection drink large volumes of water and empty the bladder at frequent regular intervals, the concentration of bacteria in the voided samples commonly falls rapidly at first and then remains almost constant. The present theoretical analysis leads to the conclusion that the rapid initial fall in concentration is a function of diuresis and that the subsequent constant output originates from bacteria bound to multiplication sites on the uroepithelium from which their progeny are shed into the urine.

  6. Theory of hydrokinetic clearance of bacteria from the urinary bladder. II. Effects of "bound" organisms and diuresis.

    PubMed

    Mackintosh, I P; Watson, B W; O'Grady, F

    1975-05-01

    When patients with urinary infection drink large volumes of water and empty the bladder at frequent regular intervals, the concentration of bacteria in the voided samples commonly falls rapidly at first and then remains almost constant. The present theoretical analysis leads to the conclusion that the rapid initial fall in concentration is a function of diuresis and that the subsequent constant output originates from bacteria bound to multiplication sites on the uroepithelium from which their progeny are shed into the urine. PMID:1120640

  7. Detecting initial orthostatic hypotension: a novel approach

    PubMed Central

    McJunkin, Brittain; Rose, Brandon; Amin, Om; Shah, Nirmita; Sharma, Sachin; Modi, Sujal; Kemper, Suzanne; Yousaf, Muhammad

    2015-01-01

    Our purpose, by modification of standard bedside tilt–testing, was to search for lesser known but important initial orthostatic hypotension (IOH), occurring transiently within the first 30 seconds of standing, heretofore only detectable with sophisticated continuous photoplethysmographic monitoring systems, not readily available in most medical facilities. In screened outpatients over 60 years of age, supine blood pressure (BP) parameters were recorded. To achieve readiness for immediate BP after standing, the cuff was re–inflated prior to standing, rather than after. Immediate, 1–, and 3–minute standing BPs were recorded. One hundred fifteen patients were studied (mean age, 71.1 years; 50.5% male). Eighteen (15.6%) had OH, of whom 14 (12.1%) had classical OH, and four (3.5%) had IOH. Early standing BP detection time was 20.1 ± 5.3 seconds. Immediate transient physiologic systolic BP decline was detected in non–OH (−8.8 ± 9.9 mm Hg; P < .0001). In contrast to classical OH (with lesser but persistent orthostatic BP decrements), IOH patients had immediate mean orthostatic systolic/diastolic BP change of −32.8 (±13.8) mm Hg/−14.0 (±8.5) mm Hg (P < .02), with recovery back to baseline by 1 minute. Two of the four IOH patients had pre–syncopal symptoms. For the first time, using standard inflation–deflation BP equipment, immediate transient standing physiologic BP decrement and IOH were demonstrated. This preliminary study confirms proof of principle that manual BP cuff inflation prior to standing may be useful and practical in diagnosing IOH, and may stimulate direct comparative studies with continuous monitoring systems. PMID:25816712

  8. Detecting initial orthostatic hypotension: a novel approach.

    PubMed

    McJunkin, Brittain; Rose, Brandon; Amin, Om; Shah, Nirmita; Sharma, Sachin; Modi, Sujal; Kemper, Suzanne; Yousaf, Muhammad

    2015-05-01

    Our purpose, by modification of standard bedside tilt-testing, was to search for lesser known but important initial orthostatic hypotension (IOH), occurring transiently within the first 30 seconds of standing, heretofore only detectable with sophisticated continuous photoplethysmographic monitoring systems, not readily available in most medical facilities. In screened outpatients over 60 years of age, supine blood pressure (BP) parameters were recorded. To achieve readiness for immediate BP after standing, the cuff was re-inflated prior to standing, rather than after. Immediate, 1-, and 3-minute standing BPs were recorded. One hundred fifteen patients were studied (mean age, 71.1 years; 50.5% male). Eighteen (15.6%) had OH, of whom 14 (12.1%) had classical OH, and four (3.5%) had IOH. Early standing BP detection time was 20.1 ± 5.3 seconds. Immediate transient physiologic systolic BP decline was detected in non-OH (-8.8 ± 9.9 mm Hg; P < .0001). In contrast to classical OH (with lesser but persistent orthostatic BP decrements), IOH patients had immediate mean orthostatic systolic/diastolic BP change of -32.8 (±13.8) mm Hg/-14.0 (±8.5) mm Hg (P < .02), with recovery back to baseline by 1 minute. Two of the four IOH patients had pre-syncopal symptoms. For the first time, using standard inflation-deflation BP equipment, immediate transient standing physiologic BP decrement and IOH were demonstrated. This preliminary study confirms proof of principle that manual BP cuff inflation prior to standing may be useful and practical in diagnosing IOH, and may stimulate direct comparative studies with continuous monitoring systems.

  9. Orthostatic hypotension in acute cerebellar infarction.

    PubMed

    Kim, Hyun-Ah; Lee, Hyung

    2016-01-01

    To investigate the frequency and pattern of orthostatic hypotension (OH) associated with acute isolated cerebellar infarction, and to identify the cerebellar structure(s) potentially responsible for OH, 29 patients (mean age 60.0) with acute isolated cerebellar infarction performed a standard battery of autonomic function tests including the head up tilt test using Finapres for recording of the beat-to-beat BP response during the acute period. Cerebellar infarction related OH was defined as fall in BP (>20 mmHg systolic BP) on tilting in patients without any disease(s) that could potentially cause autonomic dysfunction, or in patients who had a potential cause of autonomic dysfunction, but showed the absence of OH during a follow-up test. The severity and distribution of autonomic dysfunction were measured by the composite autonomic severity score (CASS). Nine patients (31 %) had OH (range 24-53 mmHg) on tilting during the acute period. Most patients (7/9) had a remarkable decrement in systolic BP immediately upon tilting, but OH rapidly normalized. Mean of maximal decrease in systolic BP during head up tilt test was 37.0 mmHg. The OH group showed mild autonomic dysfunctions (CASS, 3.7) with adrenergic sympathetic dysfunction appearing as the most common abnormality. Lesion subtraction analyses revealed that damage to the medial part of the superior semilunar lobule (Crus I) and tonsil was more frequent in OH group compared to non-OH group. Cerebellar infarction may cause a brief episode of OH. The medial part of the superior semilunar lobule and tonsil may participate in regulating the early BP response during orthostasis. PMID:26530504

  10. Dominant factors that govern pressure natriuresis in diuresis and antidiuresis: a mathematical model.

    PubMed

    Moss, Robert; Layton, Anita T

    2014-05-01

    We have developed a whole kidney model of the urine concentrating mechanism and renal autoregulation. The model represents the tubuloglomerular feedback (TGF) and myogenic mechanisms, which together affect the resistance of the afferent arteriole and thus glomerular filtration rate. TGF is activated by fluctuations in macula densa [Cl(-)] and the myogefnic mechanism by changes in hydrostatic pressure. The model was used to investigate the relative contributions of medullary blood flow autoregulation and inhibition of transport in the proximal convoluted tubule to pressure natriuresis in both diuresis and antidiuresis. The model predicts that medullary blood flow autoregulation, which only affects the interstitial solute composition in the model, has negligible influence on the rate of NaCl excretion. However, it exerts a significant effect on urine flow, particularly in the antidiuretic kidney. This suggests that interstitial washout has significant implications for the maintenance of hydration status but little direct bearing on salt excretion, and that medullary blood flow may only play a signaling role for stimulating a pressure-natriuresis response. Inhibited reabsorption in the model proximal convoluted tubule is capable of driving pressure natriuresis when the known actions of vasopressin on the collecting duct epithelium are taken into account.

  11. Posterior reversible encephalopathy syndrome in setting of postobstructive diuresis and persistent hypocalcemia.

    PubMed

    Gera, Dinesh N; Patil, Sachin B; Parikh, Mitul; Modi, Pranjal R; Kute, Vivek B; Trivedi, Hargovind L

    2012-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiographic entity of heterogenous etiologies, which are grouped together because of similar findings on neuroimaging studies, associated with similar symptom complex of headache, vision loss, altered mentation, and seizures. In this report, we describe a case of PRES in setting of postobstructive diuresis in a 5-year-old male child, whose solitary functioning kidney was obstructed by a 1.6-cm radio-opaque stone, who after percutaneous nephrostomy (PCN) diversion developed persistent hypocalcemia which persisted despite maximum replacement by iv calcium gluconate drip, and the child developed repeated generalized tonic clonic convulsions and became unconscious for 4 days. Computerized tomography (CT) scan of the brain showed typical hypodensities in bilateral occipitoparietal regions suggesting PRES. Ultimately, over a period of 4 days, his hypocalcemia could be corrected and the child was neurologically normal on the 5th day. CT scan of the brain after a month was free of any hypodensities.

  12. The role of atrial natriuretic peptide (ANP) in cold-induced diuresis (CID)

    SciTech Connect

    Agnew, J.W.; Freund, B.J.; DuBose, D.A.; McKay, J.M.; Hashiro, G.M. Tripler Army Medical Center, Honolulu, HI )

    1991-03-11

    The hormonal control of cold-induced diuresis (CID) remains unresolved. This study investigated the role of ANP, plasma vasopressin (AVP), and aldosterone (ALDO) on CID. Four semi-nude men participated in a 210 min exposure to 15C and 29C air, on separate days. These subjects drank 300 mL of water and had an intravenous saline drip throughout both exposures to replace blood and insensible fluid losses. CID was observed in 15C but not in the 29C experiment, as indicated by a greater urine output. In 15C, atrial natriuretic peptide (ANP) increased after 90 min by 41% and remained elevated for 2 h relative to 29C. No differences were observed in AVP between 15C and 29C. In the 15C versus the 29C experiment, ALDO was approximately 37% lower at the pre, 15 and 90 min time periods. Mean arterial blood pressure was generally greater but only significant at 60 min during the 15C versus the 29C experiment. Urinary NA{sup +} excretion was elevated in 15C relative to 29C while no difference in K{sup +} excretion was observed. Although pressure effects may contribute, the observed natriuresis in the absence of a kaliuresis in the cold suggests a physiological role of ANP in CID.

  13. Acute hypotension after total knee arthroplasty and its nursing strategy

    PubMed Central

    Zhang, Yu-Mei; He, Jie; Zhou, Chang; Li, Yu; Yi, De-Kun; Zhang, Xia

    2015-01-01

    Objective: To determine the factors affecting postoperative acute hypotension after total knee arthroplasty (TKA) and provide a basis for guiding the clinical prevention. Methods: Between May 2001 and May 2013, a total of 495 patients undergoing routine TKA were analyzed retrospectively. Independent risk factors related to postoperative acute hypotension after TKA were determined by univariate and multivariate analysis. Results: Of the 495 patients undergoing TKA, 61 (12.32%) developed postoperative acute hypotension after surgery. Univariate analysis showed that preoperative Neu, time of surgery, time of anesthesia, pressure of tourniquet, time of using tourniquet, preoperative hypertension, age and type of surgery were significant influencing factors, whereas by multivariate analysis, only age, pressure of tourniquet and type of surgery were significant influencing factors. Conclusion: Factors those were associated with a significantly increased postoperative acute hypotension after TKA included age, pressure of tourniquet and type of surgery. Achieving a good preoperative and postoperative evaluation and monitoring vital signs and disease change contribute to the detection, intervention and salvage for the acute hypotension. PMID:26550351

  14. [Orthostatic hypotension in the aged. Systematic exploration in 400 persons].

    PubMed

    Lewi, S; Brochier, F

    1975-03-26

    The authors study the adaptation of the blood pressure to changes in posture in 400 people, and studied the world literature on the subject. They found that postural hypotension in the elderly is quite different from that in young adults. A full study is difficult and the response to changes in posture are inconstant, this it is only possible to take into consideration changes in systolic blood pressure, and one should not neglect falls in blood pressure of low amplitude. This definition, once accepted, postural hypotension in the elderly is a frequent phenomenon which gives complex symptoms owing to the intrication of vascular disturbances and lesions of the central nervous system. Among the numerous permanent or occasional causes, more particularly those due to drugs, the role of hypovolemia seems to be of importance in orthostatic hypotension and should be sought as a routine. PMID:175464

  15. Osmotic diuresis in a mathematical model of the rat proximal tubule.

    PubMed

    Weinstein, A M

    1986-05-01

    Solute reabsorption in the presence of an osmotic load has been examined in a model of the rat proximal convoluted tubule. The model is a computer simulation of a 0.5-cm segment of tubule comprised of compliant cellular and paracellular compartments, which tracks the luminal profiles of Na, K, Cl, HCO3, phosphate, glucose, and urea. In one series of calculations, the peritubular and initial luminal glucose concentrations are varied from 1.0 to 50 mmol/liter. The resulting proximal reabsorption of glucose increases monotonically to 1.5 nmol X s-1 X cm-2. Sodium reabsorption increases with glucose perfusion concentrations between 1.0 and 10 mmol/liter and then declines with greater glucose loads. Above 10 mmol/liter glucose, there is progressive decline in mean luminal Na concentration so that diffusive paracellular backflux, as well as decreased convective reabsorption, are responsible for the natriuresis. Diuresis per se blunts reabsorption of species requiring the development of lumen-to-bath concentration gradients (i.e., K, Cl, and urea). Diminished bicarbonate reabsorption is also predicted with large glucose loads due to intraepithelial alkalinization. This derives both from cellular depolarization and bicarbonate trapping (interspace closure). It is also observed that when interspace closure occurs, a region of intraepithelial K depletion may be formed, promoting diffusive reabsorption of potassium across the tight junction. Thus a 'middle compartment model' for potassium may provide a means of achieving tubule fluid-to-plasma K ratios less than 1.0, in the absence of specific cellular uptake mechanisms. PMID:3706538

  16. Midodrine as a Countermeasure for Post-Spaceflight Orthostatic Hypotension

    NASA Technical Reports Server (NTRS)

    Stenger, Michael B.; Stein, Sydney P.; Meck, Janice V.; Platts, Steven H.

    2008-01-01

    One possible mechanism for post-spaceflight orthostatic hypotension, which affects approximately 30% of astronauts after short duration shuttle missions, is inadequate norepinephrine release during upright posture. We performed a two phased study to determine the effectiveness of an alpha1-adrenergic agonist, midodrine, as a countermeasure to post-spaceflight orthostatic hypotension. The first phase of the study examined the landing day orthostatic responses of six veteran astronauts after oral midodrine (10 mg) administered on the ground within approximately two hours of wheel stop. One female crewmember exhibited orthostatic hypotension in a previous flight but not after midodrine. Five male crewmembers, who did not exhibit orthostatic hypotension during previous flights, also did not show signs of orthostatic hypotension after midodrine. Additionally, phase one showed that midodrine did not cause hypertension in these crewmembers. In the second phase of this study, midodrine is ingested inflight (near time of ignition, TIG) and orthostatic responses are determined immediately upon landing via an 80 degree head-up tilt test performed on the crew transport vehicle (CTV). Four of ten crewmembers have completed phase two of this study. Two crewmembers completed the landing day tilt tests, while two tests were ended early due to presyncopal symptoms. All subjects had decreased landing day stroke volumes and increased heart rates compared to preflight. Midodrine appears to have increased total peripheral resistance in one crewmember who was able to complete the landing day tilt test. The effectiveness of midodrine as a countermeasure to immediate post-spaceflight orthostatic hypotension has yet to be determined; interpretation is made more difficult due to low subject number and the lack of control subjects on the CTV.

  17. Orthostatic hypotension in patients, bed rest subjects, and astronauts

    NASA Technical Reports Server (NTRS)

    Lathers, C. M.; Charles, J. B.

    1994-01-01

    Orthostatic hypotension after even short space flights has affected a significant number of astronauts. Given the need for astronauts to function at a high level of efficiency during and after their return from space, the application of pharmacologic and other treatments is strongly indicated. This report addresses the clinical problem of orthostatic hypotension and its treatments to ascertain whether pharmacologic or physiologic treatment may be useful in the prevention of orthostatic hypotension associated with space flight. Treatment of orthostatic hypotension in patients now includes increasing intravascular volume with high sodium intake and mineralocorticoids, or increasing vascular resistance through the use of drugs to stimulate alpha or block beta vascular receptors. Earlier treatment used oral sympathomimetic ephedrine hydrochloride alone or with "head-up" bed rest. Then long-acting adrenocortical steroid desoxycorticosterone preparations with high-salt diets were used to expand volume. Fludrocortisone was shown to prevent the orthostatic drop in blood pressure. The combination of the sympathomimetic amine hydroxyamphetamine and a monoamine oxidase inhibitor tranylcypromine has been used, as has indomethacin alone. Davies et al. used mineralocorticoids at low doses concomitantly with alpha-agonists to increase vasoconstrictor action. Schirger et al used tranylcypromine and methylphenidate with or without a Jobst elastic leotard garment or the alpha-adrenergic agonist midodrine (which stimulates both arterial and venous systems without direct central nervous system or cardiac effects). Vernikos et al established that the combination of fludrocortisone, dextroamphetamine, and atropine exhibited a beneficial effect on orthostatic hypotension induced by 7-day 6 degrees head-down bed rest (a model used to simulate the weightlessness of space flight). Thus, there are numerous drugs that, in combination with mechanical techniques, including lower body negative

  18. Intracranial hypotension secondary to spinal pathology: Diagnosis and treatment.

    PubMed

    Sartip, Kamyar; McKenna, Gregory; Spina, Michael; Grahovac, Stephen

    2016-04-01

    Spinal pathology resulting in cerebrospinal fluid (CSF) leak and intracranial hypotension is an infrequently reported and a potentially severe cause of headaches. We present a case of cerebrospinal fluid (CSF) leak caused by a thoracic disk herniation successfully treated with two targeted epidural blood patches. Although patients typically present with orthostatic headaches, the imaging findings of intracranial hypotension should prompt investigation of the spine for site and cause of the CSF leakage. Treatment includes autologous blood patch and surgery in refractory cases. PMID:26914140

  19. Recent advances in the treatment of orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Robertson, D.; Davis, T. L.

    1995-01-01

    Orthostatic hypotension is a fall in blood pressure on standing that causes symptoms of dizziness, visual changes, and discomfort in the head and neck. The goal of treatment is the improvement of the patient's functional capacity, rather than a target blood pressure. For treatment to be successful, it must be individualized. Non-pharmalogic interventions include carefully managed exercise, scheduled activities, and monitoring of the environmental temperature. Agents such as fludrocortisone, midodrine, and epoetin alfa offer successful pharmacologic interventions. Although these measures ease the symptoms of orthostatic hypotension, current approaches neither reverse nor stabilize the disease process in autonomic disorders.

  20. Treatment of Idiopathic Intracranial Hypotension With Tea: A Case Report

    PubMed Central

    Petramfar, Peyman; Mohammadi, S. Saeed; Hosseinzadeh, Farideh

    2016-01-01

    Introduction The syndrome of spontaneous intracranial hypotension has been increasingly diagnosed since its discovery through magnetic resonance imaging (MRI). It is a rare syndrome that is due to the leakage of cerebrospinal fluid (CSF) from a tear in the dura and can occur at any age, even among adolescents, but is most frequently seen among females in late middle age. Case Presentation Here, we describe a 32-year-old woman with a two-month history of headaches and occasional nausea and vomiting (N/V). MRI without gadolinium was normal, but meningeal enhancement was seen in MRI with gadolinium. The lumbar puncture revealed a low opening pressure. Computed tomography myelography (CT myelography) showed no leakage; Therefore, idiopathic intracranial hypotension was diagnosed. Treatment was started using tea, and the patient’s headache got significantly better in about a day. Conclusions Conservative therapy, such as bed rest and caffeine treatment with eight cups of tea daily, yielded a significant improvement in our patient. Effectively, the patient constitutes a case of idiopathic intracranial hypotension due to undetectable CSF leakage or hyper-absorption, with good response to conservative management through tea-drinking. Further investigations with an appropriate sample size are needed in order to confirm this intervention in the treatment of idiopathic intracranial hypotension. PMID:27621920

  1. [Incidence of orthostatic hypotension. Clinical study on 1010 cases].

    PubMed

    Lorenzini, M

    1982-12-15

    An investigation conducted on a series of 1010 patients selected without regard to age, sex, or pathology showed that orthostatic hypotension is very common (about 35%), especially in aged and hypertensive subjects. It was found that cardiovascular causes play a by no means unimportant part in its determination. Only 20% of the cases observed were attributable to drug treatment.

  2. Treatment of Idiopathic Intracranial Hypotension With Tea: A Case Report

    PubMed Central

    Petramfar, Peyman; Mohammadi, S. Saeed; Hosseinzadeh, Farideh

    2016-01-01

    Introduction The syndrome of spontaneous intracranial hypotension has been increasingly diagnosed since its discovery through magnetic resonance imaging (MRI). It is a rare syndrome that is due to the leakage of cerebrospinal fluid (CSF) from a tear in the dura and can occur at any age, even among adolescents, but is most frequently seen among females in late middle age. Case Presentation Here, we describe a 32-year-old woman with a two-month history of headaches and occasional nausea and vomiting (N/V). MRI without gadolinium was normal, but meningeal enhancement was seen in MRI with gadolinium. The lumbar puncture revealed a low opening pressure. Computed tomography myelography (CT myelography) showed no leakage; Therefore, idiopathic intracranial hypotension was diagnosed. Treatment was started using tea, and the patient’s headache got significantly better in about a day. Conclusions Conservative therapy, such as bed rest and caffeine treatment with eight cups of tea daily, yielded a significant improvement in our patient. Effectively, the patient constitutes a case of idiopathic intracranial hypotension due to undetectable CSF leakage or hyper-absorption, with good response to conservative management through tea-drinking. Further investigations with an appropriate sample size are needed in order to confirm this intervention in the treatment of idiopathic intracranial hypotension.

  3. Damage control resuscitation: permissive hypotension and massive transfusion protocols.

    PubMed

    Hughes, Naomi T; Burd, Randall S; Teach, Stephen J

    2014-09-01

    Evidence for changes in adult trauma management often precedes evidence for changes in pediatric trauma management. Many adult trauma centers have adopted damage-control resuscitation management strategies, which target the metabolic syndrome of acidosis, coagulopathy, and hypothermia often found in severe uncontrolled hemorrhage. Two key components of damage-control resuscitation are permissive hypotension, which is a fluid management strategy that targets a subnormal blood pressure, and hemostatic resuscitation, which is a transfusion strategy that targets coagulopathy with early blood product administration. Acceptance of damage-control resuscitation strategies is reflected in recent changes in the American College of Surgeons' Advanced Trauma Life Support curriculum; the most recent edition has decreased its initial fluid recommendation to 1 L from 2 L, and it now recommends early administration of blood products without specifying any specific ratio. These recommendations are not advocating permissive hypotension or hemostatic resuscitation directly but represent an initial step toward limiting fluid resuscitation and using blood products to treat coagulopathy earlier. Evidence for permissive hypotension exists in animal studies and few adult clinical trials. There is no evidence to support permissive hypotension strategies in pediatrics. Evidence for hemostatic resuscitation in adult trauma management is more comprehensive, and there are limited data to support its use in pediatric trauma patients with severe hemorrhage. Additional studies on the management of children with severe uncontrolled hemorrhage are needed.

  4. Prevention of supine hypotensive syndrome in pregnant women treated with transcranial magnetic stimulation.

    PubMed

    Kim, Deborah Rubin; Wang, Eileen

    2014-08-15

    In our studies of transcranial magnetic stimulation in pregnant women with major depressive disorder, two subjects had an episode of supine hypotensive syndrome and one subject had an episode of dizziness without hypotension. Prevention of the supine hypotensive syndrome in pregnant women receiving transcranial magnetic stimulation is described. PMID:24768354

  5. Potential involvement of P2Y2 receptor in diuresis of postobstructive uropathy in rats.

    PubMed

    Zhang, Yue; Kohan, Donald E; Nelson, Raoul D; Carlson, Noel G; Kishore, Bellamkonda K

    2010-03-01

    AVP resistance of the medullary collecting duct (mCD) in postobstructive uropathy (POU) has been attributed to increased production of PGE2. P2Y2 receptor activation causes production of PGE2 by the mCD. We hypothesize that increased P2Y2 receptor expression and/or activity may contribute to the diuresis of POU. Sprague-Dawley rats were subjected to bilateral ureteral obstruction for 24 h followed by release (BUO/R, n = 17) or sham operation (SHM/O, n = 15) and euthanized after 1 wk or 12 days. BUO/R rats developed significant polydipsia, polyuria, urinary concentration defect, and increased urinary PGE2 and decreased aquaporin-2 protein abundance in the inner medulla compared with SHM/O rats. After BUO/R, the relative mRNA expression of P2Y2 and P2Y6 receptors was increased by 2.7- and 4.9-fold, respectively, without significant changes in mRNA expression of P2Y1 or P2Y4 receptor. This was associated with a significant 3.5-fold higher protein abundance of the P2Y2 receptor in BUO/R than SHM/O rats. When freshly isolated mCD fractions were challenged with different types of nucleotides (ATPgammaS, ADP, UTP, or UDP), BUO/R and SHM/O rats responded to only ATPgammaS and UTP and released PGE2, consistent with involvement of the P2Y2, but not P2Y6, receptor. ATPgammaS- or UTP-stimulated increases in PGE2 were much higher in BUO/R (3.20- and 2.28-fold, respectively, vs. vehicle controls) than SHM/O (1.68- and 1.30-fold, respectively, vs. vehicle controls) rats. In addition, there were significant 2.4- and 2.1-fold increases in relative mRNA expression of prostanoid EP1 and EP3 receptors, respectively, in the inner medulla of BUO/R vs. SHM/O rats. Taken together, these data suggest that increased production of PGE2 by the mCD in POU may be due to increased expression and activity of the P2Y2 receptor. Increased mRNA expression of EP1 and EP3 receptors in POU may also help accentuate PGE2-induced signaling in the mCD.

  6. [Marked changes in the core temperature during anaphylactic shock].

    PubMed

    Kotani, N; Sakai, T; Kushikata, T; Sato, T; Shimodate, Y; Matsuki, A

    1990-07-01

    Three cases of anaphylactic shock were reported in which the core temperature was measured continuously. Two core temperature thermister probes were fixed on the forehead and the sole. Temperature dissociation between the core and the periphery disappeared in a few minutes after the administration of the causative agents. The clinical signs of the anaphylactic shock such as erythema, wheal and marked hypotension also developed in a few minutes after the disappearance of temperature dissociation. Thus treatment of anaphylactic shock could be started even before the patients develop severe hypotension. This clinical study suggests that a sudden disappearance of the temperature dissociation is a incipient sign of anaphylactic shock and to monitor the core as well as the peripheral temperature is a useful method for early diagnosis and treatment of anaphylactic shock.

  7. Recipes for obstetric spinal hypotension: The clinical context counts.

    PubMed

    Bishop, David G; Rodseth, Reitze N; Dyer, Robert A

    2016-09-01

    Hypotension following obstetric spinal anaesthesia remains a common and important problem. While recent research advances have brought us closer to the perfect recipe for the obstetric spinal anaesthetic, these advances have not been translated into practical guidelines able to reduce the unacceptable number of fatalities that occur in environments where resources are limited. In South Africa, more than half of anaesthetic deaths are still related to spinal hypotension. A gap exists between the 'perfect recipe', developed from a clinical context rooted in resource-rich research environments, and its application and performance in real-world resource-poor environments - conditions experienced by more than 75% of the world's population. This review attempts to define this knowledge gap and proposes a research agenda to address the deficiencies. PMID:27601104

  8. Amiodarone-Induced Life-Threatening Refractory Hypotension

    PubMed Central

    Doshi, Deepak; Jayawardana, Ravi

    2015-01-01

    Patient: Male, 70 Final Diagnosis: Cardiogenic shock Symptoms: Chest discomfort and intermittent palpitations Medication: Amiodarone Clinical Procedure: Intubation Specialty: Cardiology Objective: Unusual clinical course Background: Amiodarone is frequently used in emergency departments for treatment of arrhythmias. Incidence of several amiodarone-related adverse events is unknown. The literature is sparse for potentially life-threatening adverse effects of amiodarone. Case Report: We present a case of a male patient who presented with chest discomfort and rapid atrial fibrillation. He was known to have paroxysmal atrial fibrillation, which did not respond to initial beta-blocker treatment. The second-line drug amiodarone was given to the patient for rate control. He developed severe hypotension related to amiodarone and required inotropic support along with rapid-sequence intubation. Conclusions: Intravenous amiodarone can cause severe and refractory hypotension. PMID:26366832

  9. Minocycline hypersensitivity syndrome with hypotension mimicking septic shock.

    PubMed

    Colvin, J H; Sheth, A P

    2001-01-01

    Minocycline is a semisynthetic tetracycline derivative that is often used in the treatment of acne vulgaris. A serious but rare adverse effect caused by minocycline therapy is a hypersensitivity syndrome (HS), consisting of fever, skin eruption, and internal organ involvement that begins within 8 weeks of therapy initiation. We report a case of minocycline HS with unique features, namely, associated hypotension, and a rebound of the cutaneous eruption upon discontinuation of systemic steroids.

  10. Advance prediction of hypotension at cesarean delivery under spinal anesthesia.

    PubMed

    Kinsella, S M; Norris, M C

    1996-01-01

    Cardiovascular responses to supine inferior vena cava compression might predict hypotension risk during elective cesarean delivery using spinal anesthesia. In this pilot study we investigated 27 women before operation by taking blood pressure and heart rate measurements for 5 min in the left lateral position, 5 min supine, and then performed one further reading in the left lateral position and one sitting. Anesthesia with hyperbaric bupivacaine was rigorously standardised. A pre-operative 'supine stress test', combining an increase in maternal heart rate of greater than 10 beats/min or leg flexion movements while supine, was analysed. A positive supine stress test (SST) was 4.1 times more frequent in those with severe systolic hypotension below 70% of baseline (12 out of 16 women) than in those without (2 out of 11 women), with a sensitivity of 75% (95% C.I. 48% to 93%) and specificity of 82% (95% C.I. 48% to 98%). A positive test was associated with twice as much vasopressor use as a negative test (30.7 +/-/14.5 mg versus 13.5 +/-/ 9.9 mg; P = 0.0014). Unlike the SST, cardiovascular responses to the change from recumbent to sitting (tilt test) were not useful as a predictor of hypotension.

  11. Implications of a Vasodilatory Human Monoclonal Autoantibody in Postural Hypotension*

    PubMed Central

    Li, Hongliang; Zuccolo, Jonathan; Kem, David C.; Zillner, Caitlin; Lee, Jiyeon; Smith, Kenneth; James, Judith A.; Cunningham, Madeleine W.; Yu, Xichun

    2013-01-01

    Functional autoantibodies to the autonomic receptors are increasingly recognized in the pathophysiology of cardiovascular diseases. To date, no human activating monoclonal autoantibodies to these receptors have been available. In this study, we describe for the first time a β2-adrenergic receptor (β2AR)-activating monoclonal autoantibody (C5F2) produced from the lymphocytes of a patient with idiopathic postural hypotension. C5F2, an IgG3 isotype, recognizes an epitope in the N terminus of the second extracellular loop (ECL2) of β2AR. Surface plasmon resonance analysis revealed high binding affinity for the β2AR ECL2 peptide. Immunoblotting and immunofluorescence demonstrated specific binding to β2AR in H9c2 cardiomyocytes, CHO cells expressing human β2AR, and rat aorta. C5F2 stimulated cyclic AMP production in β2AR-transfected CHO cells and induced potent dilation of isolated rat cremaster arterioles, both of which were specifically blocked by the β2AR-selective antagonist ICI-118551 and by the β2AR ECL2 peptide. This monoclonal antibody demonstrated sufficient activity to produce postural hypotension in its host. Its availability provides a unique opportunity to identify previously unrecognized causes and new pharmacological management of postural hypotension and other cardiovascular diseases. PMID:24043632

  12. Spontaneous intracranial hypotension: Targeted or blind blood patch.

    PubMed

    Smith, Kyle A

    2016-03-01

    The aim of this review is to determine the efficacy and optimal strategy for epidural blood patch placement in the treatment of spontaneous intracranial hypotension. We present a 37-year-old man who developed a 4 week duration postural headache without sustaining significant trauma. The diagnosis of spontaneous intracranial hypotension with associated subdural hygromas was confirmed with lumbar puncture and radiologic imaging. Spontaneous intracranial hypotension is generally due to cerebrospinal fluid leak from the thecal sac or nerve root sleeves, although the cause of leakage is unknown. In our patient, the site of leakage was identified at cervical C1-C2 level in the spine on myelography. Conservative management with repeated epidural blood patches was successful in symptom relief and complete resolution of cerebrospinal fluid leak and subdural hygromas. We reviewed the literature for efficacy of blood patches delivered directly to the site of leakage (targeted) or to the lumbar or thoracic spine away from the site of leakage or where the site cannot be determined (blind). No clear evidence exists on comparative efficacy due to paucity of randomized trials. However, epidural blood patches in general result in positive outcomes with overall efficacy near 90%. Some trials have suggested greater efficacy for targeted rather than blind epidural blood patches, but randomized studies and long-term prognosis remain to be evaluated. PMID:26461907

  13. Advance prediction of hypotension at cesarean delivery under spinal anesthesia.

    PubMed

    Kinsella, S M; Norris, M C

    1996-01-01

    Cardiovascular responses to supine inferior vena cava compression might predict hypotension risk during elective cesarean delivery using spinal anesthesia. In this pilot study we investigated 27 women before operation by taking blood pressure and heart rate measurements for 5 min in the left lateral position, 5 min supine, and then performed one further reading in the left lateral position and one sitting. Anesthesia with hyperbaric bupivacaine was rigorously standardised. A pre-operative 'supine stress test', combining an increase in maternal heart rate of greater than 10 beats/min or leg flexion movements while supine, was analysed. A positive supine stress test (SST) was 4.1 times more frequent in those with severe systolic hypotension below 70% of baseline (12 out of 16 women) than in those without (2 out of 11 women), with a sensitivity of 75% (95% C.I. 48% to 93%) and specificity of 82% (95% C.I. 48% to 98%). A positive test was associated with twice as much vasopressor use as a negative test (30.7 +/-/14.5 mg versus 13.5 +/-/ 9.9 mg; P = 0.0014). Unlike the SST, cardiovascular responses to the change from recumbent to sitting (tilt test) were not useful as a predictor of hypotension. PMID:15321375

  14. Body water handling in response to hypertonic-saline induced diuresis in fasting northern elephant seal pups (Mirounga angustirostris)

    NASA Technical Reports Server (NTRS)

    Ortiz, Rudy M.; Wade, Charles E.; Ortiz, C. Leo

    2003-01-01

    During natural fasting conditions in postweaned northern elephant seal (NES) (Mirounga angustirostris) pups, urinary water loss is minimized and percent total body water (TBW) is maintained constant. However, following infusion of hypertonic saline, glomerular filtration rate (GFR) and urine output increased in fasting pups. Therefore, we quantified the magnitude of the hypernatremia-induced diuresis relative to the animal's total body water (TBW) pool and the percentage of filtered water reabsorbed. Following a 24 h control period, naturally fasting NES pups (n=7) were infused (4 ml min(-1)) with hypertonic saline (16.7%) at a dose of 3 mmol NaCl kg(-1) body mass. Total body water was estimated prior to infusion by tritium dilution, GFR was estimated by standard creatinine clearance, and urine output (V) was measured for 24 h during the control and post infusion periods. Percentage of filtered water reabsorbed was calculated as (1-(V/GFR))x100. Twenty-four hours following the infusion, GFR (control: 69+/-12 ml min(-1) and post-infusion: 118+/-19 ml min(-1); mean+/-S.E.) increased 77+/-28% above control and the percentage of filtered water reabsorbed was decreased 0.4+/-0.1%. The increase in urine output (control: 218+/-47 ml d(-1) and post-infusion: 883+/-92 ml d(-1)) accounted for 1.7+/-0.2% of the pups' TBW. The hypernatremia-induced diuresis was accompanied by the loss of body water indicating the lack of water retention. Although the 77% increase in GFR was only associated with a 0.4% decrease in the percentage of filtered water reabsorbed, this decrease was significant enough to result in a 4-fold increase in urine output. Despite the observed diuresis, fasting NES pups appear to possess an efficient water recycling mechanism requiring only a small percentage of body water to excrete an excess salt load. This water recycling mechanism may allow pups to avoid negative perturbations in body water as they initiate feeding in a marine environment following the

  15. Low-Volume Intense Exercise Elicits Post-exercise Hypotension and Subsequent Hypervolemia, Irrespective of Which Limbs Are Exercised

    PubMed Central

    Graham, Matthew J.; Lucas, Samuel J. E.; Francois, Monique E.; Stavrianeas, Stasinos; Parr, Evelyn B.; Thomas, Kate N.; Cotter, James D.

    2016-01-01

    Introduction: Exercise reduces arterial and central venous blood pressures during recovery, which contributes to its valuable anti-hypertensive effects and to facilitating hypervolemia. Repeated sprint exercise potently improves metabolic function, but its cardiovascular effects (esp. hematological) are less well-characterized, as are effects of exercising upper versus lower limbs. The purposes of this study were to identify the acute (<24 h) profiles of arterial blood pressure and blood volume for (i) sprint intervals versus endurance exercise, and (ii) sprint intervals using arms versus legs. Methods: Twelve untrained males completed three cycling exercise trials; 50-min endurance (legs), and 5*30-s intervals using legs or arms, in randomized and counterbalanced sequence, at a standardized time of day with at least 8 days between trials. Arterial pressure, hemoglobin concentration and hematocrit were measured before, during and across 22 h after exercise, the first 3 h of which were seated rest. Results: The post-exercise hypotensive response was larger after leg intervals than endurance (AUC: 7540 ± 3853 vs. 3897 ± 2757 mm Hg·min, p = 0.049, 95% CI: 20 to 6764), whereas exercising different limbs elicited similar hypotension (arms: 6420 ± 3947 mm Hg·min, p = 0.48, CI: −1261 to 3896). In contrast, arterial pressure at 22 h was reduced after endurance but not after leg intervals (−8 ± 8 vs. 0 ± 7 mm Hg, p = 0.04, CI: 7 ± 7) or reliably after arm intervals (−4 ± 8 mm Hg, p = 0.18 vs. leg intervals). Regardless, plasma volume expansion at 22 h was similar between leg intervals and endurance (both +5 ± 5%; CI: −5 to 5%) and between leg and arm intervals (arms: +5 ± 7%, CI: −8 to 5%). Conclusions: These results emphasize the relative importance of central and/or systemic factors in post-exercise hypotension, and indicate that markedly diverse exercise profiles can induce substantive hypotension and subsequent hypervolemia. At least for endurance

  16. Meropenem population pharmacokinetics in critically ill patients with septic shock and continuous renal replacement therapy: influence of residual diuresis on dose requirements.

    PubMed

    Ulldemolins, Marta; Soy, Dolors; Llaurado-Serra, Mireia; Vaquer, Sergi; Castro, Pedro; Rodríguez, Alejandro H; Pontes, Caridad; Calvo, Gonzalo; Torres, Antoni; Martín-Loeches, Ignacio

    2015-09-01

    Meropenem dosing in critically ill patients with septic shock and continuous renal replacement therapy (CRRT) is complex, with the recommended maintenance doses being 500 mg to 1,000 mg every 8 h (q8h) to every 12 h. This multicenter study aimed to describe the pharmacokinetics (PKs) of meropenem in this population to identify the sources of PK variability and to evaluate different dosing regimens to develop recommendations based on clinical parameters. Thirty patients with septic shock and CRRT receiving meropenem were enrolled (153 plasma samples were tested). A population PK model was developed with data from 24 patients and subsequently validated with data from 6 patients using NONMEM software (v.7.3). The final model was characterized by CL = 3.68 + 0.22 · (residual diuresis/100) and V = 33.00 · (weight/73)(2.07), where CL is total body clearance (in liters per hour), residual diuresis is the volume of residual diuresis (in milliliters per 24 h), and V is the apparent volume of distribution (in liters). CRRT intensity was not identified to be a CL modifier. Monte Carlo simulations showed that to maintain concentrations of the unbound fraction (fu ) of drug above the MIC of the bacteria for 40% of dosing interval T (referred to as 40% of the ƒ uT >MIC), a meropenem dose of 500 mg q8h as a bolus over 30 min would be sufficient regardless of the residual diuresis. If 100% of the ƒ uT >MIC was chosen as the target, oligoanuric patients would require 500 mg q8h as a bolus over 30 min for the treatment of susceptible bacteria (MIC < 2 mg/liter), while patients with preserved diuresis would require the same dose given as an infusion over 3 h. If bacteria with MICs close to the resistance breakpoint (2 to 4 mg/liter) were to be treated with meropenem, a dose of 500 mg every 6 h would be necessary: a bolus over 30 min for oligoanuric patients and an infusion over 3 h for patients with preserved diuresis. Our results suggest that residual diuresis may be an easy and

  17. Meropenem Population Pharmacokinetics in Critically Ill Patients with Septic Shock and Continuous Renal Replacement Therapy: Influence of Residual Diuresis on Dose Requirements

    PubMed Central

    Llaurado-Serra, Mireia; Vaquer, Sergi; Castro, Pedro; Rodríguez, Alejandro H.; Pontes, Caridad; Calvo, Gonzalo; Torres, Antoni; Martín-Loeches, Ignacio

    2015-01-01

    Meropenem dosing in critically ill patients with septic shock and continuous renal replacement therapy (CRRT) is complex, with the recommended maintenance doses being 500 mg to 1,000 mg every 8 h (q8h) to every 12 h. This multicenter study aimed to describe the pharmacokinetics (PKs) of meropenem in this population to identify the sources of PK variability and to evaluate different dosing regimens to develop recommendations based on clinical parameters. Thirty patients with septic shock and CRRT receiving meropenem were enrolled (153 plasma samples were tested). A population PK model was developed with data from 24 patients and subsequently validated with data from 6 patients using NONMEM software (v.7.3). The final model was characterized by CL = 3.68 + 0.22 · (residual diuresis/100) and V = 33.00 · (weight/73)2.07, where CL is total body clearance (in liters per hour), residual diuresis is the volume of residual diuresis (in milliliters per 24 h), and V is the apparent volume of distribution (in liters). CRRT intensity was not identified to be a CL modifier. Monte Carlo simulations showed that to maintain concentrations of the unbound fraction (fu) of drug above the MIC of the bacteria for 40% of dosing interval T (referred to as 40% of the ƒuT>MIC), a meropenem dose of 500 mg q8h as a bolus over 30 min would be sufficient regardless of the residual diuresis. If 100% of the ƒuT>MIC was chosen as the target, oligoanuric patients would require 500 mg q8h as a bolus over 30 min for the treatment of susceptible bacteria (MIC < 2 mg/liter), while patients with preserved diuresis would require the same dose given as an infusion over 3 h. If bacteria with MICs close to the resistance breakpoint (2 to 4 mg/liter) were to be treated with meropenem, a dose of 500 mg every 6 h would be necessary: a bolus over 30 min for oligoanuric patients and an infusion over 3 h for patients with preserved diuresis. Our results suggest that residual diuresis may be an easy and

  18. Application of controlled arterial hypotension in endoscopic rhinosurgery.

    PubMed

    Cincikas, Darius; Ivaskevicius, Juozas

    2003-01-01

    Intraoperative bleeding is one of the major problems in endoscopic surgery of sinuses. In the case of the expanded process, still more numerous interventions are performed with general anesthesia. The objective of research is to compare intraoperative hemorrhage and the visibility of the operative field during normotension and hypotension anesthesia caused by nitroglycerin and captopril when performing endoscopic operations of accessory nasal sinuses. Fifty-two patients of physical health state 1-2 according to ASA were examined: for 32 the controlled hypotension (Group H) was applied, 20 patients underwent operations in normotension (Group N). All patients on the eve of the operation were premedicated with diazepam; Group H patients on the day of operation received 6.25 mg of captopril. Anesthesia was carried out with fentanyl and halothane steam in the 50:50% mixture of oxygen and laughing gas. In Group H arterial blood pressure was lowered by nitroglycerin infusion. The average arterial blood pressure was maintained in GroupH within the limits of 50-60 mmHg. Hypotension was coordinated with the rising of the head-bed of the operating table at 5 degrees. Hemorrhage was measured by collecting blood with the pump graded with the precision of 25 ml. The visibility of the operative field was evaluated subjectively every 15 minutes according to the scale of 5 points proposed by Fromm. In both groups the average arterial blood pressure values as well as the values of the frequency of heart contractions differed statistically significantly. In the hypotensive group, hemorrhage during operation was less, on the average, (208 ml) than in Group N (349.2 ml). The visibility of the operative field was by one point, on the average, better than in Group H. No anesthetic complications were observed during investigation. In summary, it is possible to state that the controlled arterial hypotension caused by captopril and nitroglycerin reduced significantly intraoperative

  19. Dynamic FDG PET/CT imaging with diuresis demonstrates an enterovesical fistula in a lymphoma patient with repeated colon diverticulitis.

    PubMed

    Kao, Pan-Fu; Ting, Wen-Chien; Hsiao, Pei-Ching; Kao, Yu-Lin; Chang, Pai-Jung; Lee, Jong-Kang

    2013-04-01

    A 43-year-old male patient with follicular B-cell lymphoma was referred for a FDG PET/CT scan due to severe left lower abdominal pain to rule out recurrent cancer. These FDG PET/CT images and previous FDG PET/CT images 5 months ago both revealed an air bubble in the urinary bladder on the CT images. He had a recurrent urinary tract infection history for 6 months. A list-mode dynamic data acquisition with diuresis intravenous injection revealed linear FDG activity extending from the upper-left portion of the bladder to a soft tissue mass in the lower-left pelvic region. An enterovesical fistula was confirmed by surgery.

  20. [Role of V1- and V2-receptors in mechanism of physiological paradox--an increase of reabsorption of the solute free water and simultaneous rise of diuresis].

    PubMed

    Kanashkina, T A; Kuznetsova, A A; Shakhmatova, E I; Natochin, Iu V

    2006-10-01

    In experiments on non-anesthetized rats with administration into stomach of water (5 ml/100 g body mass) direct correlation has been found between an increase of diuresis and excretion of solute free water (r = 0.98, p < 0.01), while after injection to these animals of 5 x 10(-11) M arginine-vasotocin - between an increase of diuresis and simultaneous rise reabsorption of solute free water (r = 0.8, p < 0.01). The rise of diuresis after the vasotocin injection is due to inhibition of sodium re- absorption, with the solute excretion fraction increasing from 2.6 +/- 0.2 % to 11.9 +/- 1.2, p < 0.001. A similar physiological paradox - an increase of diuresis with the simultaneous increase of reabsorption of solute free water - has been revealed at night hours in children with tendency for nocturnal enuresis (r = 0.64, p < 0.01). Mechanism responsible for this phenomenon consists in a rise of diuresis due to a decrease of sodium ion reabsorption in the ascending Henle loop limb. A problem is discussed of the homeostatic significance of a decrease of sodium reabsorption combined with an increase of solute-free water reabsorption; it is suggested that this phenomenon is based on a redistribution of reabsorption inside the nephron - a decrease of ion and water reabsorption in the initial parts of the nephron distal segment and an increase of solute free water reabsorption with the antidiuretic hormone-stimulated high osmotic permeability of terminal parts of renal tubules. An intraperitoneal injection of V1-anatagonist (OPC-21268) decreased the natriuretic component of response to arginine-vasotocin, while injection of V2-antagonist (OPC-31260) eliminated the antidiuretic component.

  1. Microinjection of glycine into the hypothalamic paraventricular nucleus produces diuresis, natriuresis, and inhibition of central sympathetic outflow.

    PubMed

    Krowicki, Zbigniew K; Kapusta, Daniel R

    2011-04-01

    Strychnine-sensitive glycine receptors and glycine-immunoreactive fibers are expressed in the hypothalamic paraventricular nucleus (PVN), yet the functional significance of this innervation is unclear. Therefore, these studies examined the changes in cardiovascular and renal function and renal sympathetic nerve activity (RSNA) produced by the microinjection of glycine (5 and 50 nmol) into the PVN of conscious Sprague-Dawley rats. Microinjection of glycine into, but not outside of, the PVN dose-dependently increased urine flow rate and urinary sodium excretion and decreased RSNA. At the higher dose, PVN glycine also decreased heart rate; neither 5 nor 50 nmol PVN glycine altered mean arterial pressure. The glycine (50 nmol)-evoked diuresis and natriuresis were abolished in rats continuously infused intravenously with [Arg(8)]-vasopressin. Furthermore, chronic bilateral renal denervation prevented the bradycardia and diuresis to PVN glycine and blunted the natriuresis. In other studies, unilateral PVN pretreatment with the glycine receptor antagonist strychnine (1.6 nmol) prevented the effects of PVN glycine (50 nmol) on heart rate, RSNA, and renal excretory function. When microinjected bilaterally, PVN strychnine (1.6 nmol per site) evoked a significant increase in heart rate and RSNA without altering renal excretory function. These findings demonstrate that in conscious rats glycine acts in the PVN to enhance the renal excretion of water and sodium and decrease central sympathetic outflow to the heart and kidneys. Although endogenous PVN glycine inputs elicit a tonic control of heart rate and RSNA, the renal excretory responses to PVN glycine seem to be caused primarily by the inhibition of arginine vasopressin secretion.

  2. Patterns of renal dopamine release to regulate diuresis and natriuresis during volume expansion. Role of renal monoamine-oxidase.

    PubMed

    de Luca Sarobe, Verónica; Di Ciano, Luis; Carranza, Andrea M; Levin, Gloria; Arrizurieta, Elvira E; Ibarra, Fernando R

    2010-01-01

    Diuretic and natriuretic effects of renal dopamine (DA) are well established. However, in volume expansion the pattern of renal DA release into urine (UDAV) and the role of enzymes involved in DA synthesis/degradation have not yet been defined. The objective was to determine the pattern of UDAV during volume expansion and to characterize the involvement of monoamine-oxidase (MAO) and aromatic amino-acid decarboxylase (AADC) in this response. In this study male Wistar rats were expanded with NaCl 0.9% at a rate of 5% BWt per hour. At the beginning of expansion three groups received a single drug injection as follows: C (vehicle, Control), IMAO (MAO inhibitor Pargyline, 20 mg/kg BWt, i.v.) and BNZ (AADC inhibitor Benserazide, 25 mg/kg BWt, i.v.). Results revealed that in C rats UDAV (ng/30 min/100g BWt) increased in the first 30 min expansion from 11.5 +/- 1.20 to 21.8 +/- 3.10 (p < 0.05) and decreased thereafter. IMAO showed a similar pattern but significantly higher than C at 30 min expansion (32.5 +/- 2.20, p < 0.05). IMAO greatly reduced MAO activity from 8.29 +/- 0.35 to 1.1 +/- 0.03 nmol/mg tissue/hour and significantly increased diuresis and natriuresis over controls. BNZ abolished the early UDAV peak to 3.2+/-0.72 (p < 0.01) and though, UDAV increased over C after 60 min expansion, natriuresis and diuresis were diminished by BNZ treatment. Results indicate that an increment in renal DA release into urine occurs early in expansion and in a peak-shaped way. In this response MAO plays a predominant role.

  3. Nocturnal Systemic Hypotension Increases the Risk of Glaucoma Progression

    PubMed Central

    Charlson, Mary E.; de Moraes, Carlos Gustavo; Link, Alissa; Wells, Martin T.; Harmon, Gregory; Peterson, Janey C.; Ritch, Robert; Liebmann, Jeffrey M.

    2015-01-01

    Objective The objective of this prospective, longitudinal study of patients with normal-tension glaucoma (NTG) was to determine whether patients with nocturnal hypotension are at greater risk for visual field (VF) loss over 12 months than those without nocturnal hypotension. Design Prospective, longitudinal study. Participants Consecutive patients with NTG with at least 5 prior VF tests were screened for eligibility. Methods The baseline evaluation assessed demographic and clinical characteristics, covering systemic comorbid conditions, including systemic hypertension. All oral and ophthalmologic medications were recorded. A complete ophthalmological examination was performed at baseline and follow-up. Patients had their blood pressure (BP) monitored every 30 minutes for 48 hours with an ambulatory recording device at baseline and 6 and 12 months. Main Outcome Measures The primary outcome was based on the global rates of VF progression by linear regression of the mean VF threshold sensitivity over time (decibels/year). Results Eighty-five patients with NTG (166 eyes; mean age, 65 years; 67% were women) were included. Of the 85 patients, 29% had progressed in the 5 VFs collected before study enrollment. The nocturnal mean arterial pressure (MAP) was compared with the daytime MAP. Multivariate analysis showed that the total time that sleep MAP was 10 mmHg below the daytime MAP was a significant predictor of subsequent VF progression (P<0.02). Conclusions Cumulative nocturnal hypotension predicted VF loss in this cohort. Our data suggest that the duration and magnitude of decrease in nocturnal blood pressure below the daytime MAP, especially pressures that are 10 mmHg lower than daytime MAP, predict progression of NTG. Low nocturnal blood pressure, whether occurring spontaneously or as a result of medications, may lead to worsening of VF defects. PMID:24869467

  4. Pathophysiological basis of orthostatic hypotension in autonomic failure

    PubMed Central

    Smit, Adrianus A J; Halliwill, John R; Low, Phillip A; Wieling, Wouter

    1999-01-01

    In patients with autonomic failure orthostatic hypotension results from an impaired capacity to increase vascular resistance during standing. This fundamental defect leads to increased downward pooling of venous blood and a consequent reduction in stroke volume and cardiac output that exaggerates the orthostatic fall in blood pressure. The location of excessive venous blood pooling has not been established so far, but present data suggest that the abdominal compartment and perhaps leg skin vasculature are the most likely candidates. To improve the orthostatic tolerance in patients with autonomic failure, protective measures that reduce excessive orthostatic blood pooling have been developed and evaluated. These measures include physical counter-manoeuvres and abdominal compression. PMID:10432334

  5. A reversible cause of skin hyperpigmentation and postural hypotension.

    PubMed

    Cherqaoui, Rabia; Husain, Mehreen; Madduri, Sujay; Okolie, Pamela; Nunlee-Bland, Gail; Williams, James

    2013-01-01

    Vitamin B12 deficiency results in neuropsychiatric, hematologic, gynecologic, cardiovascular, and cutaneous manifestations. It is seen most commonly in the elderly, malabsorption diseases  (>60% of all cases), vegans, and vegetarians. Manifestations of pernicious anemia may be similar to Addison disease and may lead to a misdiagnosis. Herein, we report two cases of vitamin B12 deficiency in which clinical features shared many similarities with Addison disease. Both patients presented with progressive darkening of hands and postural hypotension that reversed with replenishment of vitamin B12. Vitamin B12 deficiency should be considered in patients presenting with skin lesions especially with other coexisting autoimmune diseases.

  6. Early experiences of vasodilators and hypotensive anesthesia in children.

    PubMed

    Brown, T C K

    2012-07-01

    The physiological application of OHMS LAW explains the basis of hypotensive anesthesia. V = IR translates into: Pressure = Flow × Resistance or Blood pressure = Cardiac Output × Peripheral Resistance. If peripheral resistance is reduced by a vasodilator such as sodium nitroprusside (a short acting, vascular smooth muscle relaxant) or phenoxybenzamine (a long acting α adrenoreceptor antagonist), blood pressure will fall and vasoconstriction and bleeding will be reduced. A less desirable alternative to lowering blood pressure could be to reduce cardiac output by suppressing myocardial contractility using a ß(1) adrenoceptor antagonist or an inhalational agent such as isoflurane.

  7. Spontaneous Intracranial Hypotension Associated with Kinetic Tremor and Ataxia

    PubMed Central

    Salazar, Richard

    2016-01-01

    Background Spontaneous intracranial hypotension (SIH) is a clinically variable syndrome caused by low cerebrospinal fluid (CSF) pressure due to a non-traumatic CSF leak. Phenomenology Shown This case describes a 68-year-old gentleman who presents with chronic and slightly progressive kinetic tremor of bilateral hands associated with gait ataxia and gait start hesitation. Educational Value This case underscores the importance of having a high index of suspicion for the diagnosis of SIH when encountering a patient presenting with late-onset progressive kinetic tremor and gait ataxia syndrome. PMID:27351232

  8. The Management of Orthostatic Hypotension in Parkinson’s Disease

    PubMed Central

    Sánchez-Ferro, Álvaro; Benito-León, Julián; Gómez-Esteban, Juan Carlos

    2013-01-01

    Orthostatic hypotension (OH) is a common and disabling symptom affecting Parkinson’s disease (PD) patients. We present the effect of the different therapies commonly used to manage PD on this clinical manifestation. For this purpose, we describe the relationship between OH and the current treatments employed in PD, such as L-DOPA, dopaminergic agonists, and continuous dopaminergic stimulation therapies. Additionally, we review the therapeutic measures that could be used to ameliorate OH. There are different approaches to deal with this manifestation, including pharmacological and non-pharmacological treatments, although none of them is specifically aimed for treating OH in PD. PMID:23772219

  9. Neurogenic Hyperadrenergic Orthostatic Hypotension – A Newly-recognized Variant of Orthostatic Hypotension in Older Adults with Elevated Norepinephrine

    PubMed Central

    Mar, Philip L; Shibao, Cyndya A.; Garland, Emily M; Black, Bonnie K; Biaggioni, Italo; Diedrich, André; Paranjape, Sachin Y; Robertson, David; Raj, Satish R

    2015-01-01

    Patients with neurogenic orthostatic hypotension (OH) typically have impaired sympathetic nervous system tone and therefore low levels of upright plasma norepinephrine. We report a subset of patients who clinically have typical neurogenic OH but who paradoxically have elevated upright levels of plasma norepinephrine. We retrospectively studied 83 OH patients evaluated at the Vanderbilt Autonomic Dysfunction Center between August 2007 and May 2013. Based upon standing norepinephrine, patients were dichotomized into a hyperadrenergic orthostatic hypotension group (hyperOH: upright NE ≥3.55 nmol/L [600 pg/mL], n=19) or a non-hyperadrenergic orthostatic hypotension group (nOH: upright NE < 3.55 nmol/L [600 pg/mL], n=64). Medical history and data from autonomic testing, including the Valsalva maneuver (VM), were analyzed. HyperOH patients had profound orthostatic falls in blood pressure, but less severe than in nOH (change in SBP: −53±31 mmHg vs. −68±33 mmHg, P=0.050; change in DBP: −18±23 mmHg vs. −30±17 mmHg, P=0.01). The expected compensatory increase in standing heart rate was similarly blunted in both hyperOH and nOH groups (84±15 bpm vs. 82±14 bpm; P=0.6). HyperOH patients had less severe sympathetic failure as evidenced by smaller falls in DBP during phase 2 of VM, and a shorter VM phase 4 blood pressure recovery time (16.5±8.9 sec vs. 31.6±16.6 sec; P<0.001) than nOH patients. Neurogenic hyperOH patients have severe neurogenic orthostatic hypotension, but have less severe adrenergic dysfunction than nOH patients. Further work is required to understand if hyperOH patients will progress to nOH or if this represents a different disorder. PMID:25706983

  10. Marking nut anaphylaxis.

    PubMed

    Fok, Jie Shen; Kral, Anita Christine; Hayball, John; Smith, William B

    2016-07-01

    Marking nut Semecarpus anacardium, so-called because it contains a pigment that has been used in the past to mark fabrics, is a known cause of contact hypersensitivity. It may be ingested as an ingredient of some traditional Hindi foods. We describe the first reported case of anaphylaxis to marking nut. PMID:27489793

  11. Marking nut anaphylaxis.

    PubMed

    Fok, Jie Shen; Kral, Anita Christine; Hayball, John; Smith, William B

    2016-07-01

    Marking nut Semecarpus anacardium, so-called because it contains a pigment that has been used in the past to mark fabrics, is a known cause of contact hypersensitivity. It may be ingested as an ingredient of some traditional Hindi foods. We describe the first reported case of anaphylaxis to marking nut.

  12. Marking nut anaphylaxis

    PubMed Central

    Kral, Anita Christine; Hayball, John; Smith, William B

    2016-01-01

    Marking nut Semecarpus anacardium, so-called because it contains a pigment that has been used in the past to mark fabrics, is a known cause of contact hypersensitivity. It may be ingested as an ingredient of some traditional Hindi foods. We describe the first reported case of anaphylaxis to marking nut. PMID:27489793

  13. Mastering Marking Madness

    ERIC Educational Resources Information Center

    Moore, Brooke

    2009-01-01

    Teachers are smart people, so why does marking reduce them to stressed and soulless messes? Because in their hearts they know that students do not learn from it, and that drives them nuts. Researchers like Lorna Earl and Dylan Wiliam have looked closely at marking systems and have proven what teachers already know deep down: marking student work…

  14. Exogenous L-arginine attenuates the effects of angiotensin II on renal hemodynamics and the pressure natriuresis-diuresis relationship.

    PubMed

    Das, Satarupa; Mattson, David L

    2014-04-01

    Administration of exogenous L-arginine (L-Arg) attenuates angiotensin-II (AngII)-mediated hypertension and kidney disease in rats. The present study assessed renal hemodynamics and pressure diuresis-natriuresis in anaesthetized rats infused with vehicle, AngII (20 ng/kg per min i.v.) or AngII + L-Arg (300 μg/kg per min i.v.). Experiments in isolated aortic rings were carried out to assess L-Arg effects on the vasculature. Increasing renal perfusion pressure (RPP) from ~100 to 140 mmHg resulted in a nine- to tenfold increase in urine flow and sodium excretion rate in control animals. In comparison, AngII infusion significantly reduced renal blood flow (RBF) and glomerular filtration rate (GFR) by 40-42%, and blunted the pressure-dependent increase in urine flow and sodium excretion rate by 54-58% at elevated RPP. Supplementation of L-Arg reversed the vasoconstrictor effects of AngII and restored pressure-dependent diuresis to levels not significantly different from control rats. Dose-dependent contraction to AngII (10(-10) mol/L to 10(-7) mol/L) was observed with a maximal force equal to 27 ± 3% of the response to 10(-5) mol/L phenylephrine. Contraction to 10(-7) mol/L AngII was blunted by 75 ± 3% with 10(-4) mol/L L-Arg. The influence of L-Arg to blunt AngII-mediated contraction was eliminated by endothelial denudation or incubation with nitric oxide synthase inhibitors. Furthermore, the addition of 10(-3) mol/L cationic or neutral amino acids, which compete with L-Arg for cellular uptake, blocked the effect of L-Arg. Anionic amino acids did not influence the effects of L-Arg on AngII-mediated contraction. These studies show that L-Arg blunts AngII-mediated vascular contraction by an endothelial- and nitric oxide synthase-dependent mechanism involving cellular uptake of L-Arg.

  15. Cortical blood flow in controlled hypotension as measured by thermal diffusion 1

    PubMed Central

    Carter, L. Philip; Atkinson, James R.

    1973-01-01

    A thermal diffusion flow probe which gave a continuous, dynamic, quantitative record of cortical blood flow (CBF) was used to assess CBF in experimental animals with controlled hypotension. Acute hypotension was produced by trimethaphan camsylate, halothane, and sodium nitroprusside. Halothane produced less reduction in CBF per drop in blood pressure than the other two agents. Images PMID:4772724

  16. Chronic elevation of IL-1β induces diuresis via a cyclooxygenase 2-mediated mechanism.

    PubMed

    Boesen, E I

    2013-07-15

    Chronic renal inflammation is an increasingly recognized phenomenon in multiple disease states, but the impact of specific cytokines on renal function is unclear. Previously, we found that 14-day interleukin-1β (IL-1β) infusion increased urine flow in mice. To determine the mechanism by which this occurs, the current study tested the possible involvement of three classical prodiuretic pathways. Chronic IL-1β infusion significantly increased urine flow (6.5 ± 1 ml/day at day 14 vs. 2.3 ± 0.3 ml/day in vehicle group; P < 0.05) and expression of cyclooxygenase (COX)-2, all three nitric oxide synthase (NOS) isoforms, and endothelin (ET)-1 in the kidney (P < 0.05 in all cases). Urinary prostaglandin E metabolite (PGEM) excretion was also significantly increased at day 14 of IL-1β infusion (1.21 ± 0.26 vs. 0.29 ± 0.06 ng/day in vehicle-infused mice; P = 0.001). The selective COX-2 inhibitor celecoxib markedly attenuated urinary PGEM excretion and abolished the diuretic response to chronic IL-1β infusion. In contrast, deletion of NOS3, or inhibition of NOS1 with L-VNIO, did not blunt the diuretic effect of IL-1β, nor did pharmacological blockade of endothelin ETA and ETB receptors with A-182086. Consistent with a primary effect on water transport, IL-1β infusion markedly reduced inner medullary aquaporin-2 expression (P < 0.05) and did not alter urinary Na⁺ or K⁺ excretion. These data indicate a critical role for COX-2 in mediating the effects of chronic IL-1β elevation on the kidney.

  17. Impact of Controlled Induced Hypotension on Cognitive Functions of Patients Undergoing Functional Endoscopic Sinus Surgery

    PubMed Central

    Nowak, Stanisław; Ołdak, Anna; Kluzik, Anna; Drobnik, Leon

    2016-01-01

    Background Controlled induced hypotension guarantees less blood loss and better visibility of the surgical site. The impact of hypotension on post-operative cognitive functions is still being discussed. The objective of this study was to evaluate the effects of controlled induced hypotension on the cognitive functions of patients undergoing functional endoscopic sinus surgery (FESS). Material/Methods We allocated 47 patients with a good grade of preoperative cognitive functions evaluated with the Mini-Mental State Examination to 3 groups (1 – mild hypotension, 2 – intermediate hypotension, 3 – severe hypotension) according to the degree of mean intraoperative arterial pressure compared with preoperative blood pressure. Cognitive functions were evaluated preoperatively, 6 h, and 30 h postoperatively with standardized tests: the Stroop Test, Trail Making Test (TMT), and Verbal Fluency Test (VFT). A decrease in the test results and increase in the number of mistakes made were considered an impairment of cognitive functions. Results A total of 47 patients (group 1 – mild hypotension – 15, group 2 – intermediate hypotension – 19, group 3 – severe hypotension – 13) were included in the study. A significant decrease was observed in all the 3 groups after Stroop A test 6h postoperatively but it improved 30h postoperatively, without differences between the groups. Neither a significant decrease in the test results nor an increase in the number of mistakes was noted for Stroop B tests, TMT A&B tests and VFT. Conclusions The degree of controlled intraoperative hypotension during FESS did not influence the results of psychometric tests. PMID:26991989

  18. Caffeine-induced natriuresis and diuresis via blockade of hepatic adenosine-mediated sensory nerves and a hepatorenal reflex.

    PubMed

    Ming, Zhi; Lautt, W Wayne

    2010-11-01

    The hepatorenal reflex, activated by intrahepatic adenosine, is involved in the regulation of urine production in healthy rats and renal pathogenesis secondary to liver injury. Hepatic adenosine A1 receptors regulate the hepatorenal reflex. The aim of the present study was to evaluate whether caffeine mediates renal natriuresis and diuresis in healthy and diseased liver through this mechanism. Rats were anesthetized and instrumented to monitor systemic, hepatic, and renal circulation and urine production. Intrahepatic (intraportal but not intravenous) caffeine (5 mg·kg-1) increased urine flow (~82%) in healthy rats. This effect was abolished by liver denervation. Intraportal infusion of adenosine decreased urine production, and this response was abolished by intraportal but not intravenous caffeine. Liver injury was induced by intraperitoneal injection of thioacetamide (500 mg·kg-1), and functional assessment was performed 24 h later. Liver injury was associated with lower (~30%) glomerular filtration rate, lower (~18%) renal arterial blood flow, and lower urine production. Intraportal but not intravenous caffeine improved basal urine production and renal ability to increase urine production in response to saline overload. The liver-dependent diuretic effect of caffeine is consistent with the hypothesis for the adenosine-mediated mechanism of hepatorenal syndrome.

  19. Diuresis and reduced urinary osmolality in rats produced by small-molecule UT-A-selective urea transport inhibitors.

    PubMed

    Esteva-Font, Cristina; Cil, Onur; Phuan, Puay-Wah; Su, Tao; Lee, Sujin; Anderson, Marc O; Verkman, A S

    2014-09-01

    Urea transport (UT) proteins of the UT-A class are expressed in epithelial cells in kidney tubules, where they are required for the formation of a concentrated urine by countercurrent multiplication. Here, using a recently developed high-throughput assay to identify UT-A inhibitors, a screen of 50,000 synthetic small molecules identified UT-A inhibitors of aryl-thiazole, γ-sultambenzosulfonamide, aminocarbonitrile butene, and 4-isoxazolamide chemical classes. Structure-activity analysis identified compounds that inhibited UT-A selectively by a noncompetitive mechanism with IC50 down to ∼1 μM. Molecular modeling identified putative inhibitor binding sites on rat UT-A. To test compound efficacy in rats, formulations and administration procedures were established to give therapeutic inhibitor concentrations in blood and urine. We found that intravenous administration of an indole thiazole or a γ-sultambenzosulfonamide at 20 mg/kg increased urine output by 3-5-fold and reduced urine osmolality by ∼2-fold compared to vehicle control rats, even under conditions of maximum antidiuresis produced by 1-deamino-8-D-arginine vasopressin (DDAVP). The diuresis was reversible and showed urea > salt excretion. The results provide proof of concept for the diuretic action of UT-A-selective inhibitors. UT-A inhibitors are first in their class salt-sparing diuretics with potential clinical indications in volume-overload edemas and high-vasopressin-associated hyponatremias.

  20. Chloride channels in stellate cells are essential for uniquely high secretion rates in neuropeptide-stimulated Drosophila diuresis.

    PubMed

    Cabrero, Pablo; Terhzaz, Selim; Romero, Michael F; Davies, Shireen A; Blumenthal, Edward M; Dow, Julian A T

    2014-09-30

    Epithelia frequently segregate transport processes to specific cell types, presumably for improved efficiency and control. The molecular players underlying this functional specialization are of particular interest. In Drosophila, the renal (Malpighian) tubule displays the highest per-cell transport rates known and has two main secretory cell types, principal and stellate. Electrogenic cation transport is known to reside in the principal cells, whereas stellate cells control the anion conductance, but by an as-yet-undefined route. Here, we resolve this issue by showing that a plasma membrane chloride channel, encoded by ClC-a, is exclusively expressed in the stellate cell and is required for Drosophila kinin-mediated induction of diuresis and chloride shunt conductance, evidenced by chloride ion movement through the stellate cells, leading to depolarization of the transepithelial potential. By contrast, ClC-a knockdown had no impact on resting secretion levels. Knockdown of a second CLC gene showing highly abundant expression in adult Malpighian tubules, ClC-c, did not impact depolarization of transepithelial potential after kinin stimulation. Therefore, the diuretic action of kinin in Drosophila can be explained by an increase in ClC-a-mediated chloride conductance, over and above a resting fluid transport level that relies on other (ClC-a-independent) mechanisms or routes. This key segregation of cation and anion transport could explain the extraordinary fluid transport rates displayed by some epithelia.

  1. Temporal changes in micturition and bladder contractility after sucrose diuresis and streptozotocin-induced diabetes mellitus in rats.

    PubMed

    Tammela, T L; Leggett, R E; Levin, R M; Longhurst, P A

    1995-06-01

    Studies were done to compare the acute effects of streptozotocin-induced diabetes and sucrose consumption on micturition, bladder mass and contractile responses of bladder strips to field stimulation and contractile agonists. Micturition changes occurred gradually in diabetic rats, reached maximal values within 7 to 14 days, and were accompanied by significant increases in bladder mass after 7 days. Bladder strips from diabetics responded to field stimulation, carbachol and KCl with significantly greater contractions than did those from controls within 7 days. Sucrose-drinking rats had maximal increases in fluid consumption and micturition frequency on the first night after starting treatment. Increases in micturition volumes were slower to develop than in diabetics. Bladder mass was significantly increased 30 and 60 days after starting sucrose treatment. Bladder strips from sucrose-drinking rats responded to field stimulation and carbachol with significantly greater contractions than did those from controls only after 60 days. Monitoring of drinking and micturition patterns established that diabetic rats drink and urinate during both the dark and light cycles. In contrast, control and sucrose-drinking rats drink and urinate principally at night. The results demonstrate that differences in bladder function between diabetic and sucrose drinking rats are apparent during the first month after treatment begins. The data suggest that the effects of diabetes and sucrose consumption on contractile bladder function are related to the diuresis-induced increases in bladder mass.

  2. Severe Hypotension, Hypoxia, and Subcutaneous Erythema Induced by Indigo Carmine Administration during Open Prostatectomy

    PubMed Central

    Voelzke, Bryan B.

    2016-01-01

    Indigo carmine (also known as 5,5′-indigodisulfonic acid sodium salt or indigotine) is a blue dye that is administered intravenously to examine the urinary tract and usually is biologically safe and inert. Indigo carmine rarely may cause adverse reactions. We treated a 66-year-old man who had general anesthesia and radical retropubic prostatectomy for prostate cancer. He had a previous history of allergy to bee sting with nausea, vomiting, and dizziness. Within 1 minute after injection of indigo carmine for evaluation of the ureters, the patient developed hypotension to 40 mmHg, severe hypoxia (the value of SpO2 (peripheral capillary oxygen saturation) was 75% on 40% inspired oxygen concentration), poor air movement and bilateral diffuse wheezing on auscultation, and marked subcutaneous erythema at the upper extremities. After treatment with 100% oxygen, epinephrine (total, 1.5 mg), hydrocortisone (100 mg), diphenhydramine (50 mg), albuterol nebulizer (0.083%), and continuous infusion of epinephrine (0.15 μg/kg/min), the vital signs became stable, and he recovered completely. In summary, indigo carmine rarely may cause life-threatening anaphylactic or anaphylactoid reaction that may necessitate rapid treatment to stabilize cardiovascular, hemodynamic, and pulmonary function.

  3. Role of renin-angiotensin system in hypotension-evoked thirst: studies with hydralazine.

    PubMed

    Stocker, S D; Sved, A F; Stricker, E M

    2000-08-01

    Injection of rats either with diazoxide (25 mg/kg iv), isoproterenol (0.33 mg/kg sc), or hydralazine (HDZ) (10 mg/kg ip) decreased arterial blood pressure from approximately 120 to 70-80 mmHg and stimulated renin secretion. However, diazoxide and isoproterenol treatments each stimulated water ingestion, whereas HDZ treatment did not. HDZ treatment did not reduce water intake evoked by systemic injection of hypertonic saline or 20% polyethylene glycol solution or by 24-h water deprivation, suggesting that HDZ treatment did not interfere with drinking behavior. In contrast, HDZ treatment markedly reduced water intake evoked by injection of diazoxide or isoproterenol or by intravenous infusion of renin. Furthermore, a highly significant correlation was observed when plasma ANG II levels were plotted as a function of plasma renin activity after intravenous infusion of renin and after diazoxide and isoproterenol treatments. However, values obtained after HDZ treatment alone or in combination with intravenous infusion of renin did not fall near the 99% confidence interval of the regression line, suggesting that HDZ treatment blocks ANG II production and/or promotes its clearance. Thus rats apparently do not increase water intake after HDZ treatment, because this drug interferes with the renin-angiotensin system. These results provide further evidence that arterial hypotension evokes thirst in rats predominantly by activation of the renin-angiotensin system.

  4. Severe Hypotension, Hypoxia, and Subcutaneous Erythema Induced by Indigo Carmine Administration during Open Prostatectomy

    PubMed Central

    Voelzke, Bryan B.

    2016-01-01

    Indigo carmine (also known as 5,5′-indigodisulfonic acid sodium salt or indigotine) is a blue dye that is administered intravenously to examine the urinary tract and usually is biologically safe and inert. Indigo carmine rarely may cause adverse reactions. We treated a 66-year-old man who had general anesthesia and radical retropubic prostatectomy for prostate cancer. He had a previous history of allergy to bee sting with nausea, vomiting, and dizziness. Within 1 minute after injection of indigo carmine for evaluation of the ureters, the patient developed hypotension to 40 mmHg, severe hypoxia (the value of SpO2 (peripheral capillary oxygen saturation) was 75% on 40% inspired oxygen concentration), poor air movement and bilateral diffuse wheezing on auscultation, and marked subcutaneous erythema at the upper extremities. After treatment with 100% oxygen, epinephrine (total, 1.5 mg), hydrocortisone (100 mg), diphenhydramine (50 mg), albuterol nebulizer (0.083%), and continuous infusion of epinephrine (0.15 μg/kg/min), the vital signs became stable, and he recovered completely. In summary, indigo carmine rarely may cause life-threatening anaphylactic or anaphylactoid reaction that may necessitate rapid treatment to stabilize cardiovascular, hemodynamic, and pulmonary function. PMID:27610263

  5. Hypotensive and Angiotensin-Converting Enzyme Inhibitory Activities of Eisenia fetida Extract in Spontaneously Hypertensive Rats

    PubMed Central

    Mao, Shumei; Li, Chengde

    2015-01-01

    Objectives. This study aimed to investigate the antihypertensive effects of an Eisenia fetida extract (EFE) and its possible mechanisms in spontaneously hypertensive rats (SHR rats). Methods. Sixteen-week-old SHR rats and Wistar-Kyoto rats (WKY rats) were used in this study. Rats were, respectively, given EFE (EFE group), captopril (captopril group), or phosphate-buffered saline (PBS) (normal control group and SHR group) for 4 weeks. ACE inhibitory activity of EFE in vitro was determined. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using a Rat Tail-Cuff Blood Pressure System. Levels of angiotensin II (Ang II), aldosterone (Ald), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1α) in plasma were determined by radioimmunoassay, and serum nitric oxide (NO) concentration was measured by Griess reagent systems. Results. EFE had marked ACE inhibitory activity in vitro (IC50 = 2.5 mg/mL). After the 4-week drug management, SHR rats in EFE group and in captopril group had lower SBP and DBP, lower levels of Ang II and Ald, and higher levels of 6-keto-PGF1α and NO than the SHR rats in SHR group. Conclusion. These results indicate that EFE has hypotensive effects in SHR rats and its effects might be associated with its ACE inhibitory activity. PMID:26798397

  6. Severe Hypotension, Hypoxia, and Subcutaneous Erythema Induced by Indigo Carmine Administration during Open Prostatectomy.

    PubMed

    Nandate, Koichiro; Voelzke, Bryan B

    2016-01-01

    Indigo carmine (also known as 5,5'-indigodisulfonic acid sodium salt or indigotine) is a blue dye that is administered intravenously to examine the urinary tract and usually is biologically safe and inert. Indigo carmine rarely may cause adverse reactions. We treated a 66-year-old man who had general anesthesia and radical retropubic prostatectomy for prostate cancer. He had a previous history of allergy to bee sting with nausea, vomiting, and dizziness. Within 1 minute after injection of indigo carmine for evaluation of the ureters, the patient developed hypotension to 40 mmHg, severe hypoxia (the value of SpO2 (peripheral capillary oxygen saturation) was 75% on 40% inspired oxygen concentration), poor air movement and bilateral diffuse wheezing on auscultation, and marked subcutaneous erythema at the upper extremities. After treatment with 100% oxygen, epinephrine (total, 1.5 mg), hydrocortisone (100 mg), diphenhydramine (50 mg), albuterol nebulizer (0.083%), and continuous infusion of epinephrine (0.15 μg/kg/min), the vital signs became stable, and he recovered completely. In summary, indigo carmine rarely may cause life-threatening anaphylactic or anaphylactoid reaction that may necessitate rapid treatment to stabilize cardiovascular, hemodynamic, and pulmonary function. PMID:27610263

  7. Correction by centrophenoxine of abnormal catecholamine response to postural stimulus in patients with orthostatic hypotension due to brainstem ischemia.

    PubMed

    Stoica, E; Enulescu, O

    1991-01-01

    The effects of centrophenoxine on catecholamine (CA) response to orthostasis and on postural blood pressure fall of 25 patients with orthostatic hypotension due to brainstem ischemia were studied. Before therapy, the patients responded to posture by a depression in norepinephrine (NE) excretion and a rise in epinephrine (E) excretion. After a 10-day treatment with centrophenoxine, 800 mg daily, the patients responded to posture like normals, i.e. by a rise in NE excretion and a reduction in E excretion. Although the orthostatic blood pressure fall was less marked after treatment, the favourable clinical effect of the drug could not be correlated significantly with the restoration of CA response to posture after treatment.

  8. Orthostatic hypotension and cognitive impairment: a dangerous association?

    PubMed

    Sambati, Luisa; Calandra-Buonaura, Giovanna; Poda, Roberto; Guaraldi, Pietro; Cortelli, Pietro

    2014-06-01

    Many studies have addressed the relation between orthostatic hypotension (OH) and cognitive impairment (CI) in the elderly, in mild cognitive impairment, vascular and neurodegenerative dementias and movement disorders, such as Parkinson's disease. However, results concerning both the increased coexistence of the two conditions and their causal relationship remain controversial. According to the literature three hypotheses can be formulated on the relation between OH and CI. In neurodegenerative disease, OH and CI may result from a common pathological process which affects areas involved in both cognition and cardiovascular autonomic control. Alternatively, OH may lead to cerebral hypoperfusion which is supposed to play a role in the development of CI. Finally, recent data suggest that CI should probably be considered more a transient symptom of OH than a chronic effect. This study reviews the literature reports on the relationship between OH and CI, and emphasises the need for longitudinal studies designed to investigate this topic.

  9. Spontaneous intracranial hypotension resulting from a thoracic osteophyte.

    PubMed

    Hung, Ling-Chien; Hsu, Yung-Chu

    2015-06-01

    We report a 34-year-old woman who presented with progressive postural headache and neck tightness over 1week. We confirmed the diagnosis of spontaneous intracranial hypotension (SIH) and spinal images showed a thoracic osteophyte caused the cerebrospinal fluid (CSF) leak. SIH caused by spinal CSF leak is generally thought to be a consequence of deficiency of the spinal meninges in conjunction with trivial trauma. Less commonly, spinal bony pathology can lead to SIH. We reviewed 13 reported patients with bony structural pathology related SIH. After two to three epidural blood patches, eight patients underwent surgery. They generally had good outcomes. In conclusion, even though surgical repair confers specific risks, it should be considered after repetitive failures of epidural blood patches. The long-term prognoses of surgical versus non-surgical patients warrants further investigation. PMID:25778385

  10. GCF Mark IV development

    NASA Technical Reports Server (NTRS)

    Mortensen, L. O.

    1982-01-01

    The Mark IV ground communication facility (GCF) as it is implemented to support the network consolidation program is reviewed. Changes in the GCF are made in the area of increased capacity. Common carrier circuits are the medium for data transfer. The message multiplexing in the Mark IV era differs from the Mark III era, in that all multiplexing is done in a GCF computer under GCF software control, which is similar to the multiplexing currently done in the high speed data subsystem.

  11. Renal medullary ETB receptors produce diuresis and natriuresis via NOS1.

    PubMed

    Nakano, Daisuke; Pollock, Jennifer S; Pollock, David M

    2008-05-01

    Endothelin-1 (ET-1) plays an important role in the regulation of salt and water excretion in the kidney. Considerable in vitro evidence suggests that the renal medullary ET(B) receptor mediates ET-1-induced inhibition of electrolyte reabsorption by stimulating nitric oxide (NO) production. The present study was conducted to test the hypothesis that NO synthase 1 (NOS1) and protein kinase G (PKG) mediate the diuretic and natriuretic effects of ET(B) receptor stimulation in vivo. Infusion of the ET(B) receptor agonist sarafotoxin S6c (S6c: 0.45 microg x kg(-1) x h(-1)) in the renal medulla of anesthetized, male Sprague-Dawley rats markedly increased the urine flow (UV) and urinary sodium excretion (UNaV) by 67 and 120%, respectively. This was associated with an increase in medullary cGMP content but did not affect blood pressure. In addition, S6c-induced diuretic and natriuretic responses were absent in ET(B) receptor-deficient rats. Coinfusion of N(G)-propyl-l-arginine (10 microg x kg(-1) x h(-1)), a selective NOS1 inhibitor, suppressed S6c-induced increases in UV, UNaV, and medullary cGMP concentrations. Rp-8-Br-PET-cGMPS (10 microg x kg(-1) x h(-1)) or RQIKIWFQNRRMKWKK-LRK(5)H-amide (18 microg x kg(-1) x h(-1)), a PKG inhibitor, also inhibited S6c-induced increases in UV and UNaV. These results demonstrate that renal medullary ET(B) receptor activation induces diuretic and natriuretic responses through a NOS1, cGMP, and PKG pathway.

  12. Interleukin-1 and tumour necrosis factor cause hypotension in the conscious rabbit.

    PubMed

    Weinberg, J R; Wright, D J; Guz, A

    1988-09-01

    1. The cardiovascular effects of intravenous injections of interleukin-1 (IL-1) and tumour necrosis factor (TNF) have been investigated in the conscious rabbit. They have been compared with the effects of bacterial lipopolysaccharide (LPS) because both IL-1 and TNF are released from macrophages by LPS. 2. IL-1, TNF and Escherichia coli J5-LPS all caused hypotension when given intravenously in a dose with low mortality. The time course of the hypotension caused by IL-1 and LPS was similar, although the maximal fall in mean blood pressure occurred earlier after IL-1. TNF produced a more sustained fall in blood pressure. Hypotension was not accompanied by a compensatory tachycardia after any of the test substances. Hypotension was associated with a fever after TNF, hypothermia after LPS and no significant change in temperature after IL-1. 3. The packed cell volume did not change during hypotension in any of the study groups, implying that the hypotension was not due to fluid loss resulting from increased capillary permeability. 4. IL-1 and TNF are candidates for the role of effectors of LPS-induced hypotension.

  13. Effect of injection rate on hypotension associated with spinal anesthesia for cesarean section.

    PubMed

    Simon, L; Boulay, G; Ziane, A F; Noblesse, E; Mathiot, J L; Toubas, M F; Hamaza, J

    2000-01-01

    Maternal hypotension is a common problem during cesarean section under spinal anesthesia. We evaluated in a prospective observational study the influence of injection speed on maternal hypotension. Hyperbaric bupivacaine 10 mg, sufentanil 2 microg and morphine 200 microg (total volume 4 mL) were injected either quickly (<15 s) or slowly (=120 s) in 50 women scheduled for elective cesarean section. Hypotension (systolic arterial pressure (SAP) <100 mmHg or <70% of baseline) was promptly treated with 5 mg ephedrine boluses. Slow injection significantly reduced the incidence of hypotension (68% in the 120 s group and 92% in the other, P =0.03). In addition, onset of hypotension was delayed, had a shorter duration and required less ephedrine for hypotension in the 120 s group (11.6 mg vs. 19.6 mg, P =0.019). Anesthesia was satisfactory for all women. We conclude that a 2 mL/min injection rate may be a simple and effective way to reduce the incidence and severity of hypotension during cesarean section under spinal anesthesia.

  14. Hypotensive Response Magnitude and Duration in Hypertensives: Continuous and Interval Exercise

    PubMed Central

    de Carvalho, Raphael Santos Teodoro; Pires, Cássio Mascarenhas Robert; Junqueira, Gustavo Cardoso; Freitas, Dayana; Marchi-Alves, Leila Maria

    2015-01-01

    Background Although exercise training is known to promote post-exercise hypotension, there is currently no consistent argument about the effects of manipulating its various components (intensity, duration, rest periods, types of exercise, training methods) on the magnitude and duration of hypotensive response. Objective To compare the effect of continuous and interval exercises on hypotensive response magnitude and duration in hypertensive patients by using ambulatory blood pressure monitoring (ABPM). Methods The sample consisted of 20 elderly hypertensives. Each participant underwent three ABPM sessions: one control ABPM, without exercise; one ABPM after continuous exercise; and one ABPM after interval exercise. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR) and double product (DP) were monitored to check post-exercise hypotension and for comparison between each ABPM. Results ABPM after continuous exercise and after interval exercise showed post-exercise hypotension and a significant reduction (p < 0.05) in SBP, DBP, MAP and DP for 20 hours as compared with control ABPM. Comparing ABPM after continuous and ABPM after interval exercise, a significant reduction (p < 0.05) in SBP, DBP, MAP and DP was observed in the latter. Conclusion Continuous and interval exercise trainings promote post-exercise hypotension with reduction in SBP, DBP, MAP and DP in the 20 hours following exercise. Interval exercise training causes greater post-exercise hypotension and lower cardiovascular overload as compared with continuous exercise. PMID:25517389

  15. Marking as Judgment

    ERIC Educational Resources Information Center

    Brooks, Val

    2012-01-01

    An aspect of assessment which has received little attention compared with perennial concerns, such as standards or reliability, is the role of judgment in marking. This paper explores marking as an act of judgment, paying particular attention to the nature of judgment and the processes involved. It brings together studies which have explored…

  16. Bilateral mesial occipital lobe infarction after cardiogenic hypotension induced by electrical shock.

    PubMed

    Kamyar, Roheena; Trobe, Jonathan D

    2009-06-01

    A 28-year-old man developed cerebral blindness from infarction of both mesial occipital lobes after cardiogenic hypotension induced by electrical shock. He remained globally encephalopathic for several weeks, but his most enduring deficit was bilateral homonymous hemianopias with macular sparing. Cerebral visual loss after electrical injury has been sparsely reported. It has been attributed to direct thermal injury of the skull or posterior dural venous sinuses. We suggest that cerebral blindness after cardiogenic hypotension in which there is no thermal injury to the scalp be attributed to hypotensive infarction of the mesial occipital lobes, which lie in the terminal domain of the posterior cerebral arteries.

  17. Pharmacologic inhibition of the renal outer medullary potassium channel causes diuresis and natriuresis in the absence of kaliuresis.

    PubMed

    Garcia, Maria L; Priest, Birgit T; Alonso-Galicia, Magdalena; Zhou, Xiaoyan; Felix, John P; Brochu, Richard M; Bailey, Timothy; Thomas-Fowlkes, Brande; Liu, Jessica; Swensen, Andrew; Pai, Lee-Yuh; Xiao, Jianying; Hernandez, Melba; Hoagland, Kimberly; Owens, Karen; Tang, Haifeng; de Jesus, Reynalda K; Roy, Sophie; Kaczorowski, Gregory J; Pasternak, Alexander

    2014-01-01

    The renal outer medullary potassium (ROMK) channel, which is located at the apical membrane of epithelial cells lining the thick ascending loop of Henle and cortical collecting duct, plays an important role in kidney physiology by regulating salt reabsorption. Loss-of-function mutations in the human ROMK channel are associated with antenatal type II Bartter's syndrome, an autosomal recessive life-threatening salt-wasting disorder with mild hypokalemia. Similar observations have been reported from studies with ROMK knockout mice and rats. It is noteworthy that heterozygous carriers of Kir1.1 mutations associated with antenatal Bartter's syndrome have reduced blood pressure and a decreased risk of developing hypertension by age 60. Although selective ROMK inhibitors would be expected to represent a new class of diuretics, this hypothesis has not been pharmacologically tested. Compound A [5-(2-(4-(2-(4-(1H-tetrazol-1-yl)phenyl)acetyl)piperazin-1-yl)ethyl)isobenzofuran-1(3H)-one)], a potent ROMK inhibitor with appropriate selectivity and characteristics for in vivo testing, has been identified. Compound A accesses the channel through the cytoplasmic side and binds to residues lining the pore within the transmembrane region below the selectivity filter. In normotensive rats and dogs, short-term oral administration of compound A caused concentration-dependent diuresis and natriuresis that were comparable to hydrochlorothiazide. Unlike hydrochlorothiazide, however, compound A did not cause any significant urinary potassium losses or changes in plasma electrolyte levels. These data indicate that pharmacologic inhibition of ROMK has the potential for affording diuretic/natriuretic efficacy similar to that of clinically used diuretics but without the dose-limiting hypokalemia associated with the use of loop and thiazide-like diuretics.

  18. Pharmacologic inhibition of the renal outer medullary potassium channel causes diuresis and natriuresis in the absence of kaliuresis.

    PubMed

    Garcia, Maria L; Priest, Birgit T; Alonso-Galicia, Magdalena; Zhou, Xiaoyan; Felix, John P; Brochu, Richard M; Bailey, Timothy; Thomas-Fowlkes, Brande; Liu, Jessica; Swensen, Andrew; Pai, Lee-Yuh; Xiao, Jianying; Hernandez, Melba; Hoagland, Kimberly; Owens, Karen; Tang, Haifeng; de Jesus, Reynalda K; Roy, Sophie; Kaczorowski, Gregory J; Pasternak, Alexander

    2014-01-01

    The renal outer medullary potassium (ROMK) channel, which is located at the apical membrane of epithelial cells lining the thick ascending loop of Henle and cortical collecting duct, plays an important role in kidney physiology by regulating salt reabsorption. Loss-of-function mutations in the human ROMK channel are associated with antenatal type II Bartter's syndrome, an autosomal recessive life-threatening salt-wasting disorder with mild hypokalemia. Similar observations have been reported from studies with ROMK knockout mice and rats. It is noteworthy that heterozygous carriers of Kir1.1 mutations associated with antenatal Bartter's syndrome have reduced blood pressure and a decreased risk of developing hypertension by age 60. Although selective ROMK inhibitors would be expected to represent a new class of diuretics, this hypothesis has not been pharmacologically tested. Compound A [5-(2-(4-(2-(4-(1H-tetrazol-1-yl)phenyl)acetyl)piperazin-1-yl)ethyl)isobenzofuran-1(3H)-one)], a potent ROMK inhibitor with appropriate selectivity and characteristics for in vivo testing, has been identified. Compound A accesses the channel through the cytoplasmic side and binds to residues lining the pore within the transmembrane region below the selectivity filter. In normotensive rats and dogs, short-term oral administration of compound A caused concentration-dependent diuresis and natriuresis that were comparable to hydrochlorothiazide. Unlike hydrochlorothiazide, however, compound A did not cause any significant urinary potassium losses or changes in plasma electrolyte levels. These data indicate that pharmacologic inhibition of ROMK has the potential for affording diuretic/natriuretic efficacy similar to that of clinically used diuretics but without the dose-limiting hypokalemia associated with the use of loop and thiazide-like diuretics. PMID:24142912

  19. [Relationship between regulation effect of salvia miltiorrhiza on AQP2 in kidney and promoting blood circulation and diuresis].

    PubMed

    Dong, Xiao-Jing; Guo, Liang-Feng; Yao, Rui; Xue, Song-Yan; Li, Feng

    2014-08-01

    Partial nature of "promoting blood circulation and dieresis" of Salvia Miltiorrhizain was initially demonstrated by investigating the regulation effect of AQP2 expression in kidney of trauma blood stasis model rats with the Salvia Miltiorrhizain so as to provide guidance for its clinical deployment of administration. Random allocation was taken to averagely divide 30 SD rats into two groups: 10 rats in normal group and 20 rats in blood stasis syndrome group. Trauma blood stasis rat model was established by quantitatively beating. Then the rat model group was divided into model group and salvia group. After 7 days of treatment, the rat kidney AQP2 expression was detected, the content of urine AQP2 was compared and the damaged local muscle and kidney pathological changes were observed by immunohistochemical method and western blot method. Compared with that of the normal group, rats in model group had inflammatory cells infiltration, blood stasis and edema of the injured local muscles and up-regulated AQP2 expression, decreasing urinary output, and kidney tissues blood stasis and edema (P < 0.05). On the other hand, compared with that of the model group, those parameters of rats in salvia group were all decreasing except urine output (P < 0.05). Such result indicated that Salvia Miltiorrhiza can reduce trauma blood stasis rat content of urine AQP2 and down-regulated AQP2 expression in kidney tissue, so as to reduce the reabsorption of water by renal tubular and increase urine output. The promoting blood circulation effect of Salvia Miltiorrhizain can alleviate the degree of the damaged tissue edema and encourage urine drainage. This therapy is closely related to the effect of regulating AQP2 in kidney by salvia, so the purpose of this study by verifying "promoting blood circulation and diuresis" as the mechanism for the regulation effect of the salvia on AQP2 expression.

  20. Aesthetic laser marking assessment

    NASA Astrophysics Data System (ADS)

    Ng, T. W.; Yeo, S. C.

    2000-04-01

    In this paper, the CIE color difference formula was applied to evaluate four types of material surfaces; anodized aluminium, stainless steel, poly-butylene tetra-phthalate (PBT), and phenol formaldehyde, marked using a Nd:YAG laser, and viewed under three common modes of illumination; tungsten, fluorescent and daylight. The color difference values were based on the spectral reflectance readings obtained from a spectrophotometer. Each material exhibited different color difference trends in relation to marking speed for the different modes of illumination. Nevertheless, general comparisons could be made in terms of operational marking speeds and the maximal color difference values for each material.

  1. Novel hypotensive agents from Verbesina caracasana: structure, synthesis and pharmacology.

    PubMed

    Botta, Bruno; Carmignani, Marco; Volpe, Anna Rita; Botta, Maurizio; Corelli, Federico; Delle Monache, Giuliano

    2003-09-01

    The number and the pharmacological activities of drugs featuring a guanidine group is actually amazing. Many synthetic guanidine derivatives have attracted pharmacologists in search of new antihypertensive drugs for their ability to block adrenergic nerve activity through central and/or peripheral mechanisms. As a result, compounds such as guanethidine, guanabenz, guanfacine, and pinacidil have been introduced in antihypertensive drug therapy. A crude methanol extract of the Venezuelan plant Verbesina caracasana Fries (Compositae), intravenously administered to mice, was found to induce biological effects such as erection of hair, initial stimulation and subsequent blockade of breathing. Biologically controlled purification yielded a series of active guanidine derivatives, namely G1-G7, which were extensively studied with the focus on the following items: (1) The structure determination of the active compounds by spectral data and a set of reactions; (2) The confirmation of the structures by a biogenetically oriented synthesis; (3) The study of the pharmacological profiles of the isolated drugs; (4) The synthesis of analogous and homologous products in the effort to shed some light on the structure-activity relationship. The metabolites of V. caracasana were characterized, in anesthetized rats, as hypotensive drugs of high (G2), mild (G1, G7) and low (G3,G5,G6) potency, devoid of consistent actions in heart rate, and provided with moderate stimulatory effects on cardiac inotropism and breathing (at selected non-toxic intravenous doses). Autonomic neurogenic components and/or peripheral adrenergic and cholinergic receptor-related pathways were involved in the cardiovascular effects. Synthetic analogs and homologs of G1 and G5 were all shown to be hypotensive drugs of low-mild potency, not affecting appreciably cardiac inotropism and/or breathing. The pharmacodynamic differences among the studied compounds were likely to depend on their ability to cross the blood

  2. Graded Compression Stockings Prevent Post-spaceflight Orthostatic Hypotension

    NASA Technical Reports Server (NTRS)

    Platts, S. H.; Brown, A. K.; Locke, J.; Stenger, M. B.

    2008-01-01

    Post-spaceflight orthostatic intolerance is characterized by hypotension and presyncope in 20-30% of returning astronauts. Previous data from our laboratory suggests that this is largely a result of decreased venous return. Currently, NASA astronauts wear an anti-gravity suit (AGS) which consists of inflatable air bladders over the calves, thighs and abdomen, which are typically pressurized from 0.5 to 1.5 PSI (27 to 78 mmHg). ISS crew members sometimes wear Russian Kentavr suits which consist of laced compression shorts and gaiters, providing 30 mmHg nominally. While these garments are effective during reentry, there are a number of drawbacks that make them impractical for postflight use. We studied the ability of commercially available, custom fit, graded compression stockings (Jobst, 55 mmHg at ankle to 6 mmHg at top of thigh, 25 mmHg mean compression) to prevent postflight orthostatic intolerance, hypothesizing that these garments would prevent orthostatic intolerance following short duration space flight. Crew members from a single Space Shuttle flight were tilted to 80 degrees for 10 min while wearing the stockings (n=5 males) upon arrival at the clinic (2 hrs after landing). Hemodynamic data were compared to data from all crewmembers tilted (without countermeasures) since return to flight (n=9). Two-way, repeated measures ANOVA, using the entire tilt time curve (0-10 min) show that systolic blood pressure (SBP, group effect p=0.008), stroke volume (SV, group effect p=0.003), and cardiac output (CO, group effect p=0.004) were higher in crewmembers who wore the Jobst stockings. A one-way ANOVA comparing the last minute standing also showed that SV (p=0.001) and CO (p less than 0.001) were higher and SBP tended to be higher (p=0.06) in Jobst subjects compared to controls. Control subjects had a higher rate of presyncope than Jobst subjects (3/9 vs 0/5) during the tilt on landing day. Orthostatic hypotension continues to present following spaceflight, despite

  3. Hypotensive anesthesia versus normotensive anesthesia during major maxillofacial surgery: a review of the literature.

    PubMed

    Barak, Michal; Yoav, Leiser; Abu el-Naaj, Imad

    2015-01-01

    Steady blood pressure within normal limits during surgery is one of the markers of the ideal and skillful anesthesia. Yet, reduced blood pressure is advantageous in some settings because it can contribute to a reduction in overall blood loss and improve the surgical field conditions. Controlled hypotension during anesthesia or hypotensive anesthesia is often used in major maxillofacial operations. Since hypotensive anesthesia carries the risk of hypoperfusion to important organs and tissues, mainly the brain, heart, and kidneys, it cannot be applied safely in all patients. In this paper we review the medical literature regarding hypotensive anesthesia during major maxillofacial surgery, the means to achieve it, and the risks and benefits of this technique, in comparison to normotensive anesthesia.

  4. Ames Fellows Award - Mark

    NASA Video Gallery

    Dr. Hans Mark is a leading expert in the fields of aerospace design and national defense policy. From 1969 to 1977, he served as Director of the NASA Ames Research Center. During his tenure, Ames b...

  5. Mark IVA microprocessor support

    NASA Technical Reports Server (NTRS)

    Burford, A. L.

    1982-01-01

    The requirements and plans for the maintenance support of microprocessor-based controllers in the Deep Space Network Mark IVA System are discussed. Additional new interfaces and 16-bit processors have introduced problems not present in the Mark III System. The need for continuous training of maintenance personnel to maintain a level of expertise consistent with the sophistication of the required tools is also emphasized.

  6. A retrospective study to correlate breech presentation and enhanced risk of postspinal hypotension during cesarean delivery

    PubMed Central

    Jain, Anshul; Pandey, Shivali; Kumar, Roopesh; Sethi, Chavi; Sharma, Sanjya

    2015-01-01

    Background Subarachnoid blockade for cesarean section still poses a threat of profound hypotension and can result in unstable maternal and fetal hemodynamics. The correlation of fetal breech and vertex presentation with the occurrence of hypotension under spinal anesthesia is reviewed in this retrospective, double-blind study. Patients and methods The study was conducted on pregnant females scheduled for a lower segment cesarean section between January 2014 and December 2014. After applying inclusion criteria, 568 patients were recruited in the study out of which 363 had vertex and 184 patients had breech presentation. They were divided into two groups, Group I and Group II. The monitoring and therapeutic data (blood pressure, heart rate, arterial oxygen saturation, and dose of vasopressor/atropine) recovered from automated data analysis were analyzed retrospectively for prevalence of hypotension, bradycardia, and hypotension with bradycardia and nausea ± vomiting. Results Among Group I, prevalence of hypotension, bradycardia, and hypotension together with bradycardia was 152 (41.83%) patients, eight (2.20%) patients, and seven (1.92%) patients, respectively. In Group II, the prevalence of hypotension, bradycardia, and hypotension with bradycardia was 93 (50.5%) patients, five (2.71%) patients, and six (3.2%) patients, respectively. The difference between the two groups was statistically significant for hypotension. For Group I, 152 patients (41.87%) experienced one, 23 patients (6.33%) experienced two, and three patients (0.82%) experienced three episodes of hypotension. In Group II, 93 (50.5%), 19 (7.89%), and two (1.08%) patients experienced such episodes. The difference was significant with respect of one and two episodes. The prevalence of intraoperative nausea was 11.01% (40 patients) in Group I, whereas 11.41% (21 patients) in Group II. Intraoperative vomiting occurred in 19 patients (5.23%) of Group I and 14 patients (7.60%) of Group II. The height of the

  7. [Analysis of bite marks].

    PubMed

    Spiessens, Marc; Van der Velden, Bram; Willems, Guy

    2005-01-01

    Precise photographs, supplemented by impressions are used to research and compare bite marks. Different materials for impressions are available to the forensic odontologist. Subsequently, the acquired information of the bite mark will be compared with the dentition of a suspect through photographs, intra- and extra oral examination and impressions. The overlay, which can be created using a variety of methods, allows the comparison between the bite mark and the dentition of the suspect. Among the most commonly used are hand-tracing of study models, wax bites or photocopies, or the radio-opaque wax bite method. Thanks to modern technology and the use of computers, analyses of bite marks have gradually become more accurate. Current research carried out at the Katholieke Universiteit Leuven will demonstrate whether the computer program ForensicIQ is able to offer an even more precise comparison between a given bite mark and the dentition of a suspect. By no means should bite mark analysis alone be allowed to lead to a guilty verdict, but it will offer the opportunity to exclude a suspect from a crime when the data do not correspond. PMID:16370436

  8. Basic characteristics of chronic hypotension cases: a longitudinal follow-up study from 1958 through 1999.

    PubMed

    Akahoshi, Masazumi; Hida, Ayumi; Imaizumi, Misa; Soda, Midori; Maeda, Renju; Ichimaru, Shinichiro; Nakashima, Eiji; Seto, Shinji; Yano, Katsusuke

    2006-01-01

    Few epidemiological studies have been conducted on the prevalence, blood pressure trends by age, and basic characteristics of chronic hypotension. Among 13,370 subjects (5,094 men and 8,276 women) examined from 1958 to 1999 in Japan, 92 were identified as chronic hypotensives (11 men and 81 women) whose systolic blood pressure (SBP, mmHg) was lower than 100 mmHg for 8 or more years. Trends of SBP and body mass index (BMI, kg/m2) were determined over a 16-year period in this group of chronic hypotensives and 276 age- and sex-matched controls (33 men and 243 women); during this 16-year period, the chronic hypotensives and controls ranged in age from 19 to 75 years. BMI, heart rate (HR, bpm), body temperature (degrees C), Hb (g/dl), and creatinine (Cre, mg/dl) were compared between the chronic hypotensives and the controls at the last examination. The chronic hypotensives had a female preponderance (0.2% in men and 1.0% in women, p=0.001), and their SBP and BMI increased little with increasing age. BMI (20.2+/-3.4), BMI-adjusted SBP (101+/-19), HR (63+/-10), body temperature (36.7+/-0.3), Hb (12.5+/-1.1), and Cre (0.81+/-0.13) were lower in the chronic hypotensives than those (22.9+/-3.4, 126+/-20, 68+/-10, 36.8+/-0.3, 12.9+/-1.1, and 0.86+/-0.12, respectively) in controls (p<0.05). The present results clearly show that chronic hypotensives have a female preponderance and low BMI, HR, body temperature, Hb, and Cre in addition to low SBP that does not increase with age.

  9. Orthostatic Hypotension and Mortality in Elderly Frail Patients

    PubMed Central

    Freud, Tamar; Punchik, Boris; Yan, Press

    2015-01-01

    Abstract Orthostatic hypotension (OH) is a common problem in the elderly age group, and some studies have reported an association between OH and increased mortality. We evaluated possible associations between OH and mortality in a retrospective study of frail elderly patients who came for a comprehensive geriatric assessment. The study included all patients ≥65 years who were assessed in the outpatient Comprehensive Geriatric Assessment Unit. Data were collected from the computerized medical record, including blood pressure, sociodemographic data, lifestyle, falls, pulse rate, body mass index, functional and cognitive status, and comorbidity. Data on mortlaity were also collected. The study population consisted of 571 patients who underwent assessment over a 9-year study period. The mean age was 83.7 ± 6.1, 35.9% were males, and 183 (32.1%) were diagnosed with OH. Systolic OH (OHS) was more common than diastolic OH (25.2% vs 15.6%). In univariate analyses, OHS was associated with increased overall mortality. Over the follow-up period, 30.2% of the OHS patients died compared with 22.3% (P = 0.037), but in the Cox models there was no statistically significant associations between OHS and overall mortality. In contrast, age, burden of comorbidity, a low high-density lipoprotein level, and low creatinine clearance were independent predictors of increased overall mortality. In a population of frail elderly patients with a high burden of comorbidity, OH was not an independent risk factor for overall mortality.

  10. [The 452th case: rash, hypotension, abdominal pain and headache].

    PubMed

    Bian, S N; Yang, H H; Wang, Q; Xu, D; Zhao, Y

    2016-09-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease characterized with multiple organ involvements. Acute acalculous cholecystitis(AAC) is an extremely rare manifestation of digestive system involvement in SLE. We reported a case of 32-year-old woman who complained skin rashes for two weeks and stomachache and oliguria for one day. She had rashes at onset, and developed fever, stomachache, hypotension and headache. Physical examination at admission indicated blood pressure 76/47 mmHg(1 mmHg=0.133 kPa), heart rate 107 beats/min, warm acra. Murphy's sign was positive. Ultrasound suggested the enlarged gallbladder with surrounding hypoecho band yet no biliary calculi were found. A diagnosis of SLE was made, characteristic with distributive shock at the onset and AAC, complicated with neuropsychiatric lupus and lupus nephritis. She had an acute and severe course of disease, which had been relieved after treatment of high dose glucocorticoid and immunosuppressants. This case arouses clinicians to pay more attention to AAC as a rare form of disease flare in SLE. Early diagnosis of AAC is crucial to a favorable prognosis and in avoid of abdominal surgery. PMID:27586989

  11. Public and patient research priorities for orthostatic hypotension.

    PubMed

    Frith, James; Bashir, Ayat S; Elliott, Chris S; Newton, Julia L

    2014-11-01

    With a rapidly expanding older population and increased survival of older people with chronic disease, we can expect to see increasing numbers of people with orthostatic hypotension (OH). Unfortunately the evidence base for people with OH, with particular relevance to older people, has not kept up and has resulted in a real lack of progress and little good evidence. There are several areas of research that could potentially benefit patients but establishing which ones are priority areas requires public and patient involvement (PPI). This process includes people/patients in the research team to maximise the relevance, success and translation of the research. This brief report describes the early involvement of older people in prioritising the research question, methods to improve adherence during a trial and the preferred methods to disseminate research output. The individuals' priority was to research non-pharmacological treatment strategies and to improve the education of patients about their condition. Education was felt to be the best strategy to promote adherence during a trial, with change in symptoms and quality of life felt to be the most important outcome measures as opposed to blood pressure. This report offers guidance for academics that are undertaking OH-related research and how they can improve its relevance and increase its translation into clinical practice. PMID:25146411

  12. Exercise training hypotension - Implications for plasma volume, renin, and vasopressin

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Sciaraffa, D.; Shvartz, E.; Keil, L. C.; Brock, P. J.

    1981-01-01

    The relation of changes in plasma volume, plasma renin activity and arginine vasopressin to changes in resting blood pressure during exercise training is investigated. Resting supine, sitting, and standing systolic and fifth-phase diastolic blood pressures were measured in ten men before and after an eight-day training period on a cycle ergometer in either a hot (39.8 C) or cool (23.8 C) environment, and compared with plasma volume, renin and vasopressin levels, heart rates, maximal oxygen uptakes, rectal temperatures and sweat rates. Following acclimatization, resting supine and sitting diastolic pressures are observed to decrease by 6 and 9 mm Hg, respectively, while no significant changes are found in the diastolic pressures of the control group or the systolic pressures of either group. Resting plasma volume is found to increase by 12.2% in the controls and by 17.6% after acclimatization following the exercise training. Results suggest that the resting hypotension produced is not attributable to changes in resting plasma volume, renin or vasopressin, although heat acclimatization, which leads to large decreases in plasma volume and increases in vasopressin and renin activity, may be useful in the treatment of hypertension.

  13. Vasopressin release during orthostatic hypotension after cardiac transplantation.

    PubMed

    Lord, S W; Brady, S; Baylis, P H; Dark, J H; Kenny, R A; McComb, J M

    1996-12-01

    At the time of cardiac transplantation all nerves from the donor ventricles are cut. These nerves may regrow, but there is no method of measuring any regrowth. Arginine vasopressin (AVP) release was studied during hypotension induced by head-up tilt and lower body negative pressure (LBNP) in transplant recipients and in normal controls. Subjects were tilted to 60 degrees for up to 60 min or until symptomatic. Lower body negative pressure (40 mmHg) was applied for 10 min after 30 min rest. Seven of 17 transplant recipients and 11 of 12 controls became symptomatic during tilt testing, and 9 of 12 controls and 9 of 17 transplant recipients became symptomatic after 10 min of LBNP. Symptoms during tilt did not predict symptoms during LBNP. Resting AVP levels were similar but osmolality was greater in transplant recipients. Resting haematocrit was reduced, and atrial natriuretic peptide increased in transplant recipients, suggesting increased plasma volume. In symptomatic subjects, changes in humoral concentrations were similar when compared between transplant recipients and normals, except that the rise in AVP at the time of symptoms was reduced in transplant recipients, with a comparable drop in blood pressure consistent with persistent cardiac afferent denervation in a subset of transplant recipients.

  14. Recent advances in orthostatic hypotension presenting orthostatic dizziness or vertigo.

    PubMed

    Kim, Hyun-Ah; Yi, Hyon-Ah; Lee, Hyung

    2015-11-01

    Orthostatic hypotension (OH), a proxy for sympathetic adrenergic failure, is the most incapacitating sign of autonomic failure. Orthostatic dizziness (OD) is known to be the most common symptom of OH. However, recent studies have demonstrated that 30-39 % of patients with OH experienced rotatory vertigo during upright posture (i.e., orthostatic vertigo, OV), which challenges the dogma that OH induces dizziness and not vertigo. A recent population-based study on spontaneously occurring OD across a wide age range showed that the one-year and lifetime prevalence of OD was 10.9 and 12.5 %, respectively. Approximately 83 % of patients with OD had at least one abnormal autonomic function test result. So far, 11 subtypes of OD have been proposed according to the pattern of autonomic dysfunction, and generalized autonomic failure of sympathetic adrenergic and parasympathetic cardiovagal functions was the most common type. Four different patterns of OH, such as classic, delayed, early, and transient type have been found in patients with OD. The head-up tilt test and Valsalva maneuver should be performed for a comprehensive evaluation of sympathetic adrenergic failure in patients with OD/OV. This review summarizes current advances in OH presenting OD/OV, with a particular focus on the autonomic dysfunction associated with OD.

  15. Recent advances in orthostatic hypotension presenting orthostatic dizziness or vertigo.

    PubMed

    Kim, Hyun-Ah; Yi, Hyon-Ah; Lee, Hyung

    2015-11-01

    Orthostatic hypotension (OH), a proxy for sympathetic adrenergic failure, is the most incapacitating sign of autonomic failure. Orthostatic dizziness (OD) is known to be the most common symptom of OH. However, recent studies have demonstrated that 30-39 % of patients with OH experienced rotatory vertigo during upright posture (i.e., orthostatic vertigo, OV), which challenges the dogma that OH induces dizziness and not vertigo. A recent population-based study on spontaneously occurring OD across a wide age range showed that the one-year and lifetime prevalence of OD was 10.9 and 12.5 %, respectively. Approximately 83 % of patients with OD had at least one abnormal autonomic function test result. So far, 11 subtypes of OD have been proposed according to the pattern of autonomic dysfunction, and generalized autonomic failure of sympathetic adrenergic and parasympathetic cardiovagal functions was the most common type. Four different patterns of OH, such as classic, delayed, early, and transient type have been found in patients with OD. The head-up tilt test and Valsalva maneuver should be performed for a comprehensive evaluation of sympathetic adrenergic failure in patients with OD/OV. This review summarizes current advances in OH presenting OD/OV, with a particular focus on the autonomic dysfunction associated with OD. PMID:26292788

  16. Structure and hypotensive activity relationships of tetrandrine derivatives in stroke-prone spontaneously hypertensive rats.

    PubMed

    Kawashima, K; Hayakawa, T; Miwa, Y; Oohata, H; Suzuki, T; Fujimoto, K; Ogino, T; Chen, Z X

    1990-01-01

    1. Structure and hypotensive activity relationships of tetrandrine (TD), an alkaloid isolated from the Chinese herb Radix stephaniae tetrandrae and its derivatives were investigated in conscious stroke-prone spontaneously hypertensive rats (SHRSP). 2. Derivatives substituted at the 7-O position with various types of alkyl group produced varying degrees of hypotensive effect. 3. While the demethylated derivative, fangchinoline (FC), and its acetylated compound had no effect on blood pressure, 7-O-methyl FC (TD), and 7-O-ethyl and 7-O-isopropyl FC at oral doses of 25 and 50 mg/kg produced a gradual and sustained hypotensive effect without any significant effects on heart rate and plasma renin concentration. 4. Substitution at the 7-O position with longer side chains such as n-propyl, n-butyl and n-pentyl groups reduced both the degree and duration of hypotensive activity. 5. Substitution of N-methyl groups at the 2 and 2' positions with quaternary ammonium or N-oxide attenuated the hypotensive activity. 6. The results of this study suggest a possibility that 7-O-ethyl and 7-O-isopropyl derivatives as well as TD can be considered as potential antihypertensive drugs because of the gradual onset and long duration of their hypotensive action in SHRSP. PMID:2187737

  17. Meetings with Mark Vishik

    NASA Astrophysics Data System (ADS)

    Kalikinskaya, E. I.

    2014-12-01

    Mark Iosifovich Vishik was my husband Vladimir Chepyzhov's advisor during his years as a student in the Faculty of Mechanics and Mathematics at Moscow State University, and afterwards they worked together for almost 30 years. This is why I knew him personally while not being a mathematician myself: we sometimes talked on the phone, and met during common trips and a few holidays. In his last years, after the death of his devoted wife who was also his best friend, my husband and I decided to visit Mark regularly in order to comfort him in his loneliness, and many other of his friends did the same. I can say without exaggeration that Mark loved to talk with me about everyday matters, to reminisce about his wife Asya Moiseevna, their friends and relatives, to tell stories of his youth and the wonderful encounters that had so enriched his life. We had the idea to write down our conversations and publish them as a book. Unfortunately, few such conversations lay ahead. The last one took place in January 2010. We did not write a book, but we did write an article [1], which was published in English in the form of an interview with Mark. The present article is based on our conversations with Mark. Here I will try to recount his memories about people who played an important role in his life.

  18. Aircraft vortex marking program

    NASA Technical Reports Server (NTRS)

    Pompa, M. F.

    1979-01-01

    A simple, reliable device for identifying atmospheric vortices, principally as generated by in-flight aircraft and with emphasis on the use of nonpolluting aerosols for marking by injection into such vortex (-ices) is presented. The refractive index and droplet size were determined from an analysis of aerosol optical and transport properties as the most significant parameters in effecting vortex optimum light scattering (for visual sighting) and visual persistency of at least 300 sec. The analysis also showed that a steam-ejected tetraethylene glycol aerosol with droplet size near 1 micron and refractive index of approximately 1.45 could be a promising candidate for vortex marking. A marking aerosol was successfully generated with the steam-tetraethylene glycol mixture from breadboard system hardware. A compact 25 lb/f thrust (nominal) H2O2 rocket chamber was the key component of the system which produced the required steam by catalytic decomposition of the supplied H2O2.

  19. The PCB mark

    SciTech Connect

    1994-12-01

    Polychlorinated biphenyls (PCBs) are a class of organic chemicals that had become widely used in industrial applications due to their practical physical and chemical properties. Historical uses of PCBs include dielectric fluids (used in utility transformers, capacitors, etc.), hydraulic fluids, and other applications requiring stable, fire-retardant materials. Due to findings that PCBs may cause adverse health effects and due to their persistence and accumulation in the environment. The Toxic Substances Control Act (TSCA), enacted on October 11, 1976, banned the manufacture of PCBs after 1978 [Section 6(e)]. The first PCB regulations, promulgated at 40 CFR Part 761, were finalized on February 17, 1978. These PCB regulations include requirements specifying disposal methods and marking (labeling) procedures, and controlling PCB use. To assist the Department of Energy (DOE) in its efforts to comply with the TSCA statute and implementing regulations, the Office of Environmental Guidance has prepared the document ``Guidance on the Management of Polychlorinated Biphenyls (PCBs).`` That document explains the requirements specified in the statute and regulations for managing PCBs including PCB use, storage, transport, and disposal. The requirements outlined at 40 CFR 761.40 through 761.45 specify marking requirements for most PCB items (i.e., any PCB Article, PCB Container, PCB Article Container, or PCB Equipment that contains PCBs). Most PCB items require PCB marks, which are defined as a descriptive name, instructions, cautions, or other information applied to PCB Items or other objects subject to these regulations. The marking regulations include requirements for PCB marks on PCB Items, storage areas, and temporary storage areas. This Information Brief supplements the PCB guidance document by responding to common questions concerning marking requirements for PCBs. It is one of a series of Information Briefs pertinent to PCB management issues.

  20. Marked ghost imaging

    NASA Astrophysics Data System (ADS)

    Chen, Wen; Chen, Xudong

    2014-06-01

    In recent years, ghost imaging has been widely applied in various areas, such as optical security. Here, we report how an object and multiple hidden marks can be simultaneously recovered by using only one rebuilt reference intensity sequence in ghost imaging. The reconstructed object can be clearly observed during the decoding, and multiple marks can be effectively hidden. This unique characteristic is established for ghost imaging system due to random selections of pixels from each reference intensity pattern, which also guarantees high security. This finding may open up a different research perspective for ghost-imaging-based security system.

  1. The sympathetic nervous system and baroreflexes in hypertension and hypotension.

    PubMed

    Izzo, J L; Taylor, A A

    1999-06-01

    Blood pressure and blood volume are closely regulated by the interrelated actions of the sympathetic nervous system (SNS) and the renin-angiotensin-aldosterone system (RAAS). Reflex vasoconstriction caused by parallel SNS and RAAS activation is modulated by two interactive negative feedback systems called baroreflex. The aortic-carotid baroreflex systems respond to momentary changes in systolic blood pressure, adjusting the degree of SNS-dependent peripheral vasoconstriction and cardiac output to allow maintenance of a relatively constant perfusion pressure. Cardiopulmonary baroreflexes respond to momentary changes in cardiac filling, adjusting the degree of peripheral venoconstriction and venous return to maintain cardiac preload and stroke volume. Under normal conditions, each baroreflex system exhibits a degree of tonic negative feedback so that it can alter SNS output immediately, providing counterregulatory increases or decreases in pressure or volume to maintain homeostasis. The SNS is inappropriately active in obesity and hypertension and plays a causal or permissive role in all forms of chronic hypertension. If the negative feedback control exerted by the baroreflexes over the SNS and renin-angiotensin-aldosterone system (RAAS) were perfect, chronic hypertension would not occur. Activity of the baroreflexes, however, is chronically altered by maladaptive changes such as cardiac and vascular fibrosis and hypertrophy. Long-term increases in SNS and RAAS activity also exert ongoing deleterious effects on the heart and vasculature by directly facilitating further cardiac hypertrophy and arterial stiffening. These effects appear to contribute to a vicious cycle of chronic hypertension and target organ damage. Other syndromes of abnormal blood pressure (BP) control, including orthostatic hypotension and baroreflex failure are examples of abnormal baroreflex activity and SNS control. PMID:10981075

  2. Cool dialysate reduces asymptomatic intradialytic hypotension and increases baroreflex variability.

    PubMed

    Chesterton, Lindsay J; Selby, Nicholas M; Burton, James O; McIntyre, Chris W

    2009-04-01

    Intradialytic hypotension (IDH) remains an important cause of morbidity and mortality in chronic hemodialysis (HD) patients and can be ameliorated by cool temperature HD. The baroreflex arc is under autonomic control and is essential in the short-term regulation of blood pressure (BP). This study aimed to investigate if the baroreflex sensitivity (BRS) response to HD differed between standard and cool-temperature dialysate. Ten patients (mean age 67+/-2 years) prone to IDH were recruited into a randomized, crossover study to compare BRS variation at dialysate temperatures of 37 degrees C (HD(37)) and 35 degrees C (HD(35)). Each patient underwent continuous beat-to-beat BP monitoring during a dialysis session of HD(37) and HD(35). During HD(37) 2 patients developed symptomatic IDH, as opposed to 1 with HD(35). However, asymptomatic IDH occurred with a frequency of 0.4 episodes per session with HD(35) and 6.2 episodes per session during HD(37) (odds ratio15.5; 95%CI 5.6-14.2). Although absolute BRS measurements did not differ between the 2 modalities, BRS variability increased during HD(35). Our study has demonstrated that in IDH-prone patients, cool HD resulted in a reduction in heart rate and a greater reduction in cardiac output and stroke volume. Mean arterial pressure was maintained through a significantly greater increase in total peripheral resistance. Furthermore, although absolute BRS values during HD were not significantly altered by a reduction in dialysate temperature, there was a greater percentage increase in BRS values during cool HD. Understanding the varied causes of, and categorizing impaired hemodynamic responses to HD will enable further individualization of HD prescriptions according to patient need.

  3. Spontaneous intracranial hypotension following epidural anesthesia: a case report.

    PubMed

    An, X; Wu, S; He, F; Li, C; Fang, X

    2016-05-01

    We report a case of refractory spontaneous intracranial hypotension (SIH) following epidural anesthesia. In this case, typical clinical symptoms and concomitant use of regional anesthesia led to the misdiagnosis of SIH as post-dural puncture headache (PDPH). A 56-year-old man received a successful appendectomy under epidural anesthesia performed at a T11-T12 intravertebral space. About 20 h later, the patient started complaining about orthostatic headache when getting up from his lying position, then a PDPH was diagnosed. However, the patient did not respond well to conservative treatment. Three months later, the first epidural blood patch was performed at the L3-L4 level, however, the patient still had an orthostatic headache. Five days later, spine magnetic resonance imaging showed multiple meningeal diverticulum in the cervicothoracic junction, and computerized tomography myelography demonstrated a C5-C6 spinal dural tear suggesting cerebrospinal fluid leaks. Finally, the patient was diagnosed as SIH and received a second epidural blood patch at the T2-T3 level and responded with improvements in symptomatology. The patient was then discharged, and at a 2-year follow-up, he had fully recovered except for some remaining neck stiffness. This case illustrates that SIH was misdiagnosed as PDPH because of the common clinical symptoms and potentially confounding events (epidural/spinal anesthesia and assumption that it was a case of PDPH). It is important to carefully observe patients in such conditions and promptly conduct suitable diagnostic tests. For a successful treatment of SIH, a timely epidural blood patch should be considered as soon as the diagnosis is established. PMID:26939569

  4. Autoregulation of cerebral blood flow in orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Novak, V.; Novak, P.; Spies, J. M.; Low, P. A.

    1998-01-01

    BACKGROUND AND PURPOSE: We sought to evaluate cerebral autoregulation in patients with orthostatic hypotension (OH). METHODS: We studied 21 patients (aged 52 to 78 years) with neurogenic OH during 80 degrees head-up tilt. Blood flow velocities (BFV) from the middle cerebral artery were continuously monitored with transcranial Doppler sonography, as were heart rate, blood pressure (BP), cardiac output, stroke volume, CO2, total peripheral resistance, and cerebrovascular resistance. RESULTS: All OH patients had lower BP (P<.0001), BFV_diastolic (P<.05), CVR (P<.007), and TPR (P<.02) during head-up tilt than control subjects. In control subjects, no correlations between BFV and BP were found during head-up tilt, suggesting normal autoregulation. OH patients could be separated into those with normal or expanded autoregulation (OH_NA; n=16) and those with autoregulatory failure (OH_AF; n=5). The OH_NA group showed either no correlation between BFV and BP (n=8) or had a positive BFV/BP correlation (R2>.75) but with a flat slope. An expansion of the "autoregulated" range was seen in some patients. The OH_AF group was characterized by a profound fall in BFV in response to a small reduction in BP (mean deltaBP <40 mm Hg; R2>.75). CONCLUSIONS: The most common patterns of cerebral response to OH are autoregulatory failure with a flat flow-pressure relationship or intact autoregulation with an expanded autoregulated range. The least common pattern is autoregulatory failure with a steep flow-pressure relationship. Patients with patterns 1 and 2 have an enhanced capacity to cope with OH, while those with pattern 3 have reduced capacity.

  5. Cardiocirculatory manifestations in Parkinson's disease patients without orthostatic hypotension.

    PubMed

    Pérez, T; Tijero, B; Gabilondo, I; Luna, A; Llorens, V; Berganzo, K; Acera, M; Gonzalez, A; Sanchez-Ferro, A; Lezcano, E; Zarranz, J J; Gómez-Esteban, J C

    2015-10-01

    The objective of this study was to characterize cardiac sympathetic denervation in Parkinson's disease (PD) patients without neurogenic orthostatic hypotension (NOH), both in terms of hemodynamics and in its relation with vascular denervation. We studied 20 PD patients without NOH. We analyzed the heart rate and blood pressure variability during various physical maneuvers. The following parameters were calculated: expiratory-inspiratory ratio, stroke volume, cardiac output, cardiac index, left ventricular ejection time, left ventricular work index, thoracic fluid content, total peripheral resistance and baroreflex sensitivity (BRS). We also measured direct and spectral derivatives of cardiac (cardiovagal) parasympathetic function. Myocardial I-123 metaiodobenzylguanidine (MIBG) scintigraphy was performed and early and late heart/mediastinum uptake ratios were analyzed. We observed that the late heart/mediastinum uptake ratio was 1.33±0.21. This parameter was correlated with years since diagnosis (correlation coefficient:-0.485; P=0.05), Unified Parkinson's Disease Rating Scale (UPDRS) III score (cc:-0.564; P=0.02) and pressure recovery time in the Valsalva maneuver (cc: 0.61; P<0.001). At rest, it was correlated with BRS (cc:0.75; P=0.003) and low-frequency diastolic blood pressure (LFDBP; cc: 0.58;P=0.017). We found no correlations with any of the cardiography impedance variables. In linear regression models, the variable that best correlated with MIBG results was LFDBP. Our results support that in absence of NOH the degree of denervation of the heart does not produce any effect on its inotropic function. Moreover, BRS and LFDBP can be used as an indirect measure of cardiac sympathetic denervation at rest. PMID:25631216

  6. Orthostatic Hypotension and Mortality in Elderly Frail Patients

    PubMed Central

    Freud, Tamar; Punchik, Boris; Yan, Press

    2015-01-01

    Abstract Orthostatic hypotension (OH) is a common problem in the elderly age group, and some studies have reported an association between OH and increased mortality. We evaluated possible associations between OH and mortality in a retrospective study of frail elderly patients who came for a comprehensive geriatric assessment. The study included all patients ≥65 years who were assessed in the outpatient Comprehensive Geriatric Assessment Unit. Data were collected from the computerized medical record, including blood pressure, sociodemographic data, lifestyle, falls, pulse rate, body mass index, functional and cognitive status, and comorbidity. Data on mortlaity were also collected. The study population consisted of 571 patients who underwent assessment over a 9-year study period. The mean age was 83.7 ± 6.1, 35.9% were males, and 183 (32.1%) were diagnosed with OH. Systolic OH (OHS) was more common than diastolic OH (25.2% vs 15.6%). In univariate analyses, OHS was associated with increased overall mortality. Over the follow-up period, 30.2% of the OHS patients died compared with 22.3% (P = 0.037), but in the Cox models there was no statistically significant associations between OHS and overall mortality. In contrast, age, burden of comorbidity, a low high-density lipoprotein level, and low creatinine clearance were independent predictors of increased overall mortality. In a population of frail elderly patients with a high burden of comorbidity, OH was not an independent risk factor for overall mortality. PMID:26091470

  7. 'Non-hypotensive' hypovolaemia reduces ascending aortic dimensions in humans

    NASA Technical Reports Server (NTRS)

    Taylor, J. A.; Halliwill, J. R.; Brown, T. E.; Hayano, J.; Eckberg, D. L.

    1995-01-01

    1. The notion that small, 'non-hypotensive' reductions of effective blood volume alter neither arterial pressure nor arterial baroreceptor activity is pervasive in the experimental literature. We tested two hypotheses: (a) that minute arterial pressure and cardiac autonomic outflow changes during hypovolaemia induced by lower body suction in humans are masked by alterations in breathing, and (b) that evidence for arterial baroreflex engagement might be obtained from measurements of thoracic aorta dimensions. 2. In two studies, responses to graded lower body suction at 0 (control), 5, 10, 15, 20 and 40 mmHg were examined in twelve and ten healthy young men, respectively. In the first, arterial pressure (photoplethysmograph), R-R interval, and respiratory sinus arrhythmia amplitude (complex demodulation) were measured during uncontrolled and controlled breathing (constant breathing frequency and tidal volume). In the second, cross-sectional areas of the ascending thoracic aorta were calculated from nuclear magnetic resonance images. 3. Lower body suction with controlled breathing resulted in an increased arterial pulse pressure at mild levels (5-20 mmHg; ANOVA, P < 0.05) and a decreased arterial pulse pressure at moderate levels (40 mmHg; ANOVA, P < 0.05). Both R-R intervals and respiratory sinus arrhythmia were negatively related to lower body suction level, whether group averages (general linear regression, r > 0.92) or individual subjects (orthogonal polynomials, 12 of 12 subjects) were assessed. 4. Aortic pulse area decreased progressively and significantly during mild lower body suction, with 47% of the total decline occurring by 5 mmHg. 5. These results suggest that small reductions of effective blood volume reduce aortic baroreceptive areas and trigger haemodynamic adjustments which are so efficient that alterations in arterial pressure escape detection by conventional means.

  8. Acute Hypotensive Response to Continuous and Accumulated Isocaloric Aerobic Bouts.

    PubMed

    Cunha, F; Midgley, A W; Pescatello, L; Soares, P P; Farinatti, P

    2016-10-01

    Evidence indicates that chronic reductions in blood pressure (BP) due to aerobic exercise depend on the ability to induce post-exercise hypotension (PEH) after each training bout. The purpose of this study was to investigate PEH after isocaloric bouts of continuous and accumulated running. 10 healthy pre-hypertensive men (aged 27.6±3.5 years) performed the following bouts of exercise: a) A continuous bout (CONT) expending a total of 400 kcal; and b) An accumulated bout split into 2×200 kcal (INTER1 and INTER2) to total 400 kcal at 75% of oxygen uptake reserve. BP, mean arterial pressure (MAP) and heart rate variability were monitored 10 min before and 60 min after control and all exercise conditions. The decrease in MAP over time after continuous (400 kcal) and accumulated (2×200 kcal) bouts of exercise was more pronounced than during control (mean diff between 1.6 and 5.4 mmHg, P≤0.01), although the magnitude of change was similar between continuous and accumulated bouts (mean diff=0.1 mmHg, P=0.79). Concomitant to the PEH, sympathovagal balance was inversely related to changes in MAP after isocaloric bouts performed continuously and cumulatively (r=- 0.72 and-0.85, P=0.019 and 0.002, respectively). In conclusion, BP decreased to similar levels after continuous and accumulated acute aerobic exercise matched for total energy expenditure. Our findings also indicate that the recovery pattern of cardiac autonomic activity may have an important role in eliciting PEH. PMID:27551937

  9. Self-tuning adaptive control of induced hypotension in humans: a comparison of isoflurane and sodium nitroprusside.

    PubMed

    Prys-Roberts, C; Millard, R K

    1990-07-01

    Induced hypotension is commonly used during surgery to decrease arterial pressure. Sodium nitroprusside and isoflurane are well-known hypotensive agents. The use of self-tuning adaptive control of induced hypotension was assessed with the use of sodium nitroprusside and isoflurane as hypotensive agents. Nineteen surgical patients were studied during closed-loop control of hypotension induced with sodium nitroprusside. This group of patients was compared with 10 similar patients in whom infusions of sodium nitroprusside were controlled manually by an anesthesiologist. Although the results of the two studies varied, no conclusion could be drawn regarding the superiority of either manual or closed-loop control. When manual versus automatic control of isoflurane-induced hypotension was assessed in a similar fashion, the two methods of induction were found to be comparable. PMID:2380754

  10. Contrasting effects of chronic ethanol feeding on centrally and peripherally evoked hypotension in telemetered female rats.

    PubMed

    El-Mas, Mahmoud M; Abdel-Rahman, Abdel A

    2004-03-01

    Our previous studies have shown that ethanol compromises hypotension produced by centrally acting antihypertensive agents in normotensive and hypertensive male rats. The present study investigated whether female rats are as susceptible as male rats to the deleterious effect of ethanol on centrally evoked hypotension. The study was extended to investigate ethanol effects on the time-domain indices of variability in blood pressure [standard deviation of mean arterial pressure (SDMAP)] and heart rate [standard deviation of beat-to-beat intervals (SDRR) and root mean square of successive differences in R-R intervals (rMSSD)]. The hemodynamic effects of a single intraperitoneal dose of clonidine (30 microg/kg) were evaluated in radiotelemetered ethanol-fed (5%, 12 weeks) and pair-fed control Sprague-Dawley rats. In control rats, clonidine caused a significant reduction in MAP that continued for at least 6 h and was associated with reductions in SDMAP and SDRR but not rMSSD, suggesting inhibition of central sympathetic tone. A maximum hypotensive response of -16.4+/-1.7 mm Hg was demonstrated 40 min after clonidine administration. Ethanol feeding significantly attenuated clonidine hypotension whereas it potentiated the associated reduction in SDMAP. To verify the selectivity of ethanol-clonidine interaction, the effects of ethanol on peripherally mediated hemodynamic responses to hydralazine (0.5 mg/kg ip) were investigated. In contrast to its antagonistic effect on clonidine hypotension, ethanol significantly potentiated the hypotensive effect of hydralazine. Together, these findings demonstrate that chronic ethanol feeding exerts opposite effects on centrally (attenuation) and peripherally (potentiation) evoked hypotension in female rats. The interaction of ethanol with antihypertensive agents may not be related to changes in hemodynamic variability.

  11. Digitally Marking RSA Moduli

    SciTech Connect

    Johnston, A.M.

    2000-10-09

    The moduli used in RSA (see [5]) can be generated by many different sources. The generator of that modulus (assuming a single entity generates the modulus) knows its factorization. They would have the ability to forge signatures or break any system based on this moduli. If a moduli and the RSA parameters associated with it were generated by a reputable source, the system would have higher value than if the parameters were generated by an unknown entity. So for tracking, security, confidence and financial reasons it would be beneficial to know who the generator of the RSA modulus was. This is where digital marking comes in. An RSA modulus ia digitally marked, or digitally trade marked, if the generator and other identifying features of the modulus (such as its intended user, the version number, etc.) can be identified and possibly verified by the modulus itself. The basic concept of digitally marking an RSA modulus would be to fix the upper bits of the modulus to this tag. Thus anyone who sees the public modulus can tell who generated the modulus and who the generator believes the intended user/owner of the modulus is.

  12. Interview with Mark Ashwill

    ERIC Educational Resources Information Center

    Landsberger, Joe

    2006-01-01

    This article presents an interview with Mark Ashwill, Director of the Institute of International Education-Vietnam in Ha Noi, Vietnam, a branch of the Institute of International Education (IIE). In this interview, Ashwill talks about his work as Director of the Institute of International Education-Vietnam, the role that communications technology…

  13. Mark 22 Reactivity

    SciTech Connect

    Buckner, M.R.

    2001-07-02

    Calculations for reactivity held in control rods have underpredicted the observed Mark 22 reactivity. Reactivity predictions by charge designers have accounted for this by including large biases which change with exposure and reactor region. The purpose of this study was to thoroughly investigate the methods and data used in the reactivity calculations. The goal was to identify errors and improvements and make necessary corrections.

  14. Teaching with Mark Dion

    ERIC Educational Resources Information Center

    Fusaro, Joe

    2011-01-01

    Mark Dion creates sculptures, installations, and interactive environments that sometimes seem contrary to what one expects from visual artists. Remarkable curiosity cabinets and carefully arranged artifacts from specific places and time periods make up a large part of his work. His work does not neatly fit into traditional lessons about elements…

  15. Brain stem adenosine receptors modulate centrally mediated hypotensive responses in conscious rats: A review.

    PubMed

    Nassar, Noha N; Abdel-Rahman, Abdel A

    2015-05-01

    Adenosine is implicated in the modulation of cardiovascular responses either at the peripheral or at central level in experimental animals. However, there are no dedicated reviews on the involvement of adenosine in mediating the hypotensive response of centrally administered clonidine in general and specifically in aortically barodenervated rats (ABD). The conscious ABD rat model exhibits surgically induced baroreflex dysfunction and exaggerated hypotensive response, compared with conscious sham-operated (SO) rats. The current review focuses on, the role of adenosine receptors in blood pressure (BP) regulation and their possible crosstalk with other receptors e.g. imidazoline (I1) and alpha (α2A) adrenergic receptor (AR). The former receptor is a molecular target for clonidine, whose hypotensive effect is enhanced approx. 3-fold in conscious ABD rats. We also discussed how the balance between the brain stem adenosine A1 and A2A receptors is regulated by baroreceptors and how such balance influences the centrally mediated hypotensive responses. The use of the ABD rat model yielded insight into the downstream signaling cascades following clonidine-evoked hypotension in a surgical model of baroreflex dysfunction. PMID:26257930

  16. Subclinical decelerations during developing hypotension in preterm fetal sheep after acute on chronic lipopolysaccharide exposure

    PubMed Central

    Lear, Christopher A.; Davidson, Joanne O.; Galinsky, Robert; Yuill, Caroline A.; Wassink, Guido; Booth, Lindsea C.; Drury, Paul P.; Bennet, Laura; Gunn, Alistair J.

    2015-01-01

    Subclinical (shallow) heart rate decelerations occur during neonatal sepsis, but there is limited information on their relationship with hypotension or whether they occur before birth. We examined whether subclinical decelerations, a fall in fetal heart rate (FHR) that remained above 100 bpm, were associated with hypotension in preterm fetal sheep exposed to lipopolysaccharide (LPS). Chronically-instrumented fetal sheep at 0.7 gestation received continuous low-dose LPS infusions (n = 15, 100 ng/kg over 24 h, followed by 250 ng/kg/24 h for 96 h) or saline (n = 8). Boluses of 1 μg LPS or saline were given at 48 and 72 h. FHR variability (FHRV) was calculated, and sample asymmetry was used to assess the severity and frequency of decelerations. Low-dose LPS infusion did not affect FHR. After the first LPS bolus, 7 fetuses remained normotensive, while 8 developed hypotension (a fall in mean arterial blood pressure of ≥5 mmHg). Developing hypotension was associated with subclinical decelerations, with a corresponding increase in sample asymmetry and FHRV (p < 0.05). The second LPS bolus was associated with similar but attenuated changes in FHR and blood pressure (p < 0.05). In conclusion, subclinical decelerations are not consistently seen during prenatal exposure to LPS, but may be a useful marker of developing inflammation-related hypotension before birth. PMID:26537688

  17. Subclinical decelerations during developing hypotension in preterm fetal sheep after acute on chronic lipopolysaccharide exposure.

    PubMed

    Lear, Christopher A; Davidson, Joanne O; Galinsky, Robert; Yuill, Caroline A; Wassink, Guido; Booth, Lindsea C; Drury, Paul P; Bennet, Laura; Gunn, Alistair J

    2015-01-01

    Subclinical (shallow) heart rate decelerations occur during neonatal sepsis, but there is limited information on their relationship with hypotension or whether they occur before birth. We examined whether subclinical decelerations, a fall in fetal heart rate (FHR) that remained above 100 bpm, were associated with hypotension in preterm fetal sheep exposed to lipopolysaccharide (LPS). Chronically-instrumented fetal sheep at 0.7 gestation received continuous low-dose LPS infusions (n = 15, 100 ng/kg over 24 h, followed by 250 ng/kg/24 h for 96 h) or saline (n = 8). Boluses of 1 μg LPS or saline were given at 48 and 72 h. FHR variability (FHRV) was calculated, and sample asymmetry was used to assess the severity and frequency of decelerations. Low-dose LPS infusion did not affect FHR. After the first LPS bolus, 7 fetuses remained normotensive, while 8 developed hypotension (a fall in mean arterial blood pressure of ≥5 mmHg). Developing hypotension was associated with subclinical decelerations, with a corresponding increase in sample asymmetry and FHRV (p < 0.05). The second LPS bolus was associated with similar but attenuated changes in FHR and blood pressure (p < 0.05). In conclusion, subclinical decelerations are not consistently seen during prenatal exposure to LPS, but may be a useful marker of developing inflammation-related hypotension before birth. PMID:26537688

  18. Refractory Hypotension after Liver Allograft Reperfusion: A Case of Dynamic Left Ventricular Outflow Tract Obstruction

    PubMed Central

    Essandoh, Michael; Otey, Andrew Joseph; Dalia, Adam; Dewhirst, Elisabeth; Springer, Andrew; Henry, Mitchell

    2016-01-01

    Hypotension after reperfusion is a common occurrence during liver transplantation following the systemic release of cold, hyperkalemic, and acidic contents of the liver allograft. Moreover, the release of vasoactive metabolites such as inflammatory cytokines and free radicals from the liver and mesentery, compounded by the hepatic uptake of blood, may also cause a decrement in systemic perfusion pressures. Thus, the postreperfusion syndrome (PRS) can materialize if hypotension and fibrinolysis occur concomitantly within 5 min of reperfusion. Treatment of the PRS may require the administration of inotropes, vasopressors, and intravenous fluids to maintain hemodynamic stability. However, the occurrence of the PRS and its treatment with inotropes and calcium chloride may lead to dynamic left ventricular outflow tract obstruction (DLVOTO) precipitating refractory hypotension. Expedient diagnosis of DLVOTO with transesophageal echocardiography is extremely vital in order to avoid potential cardiovascular collapse during this critical period. PMID:26909349

  19. Food protein-induced enterocolitis syndrome as a cause for infant hypotension.

    PubMed

    Coates, Ryan W; Weaver, Kevin R; Lloyd, Rezarta; Ceccacci, Nicole; Greenberg, Marna Rayl

    2011-11-01

    Infants with food protein-induced enterocolitis syndrome (FPIES) may present to the emergency department (ED) with vomiting and hypotension. A previously healthy, 5-month-old male presented with vomiting and hypotension 2 to 3 hours after eating squash. The patient was resuscitated with intravenous fluids, antibiotics, and admitted for presumed sepsis. No source of infection was ever found and the patient was discharged. The patient returned 8 days later with the same symptoms after eating sweet potatoes; the diagnosis of FPIES was made during this admission. Two additional ED visits occurred requiring hydration after new food exposure. FPIES should be considered in infants presenting with gastrointestinal complaints and hypotension. A dietary history, including if a new food has been introduced in the last few hours, may help facilitate earlier recognition of the syndrome. PMID:22224148

  20. Characterization of the hypotensive effects of glucagon-like peptide-2 in anesthetized rats.

    PubMed

    Iwai, Takashi; Kaneko, Maki; Sasaki-Hamada, Sachie; Oka, Jun-Ichiro

    2013-08-29

    Glucagon-like peptide-2 (GLP-2) is a proglucagon-derived peptide released from enteroendocrine cells and neurons. We recently reported that GLP-2 induced hypotension. In the present study, we characterized the mechanisms of GLP-2-induced hypotension. GLP-2 was administered peripherally or centrally to male Wistar rats anesthetized with urethane and α-chloralose. The rats were vagotomized or systemically pretreated with atropine, prazosin, or propranolol before the GLP-2 administration. The central and peripheral administration of GLP-2 reduced mean arterial blood pressure (MAP). The maximum change of MAP (maximum ΔMAP) was reduced by vagotomy or prazosin, but not propranolol. The effects of the central but not peripheral administration of GLP-2 were reduced by atropine. These results suggest that GLP-2 modulates vagal afferent inputs and inhibits the sympathetic nervous system in the brain to induce hypotension. PMID:23867714

  1. Risk prediction for acute hypotensive patients by using gap constrained sequential contrast patterns.

    PubMed

    Ghosh, Shameek; Feng, Mengling; Nguyen, Hung; Li, Jinyan

    2014-01-01

    The development of acute hypotension in a critical care patient causes decreased tissue perfusion, which can lead to multiple organ failures. Existing systems that employ population level prognostic scores to stratify the risks of critical care patients based on hypotensive episodes are suboptimal in predicting impending critical conditions, or in directing an effective goal-oriented therapy. In this work, we propose a sequential pattern mining approach which target novel and informative sequential contrast patterns for the detection of hypotension episodes. Our results demonstrate the competitiveness of the approach, in terms of both prediction performance as well as knowledge interpretability. Hence, sequential patterns-based computational biomarkers can help comprehend unusual episodes in critical care patients ahead of time for early warning systems. Sequential patterns can thus aid in the development of a powerful critical care knowledge discovery framework for facilitating novel patient treatment plans.

  2. The role of the histaminergic system in the central cardiovascular regulation in haemorrhagic hypotension.

    PubMed

    Jochem, Jerzy; Kasperska-Zajac, Alicja

    2012-01-01

    The histaminergic system consists of neurons located in tuberomammillary nucleus of the posterior hypothalamus. It affects many functions of the central nervous system, including regulation of the brainstem cardiovascular center. In this paper, we present current review of the literature concerning the role of the histaminergic system in the cardiovascular regulation in haemorrhagic hypotension. Experimental studies demonstrate that in both, normotension and critical hemorrhagic hypotension, histamine, acting as a central neurotransmitter, evokes the pressor effect. Interestingly, increases in mean arterial pressure are significantly higher in hypovolaemic than in normovolaemic animals. Many lines of evidence support the hypothesis that in haemorrhagic shock, the histaminergic system is able to activate neural and humoral compensatory mechanisms involving the sympathetic nervous and renin-angiotensin systems, arginine vasopressin and proopiomelanocortin-derived peptides. We suggest that the histaminergic system could be a new target for treatment of hemorrhagic hypotension.

  3. A rare presentation of an ancient disease: scurvy presenting as orthostatic hypotension.

    PubMed

    Zipursky, Jonathan Samuel; Alhashemi, Ahmad; Juurlink, David

    2014-01-01

    A 49-year-old man presented to hospital with severe orthostatic hypotension, gingival dysplasia and a purpuric rash involving his extremities. The orthostatic hypotension failed to respond to fluids and, on the basis of physical examination and dietary history, the patient was given a preliminary diagnosis of scurvy (ascorbic acid deficiency). Serum ascorbic acid levels were undetectable and the orthostasis was resolved within 24 h of ascorbic acid replacement. The pathogenesis of orthostatic hypotension in the setting of scurvy appears to involve impaired catecholamine synthesis and attenuated vasomotor response to α-adrenergic stimulation. We believe that this case describes a rare presentation of scurvy and highlights a previously under-reported connection between scurvy and vasomotor instability. PMID:24859547

  4. A rare presentation of an ancient disease: scurvy presenting as orthostatic hypotension.

    PubMed

    Zipursky, Jonathan Samuel; Alhashemi, Ahmad; Juurlink, David

    2014-05-23

    A 49-year-old man presented to hospital with severe orthostatic hypotension, gingival dysplasia and a purpuric rash involving his extremities. The orthostatic hypotension failed to respond to fluids and, on the basis of physical examination and dietary history, the patient was given a preliminary diagnosis of scurvy (ascorbic acid deficiency). Serum ascorbic acid levels were undetectable and the orthostasis was resolved within 24 h of ascorbic acid replacement. The pathogenesis of orthostatic hypotension in the setting of scurvy appears to involve impaired catecholamine synthesis and attenuated vasomotor response to α-adrenergic stimulation. We believe that this case describes a rare presentation of scurvy and highlights a previously under-reported connection between scurvy and vasomotor instability.

  5. Food protein-induced enterocolitis syndrome as a cause for infant hypotension.

    PubMed

    Coates, Ryan W; Weaver, Kevin R; Lloyd, Rezarta; Ceccacci, Nicole; Greenberg, Marna Rayl

    2011-11-01

    Infants with food protein-induced enterocolitis syndrome (FPIES) may present to the emergency department (ED) with vomiting and hypotension. A previously healthy, 5-month-old male presented with vomiting and hypotension 2 to 3 hours after eating squash. The patient was resuscitated with intravenous fluids, antibiotics, and admitted for presumed sepsis. No source of infection was ever found and the patient was discharged. The patient returned 8 days later with the same symptoms after eating sweet potatoes; the diagnosis of FPIES was made during this admission. Two additional ED visits occurred requiring hydration after new food exposure. FPIES should be considered in infants presenting with gastrointestinal complaints and hypotension. A dietary history, including if a new food has been introduced in the last few hours, may help facilitate earlier recognition of the syndrome.

  6. Case Marking Strategies in Kope.

    ERIC Educational Resources Information Center

    Clifton, John

    Case marking strategies in Kope, a Papuan language of Papua New Guinea, are analyzed in light of previous claims that most Papuan languages have one strategy for marking core relations and another for marking peripheral relations. A brief grammatical overview illustrates how core and peripheral relations are marked in Kope, including nominal case…

  7. [Ocular Hypotension: How the Retina Surgeon Sees the Causes and Therapeutic Options].

    PubMed

    Joussen, A M; Strauß, O; Winterhalter, S; Klamann, M; Dietrich-Ntoukas, T; Müller, B

    2016-09-01

    Ocular hypotension is a result of a lack of production or a loss of intraocular fluid. Intraocular inflammation, drugs, or proliferative vitreoretinopathy (PVR) with overgrowth of the ciliary body can result in reduced secretion of intraocular fluid. Loss of intraocular fluid can result from external loss, such as in fistulating surgery or trauma, or internally, e.g. from cyclodialysis clefts or retinal detachment. In this review, we discuss the causal therapy of ocular hypotension: fixation of the ciliary body, removal of ciliary body membranes, surgery for PVR, choice of tamponade, possibilities and limitations of an iris diaphragm, and pharmacological options. PMID:27617647

  8. Idiopathic orthostatic hypotension treated with levodopa and MAO inhibitor: a preliminary report

    PubMed Central

    Sharpe, J.; Marquez-Julio, A.; Ashby, P.

    1972-01-01

    The clinical and pathophysiological features of a case of idiopathic orthostatic hypotension (Shy-Drager syndrome) are presented. Recent reports on the pathological findings in this condition indicate that there may be a defect in catecholamine synthesis in the pigmented brain stem nuclei and sympathetic ganglia similar to that in idiopathic parkinsonism. On this basis a new form of therapy using levodopa combined with MAO inhibition is derived. The results of a trial of this therapy, which produced improvements in both the hypotension and in the extrapyramidal features of the disease, are reported. PMID:5056115

  9. Harmane produces hypotension following microinjection into the RVLM: possible role of I1-imidazoline receptors

    PubMed Central

    Musgrave, I F; Badoer, E

    2000-01-01

    The β-carboline, harmane (0.1–1.0 nmol) produces dose dependent hypotension when microinjected unilaterally into the rostral ventrolateral medulla (RVLM) of the anaesthetized rat. The potency of harmane on blood pressure is similar to that of the imidazoline, clonidine. The hypotensive effects of both clonidine and harmane are reversed by microinjection of the relatively I1-receptor selective antagonist efaroxan (20 nmol). These results are consistent with harmane acting at an I1-receptor in the RVLM. This is the first report of an endogenous ligand for I1-receptors that has central effects on blood pressure. PMID:10725251

  10. Patients' choice of portable folding chairs to reduce symptoms of orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Smit, A. A.; Wieling, W.; Opfer-Gehrking, T. L.; van Emmerik-Levelt, H. M.; Low, P. A.

    1999-01-01

    Patients with neurogenic orthostatic hypotension may use portable folding chairs to prevent or reduce symptoms of low blood pressure. However, a concomitant movement disorder may limit the use of these chairs in daily living. In this prospective study, 13 patients with orthostatic hypotension, balance disturbance associated with motor disability, or both examined three commercially available portable folding chairs. A questionnaire was used to document the characteristics in chair design that were relevant for satisfactory use to these patients. Armrests, seat width, and an adjustable sitting height were found to be important features of a portable folding chair. One chair was selected by 11 of 13 patients to fit most needs.

  11. False-positive focused abdominal sonography in trauma in a hypotensive child: case report.

    PubMed

    Imamedjian, Isabelle; Baird, Robert; Dubrovsky, Alexander Sasha

    2015-06-01

    We report a case of a false-positive focused abdominal sonography in trauma (FAST) examination in a persistently hypotensive pediatric trauma patient, performed 12 hours after the trauma, suspected to be caused by massive fluid resuscitation leading to ascites. While a positive FAST in a hypotensive trauma patient usually indicates hemoperitoneum, this case illustrates that the timing of the FAST examination relative to the injury, as well as clinical evolution including the volume of fluid resuscitation, need to be considered when interpreting the results of serial and/or late FAST examinations. PMID:26035503

  12. Transient severe hypotension with once-weekly subcutaneous injection of teriparatide in osteoporotic patient: a case report and insight for the drug interaction between hypotensive agents and teriparatide.

    PubMed

    Enishi, Tetsuya; Uemura, Hirokazu; Katoh, Shinsuke; Inatsugi, Masanori; Minato, Sho; Inatsugi, Kei; Inatsugi, Mikiko; Sato, Nori; Siryo, Koichi

    2015-01-01

    Teriparatide, a recombinant form of parathyroid hormone, were well recognized as a useful option for the treatment of the osteoporosis. Although some side effects of teriparatide include headache, nausea, dizziness, and limb pain were reported. Here we present a 80-year-old woman of transient asymptomatic hypotension with once-weekly subcutaneous injection of teriparatide for the treatment of osteoporosis with hypertension disease as acute-phase reactions. Systolic blood pressure decreased in both 30 min and 60 min after injection compared with before injection. Heart rate increased with passage of time. Statistically significant were observed among before, 30 min, 60 min after injection of teriparatide. Slight nausea was seen as subjective symptoms with the first and second injection after 30 min. This case indicates careful attention, at least 1 hr, was recommended with weekly subcutaneous injections of teriparatide in the treatment for osoteoproteic patient with hypertension decreases. This is a first report, to the best of our knowledge, to demonstrate the transient asymptomatic hypotension after once-weekly injection of teriparatide with hypertension disease. Transient hypotension occurred after injection of teriparatide during the treatment period and was asymptomatic except for the first 2 injections.

  13. Effective plasma volume in cirrhosis with ascites. Evidence that a decreased value does not account for renal sodium retention, a spontaneous reduction in glomerular filtration rate (GFR), and a fall in GFR during drug-induced diuresis

    PubMed Central

    Lieberman, Fred L.; Ito, Sosuke; Reynolds, Telfer B.

    1969-01-01

    A reduction in effective (nonportal) plasma volume is considered the basis for renal sodium retention, a spontaneous reduction in glomerular filtration rate (GFR), and a fall in GFR occurring during drug-induced diuresis in patients with cirrhosis and ascites. In the present study the concept of a reduced effective plasma volume in cirrhosis is challenged by two lines of evidence, even though effective plasma volume itself could not be measured. (a) Total plasma volume failed to rise in 10 patients with the spontaneous loss of ascites, the appearance of sodium in the urine, and a rise in GFR. Portal pressure remained constant in these patients as ascites left, suggesting that effective plasma volume had not increased while portal plasma volume decreased. (b) Reduction of GFR could not be prevented in five patients with cirrhosis and ascites while total plasma volume was prevented from falling with albumin infusions during drug-induced diuresis. Reduction of GFR during drug-induced diuresis in 15 patients with cirrhosis and ascites was completely reversed with saline infusion despite continued diuresis with the identical drugs, excluding drug nephrotoxicity as the cause for the reduced GFR. The ascites of cirrhosis might no longer be regarded as a cause of effective plasma volume contraction, stimulating renal sodium retention and a reduction in GFR. More likely, this form of ascites is a result of plasma volume expansion and sodium retention. The causes for renal sodium retention and a spontaneous reduction in GFR remain unknown. The cause for a fall in GFR during drug-induced diuresis also remains unknown, but effective plasma volume contraction and drug nephrotoxicity seem excluded. Images PMID:5771197

  14. Urea and NaCl regulate UT-A1 urea transporter in opposing directions via TonEBP pathway during osmotic diuresis.

    PubMed

    Kim, Yu-Mi; Kim, Wan-Young; Lee, Hyun-Wook; Kim, Jin; Kwon, H Moo; Klein, Janet D; Sands, Jeff M; Kim, Dongun

    2009-01-01

    In our previous studies of varying osmotic diuresis, UT-A1 urea transporter increased when urine and inner medullary (IM) interstitial urea concentration decreased. The purposes of this study were to examine 1) whether IM interstitial tonicity changes with different urine urea concentrations during osmotic dieresis and 2) whether the same result occurs even if the total urinary solute is decreased. Rats were fed a 4% high-salt diet (HSD) or a 5% high-urea diet (HUD) for 2 wk and compared with the control rats fed a regular diet containing 1% NaCl. The urine urea concentration decreased in HSD but increased in HUD. In the IM, UT-A1 and UT-A3 urea transporters, CLC-K1 chloride channel, and tonicity-enhanced binding protein (TonEBP) transcription factor were all increased in HSD and decreased in HUD. Next, rats were fed an 8% low-protein diet (LPD) or a 0.4% low-salt diet (LSD) to decrease the total urinary solute. Urine urea concentration significantly decreased in LPD but significantly increased in LSD. Rats fed the LPD had increased UT-A1 and UT-A3 in the IM base but decreased in the IM tip, resulting in impaired urine concentrating ability. The LSD rats had decreased UT-A1 and UT-A3 in both portions of the IM. CLC-K1 and TonEBP were unchanged by LPD or LSD. We conclude that changes in CLC-K1, UT-A1, UT-A3, and TonEBP play important roles in the renal response to osmotic diuresis in an attempt to minimize changes in plasma osmolality and maintain water homeostasis.

  15. Role in diuresis of a calcitonin receptor (GPRCAL1) expressed in a distal-proximal gradient in renal organs of the mosquito Aedes aegypti (L.).

    PubMed

    Kwon, Hyeogsun; Lu, Hsiao-Ling; Longnecker, Michael T; Pietrantonio, Patricia V

    2012-01-01

    Evolution of anthropophilic hematophagy in insects resulted in the coordination of various physiological processes for survival. In female mosquitoes, a large blood meal provides proteins for egg production and as a trade-off, rapid elimination of the excess water and solutes (Na(+), Cl(-)) is critical for maintaining homeostasis and removing excess weight to resume flight and avoid predation. This post-prandial excretion is achieved by the concerted action of multiple hormones. Diuresis and natriuresis elicited by the calcitonin-like diuretic hormone 31 (DH(31)) are believed to be mediated by a yet uncharacterized calcitonin receptor (GPRCAL) in the mosquito Malpighian tubules (MTs), the renal organs. To contribute knowledge on endocrinology of mosquito diuresis we cloned GPRCAL1 from MT cDNA. This receptor is the ortholog of the DH(31) receptor from Drosophila melanogaster that is expressed in principal cells of the fruit fly MT. Immunofluorescence similarly showed AaegGPRCAL1 is present in MT principal cells in A. aegypti, however, exhibiting an overall gradient-like pattern along the tubule novel for a GPCR in insects. Variegated, cell-specific receptor expression revealed a subpopulation of otherwise phenotypically similar principal cells. To investigate the receptor contribution to fluid elimination, RNAi was followed by urine measurement assays. In vitro, MTs from females that underwent AaegGPRcal1 knock-down exhibited up to 57% decrease in the rate of fluid secretion in response to DH(31). Live females treated with AaegGPRcal1 dsRNA exhibited 30% reduction in fluid excreted after a blood meal. The RNAi-induced phenotype demonstrates the critical contribution of this single secretin-like family B GPCR to fluid excretion in invertebrates and highlights its relevance for the blood feeding adaptation. Our results with the mosquito AaegGPRCAL1 imply that the regulatory function of calcitonin-like receptors for ion and fluid transport in renal organs arose early

  16. Changes of some amino acid concentrations in the medial vestibular nucleus of conscious rats following acute hypotension.

    PubMed

    Li, Xiang-Lan; An, Ying; Jin, Qing-Hua; Kim, Min Sun; Park, Byung Rim; Jin, Yuan-Zhe

    2010-06-14

    Microdialysis and high performance liquid chromatography (HPLC) were used to measure the changes of certain amino acids in the medial vestibular nucleus (MVN) of conscious rats in order to understand whether those amino acids are involved in the regulation of blood pressure. Acute hypotension was induced by infusing sodium nitroprusside (SNP) into the femoral vein. In the control group, glutamate (Glu) release increased, though gamma-aminobutyric acid (GABA) and taurine (Tau) release decreased in the MVN following acute hypotension. In the unilateral labyrinthectomy group, the levels of Glu, GABA, and Tau were unchanged in the ipsilateral MVN to the lesion following acute hypotension. Furthermore, in the contralateral MVN to the lesion, Glu release increased, and GABA and Tau release decreased following acute hypotension. These results suggest that SNP-induced acute hypotension can influence the activity of neurons in the MVN through afferent signals from peripheral vestibular receptors, and that certain amino acid transmitters in the MVN are involved in this process.

  17. The Mark 3 Haploscope

    NASA Technical Reports Server (NTRS)

    Decker, T. A.; Williams, R. E.; Kuether, C. L.; Logar, N. D.; Wyman-Cornsweet, D.

    1975-01-01

    A computer-operated binocular vision testing device was developed as one part of a system designed for NASA to evaluate the visual function of astronauts during spaceflight. This particular device, called the Mark 3 Haploscope, employs semi-automated psychophysical test procedures to measure visual acuity, stereopsis, phoria, fixation disparity, refractive state and accommodation/convergence relationships. Test procedures are self-administered and can be used repeatedly without subject memorization. The Haploscope was designed as one module of the complete NASA Vision Testing System. However, it is capable of stand-alone operation. Moreover, the compactness and portability of the Haploscope make possible its use in a broad variety of testing environments.

  18. Epidural blood flow during prostaglandin E1 or trimethaphan induced hypotension.

    PubMed

    Abe, K; Kakiuchi, M; Shimada, Y

    1993-11-01

    To evaluate the effect of prostaglandin E1 (PGE1) or trimethaphan (TMP) induced hypotension on epidural blood flow (EBF) during spinal surgery, EBF was measured using the heat clearance method in 30 patients who underwent postero-lateral interbody fusion under isoflurane anaesthesia. An initial dose of 0.1 microgram.kg-1.min-1 of PGE1 (15 patients), or 10 micrograms.kg-1.min-1 of TMP (15 patients) was administered intravenously after the dural opening and the dose was adjusted to maintain the mean arterial blood pressure (MAP) at about 60 mmHg. The hypotensive drug was discontinued at the completion of the operative procedure. After starting PGE1 or TMP, MAP and rate pressure product (RPP) decreased significantly compared with preinfusion values (P < 0.01), and the degree of hypotension due to PGE1 remained constant until 60 min after its discontinuation. Heart rate (HR) did not change in either group. EBFF did not change during PGE1 infusion whereas in the TMP group, EBF decreased significantly at 30 and 60 min after the start of TMP (preinfusion: 45.9 +/- 13.9 ml/100g/min. 30 min: 32.3 +/- 9.9 ml/100 g/min (P < 0.05). 60 min: 30 +/- 7.5 ml/100 g/min (P < 0.05)). These results suggest that PGE1 may be preferable to TMP for hypotensive anaesthesia in spinal surgery because TMP decreased EBF.

  19. Essential Hypotension Is Accompanied by Deficits in Attention and Working Memory

    ERIC Educational Resources Information Center

    Duschek, Stefan; Matthias, Ellen; Schandry, Rainer

    2005-01-01

    In the present study, the authors investigated the relationship between low blood pressure (BP) and attentional performance through the application of a multidimensional diagnostic approach. The authors compared 40 subjects with essential hypotension (mean systolic BP = 97.6 mmHg) with 40 normotensive controls (mean systolic BP = 124.1 mmHg) using…

  20. Fos expression in brain stem nuclei of pregnant rats after hydralazine-induced hypotension.

    PubMed

    Curtis, K S; Cunningham, J T; Heesch, C M

    1999-08-01

    Fos and dopamine beta-hydroxylase immunoreactivity were evaluated in the brain stems of 21-day pregnant and virgin female rats injected with either hydralazine (HDZ; 10 mg/kg iv) or vehicle. HDZ produced significant hypotension in both groups, although baseline blood pressure was lower in pregnant rats (96 +/- 2.5 mmHg) than in virgin female rats (121 +/- 2.8 mmHg). There were no differences in Fos immunoreactivity in the brain stems of pregnant and virgin female rats after vehicle treatment. HDZ-induced hypotension significantly increased Fos expression in both groups; however, the magnitude of the increases differed in the caudal ventrolateral medulla (CVL), the area postrema (AP), and the rostral ventrolateral medulla (RVL). Fos expression after HDZ in pregnant rats was augmented in noncatecholaminergic neurons of the CVL but was attenuated in the AP and in noncatecholaminergic neurons in the RVL. These results are consistent with differences in the sympathetic response to hypotension between pregnant and virgin female rats and indicate that the central response to hypotension may be different in pregnant rats.

  1. Dynamic regulation of heart rate during acute hypotension: new insight into baroreflex function

    NASA Technical Reports Server (NTRS)

    Zhang, R.; Behbehani, K.; Crandall, C. G.; Zuckerman, J. H.; Levine, B. D.; Blomqvist, C. G. (Principal Investigator)

    2001-01-01

    To examine the dynamic properties of baroreflex function, we measured beat-to-beat changes in arterial blood pressure (ABP) and heart rate (HR) during acute hypotension induced by thigh cuff deflation in 10 healthy subjects under supine resting conditions and during progressive lower body negative pressure (LBNP). The quantitative, temporal relationship between ABP and HR was fitted by a second-order autoregressive (AR) model. The frequency response was evaluated by transfer function analysis. Results: HR changes during acute hypotension appear to be controlled by an ABP error signal between baseline and induced hypotension. The quantitative relationship between changes in ABP and HR is characterized by a second-order AR model with a pure time delay of 0.75 s containing low-pass filter properties. During LBNP, the change in HR/change in ABP during induced hypotension significantly decreased, as did the numerator coefficients of the AR model and transfer function gain. Conclusions: 1) Beat-to-beat HR responses to dynamic changes in ABP may be controlled by an error signal rather than directional changes in pressure, suggesting a "set point" mechanism in short-term ABP control. 2) The quantitative relationship between dynamic changes in ABP and HR can be described by a second-order AR model with a pure time delay. 3) The ability of the baroreflex to evoke a HR response to transient changes in pressure was reduced during LBNP, which was due primarily to a reduction of the static gain of the baroreflex.

  2. Effects of hemorrhagic hypotension on tyrosine concentrations in rat spinal cord and plasma

    NASA Technical Reports Server (NTRS)

    Conlay, L. A.; Maher, T. J.; Roberts, C. H.; Wurtman, R. J.

    1988-01-01

    Tyrosine is the precursor for catecholamine neurotransmitters. When catecholamine-containing neurons are physiologically active (as sympathoadrenal cells are in hypotension), tyrosine administration increases catecholamine synthesis and release. Since hypotension can alter plasma amino acid composition, the effects of an acute hypotensive insult on tyrosine concentrations in plasma and spinal cord were examined. Rats were cannulated and bled until the systolic blood pressure was 50 mmHg, or were kept normotensive for 1 h. Tyrosine and other large neutral amino acids (LNAA) known to compete with tyrosine for brain uptake were assayed in plasma and spinal cord. The rate at which intra-arterial (H-3)tyrosine disappeared from the plasma was also estimated in hemorrhaged and control rats. In plasma of hemorrhaged animals, both the tyrosine concentration and the tyrosine/LNAA ratio was elevated; moreover, the disappearance of (H-3)tyrosine was slowed. Tyrosine concentrations also increased in spinal cords of hemorrhaged-hypotensive rats when compared to normotensive controls. Changes in plasma amino acid patterns may thus influence spinal cord concentrations of amino acid precursors for neurotransmitters during the stress of hemorrhagic shock.

  3. The benefits of using Guyton's model in a hypotensive control system.

    PubMed

    Nguyen, Chi-Ngon; Simanski, Olaf; Kähler, Ralf; Schubert, Agnes; Janda, Matthias; Bajorat, Jörn; Lampe, Bernhard

    2008-02-01

    In order to improve the intraoperative applications, this paper presents the advantages of using Guyton's model in hypotensive control system development. In this system, the mean arterial pressure is decreased and maintained at a low level during anaesthesia by controlling sodium nitroprusside infusion rate. The key of the study is to develop a physiological model of cardiovascular dynamics to present the mean arterial pressure response to sodium nitroprusside, which was considered as a linear model in most of known blood pressure control systems. Being linear, the previous models cannot accurately mimic a physiological system of human circulation, especially at deep hypotensive control with strong reaction of the body. The enhanced model in this study was modified based on Guyton's model of human circulation. It is useful to design a PID controller, which allows studying and handling the wide range of the body sensitivities. This model is also helpful for studying the behaviors of patients under anaesthesia conditions, such as the perfusion of organs and the reaction of the body at hypotensive state. A fuzzy gain scheduler and a supervising algorithm were also developed for online tuning the controller to handle the behavior of the body. The control system was tested on 25 experiments on seven pigs in the animal laboratory. Simulation and experiment results proved the usefulness of Guyton's model in control system design which can present the dynamical response of blood pressure in the circulation under and after hypotensive control. The results also indicated the safety and stability of the controller.

  4. Hypovolemia-induced Orthostatic Hypotension Relates To Hypo-sympathetic Responsiveness

    NASA Technical Reports Server (NTRS)

    Meck, Janice V.

    2007-01-01

    We report a new model which uses hypovolemia to force humans into a hemodynamic state that is similar to that after spaceflight. This model can be used to test candidate countermeasures for postflight orthostatic hypotension and to identify crewmembers who will be most susceptible to that symptom on landing day.

  5. Viscoelastic mechanisms of aortic baroreceptor resetting to hypotension and to hypertension.

    PubMed

    Xavier-Neto, J; Moreira, E D; Krieger, E M

    1996-10-01

    Viscoelastic and electrophysiological mechanisms have been implicated in the resetting of baroreceptors in hypertension, but resetting in response to hypotension has been less studied. To evaluate the temporal relationship between viscoelastic mechanisms and acute resetting, we examined the "in vivo" behavior of aortic caliber and aortic baroreceptor activity during step changes in pressure. Fifteen-minute hemorrhage in Wistar rats produced stable hypotension (30 mmHg) and viscoelastic contraction (111 +/- 14.2 microns systolic caliber; P < 0.01). Integrated aortic activity fell to 19.8 +/- 3.9% of control (P < 0.001) after 3 s of hypotension but recovered to 64 +/- 4.1% 15 min later (P < 0.01 from 3 s). Recovery of baroreceptor activity was linearly correlated to viscoelastic contraction (r = 0.963; P < 0.0001). Thirty-minute phenylephrine infusion (1.0-4.0 micrograms/min) produced stable hypertension (30 mmHg) and viscoelastic dilation (211 +/- 37.0 microns systolic caliber). Integrated aortic activity increased to 218.0 +/- 18% of control values (P < 0.001) 30 s after hypertension and was reduced to 164.0 +/- 12.0% (P < 0.001 from 3 s) within 30 min. Reduction of baroreceptor activity correlated linearly with viscoelastic relaxation (r = 0.963; P < 0.0001). The results indicate that in the in vivo rat aorta, viscoelastic mechanisms parallel and may contribute to the baroreceptor resetting during hypotension and hypertension.

  6. Intraspinal hemorrhage in spontaneous intracranial hypotension: link to superficial siderosis? Report of 2 cases.

    PubMed

    Schievink, Wouter I; Wasserstein, Philip; Maya, M Marcel

    2016-03-01

    Spontaneous intracranial hypotension due to a spinal CSF leak has become a well-recognized cause of headaches, but such spinal CSF leaks also are found in approximately half of patients with superficial siderosis of the CNS. It has been hypothesized that friable vessels at the site of the spinal CSF leak are the likely source of chronic bleeding in these patients, but such an intraspinal hemorrhage has never been visualized. The authors report on 2 patients with spontaneous intracranial hypotension and intraspinal hemorrhage, offering support for this hypothesis. A 33-year-old man and a 62-year-old woman with spontaneous intracranial hypotension were found to have a hemorrhage within the ventral spinal CSF collection and within the thecal sac, respectively. Treatment consisted of microsurgical repair of a ventral dural tear in the first patient and epidural blood patching in the second patient. The authors suggest that spontaneous intracranial hypotension should be included in the differential diagnosis of spontaneous intraspinal hemorrhage, and that the intraspinal hemorrhage can account for the finding of superficial siderosis when the CSF leak remains untreated.

  7. Autonomic ganglionitis with severe hypertension, migraine, and episodic but fatal hypotension.

    PubMed

    Lee, H C; Coulter, C L; Adickes, E D; Porterfield, J; Robertson, D; Bravo, E; Pettinger, W A

    1996-09-01

    We report the clinical, pathologic, and immunohistochemical features of a severe hypertensive patient with recurrent migraine-induced hypotension. The patient died of migraine-induced vasomotor paralysis despite prompt institutions of fluid and sympathomimetic and parasympatholytic agents. Postmortem study revealed autonomic ganglionitis and neuritis.

  8. In vivo study of hepatic oxidative stress and mitochondrial function in rabbits with severe hypotension after propofol prolonged infusion.

    PubMed

    Campos, Sónia; Félix, Luís; Venâncio, Carlos; de Lurdes Pinto, Maria; Peixoto, Francisco; de Pinho, Paula Guedes; Antunes, Luís

    2016-01-01

    lipid-based emulsions can be involved in the regulation of different pathways that ultimately lead to a decrease of state 3 mitochondrial respiration rate. The infusion of propofol Lipuro during prolonged periods, in addition to marked hypotension and hypoperfusion, also showed to have higher anti-oxidant activity and lower impairment of the mitochondrial function comparatively to the improved lipid formulation, SMOFlipid, using the rabbit as animal model. PMID:27588242

  9. Effect of perturbations and a meal on superior mesenteric artery flow in patients with orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Fujimura, J.; Camilleri, M.; Low, P. A.; Novak, V.; Novak, P.; Opfer-Gehrking, T. L.

    1997-01-01

    Our aims were to evaluate to role of superior mesenteric blood flow in the pathophysiology of orthostatic hypotension in patients with generalized autonomic failure. METHODS: Twelve patients with symptomatic neurogenic orthostatic hypotension and 12 healthy controls underwent superior mesenteric artery flow measurements using Doppler ultrasonography during head-up tilt and tilt plus meal ingestion. Autonomic failure was assessed using standard tests of the function of the sympathetic adrenergic, cardiovagal and postganglionic sympathetic sudomotor function. RESULTS: Superior mesenteric flow volume and time-averaged velocity were similar in patients and controls at supine rest; however, responses to cold pressor test and upright tilt were attenuated (p < 0.05) in patients compared to controls. Head-up tilt after the meal evoked a profound fall of blood pressure and mesenteric blood flow in the patients; the reduction of mesenteric blood flow correlated (r = 0.89) with the fall of blood pressure in these patients, providing another manifestation of failed baroreflexes. We make the novel finding that the severity of postprandial orthostatic hypotension regressed negatively with the postprandial increase in mesenteric flow in patients with orthostatic hypotension. CONCLUSION: Mesenteric flow is under baroreflex control, which when defective, results in, or worsens orthostatic hypotension. Its large size and baroreflexivity renders it quantitatively important in the maintenance of postural normotension. The effects of orthostatic stress can be significantly attenuated by reducing the splanchnic-mesenteric volume increase in response to food. Evaluation of mesenteric flow in response to eating and head-up tilt provide important information on intra-abdominal sympathetic adrenergic function, and the ability of the patient to cope with orthostatic stress.

  10. Neurogenic orthostatic hypotension: a double-blind, placebo-controlled study with midodrine

    NASA Technical Reports Server (NTRS)

    Jankovic, J.; Gilden, J. L.; Hiner, B. C.; Kaufmann, H.; Brown, D. C.; Coghlan, C. H.; Rubin, M.; Fouad-Tarazi, F. M.

    1993-01-01

    PURPOSE: To investigate the efficacy and safety of midodrine for treatment of patients with orthostatic hypotension due to autonomic failure. PATIENTS: Ninety-seven patients with orthostatic hypotension were randomized in a 4-week, double-blinded, placebo-controlled study with a 1-week placebo run-in period. Patients ranged in age from 22 to 86 years (mean: 61 years). METHODS: After a 1-week run-in phase, either placebo or midodrine at a dose of 2.5 mg, 5 mg, or 10 mg was administered three times a day for 4 weeks. Both the placebo group and the 2.5-mg midodrine group received constant doses throughout the double-blind phase. The patients receiving 5 mg or 10 mg of midodrine were given doses that were increased at weekly intervals by 2.5-mg increments until the designated dose was reached. Efficacy evaluations were based on an improvement at 1-hour postdose in standing systolic blood pressure and in symptoms of orthostatic hypotension (syncope, dizziness/lightheadedness, weakness/fatigue, and low energy level). RESULTS: Midodrine (10 mg) increased standing systolic blood pressure by 22 mm Hg (28%, p < 0.001 versus placebo). Midodrine improved (p < 0.05) the following symptoms of orthostatic hypotension compared to placebo: dizziness/lightheadedness, weakness/fatigue, syncope, low energy level, impaired ability to stand, and feelings of depression. The overall side effects were mainly mild to moderate. One or more side effects were reported by 22% of the placebo group compared with 27% of the midodrine-treated group. Scalp pruritus/tingling, which was reported by 10 of 74 (13.5%) of the midodrine-treated patients, was most frequent. Other reported side effects included supine hypertension (8%) and feelings of urinary urgency (4%). CONCLUSION: We conclude that midodrine is an effective and well-tolerated treatment for moderate-to-severe orthostatic hypotension associated with autonomic failure.

  11. Activated protein C suppresses adrenomedullin and ameliorates lipopolysaccharide-induced hypotension.

    PubMed

    Gupta, Akanksha; Berg, David T; Gerlitz, Bruce; Richardson, Mark A; Galbreath, Elizabeth; Syed, Samreen; Sharma, Avadhesh C; Lowry, Stephen F; Grinnell, Brian W

    2007-10-01

    Activated protein C (APC) is an important modulator of vascular function that has antithrombotic and anti-inflammatory properties. Studies in humans have shown modulation of endotoxin-induced hypotension by recombinant human APC, drotrecogin alfa (activated), however, the mechanism for this effect is unclear. We have found that APC suppresses the induction of the potent vasoactive peptide adrenomedullin (ADM) and could downregulate lipopolysaccharide (LPS)-induced ADM messenger RNA (mRNA) and nitrite levels in cell culture. This effect was dependent on signaling through protease-activated receptor 1. Addition of 1400W, an irreversible inducible nitric oxide synthase (iNOS) inhibitor, inhibited LPS-induced ADM mRNA, suggesting that ADM induction is NO mediated. Furthermore, in a rat model of endotoxemia, APC (100 microg/kg, i.v.) prevented LPS (10 mg/kg, i.v.)-induced hypotension, and suppressed ADM mRNA and protein expression. APC also inhibited iNOS mRNA and protein levels along with reduction in NO by-products (NOx). We also observed a significant reduction in iNOS-positive leukocytes adhering to vascular endothelium after APC treatment. Moreover, we found that APC inhibited the expression of interferon-gamma (IFN-gamma), a potent activator of iNOS. In a human study of LPS-induced hypotension, APC reduced the upregulation of plasma ADM levels, coincident with protection against the hypotensive response. Overall, we demonstrate that APC blocks the induction of ADM, likely mediated by IFN-gamma and iNOS, and suggests a mechanism that may account for ameliorating LPS-induced hypotension. Furthermore, our data provide a new understanding for the role of APC in modulating vascular response to insult.

  12. A de novo transcriptome of the Malpighian tubules in non-blood-fed and blood-fed Asian tiger mosquitoes Aedes albopictus: insights into diuresis, detoxification, and blood meal processing.

    PubMed

    Esquivel, Carlos J; Cassone, Bryan J; Piermarini, Peter M

    2016-01-01

    Background. In adult female mosquitoes, the renal (Malpighian) tubules play an important role in the post-prandial diuresis, which removes excess ions and water from the hemolymph of mosquitoes following a blood meal. After the post-prandial diuresis, the roles that Malpighian tubules play in the processing of blood meals are not well described. Methods. We used a combination of next-generation sequencing (paired-end RNA sequencing) and physiological/biochemical assays in adult female Asian tiger mosquitoes (Aedes albopictus) to generate molecular and functional insights into the Malpighian tubules and how they may contribute to blood meal processing (3-24 h after blood ingestion). Results/Discussion. Using RNA sequencing, we sequenced and assembled the first de novo transcriptome of Malpighian tubules from non-blood-fed (NBF) and blood-fed (BF) mosquitoes. We identified a total of 8,232 non-redundant transcripts. The Malpighian tubules of NBF mosquitoes were characterized by the expression of transcripts associated with active transepithelial fluid secretion/diuresis (e.g., ion transporters, water channels, V-type H(+)-ATPase subunits), xenobiotic detoxification (e.g., cytochrome P450 monoxygenases, glutathione S-transferases, ATP-binding cassette transporters), and purine metabolism (e.g., xanthine dehydrogenase). We also detected the expression of transcripts encoding sodium calcium exchangers, G protein coupled-receptors, and septate junctional proteins not previously described in mosquito Malpighian tubules. Within 24 h after a blood meal, transcripts associated with active transepithelial fluid secretion/diuresis exhibited a general downregulation, whereas those associated with xenobiotic detoxification and purine catabolism exhibited a general upregulation, suggesting a reinvestment of the Malpighian tubules' molecular resources from diuresis to detoxification. Physiological and biochemical assays were conducted in mosquitoes and isolated Malpighian tubules

  13. A de novo transcriptome of the Malpighian tubules in non-blood-fed and blood-fed Asian tiger mosquitoes Aedes albopictus: insights into diuresis, detoxification, and blood meal processing

    PubMed Central

    Esquivel, Carlos J.; Cassone, Bryan J.

    2016-01-01

    Background. In adult female mosquitoes, the renal (Malpighian) tubules play an important role in the post-prandial diuresis, which removes excess ions and water from the hemolymph of mosquitoes following a blood meal. After the post-prandial diuresis, the roles that Malpighian tubules play in the processing of blood meals are not well described. Methods. We used a combination of next-generation sequencing (paired-end RNA sequencing) and physiological/biochemical assays in adult female Asian tiger mosquitoes (Aedes albopictus) to generate molecular and functional insights into the Malpighian tubules and how they may contribute to blood meal processing (3–24 h after blood ingestion). Results/Discussion. Using RNA sequencing, we sequenced and assembled the first de novo transcriptome of Malpighian tubules from non-blood-fed (NBF) and blood-fed (BF) mosquitoes. We identified a total of 8,232 non-redundant transcripts. The Malpighian tubules of NBF mosquitoes were characterized by the expression of transcripts associated with active transepithelial fluid secretion/diuresis (e.g., ion transporters, water channels, V-type H+-ATPase subunits), xenobiotic detoxification (e.g., cytochrome P450 monoxygenases, glutathione S-transferases, ATP-binding cassette transporters), and purine metabolism (e.g., xanthine dehydrogenase). We also detected the expression of transcripts encoding sodium calcium exchangers, G protein coupled-receptors, and septate junctional proteins not previously described in mosquito Malpighian tubules. Within 24 h after a blood meal, transcripts associated with active transepithelial fluid secretion/diuresis exhibited a general downregulation, whereas those associated with xenobiotic detoxification and purine catabolism exhibited a general upregulation, suggesting a reinvestment of the Malpighian tubules’ molecular resources from diuresis to detoxification. Physiological and biochemical assays were conducted in mosquitoes and isolated Malpighian

  14. Association and moderation of self-reported hypotension with traffic noise exposure: a neglected relationship.

    PubMed

    Lercher, Peter; Widmann, Ulrich

    2013-01-01

    In a short-term experimental study about one-third of subjects exposed to noise shows both increases and decreases in blood pressure. While the association of noise with hypertension is established it is not yet known whether hypotension is associated with noise in field studies. In a cross-sectional study the association of self-reported hypotension and low blood pressure readings with traffic noise was examined in adults (age 25-65, N = 1989, participation = 62%). Noise exposure was based on both, short and long-term day/night recordings and standard noise mapping. Questionnaire data on socio-demographics, housing, life-style, noise and weather sensitivity, health status, mental and physical symptoms were available to adjust for potential confounding and testing for moderation. Non-linear multiple regression was applied to estimate the association between the two outcomes and overall noise exposure. We did not observe a stable relation between noise and low blood pressure readings since the number of subjects based on the recommended cut-off points (5 th percentile or 110 (100)/60 mmHg) was too small. However, self-reported hypotension was non-linearly associated with noise exposure ( P = 0.044) in the presence of a strong sex × age effect modification ( P < 0.0001). Another significant moderation by noise were observed with reported symptoms of exhaustion ( P = 0.03). Weather sensitivity showed a significant interaction with noise sensitivity ( P = 0.02) and also a non-linear interaction with age ( P = 0.02). The results remained stable after adjustment for variables known to be associated with constitutional hypotension. The exposure-effect curve ascends around sound levels of 55 dBA. The results suggest a novel moderated association of noise with self-reported hypotension, predominantly in weather sensitive women with symptoms of exhaustion. Further and larger studies are needed to replicate the potential moderating effect of noise on persons with

  15. Head-down bed rest impairs vagal baroreflex responses and provokes orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Convertino, Victor A.; Doerr, Donald F.; Eckberg, Dwain L.; Fritsch, Janice M.; Vernikos-Danellis, Joan

    1990-01-01

    The hypothesis that baroreflex malfunction contributes to orthostatic hypotension in microgravity was tested by studying vagally mediated carotid baroreceptor-cardiac reflexes in healthy human subjects before, during, and after 30 days of 6-deg head-down bed rest. The baroreflex response relationships were provoked with ramped neck pressure-suction sequences comprising pressure elevations to 40 mm Hg followed by serial R-wave-triggered 15-mm Hg reductions to -65 mm0 Hg; each R-R interval was plotted as a function of systolic pressure minus the neck chamber pressure applied during the interval. It is shown that head-down bed rest led to an impairment of vagal baroreflex function and that it was associated with an impairment of hemodynamic adjustments to standing, indicating that baroreflex impairment may contribute to orthostatic hypotension observed in spacecrews after a flight.

  16. Antioxidant and Vasodilator Activity of Ugni molinae Turcz. (Murtilla) and Its Modulatory Mechanism in Hypotensive Response

    PubMed Central

    Jofré, Ignacio; Pezoa, Cesar; Scheuermann, Erick; Rosalen, Pedro Luiz; Romero, Fernando

    2016-01-01

    Hypertension is a systemic condition with high morbidity and mortality rates worldwide, which poses an increased risk for cardiovascular diseases. In this study, we demonstrated the antioxidant and vasodilator activity of Ugni molinae Turcz. (Murtilla) fruit, a berry native to Chile and proposed models to explain its modulatory mechanism in hypotensive response. Murtilla fruits were cultivated in a germplasm bank and submitted to chemical and biological analyses. The phenolic compounds gallic acid, Catechin, Quercetin-3-β-D-glucoside, Myricetin, Quercetin, and Kaempferol were identified. Murtilla extract did not generate toxic effects on human endothelial cells and had significant antioxidant activity against ROS production, lipid peroxidation, and superoxide anion production. Furthermore, it showed dose-dependent vasodilator activity in aortic rings in the presence of endothelium, whose hypotensive mechanism is partially mediated by nitric oxide synthase/guanylate cyclase and large-conductance calcium-dependent potassium channels. Murtilla fruits might potentially have beneficial effects on the management of cardiovascular diseases.

  17. Association between vasovagal hypotension and low sympathetic neural activity during presyncope

    NASA Technical Reports Server (NTRS)

    Cooke, William H.; Convertino, Victor A.

    2002-01-01

    Recent studies suggest that an underlying mechanism for susceptibility of patients and astronauts to presyncope includes hypoadrenergic responses to orthostatic stress. However, data used to reach this conclusion are open to various interpretations. In this report, maintenance of sympathetic neural activity (MSNA; peroneal nerve microneurography) during -60 mmHg lower body negative pressure (LBNP) was associated with maintenance of orthostatic tolerance, and disappearance of MSNA was associated with hypotension and pre-syncope. However, MSNA was substantially higher during progressive increases of negative pressure in the presyncopal subject, compared to the non-presyncopal subjects. The data from this case report question the notion that orthostatic hypotension occurs due to inadequate sympathetic neural activation during orthostatic stress in apparently normal, healthy subjects.

  18. Antioxidant and Vasodilator Activity of Ugni molinae Turcz. (Murtilla) and Its Modulatory Mechanism in Hypotensive Response

    PubMed Central

    Jofré, Ignacio; Pezoa, Cesar; Scheuermann, Erick; Rosalen, Pedro Luiz; Romero, Fernando

    2016-01-01

    Hypertension is a systemic condition with high morbidity and mortality rates worldwide, which poses an increased risk for cardiovascular diseases. In this study, we demonstrated the antioxidant and vasodilator activity of Ugni molinae Turcz. (Murtilla) fruit, a berry native to Chile and proposed models to explain its modulatory mechanism in hypotensive response. Murtilla fruits were cultivated in a germplasm bank and submitted to chemical and biological analyses. The phenolic compounds gallic acid, Catechin, Quercetin-3-β-D-glucoside, Myricetin, Quercetin, and Kaempferol were identified. Murtilla extract did not generate toxic effects on human endothelial cells and had significant antioxidant activity against ROS production, lipid peroxidation, and superoxide anion production. Furthermore, it showed dose-dependent vasodilator activity in aortic rings in the presence of endothelium, whose hypotensive mechanism is partially mediated by nitric oxide synthase/guanylate cyclase and large-conductance calcium-dependent potassium channels. Murtilla fruits might potentially have beneficial effects on the management of cardiovascular diseases. PMID:27688827

  19. 46 CFR 108.661 - Unit markings: Draft marks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... corner column, continuing to the footing or lower displacement hull. (b) The bottom of each mark must be... unit to the surface of the water, except that where a unit has a permanent appendage extending below... surface of the water. (e) In cases where draft marks are obscured due to operational constraints or...

  20. 46 CFR 108.661 - Unit markings: Draft marks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... corner column, continuing to the footing or lower displacement hull. (b) The bottom of each mark must be... unit to the surface of the water, except that where a unit has a permanent appendage extending below... surface of the water. (e) In cases where draft marks are obscured due to operational constraints or...

  1. 46 CFR 108.661 - Unit markings: Draft marks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... corner column, continuing to the footing or lower displacement hull. (b) The bottom of each mark must be... unit to the surface of the water, except that where a unit has a permanent appendage extending below... surface of the water. (e) In cases where draft marks are obscured due to operational constraints or...

  2. Improving Marking Quality through a Taxonomy of Mark Schemes

    ERIC Educational Resources Information Center

    Ahmed, Ayesha; Pollitt, Alastair

    2011-01-01

    At the heart of most assessments lies a set of questions, and those who write them must achieve "two" things. Not only must they ensure that each question elicits the kind of performance that shows how "good" pupils are at the subject, but they must also ensure that each mark scheme gives more marks to those who are "better" at it. We outline a…

  3. Circulating [Met]enkephalin and catecholamine responses to acute hypotension and hypertension in anaesthetized greyhounds.

    PubMed Central

    Mason, D. F.; Medbak, S.; Rees, L. H.

    1987-01-01

    The effects of either hypotension induced by sodium nitroprusside or hexamethonium or hypertension produced by angiotensin II or noradrenaline on the circulating levels of methionine enkephalin ([Met]enkephalin)-like immunoreactivity (MLI), adrenaline and noradrenaline in anaesthetized greyhounds were examined. Nitroprusside infusions (200 and 400 micrograms min-1) induced a fall in blood pressure accompanied by significant rises in plasma MLI and catecholamine concentrations. Concomitant administration of a high dose of naloxone did not alter the fall in blood pressure produced by nitroprusside but was associated with greater rises in circulating MLI and catecholamines when compared to nitroprusside alone, suggesting that [Met]enkephalin is not involved in the hypotensive action of nitroprusside. Intravenous hexamethonium (2.5 mg kg-1) provoked a fall in blood pressure which was not associated with any changes in plasma MLI. However, it produced a fall in plasma noradrenaline and a rise in plasma adrenaline. Thus it appears that neural mechanisms are required, at least in part, for the release of MLI. Angiotensin II (1.25 micrograms kg-1 min-1) and noradrenaline (8 micrograms kg-1 min-1) infusions produced an elevation in blood pressure without altering the circulating MLI levels. Study of the molecular forms of circulating MLI, before and during hypotension, revealed that the large molecular weight enkephalin-containing peptides with approximate molecular sizes of 18kD and 8kD were the predominant forms both in the basal and stimulated states. It is concluded that circulating [Met]enkephalin is not involved in the tonic control of blood pressure but it may modulate catecholamine release following hypotension as part of the stress response. PMID:3594068

  4. Adrenergic and prostanoid mechanisms in control of cerebral blood flow in hypotensive newborn pigs

    SciTech Connect

    Armstead, W.M.; Leffler, C.W.; Busija, D.W.; Beasley, D.G.; Mirro, R. )

    1988-04-01

    The interaction between adrenergic and prostanoid mechanisms in the control of cerebral hemodynamics in the conscious, hypotensive newborn pig was investigated. Pretreatment with the selective {alpha}{sub 1}- and {alpha}{sub 2}-adrenoceptor antagonists prazosin and yohimbine, respectively, had no effect on cerebral blood flow, calculated cerebral vascular resistance, or cerebral metabolic rate either before or after hemmorrhagic hypotension. Indomethacin treatment (5 mg/kg ia) of piglets following hemorrhage caused a significant decrease in blood flow to all brain regions within 20 min. This decrease in cerebral blood flow resulted from increased cerebral vascular resistances of 54 and 177%, 20 and 40 min after treatment, respectively. Cerebral oxygen consumption was reduced from 2.42 {+-} 0.28 to 1.45 {+-} 0.28 ml{center dot}100 g{sup {minus}1} and to 1.0 {+-} 0.28 ml{center dot}100 g{sup {minus}1}{center dot}min{sup {minus}1} 20 and 40 min after indomethacin, respectively, in hemorrhaged piglets. Decreases in cerebral blood flow and metabolic rate and increases in vascular resistance on treatment with indomethacin were the same as in animals pretreated with vehicle, prazosin, or yohimbine. These data are consistent with the hypothesis that the prostanoid system contributes to the maintenance of cerebral blood flow and cerebral metabolic rate during hypotension in the newborn, as reported previously. These data do not implicate removal of sympathetic modulation by prostanoids as a mechanism for indomethacin-induced cerebral vasoconstriction in hypotensive newborn piglets.

  5. A huge ovarian mucinous cystadenoma causing virilization, preterm labor, and persistent supine hypotensive syndrome during pregnancy

    PubMed Central

    Acar, Canan; Temizkan, Osman; Ozagari, Aysim; Gozukara, Ilay; Akyol, Atif

    2016-01-01

    Mucinous cystadenoma (MC) of the ovary is an unilateral, multilocular cystic benign epithelial tumor. Supposed to be hormone responsive, MC reaches huge sizes during pregnancy. Aortocaval compression is common during pregnancy, especially when the pregnant woman is in the supine position. However, the compression recovers with a change in position. The authors report the first case of a huge mucinous cystadenoma of the ovary complicating pregnancy and causing virilization, premature labor, and persistent supine hypotensive syndrome. PMID:27547742

  6. Hypotensive effects of ghrelin receptor agonists mediated through a novel receptor

    PubMed Central

    Callaghan, Brid; Kosari, Samin; Pustovit, Ruslan V; Sartor, Daniela M; Ferens, Dorota; Ban, Kung; Baell, Jonathan; Nguyen, Trung V; Rivera, Leni R; Brock, James A; Furness, John B

    2014-01-01

    BACKGROUND AND PURPOSE Some agonists of ghrelin receptors cause rapid decreases in BP. The mechanisms by which they cause hypotension and the pharmacology of the receptors are unknown. EXPERIMENTAL APPROACH The effects of ligands of ghrelin receptors were investigated in rats in vivo, on isolated blood vessels and on cells transfected with the only molecularly defined ghrelin receptor, growth hormone secretagogue receptor 1a (GHSR1a). KEY RESULTS Three agonists of GHSR1a receptors, ulimorelin, capromorelin and CP464709, caused a rapid decrease in BP in the anaesthetized rat. The effect was not reduced by either of two GHSR1a antagonists, JMV2959 or YIL781, at doses that blocked effects on colorectal motility, in vivo. The rapid hypotension was not mimicked by ghrelin, unacylated ghrelin or the unacylated ghrelin receptor agonist, AZP531. The early hypotension preceded a decrease in sympathetic nerve activity. Early hypotension was not reduced by hexamethonium or by baroreceptor (sino-aortic) denervation. Ulimorelin also relaxed isolated segments of rat mesenteric artery, and, less potently, relaxed aorta segments. The vascular relaxation was not reduced by JMV2959 or YIL781. Ulimorelin, capromorelin and CP464709 activated GHSR1a in transfected HEK293 cells at nanomolar concentrations. JMV2959 and YIL781 both antagonized effects in these cells, with their pA2 values at the GHSR1a receptor being 6.55 and 7.84. CONCLUSIONS AND IMPLICATIONS Our results indicate a novel vascular receptor or receptors whose activation by ulimorelin, capromorelin and CP464709 lowered BP. This receptor is activated by low MW GHSR1a agonists, but is not activated by ghrelin. PMID:24670149

  7. Effects of exercise intensity on postexercise hypotension after resistance training session in overweight hypertensive patients.

    PubMed

    Cavalcante, Paula Andréa M; Rica, Roberta L; Evangelista, Alexandre L; Serra, Andrey J; Figueira, Aylton; Pontes, Francisco Luciano; Kilgore, Lon; Baker, Julien S; Bocalini, Danilo S

    2015-01-01

    Among all nonpharmacological treatments, aerobic or resistance training (RT) has been indicated as a significantly important strategy to control hypertension. However, postexercise hypotension responses after intensity alterations in RT are not yet fully understood. The purpose of this study was to compare the outcomes of differing intensities of RT on hypertensive older women. Twenty hypertensive older women participated voluntarily in this study. After a maximum voluntary contraction test (one repetition maximum) and determination of 40% and 80% experimental loads, the protocol (3 sets/90″ interset rest) was performed in a single session with the following exercises: leg press, leg extension, leg curl, chest press, elbow flexion, elbow extension, upper back row, and abdominal flexion. Systolic and diastolic blood pressures were evaluated at rest, during exercise peak, and after 5, 10, 15, 30, 45, and 60 minutes of exercise and compared to the control. Both experimental loads were effective (P<0.01) in promoting postexercise systolic hypotension (mmHg) compared to controls, after 30, 45, and 60 minutes, respectively, at 40% (113±2, 112±4, and 110±3 mmHg) and 80% (111±3, 111±4, and 110±4 mmHg). Both procedures promoted hypotension with similar systolic blood pressures (40%: -11%±1.0% and 80%: -13%±0.5%), mean arterial blood pressures (40%: -12%±5.5% and 80%: -12%±3.4%), and rate-pressure products (40%: -15%±2.1% and 80%: -17%±2.4%) compared to control measures (systolic blood pressure: 1%±1%, mean arterial blood pressure:\\ 0.6%±1.5%, rate-pressure product: 0.33%±1.1%). No differences were found in diastolic blood pressure and heart rate measures. In conclusion, hypertensive older women exhibit postexercise hypotension independently of exercise intensity without expressed cardiovascular overload during the session. PMID:26425078

  8. Droxidopa and Reduced Falls in a Trial of Parkinson Disease Patients With Neurogenic Orthostatic Hypotension

    PubMed Central

    Hauser, Robert A.; Heritier, Stephane; Rowse, Gerald J.; Hewitt, L. Arthur; Isaacson, Stuart H.

    2016-01-01

    Objectives Droxidopa is a prodrug of norepinephrine indicated for the treatment of orthostatic dizziness, lightheadedness, or the “feeling that you are about to black out” in adult patients with symptomatic neurogenic orthostatic hypotension caused by primary autonomic failure including Parkinson disease (PD). The objective of this study was to compare fall rates in PD patients with symptomatic neurogenic orthostatic hypotension randomized to droxidopa or placebo. Methods Study NOH306 was a 10-week, phase 3, randomized, placebo-controlled, double-blind trial of droxidopa in PD patients with symptomatic neurogenic orthostatic hypotension that included assessments of falls as a key secondary end point. In this report, the principal analysis consisted of a comparison of the rate of patient-reported falls from randomization to end of study in droxidopa versus placebo groups. Results A total of 225 patients were randomized; 222 patients were included in the safety analyses, and 197 patients provided efficacy data and were included in the falls analyses. The 92 droxidopa patients reported 308 falls, and the 105 placebo patients reported 908 falls. In the droxidopa group, the fall rate was 0.4 falls per patient-week; in the placebo group, the rate was 1.05 falls per patient-week (prespecified Wilcoxon rank sum P = 0.704; post hoc Poisson-inverse Gaussian test P = 0.014), yielding a relative risk reduction of 77% using the Poisson-inverse Gaussian model. Fall-related injuries occurred in 16.7% of droxidopa-treated patients and 26.9% of placebo-treated patients. Conclusions Treatment with droxidopa appears to reduce falls in PD patients with symptomatic neurogenic orthostatic hypotension, but this finding must be confirmed. PMID:27332626

  9. A quality improvement project: Strategies to reduce intradialytic hypotension in hemodialysis patients.

    PubMed

    Ghaffar, Umbar; Easom, Andrea K

    2015-05-01

    Intradialytic hypotension is defined as a decrease in systolic blood pressure by ≥ 20 mm Hg or a decrease in mean arterial pressure by 10 mm Hg, and is associated with symptoms that include abdominal discomfort, yawning, sighing, nausea, vomiting, muscle cramps, restlessness, dizziness or fainting, and anxiety. The incidence of a symptomatic reduction in blood pressure during (or immediately following) dialysis ranges from 15-50% of dialysis sessions. It is a major cause for morbidity in elderly hemodialysis patients and those with cardiovascular compromise. It impairs patient well-being, limits ultrafiltration, and increases the risk for coronary and cerebral ischemic events as well as vascular access thrombosis. Several studies have shown a poorer survival in dialysis patients who experience frequent hypotensive episodes on dialysis as opposed to those who do not. In our outpatient dialysis unit, we identified that 9% of our dialysis patients experienced a decrease in their systolic blood pressure to below 80 during dialysis. The purpose of this quality improvement project was to study the factors associated with intradialytic hypotension in these patients and institute appropriate measures to mitigate this issue. Another aim was to educate the dialysis staff on how to manage these patients. Patients were selected using data from weekly rounding reports and orders were written for interventions including ultrafiltration profiling, cool (36 degrees C) dialysate, weight-based ultrafiltration, etc. Outcomes were studied over a period of 3 months. We found that up to 40% of patients experienced an improvement in their blood pressure profile over the period of the study, suggesting that simple changes to dialysis prescription can result in a significant reduction in the incidence of intradialytic hypotension.

  10. Centrally injected histamine increases posterior hypothalamic acetylcholine release in hemorrhage-hypotensive rats.

    PubMed

    Altinbas, Burcin; Yilmaz, Mustafa S; Savci, Vahide; Jochem, Jerzy; Yalcin, Murat

    2015-01-01

    Histamine, acting centrally as a neurotransmitter, evokes a reversal of hemorrhagic hypotension in rats due to the activation of the sympathetic and the renin-angiotensin systems as well as the release of arginine vasopressin and proopiomelanocortin-derived peptides. We demonstrated previously that central nicotinic cholinergic receptors are involved in the pressor effect of histamine. The aim of the present study was to examine influences of centrally administrated histamine on acetylcholine (ACh) release at the posterior hypothalamus-a region characterized by location of histaminergic and cholinergic neurons involved in the regulation of the sympathetic activity in the cardiovascular system-in hemorrhage-hypotensive anesthetized rats. Hemodynamic and microdialysis studies were carried out in Sprague-Dawley rats. Hemorrhagic hypotension was induced by withdrawal of a volume of 1.5 ml blood/100 g body weight over a period of 10 min. Acute hemorrhage led to a severe and long-lasting decrease in mean arterial pressure (MAP), heart rate (HR), and an increase in extracellular posterior hypothalamic ACh and choline (Ch) levels by 56% and 59%, respectively. Intracerebroventricularly (i.c.v.) administered histamine (50, 100, and 200 nmol) dose- and time-dependently increased MAP and HR and caused an additional rise in extracellular posterior hypothalamic ACh and Ch levels at the most by 102%, as compared to the control saline-treated group. Histamine H1 receptor antagonist chlorpheniramine (50 nmol; i.c.v.) completely blocked histamine-evoked hemodynamic and extracellular posterior hypothalamic ACh and Ch changes, whereas H2 and H3/H4 receptor blockers ranitidine (50 nmol; i.c.v.) and thioperamide (50 nmol; i.c.v.) had no effect. In conclusion, centrally administered histamine, acting via H1 receptors, increases ACh release at the posterior hypothalamus and causes a pressor and tachycardic response in hemorrhage-hypotensive anesthetized rats.

  11. The paradoxical role of urinary macromolecules in the aggregation of calcium oxalate: a further plea to increase diuresis in stone metaphylaxis.

    PubMed

    Baumann, J M; Affolter, B

    2016-08-01

    This study was designed to get information on aggregation (AGN) of urinary calcium oxalate crystals (CaOx) which seems to occur in stone formation despite a protecting coat of urinary macromolecules (UMs). CaOx crystallization was directly produced in urine, control and albumin solution by Ox titration and was spectrophotometrically followed. A rapid decrease of optical density indicating AGN was absent in 14 of 15 freshly voided urines of 5 healthy controls. However, in the presence of UM-coated hydroxyapatite all urines with relative high sodium concentration, being an indicator of concentrated urine, showed a pronounced AGN which was abolished when these urines were diluted. Albumin relatively found to be an inhibitor of AGN showed after temporary adsorption on Ca Phosphate (CaP) massive self-AGN and changed to a promoter of CaOx AGN. Self-AGN after adsorption on surfaces especially of CaP, being an important compound of Randall's plaques, can thus explain this paradoxical behavior of UMs. Aggregated UMs probably bridge zones of electrostatic repulsion between UM-coated crystals with identical electrical surface charge. These zones extend by urine dilution which decreases ionic strength. Diminution of urinary concentration by increasing diuresis seems, therefore, to be important in stone metaphylaxis.

  12. The paradoxical role of urinary macromolecules in the aggregation of calcium oxalate: a further plea to increase diuresis in stone metaphylaxis.

    PubMed

    Baumann, J M; Affolter, B

    2016-08-01

    This study was designed to get information on aggregation (AGN) of urinary calcium oxalate crystals (CaOx) which seems to occur in stone formation despite a protecting coat of urinary macromolecules (UMs). CaOx crystallization was directly produced in urine, control and albumin solution by Ox titration and was spectrophotometrically followed. A rapid decrease of optical density indicating AGN was absent in 14 of 15 freshly voided urines of 5 healthy controls. However, in the presence of UM-coated hydroxyapatite all urines with relative high sodium concentration, being an indicator of concentrated urine, showed a pronounced AGN which was abolished when these urines were diluted. Albumin relatively found to be an inhibitor of AGN showed after temporary adsorption on Ca Phosphate (CaP) massive self-AGN and changed to a promoter of CaOx AGN. Self-AGN after adsorption on surfaces especially of CaP, being an important compound of Randall's plaques, can thus explain this paradoxical behavior of UMs. Aggregated UMs probably bridge zones of electrostatic repulsion between UM-coated crystals with identical electrical surface charge. These zones extend by urine dilution which decreases ionic strength. Diminution of urinary concentration by increasing diuresis seems, therefore, to be important in stone metaphylaxis. PMID:26920852

  13. Oscillometry and direct blood pressure: a comparative clinical study during deliberate hypotension.

    PubMed

    Gourdeau, M; Martin, R; Lamarche, Y; Tétreault, L

    1986-05-01

    Oscillometry using an automatic monitor was compared with invasive blood pressure monitoring in 21 patients scheduled for surgery under general anaesthesia with deliberate hypotension. Six ranges of mean blood pressure measurements were studied, two of which were hypotensive. An excellent correlation was found between the two methods (systolic: r = 0.94; mean: r = 0.93; diastolic: r = 0.88) but there was a large variability among individual subjects. For systolic, diastolic and mean intra-arterial readings above an approximative value of 10.64 KPa (80 mmHg), the oscillometric monitor was found to underestimate blood pressure. Inversely, it was found to overestimate blood pressure for intra-arterial readings under the approximative value of 10.8 KPa (80 mmHg). We conclude that the non-invasive monitor represents a good trend estimation of the invasive radial blood pressure technique, but that wide inter-individual variability and the overestimation of blood pressure below an approximative value of 10.64 KPa (80 mmHg) precludes interchange of techniques when absolute values are considered, especially during controlled hypotension. However, oscillometry could represent a better estimate of central aortic pressure.

  14. Role of vagal activity on bradicardic and hypotensive effects of caffeic acid phenethyl ester (CAPE).

    PubMed

    Iraz, Mustafa; Fadillioglu, Ersin; Tasdemir, Seda; Erdogan, Selim

    2005-01-01

    Caffeic acid phenethyl ester (CAPE) is a phenolic active component of propolis of honeybee hives and reduces heart rate and blood pressure in rats. The objective of this study was to investigate the role of vagal activity and atropine blockage on the bradycardic and hypotensive effects of CAPE in rats. The rats were divided into five groups (n = 8). Saline and vehicle (10% ethanol) of CAPE were given to the first and second groups, respectively. Group 3 was treated with 5 mg/kg CAPE. Group 4 bivagotomized and treated with 5 mg/kg CAPE. Group 5 treated with atropine (5 microg/microL/min) continuously and treated with CAPE. The electrophysiological monitoring was done for each experiment under urethane anesthetize. As a result, CAPE caused intense and transient bradycardia and hypotension. Vagotomy completely abolished bradycardia occurred via CAPE injection; however atropine attenuated bradycardic effects of CAPE. On the other hand, hypotensive effect of CAPE was affected from neither bilateral vagotomy nor atropine treatment. It was thought that CAPE may exert its effects on heart rate via a central parasympathetic control mechanism, but not on central parasympathetic blood pressure control system.

  15. [Use of citrulline malate (stimol) in patients with autonomic dystonia associated with arterial hypotension].

    PubMed

    Oknin, V Iu; Fedotova, A V; Veĭn, A M

    1999-01-01

    To study possibilities of a therapeutic correction of asthenic syndrome in individuals with chronic arterial hypotension with malate citrulline, the study was made of 12 women and 3 men with psychoautonomic syndrome (autonomic dystonia), combined with chronic constitutional arterial hypotension. Their age was from 27 to 45 years (mean age--37.6). A control group comprised 14 healthy individuals. Both a state of autonomic nervous system and manifestations of arterial hyportension were analyzed by means of complex scored questionnaires. Mental condition was assessed by the tests of Spilberger (evaluation of reactive and personal anxiety) and of Beck (estimation of depressive manifestations). In all the examined individuals with chronic arterial hypotension, there was psychoautonomic syndrome combined with complaints to asthenic manifestations, namely, to low performance and fatigue. Stimol was prescribed in the form of 50% solution in daily dose of 6 g (3 administrations). The therapy resulted in regression of clinical manifestations of both psychoautonomic syndrome and asthenic symptoms. A mechanism of the drug's action works through favourable changes in cerebral and muscular cells, that, in turn, had an influence on other manifestations of psychoautonomic syndrome. PMID:11530455

  16. Angiotensinergic stimulation of vascular endothelium in mice causes hypotension, bradycardia, and attenuated angiotensin response

    PubMed Central

    Ramchandran, Ramaswamy; Takezako, Takanobu; Saad, Yasser; Stull, Linda; Fink, Bruno; Yamada, Hirotsugu; Dikalov, Sergey; Harrison, David G.; Moravec, Christine; Karnik, Sadashiva S.

    2006-01-01

    It is not clear whether endothelial cell (EC) activation by the hormone angiotensin II (Ang II) modulates contraction of vascular smooth muscle cells (VSMCs) in the vasculature and whether impairment of this regulation in vivo contributes to hypertension. Delineation of the actions of Ang II through the type 1 receptor (AT1R) on ECs in the blood vessels has been a challenging problem because of the predominance of the AT1R functions in VSMCs that lie underneath the endothelium. We have obviated this limitation by generating transgenic (TG) mice engineered to target expression of the constitutively active N111G mutant AT1R only in ECs. In these TG mice, the enhanced angiotensinergic signal in ECs without infusion of Ang II resulted in hypotension and bradycardia. The pressor response to acute infusion of Ang II was significantly reduced. Increased expression of endothelial nitric oxide synthase and production of hypotensive mediators, nitric oxide and cyclic guanosine monophosphate, cause these phenotypes. Hypotension and bradycardia observed in the TG mice could be rescued by treatment with an AT1R-selective antagonist. Our results imply that the Ang II action by means of EC-AT1R is antagonistic to vasoconstriction in general, and it may moderate the magnitude of functional response to Ang II in VSMCs. This control mechanism in vivo most likely is a determinant of altered hemodynamic regulation involved in endothelial dysfunction in hypertensive cardiovascular disease. PMID:17148616

  17. AGN 191976: a novel thromboxane A2-mimetic with ocular hypotensive properties.

    PubMed

    Krauss, A H; Woodward, D F; Chen, J; Gibson, L L; Lai, R K; Protzman, C E; Shan, T; Williams, L S; Gac, T S; Burk, R M

    1995-01-01

    The possible subdivision of thromboxane A2-sensitive (TP) receptors is currently a controversial subject. We report herein on a novel thromboxane A2 mimetic, AGN 191976, which has almost identical pharmacological activity to the well-characterized prostaglandin H2/thromboxane A2 (PGH2/TxA2) mimetic U-46619, but its effects on intraocular pressure are quite distinct from U-46619. Prostanoid receptor activity was determined in vitro using different smooth muscle assays and platelets. Intraocular pressure was measured tonometrically in ocular normotensive Beagle dogs and Cynomolgus monkeys. Conjunctival microvascular permeability was determined in guinea pigs. Despite closely resembling U-46619 as a potent and selective TP receptor agonist, AGN 191976 was a potent ocular hypotensive in dogs and monkeys whereas U-46619 did not lower IOP in either species. The ocular hypotensive effect of AGN 191976 in dogs was attenuated by pretreatment with the TP receptor antagonist SQ 29548. Thus, the ocular hypotensive effects of AGN 191976 are consistent with TP receptor stimulation. Both TxA2-mimetics caused plasma leakage in the guinea pig conjunctiva. The disparate activities of U-46619 and AGN 191976 in our studies suggest the existence of heterogeneous populations of TP-receptors in the eye.

  18. Green coffee bean extract and its metabolites have a hypotensive effect in spontaneously hypertensive rats.

    PubMed

    Suzuki, Atsushi; Kagawa, Daiji; Ochiai, Ryuji; Tokimitsu, Ichiro; Saito, Ikuo

    2002-01-01

    The effects of a water-soluble green coffee bean extract (GCE) on blood pressure were investigated using spontaneously hypertensive rats (SHR). There was a dose-dependent reduction in blood pressure after a single ingestion (180 to 720 mg/kg, p.o.) or long-term ingestion (0.25 to 1% diet for 6 weeks) of GCE. A single oral ingestion (50 to 200 mg/kg) of 5-caffeoylquinic acid (5-CQA), the major component of GCE, dose-dependently decreased blood pressure, suggesting that 5-CQA is involved in the hypotensive effect of GCE in SHR. Because significant increases in caffeic acid (CA) or ferulic acid (FA) were detected in plasma after oral ingestion of 5-CQA in SHR, these acids (2.5, 5,10 micromol/kg) were intravenously injected into SHR under anesthesia and the carotid arterial pressure was measured. Of the two components, FA had a stronger depressor effect than CA. The depressor effect of FA (50 mg/kg, p.o.) was attenuated by the concurrent injection of atropine sulfate (5 mg/kg, s.c.), suggesting that the hypotensive effect of FA in SHR might be mediated via the muscarinic acetylcholine receptors. These findings indicate that oral ingestion of GCE or 5-CQA decreases blood pressure in SHR, and that FA, which is a metabolite of 5-CQA, is a candidate hypotensive component.

  19. Permissive Hypotension: Potentially Harmful in the Elderly? A National Trauma Data Bank Analysis.

    PubMed

    Bridges, Lindsay C; Waibel, Brett H; Newell, Mark A

    2015-08-01

    Permissive hypotension is a component of damage control resuscitation that aims to provide a directed, controlled resuscitation, while countering the "lethal triad." This principle has not been specifically studied in elderly (ELD) trauma patients (≥55 years). Given the ELD population's lack of physiologic reserve and risk of inadequate perfusion with "normal" blood pressures, we hypothesized that utilized a permissive hypotension strategy in ELD trauma patients would result in worse outcomes compared with younger patients (18-54 years). A retrospective review of National Trauma Data Bank reports from 2009 and 2010, identifying critically ill patients undergoing a "damage control laparotomy," was performed to determine the effect of age and systolic blood pressure on outcome. Logistic regression analysis, including evaluation of an interaction between age and admission blood pressure, was performed on mortality using admission demographics, physiology, injury severity, mechanism of injury, and in-hospital complications. Although there was a higher likelihood of death with greater age, lower admission systolic blood pressure, lower Glasgow Coma Score, increased injury severity score, and acute renal failure, a synergistic effect of age and blood pressure on mortality was not identified. Permissive hypotension appears to be a possible management strategy in ELD trauma patients.

  20. Adenosinergic modulation of the imidazoline I₁-receptor-dependent hypotensive effect of ethanol in acute renal failure.

    PubMed

    Harraz, Osama F; El-Gowelli, Hanan M; Mohy El-Din, Mahmoud M; Ghazal, Abdel-Rheem M; El-Mas, Mahmoud M

    2012-08-01

    We reported that inhibition of central sympathetic pools of imidazoline I(1) receptors abolishes the hypotensive effect of ethanol in rats with glycerol-induced acute renal failure (ARF). This study investigated whether adenosine receptors modulate the ethanol-I(1)-receptor interaction. The effect of selective blockade of adenosine A(1), A(2A), or A(2B) receptors on hemodynamic responses to ethanol in the absence and presence of the I(1)-receptor agonist moxonidine was determined in ARF rats. Ethanol (1g/kg i.v.) decreased and increased blood pressure (BP) and heart rate (HR), respectively. Pretreatment with moxonidine abolished the hypotensive but not the tachycardic effect of ethanol. The hypotensive effect of ethanol remained unaltered after selective blockade of A(1), A(2A), or A(2B) receptors with 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) and 8-(3-chlorostyryl) caffeine (CSC) and alloxazine, respectively. Neither was ethanol hypotension affected after inhibition of adenosine uptake by dipyridamole (DPY). Alternatively, the ability of moxonidine to abolish ethanol hypotension was still evident in presence of alloxazine whereas it disappeared or weakened in rats pretreated with CSC and DPCPX, respectively. These findings implicate adenosine A(2A) receptors in the moxonidine-evoked inhibition of the hypotensive action of ethanol. A modulatory role for adenosine A(1) site in the ethanol-I(1)-receptor interaction is also possible through as yet unidentified mechanism. PMID:22613216

  1. Swash mark and grain flow

    USGS Publications Warehouse

    Sallenger,, Asbury H.

    1981-01-01

    Swash marks composed entirely of coarse sand are commonly found on coarse-sand beaches. These swash marks are 10 to 30 centimeters in width and a few millimeters to one centimeter in height. Previous observations, mostly on finer-sand beaches, indicate swash marks are seldom over a few millimeters in height and are commonly composed of material readily floated by surface tension (e.g., mica flakes and shell fragments). Swash marks composed of coarse sand have both fining seaward and fining with depth trends in grain size. Apparently, the leading margin of a wave upwash drives a highly concentrated flow of grains in which both grain size and grain velocity decrease with depth. Therefore, large grains are transported at greater velocities than are smaller grains. Thus, at the maximum advance of an upwash, a swash mark is deposited which has the observed fining seaward and fining with depth trends in grain size.

  2. Pharmacological Evidence of α2-Adrenergic Receptors in the Hypotensive Effect of Platonia insignis Mart.

    PubMed Central

    Mendes, Marcelo Bezerra; da Silva-Filho, José Couras; Sabino, Carla Kelly Barroso; Arcanjo, Daniel Dias Rufino; Sousa, Cleyton Marcos Melo; Costa, Isabella Cristhina Gonçalves; Chaves, Mariana Helena; Oliveira, Rita de Cássia Meneses

    2014-01-01

    Abstract Platonia insignis Mart. (Clusiaceae) is a medicinal plant from the Brazilian Amazon region. The present study evaluated the biological potential of the ethanol extract (Pi-EtOH) and ethyl acetate fraction (Pi-EtOAc) of the P. insignis fruit shells on the cardiovascular system of rats. Pi-EtOH or Pi-EtOAc (12.5, 25, and 50 mg/kg) was administered intravenously in normotensive rats (260–300 g), and the mean arterial pressure and the heart rate were monitored. The Pi-EtOH induced hypotension (−11.56±0.89, −7.43±0.85, and −17.56±1.97 mmHg) followed by bradycardia in two highest doses (−8.89±3.62 and −15.79±1.83 beats/min) and Pi-EtOAc, at the same doses, induced hypotension (−11.2±1.03, −14.48±1.13, −29.89±2.67 mmHg) more intensively, followed by tachycardia at the dose 12.5 and 25 mg/kg (15.64±2.06, 19.31±1.92 beats/min) and bradycardia at a dose of 50 mg/kg (−9.98±7.33 beats/min). The hypotensive response from Pi-EtOAc was not attenuated when used in the pretreatment with L-NAME, verapamil, propranolol, and hexamethonium. However, when using yohimbine, the hypotensive effect was inhibited (−4.42±1.28 (P<.05), −3.29±0.99 (P<.05), 2.06±1.18 mmHg (P<.05); Student's t-test). Hence, the Pi-EtOAc seems to act similarly to the α2-adrenergic agonist in this hypotensive effect. PMID:25055183

  3. Tyrosine Hydroxylase Phosphorylation in Catecholaminergic Brain Regions: A Marker of Activation following Acute Hypotension and Glucoprivation

    PubMed Central

    Damanhuri, Hanafi A.; Burke, Peter G. R.; Ong, Lin K.; Bobrovskaya, Larisa; Dickson, Phillip W.; Dunkley, Peter R.; Goodchild, Ann K.

    2012-01-01

    The expression of c-Fos defines brain regions activated by the stressors hypotension and glucoprivation however, whether this identifies all brain sites involved is unknown. Furthermore, the neurochemicals that delineate these regions, or are utilized in them when responding to these stressors remain undefined. Conscious rats were subjected to hypotension, glucoprivation or vehicle for 30, 60 or 120 min and changes in the phosphorylation of serine residues 19, 31 and 40 in the biosynthetic enzyme, tyrosine hydroxylase (TH), the activity of TH and/or, the expression of c-Fos were determined, in up to ten brain regions simultaneously that contain catecholaminergic cell bodies and/or terminals: A1, A2, caudal C1, rostral C1, A6, A8/9, A10, nucleus accumbens, dorsal striatum and medial prefrontal cortex. Glucoprivation evoked phosphorylation changes in A1, caudal C1, rostral C1 and nucleus accumbens whereas hypotension evoked changes A1, caudal C1, rostral C1, A6, A8/9, A10 and medial prefrontal cortex 30 min post stimulus whereas few changes were evident at 60 min. Although increases in pSer19, indicative of depolarization, were seen in sites where c-Fos was evoked, phosphorylation changes were a sensitive measure of activation in A8/9 and A10 regions that did not express c-Fos and in the prefrontal cortex that contains only catecholaminergic terminals. Specific patterns of serine residue phosphorylation were detected, dependent upon the stimulus and brain region, suggesting activation of distinct signaling cascades. Hypotension evoked a reduction in phosphorylation in A1 suggestive of reduced kinase activity. TH activity was increased, indicating synthesis of TH, in regions where pSer31 alone was increased (prefrontal cortex) or in conjunction with pSer40 (caudal C1). Thus, changes in phosphorylation of serine residues in TH provide a highly sensitive measure of activity, cellular signaling and catecholamine utilization in catecholaminergic brain regions, in the

  4. CE Marking - the Essential Requirements

    NASA Astrophysics Data System (ADS)

    Playle, Mervyn

    The European Union (EU) harmonisation project introduced the CE marking of products to enable the free, unhindered movement of goods throughout the European market. The CE mark replaced the EC mark in the mid 1990s and is fundamental to the New Approach Directives. When a product falls within the scope of a New Approach Directive the manufacturer must comply with the 'goal setting' essential requirements of the directive, to follow one of the conformity assessment procedures provided for, and to draw up the technical documentation specified. Although not mandatory, a manufacturer can choose to satisfy the essential requirements through the application of European harmonised standards.

  5. 19 CFR 134.21 - Special marking.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... COUNTRY OF ORIGIN MARKING Marking of Containers or Holders § 134.21 Special marking. This subpart includes only country of origin marking requirements and exceptions under section 304(b), Tariff Act of 1930,...

  6. Effect of different phenylephrine bolus doses for treatment of hypotension during spinal anaesthesia in patients undergoing elective caesarean section.

    PubMed

    Mohta, M; Harisinghani, P; Sethi, A K; Agarwal, D

    2015-01-01

    The efficacy of phenylephrine might be improved by giving doses higher than that traditionally used (100 µg). This study compared the effects of three initial bolus doses of intravenous phenylephrine; 100 µg (group P100), 125 µg (group P125) and 150 µg (group P150), for the treatment of post-spinal hypotension in patients undergoing elective caesarean delivery. If hypotension was not corrected by this dose, additional boluses of 25 µg were given every minute. Further hypotensive episodes were treated with half the initial bolus dose, followed by 25 µg boluses, as required. Umbilical arterial and venous blood samples were obtained for blood gas analysis and Apgar scores recorded. One hundred and twenty subjects (40 per group) who developed post-spinal hypotension (75%) were included in this randomised, double blind trial. Although systolic blood pressure was higher at certain time-points after 150 µg phenylephrine, there were no statistically significant differences in the effectiveness of the first bolus of phenylephrine to treat hypotension (85%, 95% and 95% in groups P100, P125 and P150, respectively, P=0.215); the additional dose of phenylephrine after the first bolus (P=0.810); the number of additional boluses (P=0.318) or of hypotensive episodes (P=0.118). There were no significant differences in the number of patients developing reactive hypertension or bradycardia, in maternal side-effects or in neonatal outcomes. Although the study may have been underpowered, initial phenylephrine bolus doses of 100 µg, 125 µg and 150 µg did not significantly differ in efficacy to treat post-spinal hypotension in these patients.

  7. Early blood pressure, anti-hypotensive therapy and outcomes at 18 to 22 month corrected age in extremely preterm infants

    PubMed Central

    Batton, Beau; Li, Lei; Newman, Nancy S.; Das, Abhik; Watterberg, Kristi L.; Yoder, Bradley A.; Faix, Roger G.; Laughon, Matthew M.; Stoll, Barbara J.; Higgins, Rosemary D.; Walsh, Michele C.

    2016-01-01

    Objective Investigate relationships between early blood pressure (BP) changes, receipt of anti-hypotensive therapy, and 18 – 22 month corrected age (CA) outcomes for extremely preterm infants. Design Prospective observational study of infants 230/7 – 266/7 weeks gestational age (GA). Hourly BP values and anti-hypotensive therapy exposure in the first 24 hours were recorded. Four groups were defined: infants who did or did not receive anti-hypotensive therapy in whom BP did or did not rise at the expected rate (defined as an increase in the mean arterial BP of ≥5 mmHg/day). Random-intercept logistic modeling controlling for center clustering, GA, and illness severity was used to investigate the relationship between BP, anti-hypotensive therapies, and infant outcomes. Setting Sixteen academic centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Main Outcome Measures Death or neurodevelopmental impairment / developmental delay (NIDD) at 18 – 22 months CA. Results Of 367 infants, 203 (55%) received an anti-hypotensive therapy, 272 (74%) survived to discharge, and 331 (90%) had a known outcome at 18 – 22 months CA. With logistic regression, there was an increased risk of death/NIDD with anti-hypotensive therapy versus no treatment (odds ratio: 1.836, 95% confidence interval: 1.092 – 3.086), but not NIDD alone (odds ratio: 1.53, 95% confidence interval: 0.708 – 3.307). Conclusion Independent of early BP changes, anti-hypotensive therapy exposure was associated with an increased risk of death/NIDD at 18 to 22 months CA when controlling for risk factors known to affect survival and neurodevelopment. PMID:26567120

  8. Surgical skin-marking techniques.

    PubMed

    Granick, M S; Heckler, F R; Jones, E W

    1987-04-01

    Surgical skin-marking inks and dyes are in everyday use for designing and planning incisions in plastic and reconstructive surgery. We have traced the historical development of surgical skin-marking techniques from ancient times to the present. The biochemical characteristics of the commonly used marking agents are discussed. A three-part experiment utilizing a pig model was carried out to test the tissue inflammatory response to the various dyes and inks when used intradermally as tattoos, the persistence of such tattoos, and the ease of skin erasure for each of eight stains. Methylene blue and gentian violet are recommended as the best all-purpose marking agents. The use of proprietary inks is discouraged.

  9. Surgical skin-marking techniques.

    PubMed

    Granick, M S; Heckler, F R; Jones, E W

    1987-04-01

    Surgical skin-marking inks and dyes are in everyday use for designing and planning incisions in plastic and reconstructive surgery. We have traced the historical development of surgical skin-marking techniques from ancient times to the present. The biochemical characteristics of the commonly used marking agents are discussed. A three-part experiment utilizing a pig model was carried out to test the tissue inflammatory response to the various dyes and inks when used intradermally as tattoos, the persistence of such tattoos, and the ease of skin erasure for each of eight stains. Methylene blue and gentian violet are recommended as the best all-purpose marking agents. The use of proprietary inks is discouraged. PMID:2434965

  10. Effects of acute diuresis stress on egr-1 (zif268) mRNA levels in brain regions associated with motivated behavior.

    PubMed

    Aher, Chetan V; Duwaerts, Caroline C; Akama, Keith T; Lucas, Louis R

    2010-01-15

    Stressors evoke a well-studied physiological stress-response, namely, an immediate systemic release of catecholamines from the adrenals followed shortly afterwards by the release of adrenal steroids. The intensity of that response can often be inferred by the amount of adrenal steroids released into the circulatory system. It is still unclear however how the intensity and duration of the stressor affect a number of brain regions, including those in the motivational system. The present study sought to determine whether a brief stressor, such as an isotonic saline injection, activated the brain's motivational system in mesolimbic regions compared with a more intense stressor exemplified by pharmacological challenges caused by the administration of a diuretic. Adult male Sprague-Dawley rats were either injected (s.c.) with isotonic saline or 5mg of the diuretic, furosemide. Controls did not receive any injections. Animals were sacrificed at 30, 60, 120, and 240 min after injection and trunk blood and brains were collected. Serum corticosterone and aldosterone levels were assessed through radioimmunoassay and mesolimbic brain activity was determined through in situ hybridization of mRNA expression of the immediate-early gene egr-1 in the caudate-putamen and nucleus accumbens. While both adrenal steroids demonstrated an initial peak in both stress groups, levels were higher and longer lasting in rats treated with furosemide. Interestingly, egr-1 mRNA levels were significantly higher only in the furosemide-treated group compared with controls. These findings suggest that a selective activation of motivational circuits occurs under thirst and salt-appetite-induced conditions such as those caused by diuresis.

  11. [Effect of Zhuangyao Jianshen Wan (ZYJCW) on P2X1 and P2X3 mRNA expressions in rats with diuresis caused by kidney deficiency].

    PubMed

    Chen, Jia-yi; Jiang, Wei-wen; He, Feng-lei; Mo, Guo-qiang; Guo, Zhong-hui; Wang, Xiao-dan; Wu, Qing-he; Cao, Hong-yin

    2015-08-01

    To investigate the urination-reducing effect and mechanism of Zhuangyao Jianshen Wan (ZYJCW). In this study, SI rats were subcutaneously injected with 150 mg · kg(-1) dose of D-galactose to prepare the sub-acute aging model and randomly divided into the model group, the Suoquan Wan group (1.17 g · kg(-1) · d(-1)), and ZYJCW high, medium and low dose groups (2.39, 1.20, 0.60 g · kg(-1) · d(-1)) , with normal rats in the blank group. They were continuously administered with drugs for eight weeks. The metabolic cage method was adopted to measure the 24 h urine volume and 5 h water load urine volume in rats. The automatic biochemistry analyzer was adopted to detect urine concentrations of Na+, Cl-, K+. The ELISA method was used to determine serum aldosterone (ALD) and antidiuretic hormone (ADH). The changes in P2X1 and P2X3 mRNA expressions in bladder tissues of rats were detected by RT-PCR. According to the results, both ZYJCW high and medium dose groups showed significant down-regulations in 24 h urine volume and 5 h water load urine volume in (P <0.05, P <0.01), declines in Na+ and Cl- concentrations in urine (P <0.01), notable rises in plasma ALD and ADH contents (P <0.05, P <0.01) and remarkable down-regulations in the P2X1 and P2X3 mRNA expressions in bladder tissues (P <0.01). The ZYJCW low dose group revealed obvious reductions in Na+ and Cl- concentrations in urine (P <0.01). The results indicated that ZYJCW may show the urination-reducing effect by down-regulating the P2X1 and P2X3 mRNA expressions in bladder tissues of rats with diuresis caused by kidney deficiency.

  12. The Effect of the Vesical Adaptation Response to Diuresis on Lower Urinary Tract Symptoms after Robot-Assisted Laparoscopic Radical Prostatectomy: A Pilot Proof of Concept Study

    PubMed Central

    Haga, Nobuhiro; Aikawa, Ken; Hoshi, Seiji; Yabe, Michihiro; Akaihata, Hidenori; Hata, Junya; Sato, Yuichi; Ogawa, Soichiro; Ishibashi, Kei; Kojima, Yoshiyuki

    2016-01-01

    Background When urine output increases, voided volume at each voiding also increases in normal subjects. This is generally understood as a vesical adaptation response to diuresis (VARD). Because lower urinary tract symptoms (LUTS) are supposed to be improved by the change in bladder function after robot-assisted laparoscopic radical prostatectomy (RARP), the aim of the present study was to investigate whether VARD is involved in the improvement of LUTS after RARP. Methods 100 consecutive patients who underwent RARP and had the International Prostate Symptom Score (IPSS), quality of life (QOL) index, a frequency-volume chart (FVC), uroflowmetry, and post-voided residual urine (PVR) available were evaluated before and after RARP. This cohort was divided into patients with and without preoperative LUTS according to the preoperative IPSS total score. VARD was defined as the presence of a significant correlation between the urine output rate and voided volume at each voiding (R2>0.2). Results In patients with preoperative LUTS, the IPSS total, storage, and voiding symptom scores were significantly improved after RARP (all P<0.001). The QOL index was also significantly improved after RARP (P<0.05). Although VARD was not seen before RARP (R2 = 0.05), it was seen after RARP (3 months R2 = 0.22, 12 months R2 = 0.23). PVR was significantly reduced after RARP (P = 0.004). Conclusions Improvement of LUTS was seen with acquisition of VARD after RARP. As a result, urinary QOL was also improved in patients with preoperative LUTS. RARP might be an effective procedure for amelioration of LUTS by the acquisition of VARD. PMID:27447829

  13. The OVLT initiates the fall in arterial pressure evoked by high dose lipopolysaccharide: Evidence that dichotomous, dose-related mechanisms mediate endotoxic hypotension

    PubMed Central

    Feleder, Carlos; Yilmaz, M. Sertac; Peng, Jianya; Göktalay, Gökhan; Millington, William R.

    2015-01-01

    This study tested the hypothesis that lipopolysaccharide (LPS) lowers arterial pressure through two different mechanisms depending on the dose. Previously, we found that a low hypotensive dose of LPS (1 mg/kg) lowers arterial pressure by activating vagus nerve afferents. Here we report that hypotension evoked by high dose LPS (15 mg/kg) can be prevented by injecting lidocaine into the OVLT but not by vagotomy or inactivation of the NTS. The hypotension produced by both LPS doses was correlated with elevated extracellular norepinephrine concentrations in the POA and prevented by blocking alpha-adrenergic receptors. Thus, initiation of endotoxic hypotension is dose-related, mechanistically. PMID:26198924

  14. Terlipressin as rescue therapy for intractable hypotension due to septic shock in children.

    PubMed

    Matok, Ilan; Vard, Amir; Efrati, Ori; Rubinshtein, Marina; Vishne, Tali; Leibovitch, Leah; Adam, Miriam; Barzilay, Zohar; Paret, Gideon

    2005-04-01

    Intractable hypotension due to septic shock is associated with high mortality rates in critically ill children worldwide. The use of terlipressin (triglycyl-lysine-vasopressin), an analog of vasopressin with a longer duration of action, recently emerged as a treatment of hypotension not responsive to vasopressors and inotropes. This was a retrospective study set in an 18-bed pediatric critical care department in a tertiary care children's hospital. We reviewed the files of all children with septic shock who were treated with terlipressin between January 2003 and February 2004. Fourteen children (mean age, 5.6 years; range, 4 days to 17.7 years) were treated with terlipressin in 16 septic shock episodes. Significant improvements in respiratory and hemodynamic indices were noted shortly after treatment. Mean arterial blood pressure increased significantly from 54 +/- 3 to 72 +/- 5 mmHg 10 min after terlipressin administration (P = 0.001). Heart rate decreased from 153.0 +/- 6.5 beats/min to 138.0 +/- 7.5 beats/min 12 h after treatment onset (P = 0.003). Epinephrine infusion was decreased or stopped in eight patients after terlipressin administration. Urine output increased from 1.6 +/- 0.5 mL/kg/h to 4.3 +/- 1.2 mL/kg/h 1 h after treatment onset (P = 0.011). PaO2 increased from 95.1 +/- 12.3 mmHg to 110.1 +/- 20.5 mmHg, and the oxygenation index decreased from 10.2 +/- 2.2 to 9.2 +/- 1.7. Terlipressin treatment of hypotension due to septic shock was successful in eight out of 16 episodes. Six of the 14 patients with poor prognosis for survival recovered. We conclude that terlipressin improves hemodynamic indices and renal function in critically ill children. Terlipressin should be considered as a rescue therapy in intractable shock not responsive to catecholamines in children.

  15. Attenuation of homeostatic responses to hypotension and glucoprivation after destruction of catecholaminergic rostral ventrolateral medulla neurons.

    PubMed

    Madden, Christopher J; Stocker, Sean D; Sved, Alan F

    2006-09-01

    This study determined the effect of destruction of rostral ventrolateral medulla (RVLM)-C1 cells on integrated sympathetic and hormonal responses to hypotension or glucoprivation. Injection of anti-dopamine beta-hydroxylase-saporin into the RVLM resulted in 29-99% depletion of RVLM-C1 neurons and approximately 60% reduction in the number of A5 neurons. As in our previous study in unanesthetized rats, resting mean arterial pressure (MAP) was reduced by approximately 10 mmHg in rats with >80% depletion of RVLM-C1 cells compared with control rats, although resting heart rate (HR) did not differ significantly. In the present study, resting plasma levels of norepinephrine (NE) did not differ significantly between control rats and rats with >80% depletion of RVLM-C1 cells, although there was a tendency for RVLM-C1 lesioned rats to have lower levels. Also consistent with our previous study, hydralazine (HDZ)-evoked hypotension resulted in smaller increases in HR and plasma levels of NE in rats with >80% depletion of RVLM-C1 cells compared with control rats. Furthermore, the elevated plasma levels of posterior pituitary hormones vasopressin and oxytocin evoked by HDZ were blunted in RVLM-C1 lesioned rats compared with control rats, even though MAP fell to lower levels in the lesioned rats. Plasma renin activity, plasma osmolality, and plasma protein concentrations did not differ between control rats and rats with >80% depletion of RVLM-C1 neurons. In response to systemic administration of 2-deoxyglucose, the circulating level of epinephrine and the resulting hyperglycemia were attenuated in rats with >80% depletion of RVLM-C1 cells compared with control rats. These results demonstrate that RVLM-C1 cells, in addition to playing a role in acute cardiovascular reflexes, play an important role in integrated sympathetic and hormonal responses to homeostatic challenges such as hypotension and glucoprivation.

  16. Role of physical countermaneuvers in the management of orthostatic hypotension: efficacy and biofeedback augmentation

    NASA Technical Reports Server (NTRS)

    Bouvette, C. M.; McPhee, B. R.; Opfer-Gehrking, T. L.; Low, P. A.

    1996-01-01

    OBJECTIVE: To evaluate the efficacy of various physical countermaneuvers in reducing orthostatic hypotension and its associated symptoms and to assess the efficacy of biofeedback training in enhancing the effectiveness of physical countermaneuvers. MATERIAL AND METHODS: In nine study subjects with neurogenic orthostatic hypotension, four training sessions on physical countermaneuvers were performed after tilt-up, three with visual feedback on the effect of physical countermaneuvers on blood pressure and other cardiovascular variables. Blood pressure change and orthostatic symptoms during tilt-up were determined, as were the changes in total peripheral resistance, stroke index, and heart rate. RESULTS: The five female and four male patients had a mean age of 53 years and a mean duration of symptoms of 4.2 years. On an orthostatic symptom scale of 0 to 10, these patients had a mean symptom score of 7.3. The increment in systolic blood pressure was better for some maneuvers (such as leg crossing and a combination) than others (such as neck flexion and abdominal contraction). Three patterns of responses to biofeedback were found. Simple maneuvers such as squatting did not improve with training; visual feedback was needed for maneuvers such as thigh contraction, and performance declined without biofeedback; the third pattern, seen in maneuvers such as leg crossing, showed continued improvement with training, even without biofeedback. A survey at 3 to 4 months after training revealed continued use of physical maneuvers (3.8 +/- 3.1 per day), increased standing time with each episode of presyncopal symptoms (8.3 +/- 5.8 minutes), and continued global symptomatic improvement. Total peripheral resistance, but not heart rate or stroke index, showed significant regression with blood pressure improvement. CONCLUSION: Physical countermaneuvers are efficacious in reducing orthostatic hypotension, can be augmented by use of biofeedback, and may significantly improve the

  17. Chronic Renin-Angiotensin System (RAS) Blockade May Not Induce Hypotension During Anaesthesia for Bariatric Surgery.

    PubMed

    Salvetti, Guido; Di Salvo, Claudio; Ceccarini, Giovanni; Abramo, Antonio; Fierabracci, Paola; Magno, Silvia; Piaggi, Paolo; Vitti, Paolo; Santini, Ferruccio

    2016-06-01

    The use of angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARB) for the treatment of hypertensive obese patients is steadily increasing. Some studies have reported that the use of these drugs was associated with an increased risk of hypotensive episodes, during general anaesthesia. The number of bariatric procedures is also increasing worldwide, but there is a lack of studies investigating the hypotensive effect of renin-angiotensin system (RAS) blockers in severely obese patients during general anaesthesia for bariatric surgery. The aim of this pilot study was to evaluate hemodynamic changes induced by general anaesthesia in obese patients chronically treated with ACE-I or ARB compared to a control group not treated with antihypertensive therapy. Fourteen obese subjects (mean body mass index (BMI) 47.5 kg/m(2)) treated with ACE-I or ARB and twelve obese (mean BMI 45.7 kg/m2) controls not treated with antihypertensive therapy underwent general anaesthesia to perform laparoscopic bariatric surgery. Systolic blood pressure, diastolic blood pressure, and heart rate were monitored continuously and registered at different time points: T0 before induction, then at 2, 5, 7, 10, 15, 20, 30, 60, 90, 120, and 150 min after induction, and the last time point taken following recovery from anaesthesia. A progressive reduction of both systolic and diastolic blood pressure values was observed without significant differences between the two groups. A similar trend of heart rate values was observed. In conclusion, our pilot study suggests that RAS blockers may be continued during the perioperative period in patients undergoing bariatric surgery, without increasing the risk of hypotensive episodes.

  18. [Hypotension controlled with ATP in orthopedic surgery: incidence of atrio-ventricular conduction disorders].

    PubMed

    Colì, A; Fabbri, G; Lari, S; Ballati, S; Cipressi, M; Lari, F

    1994-01-01

    Adenosine triphosphate (ATP) has been effectively used for induced hypotension in man. Atrio-Ventricular (A-V) conduction disturbances have been observed after adenosine bolus injection and during continuous ATP i.v. infusion. The present perspective investigation was designed to determine the incidence of A-V conduction disturbances during ATP-induced hypotension. Thirty-five normotensive healthy patients (ASA I-II) with no preoperative therapy were subjected to the same anesthetic technique for orthopedic surgery. Premedication consisted of diazepam and atropine. Anesthesia was induced with thiopental and fentanyl followed by atracurium for intubation. The maintenance anesthesia consisted of isoflurane (1.5% inspired)-N2O (60%) in oxygen and incremental doses of fentanyl; the lungs were mechanically ventilated. Dipyridamole (0.15 mg kg-1) was given 15 min prior to ATP-infusion. ATP was administered by an infusion pump at a dosage of 0.025-0.05 mg kg-1 min-1. The ECG was recorded with a Mingograph 34 tape-recorder using 3 pregelled electrodes positioned to give an effective V6 lead pattern. MAP was reduced by 25% and HR increased by 6%. The mean duration of ATP-induced hypotension was 75 min +/- 50 and the mean dose of ATP infused was 200 mg +/- 161. Six patients (17%) showed A-V conduction disturbances. There was a I A-V Block (AVB) in 2 cases, a II AVB in 2 cases and a III AVB in 2 cases. In every case the arrhythmia disappeared spontaneously or after ATP-infusion suspension.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8208448

  19. Up-regulation of the adrenomedullin system mediates hypotension and hypoaldosteronism induced by simulated microgravity.

    PubMed

    Andreis, Paola G; Rossi, Gian Paolo; Bova, Sergio; Neri, Giuliano; Nussdorfer, Gastone G; Mazzocchi, Giuseppina

    2004-04-01

    We recently demonstrated that prolonged simulated microgravity (SMG) induced hypotension and hypoaldosteronism in rats, and gathered preliminary evidence for an involvement of circulating adrenomedullin (AM). Thus, we aimed to investigate whether short-term SMG elicits the same effects, and whether up-regulation of adrenal AM system plays a relevant role. Rats were exposed for 8 days to SMG in the form of hindlimb unweighting, and then, along with control animals, were given an intraperitoneal injection of AM22-52 and/or angiotensin-II (Ang-II) (100 nmoles/kg) or the saline vehicle. Systolic blood pressure (SBP) was measured by tail-cuff sphygmomanometry. The adrenal expression of AM was assayed by semiquantitative RT-PCR. The plasma concentrations of aldosterone (PAC) and AM, and adrenal AM content were measured by RIA. Short-term SMG induced significant decreases in SBP and PAC. Conversely, both the plasma and adrenal levels of AM, and adrenal AM mRNA were enhanced in SMG-exposed animals. The SMG-induced hypotension and hypoaldosteronism were reversed by AM22-52, an AM-receptor antagonist, thereby demonstrating a causal link between these effects and the up-regulation of AM system. SMG hampered SBP and PAC responses to Ang-II; the co-administration of AM22-52 restored these responses. These findings accord well with the known ability of AM to counteract the effects of Ang-II on both blood vessels and adrenocortical cells. Taken together, our findings allow us to conclude that up-regulation of the adrenal AM system i) occurs early and takes part in the adaptative changes occurring during SMG conditions; and ii) may account for both hypotension and hypoaldosteronism on returning to the normogravitational environment.

  20. Hypotension in the Right Lateral Position Secondary to Inferior Vena Cava Abnormality.

    PubMed

    Hutton, Meredith J H; Swamy, Ganesh; Shinkaruk, Kelly; Duttchen, Kaylene

    2015-09-15

    Surgical positioning is accompanied by numerous anesthetic considerations, particularly its potential effects on the cardiovascular, respiratory, and nervous systems. Clinical studies have shown that lateral positioning does not affect hemodynamics; however, with the addition of trunk flexion, there is a decrease in cardiac output, which may be secondary to caval compression. In this report, we describe a unique case of hypotension that arose in a patient positioned only in the right lateral decubitus position with flexion and that was exacerbated by an abnormally narrow inferior vena cava. PMID:26361387

  1. Acute Radiation Hypotension in the Rabbit: a Model for the Human Radiation Shock Syndrome.

    NASA Astrophysics Data System (ADS)

    Makale, Milan Theodore

    This study has shown that total body irradiation (TBI) of immature (40 to 100 day old) rabbits leads to an acute fall in mean arterial pressure (MAP) 30 to 90 minutes after exposure, which takes no more than about three minutes, and often results in pressures which are less than 50% of the lowest pre-exposure MAP. This is termed acute cardiovascular collapse (ACC). ACC is often accompanied by ECG T-wave elevation, a sharp rise in ear temperature, labored breathing, pupillary constriction, bladder emptying, and loss of abdominal muscle tone. About 73% of 40 to 100 day rabbits exhibit ACC; the others and most older rabbits display gradual pressure reductions (deliberate hypotension) which may be profound, and which may be accompanied by the same changes associated with ACC. ACC and deliberate hypotension occurred in rabbits cannulated in the dorsal aorta, and in non-operated animals. The decline in MAP for all 40 to 100 day cannulated rabbits (deliberate and ACC responders) is 55.4%. The experiments described below only involved 40 to 100 day cannulated TBI rabbits. Heart region irradiation resulted in an average MAP decline of 29.1%, with 1/15 rabbits showing ACC. Heart shielding during TBI reduced the decline in MAP to 19%, with 1/10 rabbits experiencing ACC. These results imply that the heart region, which includes the heart, part of the lungs, neural receptors, roots of the systemic vessels, and the blood, is a sensitive target. Bilateral vagotomy reduced the decline in MAP to 24.9%, and abolished ACC. Atropine (6 mg/kg) reduced the frequency of ACC to 26%, and the decline in MAP to 41.4%. In 11/13 rabbits the voltage generated by left vagal transmission rose after TBI. The vagi appear to participate in radiation hypotension. Heart shielding together with bilateral vagotomy reduced the decline in MAP to only 9.9%, with no ACC responders. The mean right ventricular pressure (MRVP) rose after TBI in 8/10 rabbits. In animals which displayed either ACC or steep

  2. Iterative epidural blood patch for recurrent spontaneous intracranial hypotension during pregnancy.

    PubMed

    Grange, Joséphine; Lorre, Gilbert; Ducarme, Guillaume

    2016-11-01

    A 30-year-old woman at 28 weeks presented with sudden onset of intense headache, epigastric pain, hot flushes, nausea, vomiting, and stiff neck. Cerebral magnetic resonance imaging showed pathognonomic signs of spontaneous intracranial hypotension (SIH). Epidural blood patch was performed 2 times during pregnancy for symptoms relief in spite of medical treatments. No other recurrence was noted until the spontaneous delivery. SIH is a rare entity during pregnancy which may be diagnosed using magnetic resonance imaging. Iterative Epidural blood patch should be proposed to patients with SIH during pregnancy because it allowed faster symptoms improvement and patient relief with complete recovery than medical treatment only. PMID:27687382

  3. Urocortin and inflammation: confounding effects of hypotension on measures of inflammation.

    PubMed

    Torpy, D J; Webster, E L; Zachman, E K; Aguilera, G; Chrousos, G P

    1999-01-01

    Urocortin, a newly isolated 40-amino-acid mammalian peptide homologous to corticotropin-releasing hormone (CRH), activates both CRH type 1 and 2 receptors, but may be an endogenous ligand for CRH receptor type 2. Urocortin given systemically inhibited heat-induced paw edema in the rat, and was therefore ascribed anti-inflammatory properties. We examined the effects of urocortin in the carrageenin-induced subcutaneous inflammation model. Rats were treated with urocortin 200 (n = 6) or 20 nmol/kg (n = 6); inflammatory exudates were reduced by approximately 30% compared to controls (n = 7) at both doses. However, since subcutaneous urocortin has been shown to reduce arterial blood pressure, we tested the hypothesis that its antiedema and antiextravasatory effects were secondary to arterial hypotension. Therefore, we examined the parallel effects of urocortin- and hydralazine-induced hypotension on acute inflammation induced by carrageenin in the rat. Rats were treated with subcutaneous carrageenin and control injections (n = 8), carrageenin and urocortin (20 nmol/kg, n = 9), or carrageenin and intraperitoneal hydralazine (10 mg/kg, n = 8). Mean arterial blood pressure was measured hourly for 7 h in 12 animals, and after 2 h, the nadir of treatment, in a further 13 animals. Rats were then sacrificed, and the inflammatory exudate volume and leukocyte count were measured. Mean exudate volumes were reduced from 4.8 +/- 0.5 ml (controls) to 2.4 +/- 0.3 ml (p = 0.004) and 2.9 +/- 0.6 ml (p = 0.007) in urocortin- and hydralazine-treated animals, respectively. Urocortin and hydralazine both produced a significant fall in blood pressure compared to controls, with mean arterial pressure 2 h after carrageenin injection falling to 51.0 +/- 4.1 (p < 0.001) and 34.6 +/- 4.6 (p < 0.001) vs. 92.9 +/- 3.7 mm Hg in controls, respectively. A significant positive correlation was noted between blood pressure and inflammatory exudate volume (r = 0. 52, p = 0.007). As both hydralazine and

  4. Noninvasive transcutaneous bionic baroreflex system prevents severe orthostatic hypotension in patients with spinal cord injury.

    PubMed

    Yoshida, Masayoshi; Murayama, Yoshinori; Chishaki, Akiko; Sunagawa, Kenji

    2008-01-01

    Central baroreflex failure in patients with spinal cord injury results in serious orthostatic hypotension. We examined if transcutaneous electrical stimulation regulates arterial pressure in those patients. We identified skin regions capable of increasing arterial pressure and determined respective transfer function. Using the transfer function, we designed the feedback regulator (i.e., bionic baroreflex system) to control arterial pressure. Orthostatic stress decreased arterial pressure profoundly. Activation of bionic regulator restored and maintained arterial pressure at pre-specified levels. We conclude that the transcutaneous bionic system is noninvasive and capable of stabilizing arterial pressure in patients with spinal cord injury.

  5. The use of antigravity suits in the treatment of idiopathic orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Landmark, K.; Kravik, S.

    1980-01-01

    Idiopathic orthostatic hypotension is an uncommon disease characterized by a drop in blood pressure when going from a recumbent to a standing position. Treatment by medication generally produces poor results. Three patients at the Royal Hospital in Oslo were treated with antigravity suits and all were able to maintain adequate blood pressures in the standing position. One patient improved dramatically and was able to take short walks while wearing the suit. The two other patients, however, felt that wearing the suits eventually became uncomfortable. This treatment represents a useful treatment alternative for intractable cases.

  6. Coronary artery slow flow associated with angina pectoris and hypotension--a case report.

    PubMed

    Burckhartt, B A; Mukerji, V; Alpert, M A

    1998-06-01

    A 56-year-old woman with a history of angina pectoris developed substernal chest pressure and hypotension during coronary angiography. Her baseline coronary angiogram appeared normal. During this episode, injection of contrast medium into the left coronary artery demonstrated coronary artery slow flow in the left anterior descending artery and branches of the circumflex coronary artery, which normalized following the sublingual administration of nitroglycerin. There were no focal areas of coronary artery spasm. This phenomenon may represent a heretofore undescribed mechanism for myocardial ischemia and its sequelae.

  7. Role of Mas receptor antagonist (A779) on pressure diuresis and natriuresis and renal blood flow in the absence of angiotensin II receptors type 1 and 2 in female and male rats.

    PubMed

    Mansoori, A; Oryan, S; Nematbakhsh, M

    2014-10-01

    Sexual differences in blood pressure are associated with angiotensin 1-7 (Ang1-7) and its receptor and enzyme function targeting. Blockade of angiotensin II (AngII) receptors type 1 and 2 (AT1R and AT2R) inhibits some actions of Ang1-7. We described the role of Ang1-7 receptor (MasR) antagonist (A779) on kidney hemodynamics when AT1R and AT2R are blocked with losartan and PD123319. In anaesthetized male and female rats after blockade of both AT1R and AT2R, the renal perfusion pressure (RPP) was controlled in two levels of 80 and 100 mmHg via an adjustable clamp placed around the aorta above the level of the renal arteries. Then, the effects of saline vehicle and MasR blocker (A779) were tested on pressure natriuresis and diuresis, renal blood flow (RBF), and renal vascular resistance (RVR). In the absence of AT1R and AT2R; RVR, RBF/wet kidney tissue weight, and serum level of renin did not alter in both genders either MasR was blocked or not. However, urine flow rate (UF) and sodium excretion (UNaV) increased significantly at the pressure level of 100 mmHg in the presence of MasR in male (P<0.05) but not in female rats. When AT1R and AT2R were blocked, the impact of MasR is gender-related in pressure natriuresis and diuresis, and pressure natriuresis and diuresis in male rats (not female) increases in the presence of MasR.

  8. Carotid-cardiac baroreflex - Relaxation with orthostatic hypotension following simulated microgravity and implications for development of countermeasures

    NASA Technical Reports Server (NTRS)

    Convertino, Victor A.

    1991-01-01

    An examination has been made of the function of the human carotid-cardiac baroreflex (CCB) under the influence of simulated microgravity, varying states of vascular volume, and acute exercise. Results have been obtained which suggest that acute fluid replacement prior to reentry may not reverse the impaired baroreflex associated with postflight hypotension. It is also noted that one bout of maximal exercise increased baroreflex sensitivity and buffer capacity through 24 hrs post exercise; these baroreflex changes were the opposite of those following head-down bedrest. Contributions of reduced blood volume and impaired CCB function to orthostatic hypotension following microgravity appear to be separate and additive, so that maximal exercise and fluid replacement could be a potent countermeasure against postflight hypotension.

  9. Methylene blue, midodrine, and pseudoephedrine: a review of alternative agents for refractory hypotension in the intensive care unit.

    PubMed

    Van Berkel, Megan A; Fuller, Laura A; Alexandrov, Anne W; Jones, G Morgan

    2015-01-01

    Hypotensive episodes are common among patients in the intensive care unit and can lead to multiorgan failure if uncontrolled. Fluid administration and continuous infusion of vasoactive agents are frequently used for management of hypotension; however, both therapies may be associated with adverse effects including pulmonary edema and tissue necrosis. In addition, availability of these first-line agents has been impacted by the increasing occurrence of drug shortages. Methylene blue, pseudoephedrine, and midodrine have been considered potential alternatives to standard therapy. These agents may not only be used when first-line agents are unavailable due to shortages, but they may also aid in reducing the cumulative dose of other vasoactive agents used. The purpose of this review was to discuss strategies for the safe and effective use of methylene blue, pseudoephedrine, and midodrine for the treatment of hypotension in the critically ill.

  10. Postexercise hypotension and sustained postexercise vasodilatation: what happens after we exercise?

    PubMed

    Halliwill, John R; Buck, Tahisha M; Lacewell, Alisha N; Romero, Steven A

    2013-01-01

    A single bout of aerobic exercise produces a postexercise hypotension associated with a sustained postexercise vasodilatation of the previously exercised muscle. Work over the last few years has determined key pathways for the obligatory components of postexercise hypotension and sustained postexercise vasodilatation and points the way to possible benefits that may result from these robust responses. During the exercise recovery period, the combination of centrally mediated decreases in sympathetic nerve activity with a reduced signal transduction from sympathetic nerve activation into vasoconstriction, as well as local vasodilator mechanisms, contributes to the fall in arterial blood pressure seen after exercise. Important findings from recent studies include the recognition that skeletal muscle afferents may play a primary role in postexercise resetting of the baroreflex via discrete receptor changes within the nucleus tractus solitarii and that sustained postexercise vasodilatation of the previously active skeletal muscle is primarily the result of histamine H(1) and H(2) receptor activation. Future research directions include further exploration of the potential benefits of these changes in the longer term adaptations associated with exercise training, as well as investigation of how the recovery from exercise may provide windows of opportunity for targeted interventions in patients with hypertension and diabetes.

  11. Phenylephrine infusion for spinal-induced hypotension in elective cesarean delivery: Does preload make a difference?

    PubMed Central

    Bottiger, Brandi A; Bezinover, Dmitri S; Mets, Berend; Dalal, Priti G; Prozesky, Jansie; Ural, Serdar; Vaida, Sonia

    2016-01-01

    Background and Aims: Patients undergoing elective cesarean delivery (CD) have a high-risk of spinal-induced hypotension (SIH). We hypothesized that a colloid preload would further reduce SIH when compared with a crystalloid preload. Material and Methods: Eighty-two healthy parturients undergoing elective CD were included in the study. Patients were randomly assigned to two groups (41 patients in each group) to receive either Lactated Ringer's solution (1500 ml) or hydroxyethyl starch (6% in normal saline, 500 ml) 30 min prior to placement of spinal anesthesia. All patients were treated with a phenylephrine infusion (100 mcg/min), titrated during the study. Results: There was no statistical difference between groups with regards to the incidence of hypotension (10.8% in the colloid group vs. 27.0% in the crystalloid group, P = 0.12). There was also no difference between groups with respect to bradycardia, APGAR scores, and nausea and vomiting. Significantly less phenylephrine (1077.5 ± 514 mcg) was used in the colloid group than the crystalloid group (1477 ± 591 mcg, P = 0.003). Conclusion: The preload with 6% of hydroxyethyl starch before CD might be beneficial for the prevention of SIH. PMID:27625478

  12. Involvement of interleukin-1 receptor mechanisms in development of arterial hypotension in rat heatstroke.

    PubMed

    Lin, M T; Liu, H H; Yang, Y L

    1997-10-01

    Rats, under urethan anesthesia, were exposed to a high ambient temperature (42 degrees C) to induce heatstroke and to assess the hemodynamic changes associated with heatstroke. Compared with normothermic controls, rats with heatstroke showed higher values of colonic temperature, heart rate, and plasma levels of interleukin (IL)-1 but lower values of R wave amplitude, P-R and Q-T intervals, systolic wave amplitude, diastolic and dicrotic wave duration, mean arterial pressure, stroke volume, and cardiac output. Animals injected intravenously with an IL-1-receptor antagonist at the time of heatstroke induction were protected from some of the cardiovascular effects of heatstroke, such as depressed ventricular depolarization, decreased stroke volume, decreased cardiac output, and arterial hypotension. The hemodynamic changes associated with heatstroke could be mimicked by IL-1beta administration. Other cardiovascular parameters such as total peripheral vascular resistance were unaffected by heatstroke induction or IL-1beta treatment. The results indicate that a selective decline in stroke volume or ventricular depolarization resulting from increased plasma levels of IL-1 may be an important mechanism signaling arterial hypotension or circulatory failure in rat heatstroke.

  13. Tender Endothelium Syndrome: Combination of Hypotension, Bradycardia, Contrast Induced Chest Pain, and Microvascular Angina.

    PubMed

    Goberdhan, Shivesh; Chiew, Soon Kwang; Syed, Jaffer

    2016-01-01

    Hypotension, bradycardia, and contrast induced chest pain are potential complications of cardiac catheterization and coronary angiography. Catheter-induced coronary spasm has been occasionally demonstrated, but its relationship to spontaneous coronary spasm is unclear. We describe a 64-year-old female who underwent coronary artery bypass surgery in 1998 on the basis of an angiographic diagnosis of severe left main disease, who recently presented with increasingly frequent typical angina. Repeat coronary angiography was immediately complicated by severe chest pain, hypotension, and bradycardia but demonstrated only mild disease of the left main artery and entire coronary tree with complete occlusion of her prior grafts. This reaction was almost identical to that observed during her original coronary angiogram. We now believe her original angiogram was complicated by severe catheter-induced left main spasm, with the accompanying contrast reaction attributed to left main disease, and the occlusion of coronary grafts explained by the absence of significant left main disease. The combination of these symptoms has not been documented in the literature. In this instance, these manifestations erroneously led to coronary bypass surgery. It is unknown whether routine, systematic injection of intracoronary nitroglycerin prior to angiography might blunt the severity of such reactions. PMID:26981290

  14. Temazepam, but not zolpidem, causes orthostatic hypotension in astronauts after spaceflight

    NASA Technical Reports Server (NTRS)

    Shi, Shang-Jin; Garcia, Kathleen M.; Meck, Janice V.

    2003-01-01

    Insomnia is a common symptom, not only in the adult population but also in many astronauts. Hypnotics, such as temazepam (a benzodiazepine) and zolpidem (an imidazopyridine), are often taken to relieve insomnia. Temazepam has been shown clinically to have hemodynamic side effects, particularly in the elderly; however, the mechanism is not clear. Zolpidem does not cause hemodynamic side effects. The purpose of this study was to determine whether the use of different hypnotics during spaceflight might contribute significantly to the high incidence of postflight orthostatic hypotension, and to compare the findings in astronauts with clinical research. Astronauts were separated into three groups: control (n = 40), temazepam (15 or 30 mg; n = 9), and zolpidem (5 or 10 mg; n = 8). In this study, temazepam and zolpidem were only taken the night before landing. The systolic and diastolic blood pressures and heart rates of the astronauts were measured during stand tests before spaceflight and on landing day. On landing day, systolic pressure decreased significantly and heart rate increased significantly in the temazepam group, but not in the control group or in the zolpidem group. Temazepam may aggravate orthostatic hypotension after spaceflight when astronauts are hemodynamically compromised. Temazepam should not be the initial choice as a sleeping aid for astronauts. These results in astronauts may help to explain the hemodynamic side effects in the elderly who are also compromised. Zolpidem may be a better choice as a sleeping aid in these populations.

  15. [Orthostatic hypotension in complicated diabetes mellitus: study of the renin-angiotensin-aldosterone system (author's transl)].

    PubMed

    Lefebvre, J; Blacker, C; Fossati, P; Linquette, M

    1979-03-01

    Plasma renin activity (P.R.A.) and plasma aldosterone (P.A.) were studied basally and after various stimuli in eight diabetic subjects with orthostatic hypotension and autonomic neuropathy. Five of them had chronic renal failure and proteinuria. On a diet containing 100 mEq Na/24 H, mean P.R.A. was 0,80 +/- 0,32 ng/ml/h in the supine position and 0,95 +/- 0,43 ng/ml/h in the upright position (N.S.); mean P.A. was 111 +/- 77 pg/ml in the supine position and 234 pg/ml in the upright position (p less than 0,01). On a diet containing 10 mEq Na/24 H, mean P.R.A. was 1,54 +/- 0,76 ng/ml/h in the supine position and 2,44 +/- 1,53 ng/ml/h in the upright position (N.S.). There was little stimulation of P. R. A. by low sodium intakes. After furosemide (n = 6), epinephrine + norepinephrine (n = 4) or diazoxide (n = 2), there was no stimulation of P.R.A. and P.A. Thus in diabetic patients with orthostatic hypotension and autonomic neuropathy basal values of P.R.A. and P.A. are in the normal range but there is dysregulation of renin-angiotensin-aldosterone system.

  16. Long-term hypotensive effect of beta-agonist in conscious dogs.

    PubMed

    Nuwayhid, B S; Young, D B; Tipayamontri, U; Montani, J P

    1988-09-01

    The purpose of this study was to investigate the arterial pressure response to long-term administration of beta-agonists in the chronically instrumented conscious animal model. Chronically instrumented dogs were given intravenous infusions of ritodrine (2 micrograms.kg-1.min-1) for a period of 2 wk. Several cardiovascular and renal parameters were monitored before, during, and after the ritodrine infusion, and renal function curves were constructed. After the 1st wk of infusion, a new steady state was reestablished, and this was characterized by hypotension, reduced plasma protein concentration, elevated cardiac output, expanded extracellular fluid space, and near normal levels of activity of renin-angiotensin-aldosterone systems. The renal function curve during ritodrine infusion shifted to the left with no change in slope. We propose the following: 1) the persistence of hypotension is most probably related to the resetting of the arterial pressure-kidney blood volume servocontrol mechanisms, and 2) the persistent elevation of cardiac output and reduction in peripheral resistance are most probably related to increased oxygen and nutrient demand during beta-agonist infusions.

  17. Arterial baroreflex control of sympathetic nerve activity during acute hypotension: effect of fitness

    NASA Technical Reports Server (NTRS)

    Fadel, P. J.; Stromstad, M.; Hansen, J.; Sander, M.; Horn, K.; Ogoh, S.; Smith, M. L.; Secher, N. H.; Raven, P. B.

    2001-01-01

    We examined arterial baroreflex control of muscle sympathetic nerve activity (MSNA) during abrupt decreases in mean arterial pressure (MAP) and evaluated whether endurance training alters baroreflex function. Acute hypotension was induced nonpharmacologically in 14 healthy subjects, of which 7 were of high fitness (HF) and 7 were of average fitness (AF), by releasing a unilateral arterial thigh cuff after 9 min of resting ischemia under two conditions: control, which used aortic and carotid baroreflex (ABR and CBR, respectively) deactivation; and suction, which used ABR deactivation alone. The application of neck suction to counteract changes in carotid sinus transmural pressure during cuff release significantly attenuated the MSNA response (which increased 134 +/- 32 U/14 s) compared with control (which increased 195 +/- 43 U/14 s) and caused a greater decrease in MAP (19 +/- 2 vs. 15 +/- 2 mmHg; P < 0.05). Furthermore, during both trials, the HF subjects exhibited a greater decrease in MAP compared with AF subjects despite an augmented baroreflex control of MSNA. These data indicate that the CBR contributes importantly to the MSNA response during acute systemic hypotension. Additionally, we suggest that an impaired control of vascular reactivity hinders blood pressure regulation in HF subjects.

  18. Postural hypotension as the initial presentation of fulminant right ventricular myocarditis.

    PubMed

    Ho, Cheng-Hsuan; Wu, Ya-Chieh; Lin, Yen-Yue; Hsu, Chin-Wang; Tsai, Shih-Hung

    2010-07-01

    Myocarditis can be totally asymptomatic or can manifest with chest pain syndromes, ranging from mild persistent chest pain of acute myopericarditis to severe symptoms that mimic acute myocardial infarction. About 60% of patients may have antecedent arthralgias, malaise, fevers, sweats, or chills consistent with viral infections 1 to 2 weeks before onset. Here, we report a postpartum young woman who developed postural hypotension as the first manifestation of fulminant myocarditis with initially acute "cold and dry" right-sided heart failure and cardiogenic shock. Common causes of postural hypotension include volume depletion, medications, diabetes, alcohol, infection, and varicose veins as well as dysautonomic syndromes. Fulminant myocarditis can cause cardiogenic shock. Myocardial inflammation more frequently affects localized areas of the left ventricle free wall, rarely right ventricle (RV). However, predominant RV involvement with acute right-sided heart failure and low cardiac output syndrome can be easily overlooked due to lack of typical heart failure signs. On reviewing medical literatures, we had found no report regarding the RV involvement with acute right-sided heart failure as the initial presentation of fulminant myocarditis. PMID:20637387

  19. Pharmacological evidence of hypotensive activity of Marrubium vulgare and Foeniculum vulgare in spontaneously hypertensive rat.

    PubMed

    El Bardai, S; Lyoussi, B; Wibo, M; Morel, N

    2001-05-01

    The hypotensive effects of the water extract of Marrubium vulgare L. and Foeniculum vulgare L. were investigated in spontaneously hypertensive rats (SHR) and in normotensive Wistar-Kyoto rats (WKY). Oral administration of Marrubium or Foeniculum extract lowered the systolic blood pressure of SHR but not of WKY. In SHR, Foeniculum but not Marrubium treatment increased water, sodium and potassium excretion. Ex vivo as well as in vitro, Marrubium extract inhibited the contractile responses of rat aorta to noradrenaline and to KCl (100 mM). Inhibition was greater in aorta from SHR compared to WKY and was not affected by the NO synthase inhibitor N-nitro-L-arginine. Vascular effects of Foeniculum extract were less pronounced than those of Marrubium and were blocked by N-nitro-L-arginine. These results indicate that hypotensive activity of Marrubium and Foeniculum extracts seems to be mediated through different pathways: Foeniculum appeared to act mainly as a diuretic and a natriuretic while Marrubium displayed vascular relaxant activity.

  20. Hemodynamic Effects of Midodrine After Space Flight in Astronauts Without Orthostatic Hypotension

    NASA Technical Reports Server (NTRS)

    Platts, Steven H.; Ziegler, Michael G.; Waters, Wendy W.; Meck, Janice V.

    2006-01-01

    Orthostatic hypotension and presyncope are common and potentially serious risks for astronauts returning from space. Susceptible subjects fail to generate an adequate adrenergic response to upright posture. The -1 adrenergic agonist, midodrine, may be an effective countermeasure. We tested the hypothesis that midodrine would have no negative hemodynamic effect on healthy astronauts returning from space. Five male astronauts participated in preflight and postflight tilt testing on a control flight as well as on the test flights, where midodrine (10 mg, orally) was administered after landing, approximately 1 hour before testing. None of these astronauts exhibited orthostatic hypotension or presyncope before or after either flight. Midodrine did not cause any untoward reactions in these subjects before or after flight, in fact a modest beneficial effect was seen on postflight tachycardia (p=0.036). These data show that midodrine protected against post-spaceflight increases in heart rate, without having any adverse hemodynamic effects on non-presyncopal, male astronauts. Among these subjects, midodrine was a safe cardiovascular countermeasure.

  1. Hemodilution and induced hypotension for insertion of a Harrington rod in a Jehovah's Witness patient.

    PubMed

    Wong, K C; Webster, L R; Coleman, S S; Dunn, H K

    1980-10-01

    The case of a 28-year-old Jehovah's Witness illustrates the feasibility of using a combined technique of induced hypotension and hemodilution to minimize the surgical loss of red blood cells during the insertion of a Harrington rod. A Swan-Ganz catheter with thermister tip was inserted to measure pulmonary arterial pressure, pulmonary arterial wedge pressure and cardiac output. Other intraoperative monitoring included continuous arterial pressure, electrocardiography, oropharyngeal temperature, esophageal stethoscope, arm-cuff blood pressure and urinary output from an indwelling Foley catheter. A total of 10 L of crystalloid was infused over a 2 1/2-hour period while hypotension was induced by intravenous nitroprusside and enflurane anesthesia. Hematocrit was diluted from 46% to 26% intraoperatively with an estimated surgical blood loss of 2,740 ml. The 24-hour postoperative hematocrit was 30% and recovery was uneventful. This method may be useful in any orthopedic procedure in which heavy blood loss is anticipated and the patient refuses transfusion of blood or blood products. However, the patient must be in good health and have an uncompromised cardiopulmonary system.

  2. Tender Endothelium Syndrome: Combination of Hypotension, Bradycardia, Contrast Induced Chest Pain, and Microvascular Angina

    PubMed Central

    Chiew, Soon Kwang; Syed, Jaffer

    2016-01-01

    Hypotension, bradycardia, and contrast induced chest pain are potential complications of cardiac catheterization and coronary angiography. Catheter-induced coronary spasm has been occasionally demonstrated, but its relationship to spontaneous coronary spasm is unclear. We describe a 64-year-old female who underwent coronary artery bypass surgery in 1998 on the basis of an angiographic diagnosis of severe left main disease, who recently presented with increasingly frequent typical angina. Repeat coronary angiography was immediately complicated by severe chest pain, hypotension, and bradycardia but demonstrated only mild disease of the left main artery and entire coronary tree with complete occlusion of her prior grafts. This reaction was almost identical to that observed during her original coronary angiogram. We now believe her original angiogram was complicated by severe catheter-induced left main spasm, with the accompanying contrast reaction attributed to left main disease, and the occlusion of coronary grafts explained by the absence of significant left main disease. The combination of these symptoms has not been documented in the literature. In this instance, these manifestations erroneously led to coronary bypass surgery. It is unknown whether routine, systematic injection of intracoronary nitroglycerin prior to angiography might blunt the severity of such reactions. PMID:26981290

  3. [Central hemodynamics and cerebrovascular disorders in patients with idiopathic arterial hypotension].

    PubMed

    Foniakin, A V; Mashin, V Vl; Ataian, A S; Saprygina, L V

    2012-01-01

    A total of 65 patients (mean age 40.2 +/- 8.1 yr) with neurologic and neuropsychological disorders associated with long-term idiopathic arterial hypotension (IAH) were studied to estimate the state of their central blood circulation. Neuropsychological conditions were estimated from the state of higher psychic functions, such as memory speech, gnosis, praxis, cognition, attention, counting, writing, and reading abilities. Central hemodynamics was studied by 24 hr monitoring arterial pressure and echocardiography. Group 1 included patients without neurologic problems (n = 19), group 2 consisted of patients with early manifestations of chronic cerebrovascular insufficiency (n = 46, 71%). They were older than patients of group 1 and had a long history of IAH. It was shown that most patients presented with stably reduced systolic and diastolic AP and non-dipper type of low 24-hour SAD index. The cardiac index was elevated due to increased left ventricular ejection fraction (group 1) or increased heart rate (group 2). The severity of neuropsychic disorder was negatively related to SAD and DAD indices and positively to systolic hypotension time. PMID:23516869

  4. Preoperative ephedrine counters hypotension with propofol anesthesia during valve surgery: a dose dependent study.

    PubMed

    El-Tahan, Mohamed R

    2011-01-01

    The prophylactic use of small doses of ephedrine may counter the hypotension response to propofol anesthesia with minimal hemodynamic changes. One hundred-fifty patients scheduled for valve surgery were randomly assigned into five groups (n = 30 for each) to receive saline, 0.07, 0.1, or 0.15 mg/kg of ephedrine, or phenylephrine 1.5 μg/kg before induction of propofol-fentanyl anesthesia. After induction, patient receiving ephedrine had higher mean arterial pressure, systemic vascular resistance (SVRI), cardiac (CI), stroke volume (SVI), and left ventricular stroke work (LVSWI) indices. Patients received 0.15 mg/kg of ephedrine showed additional increased heart rate and frequent ischemic episodes (P < 0.001). However, those who received phenylephrine showed greater rise in SVRI, reduced CI, SVI, and LVSWI and more frequent ischemic episodes. We conclude that the prophylactic use of small doses of ephedrine (0.07-0.1 mg/kg) is safe and effective in the counteracting propofol-induced hypotension during anesthesia for valve surgery.

  5. Arterial baroreflex control of sympathetic nerve activity during acute hypotension: effect of fitness.

    PubMed

    Fadel, P J; Stromstad, M; Hansen, J; Sander, M; Horn, K; Ogoh, S; Smith, M L; Secher, N H; Raven, P B

    2001-06-01

    We examined arterial baroreflex control of muscle sympathetic nerve activity (MSNA) during abrupt decreases in mean arterial pressure (MAP) and evaluated whether endurance training alters baroreflex function. Acute hypotension was induced nonpharmacologically in 14 healthy subjects, of which 7 were of high fitness (HF) and 7 were of average fitness (AF), by releasing a unilateral arterial thigh cuff after 9 min of resting ischemia under two conditions: control, which used aortic and carotid baroreflex (ABR and CBR, respectively) deactivation; and suction, which used ABR deactivation alone. The application of neck suction to counteract changes in carotid sinus transmural pressure during cuff release significantly attenuated the MSNA response (which increased 134 +/- 32 U/14 s) compared with control (which increased 195 +/- 43 U/14 s) and caused a greater decrease in MAP (19 +/- 2 vs. 15 +/- 2 mmHg; P < 0.05). Furthermore, during both trials, the HF subjects exhibited a greater decrease in MAP compared with AF subjects despite an augmented baroreflex control of MSNA. These data indicate that the CBR contributes importantly to the MSNA response during acute systemic hypotension. Additionally, we suggest that an impaired control of vascular reactivity hinders blood pressure regulation in HF subjects. PMID:11356607

  6. Phenylephrine infusion for spinal-induced hypotension in elective cesarean delivery: Does preload make a difference?

    PubMed Central

    Bottiger, Brandi A; Bezinover, Dmitri S; Mets, Berend; Dalal, Priti G; Prozesky, Jansie; Ural, Serdar; Vaida, Sonia

    2016-01-01

    Background and Aims: Patients undergoing elective cesarean delivery (CD) have a high-risk of spinal-induced hypotension (SIH). We hypothesized that a colloid preload would further reduce SIH when compared with a crystalloid preload. Material and Methods: Eighty-two healthy parturients undergoing elective CD were included in the study. Patients were randomly assigned to two groups (41 patients in each group) to receive either Lactated Ringer's solution (1500 ml) or hydroxyethyl starch (6% in normal saline, 500 ml) 30 min prior to placement of spinal anesthesia. All patients were treated with a phenylephrine infusion (100 mcg/min), titrated during the study. Results: There was no statistical difference between groups with regards to the incidence of hypotension (10.8% in the colloid group vs. 27.0% in the crystalloid group, P = 0.12). There was also no difference between groups with respect to bradycardia, APGAR scores, and nausea and vomiting. Significantly less phenylephrine (1077.5 ± 514 mcg) was used in the colloid group than the crystalloid group (1477 ± 591 mcg, P = 0.003). Conclusion: The preload with 6% of hydroxyethyl starch before CD might be beneficial for the prevention of SIH.

  7. Refractory Hypotension as an Initial Presentation of Bilateral Subclavian Artery Stenosis

    PubMed Central

    Wylie, John V.; Carrozza, Joseph P.

    2016-01-01

    Bilateral subclavian stenosis is a rare clinical condition. An interbrachial pressure difference of 15 mm Hg can raise suspicion for unilateral subclavian artery stenosis, but the diagnosis of bilateral subclavian artery stenosis can be challenging. We present a case of a 75-year-old woman who presented with refractory hypotension after surgery. Initial vitals revealed blood pressure in the 60s/50s mm Hg in both arms. Cardiopulmonary examination was remarkable for diminished pulses in all 4 extremities and audible carotid bruits. She continued to be hypotensive despite aggressive fluid resuscitation. Troponin T peaked at 0.24 ng/mL (reference < 0.04), and an echocardiogram revealed a reduction in ejection fraction (37% from 50%). Left and right heart catheterization demonstrated normal filling pressures and cardiac output. During the procedure, however, it was noted that the patient's central blood pressure was 70–80 mm Hg higher than cuff pressures obtained in either arm. Selective angiography revealed 90% left subclavian ostial stenosis as well as 70% stenosis of the right subclavian artery. PMID:27547473

  8. Alkaloids in Erythrina by UPLC-ESI-MS and In Vivo Hypotensive Potential of Extractive Preparations

    PubMed Central

    Merlugo, Liara; Santos, Marí C.; Sant'Anna, Liane S.; Cordeiro, Everson W. F.; Batista, Luiz A. C.; Miotto, Silvia T. S.; Garcia, Cássia V.; Moreira, Cleci M.; Mendez, Andreas S. L.

    2015-01-01

    Erythrina species are used in popular medicine as sedative, anxiolytic, anti-inflammatory, and antihypertensive. In this work, we investigated the chemical composition of extracts obtained from leaves of E. falcata and E. crista-galli. The hypotensive potential of E. falcata and the mechanism of action were also studied. The extracts were obtained by maceration and infusion. The total content of phenolic compounds and flavonoids was estimated by spectrophotometric methods. The chemical constituents were studied performing a chromatographic analysis by UPLC-ESI-MS. For in vivo protocols, blood pressure and heart rate were measured by the invasive hemodynamic monitoring method. Different concentrations of extracts and drugs such as L-NAME, losartan, hexamethonium, and propranolol were administrated i.v. The results of total phenolic contents for E. falcata and E. crista-galli were 1.3193–1.4989 mgGAE/mL for maceration and 0.8771–0.9506 mgGAE/mL for infusion. In total flavonoids, the content was 7.7829–8.1976 mg RE/g for maceration and 9.3471–10.4765 RE mg/g for infusion. The chemical composition was based on alkaloids, suggesting the presence of erythristemine, 11β-methoxyglucoerysodine, erysothiopine, 11β-hydroxyerysodine-glucose, and 11-hydroxyerysotinone-rhamnoside. A potent dose-dependent hypotensive effect was observed for E. falcata, which may be related to the route of β-adrenergic receptors. PMID:26356581

  9. Refractory Hypotension as an Initial Presentation of Bilateral Subclavian Artery Stenosis.

    PubMed

    Afari, Maxwell Eyram; Wylie, John V; Carrozza, Joseph P

    2016-01-01

    Bilateral subclavian stenosis is a rare clinical condition. An interbrachial pressure difference of 15 mm Hg can raise suspicion for unilateral subclavian artery stenosis, but the diagnosis of bilateral subclavian artery stenosis can be challenging. We present a case of a 75-year-old woman who presented with refractory hypotension after surgery. Initial vitals revealed blood pressure in the 60s/50s mm Hg in both arms. Cardiopulmonary examination was remarkable for diminished pulses in all 4 extremities and audible carotid bruits. She continued to be hypotensive despite aggressive fluid resuscitation. Troponin T peaked at 0.24 ng/mL (reference < 0.04), and an echocardiogram revealed a reduction in ejection fraction (37% from 50%). Left and right heart catheterization demonstrated normal filling pressures and cardiac output. During the procedure, however, it was noted that the patient's central blood pressure was 70-80 mm Hg higher than cuff pressures obtained in either arm. Selective angiography revealed 90% left subclavian ostial stenosis as well as 70% stenosis of the right subclavian artery. PMID:27547473

  10. An Abdominal CT may be Safe in Selected Hypotensive Trauma Patients with Positive FAST Exam

    PubMed Central

    Cook, Mackenzie R.; Holcomb, John B.; Rahbar, Mohammad H.; Alarcon, Louis H.; Bulger, Eileen M.; Brasel, Karen J.; Schreiber, Martin A.

    2016-01-01

    Background Positive Focused Assessment with Sonography in Trauma (FAST) and hypotension often indicates urgent surgery. An abdomen/pelvis CT (apCT) may allow less invasive management but the delay may be associated with adverse outcomes. Methods Patients in the Prospective Observational Multicenter Major Trauma Transfusion study with hypotension and a positive FAST (HF+) who underwent a CT (apCT+) were compared to those who did not. Results Of the 92 HF+ identified, 32(35%) underwent apCT during initial evaluation and apCT was associated with decreased odds of an emergency operation, OR 0.11 95% CI (0.001–0.116) and increased odds of angiographic intervention, OR 14.3 95% CI (1.5–135). There was no significant difference in 30 day mortality or need for dialysis. Conclusion An apCt in HF+ patients is associated with reduced odds of emergency surgery, but not mortality. Select HF+ patients can safely undergo apCT to obtain clinically useful information. PMID:25805456

  11. Impact of intraoperative hypotension and blood pressure fluctuations on early postoperative delirium after non-cardiac surgery†‡

    PubMed Central

    Hirsch, J.; DePalma, G.; Tsai, T. T.; Sands, L. P.; Leung, J. M.

    2015-01-01

    Introduction Postoperative delirium is common in older patients. Despite its prognostic significance, the pathophysiology is incompletely understood. Although many risk factors have been identified, no reversible factors, particularly ones potentially modifiable by anaesthetic management, have been identified. The goal of this prospective cohort study was to investigate whether intraoperative hypotension was associated with postoperative delirium in older patients undergoing major non-cardiac surgery. Methods Study subjects were patients >65 years of age, undergoing major non-cardiac surgery, who were enrolled in an ongoing prospective observational study of the pathophysiology of postoperative delirium. Intraoperative blood pressure was measured and predefined criteria were used to define hypotension. Delirium was measured by the Confusion Assessment Method on the first two postoperative days. Data were analysed using t-tests, two-sample proportion tests and ordered logistic regression multivariable models, including correction for multiple comparisons. Results Data from 594 patients with a mean age of 73.6 years (sd 6.2) were studied. Of these 178 (30%) developed delirium on day 1 and 176 (30%) on day 2. Patients developing delirium were older, more often female, had lower preoperative cognitive scores, and underwent longer operations. Relative hypotension (decreases by 20, 30, or 40%) or absolute hypotension [mean arterial pressure (MAP)<50 mm Hg] were not significantly associated with postoperative delirium, nor was the duration of hypotension (MAP<50 mm Hg). Conversely, intraoperative blood pressure variance was significantly associated with postoperative delirium. Discussion These results showed that increased blood pressure fluctuation, not absolute or relative hypotension, was predictive of postoperative delirium. PMID:25616677

  12. Prevention of hypotension induced by combined spinal epidural anesthesia using continuous infusion of vasopressin: A randomized trial

    PubMed Central

    Shamshery, Chetna; Kannaujia, Ashish; Madabushi, Rajashree; Singh, Dinesh; Srivastava, Divya; Jafa, Shobhana

    2016-01-01

    Background: Central neuraxial blockade (CNB) is an established technique of providing anesthesia for surgeries of the lower limb and abdomen. Hypotension is the most common side effect of CNB. It was hypothesized that by supplementing the initial burst of vasopressin following hypovolemia, hypotension following combined spinal epidural anesthesia (CSEA) could be avoided. Materials and Methods: A total of 122 patients undergoing lower limb and abdomen surgeries were included in the study, with 61 patients randomized into two groups - I and II. Patients in Group I received infusion of normal saline as soon as CSEA was applied. When systolic blood pressure (SBP) decreased to <90 mmHg, they received a 6 mg bolus of mephentermine to counteract hypotension. Patients in Group II received a continuous infusion of vasopressin as soon as CSEA was applied. If despite maximum dose of vasopressin, SBP dropped to < 90 mmHg, then intravenous mephentermine was administered to counteract hypotension. Hemodynamic parameters and side effects were noted. Results: Level of block attained in both groups was comparable in terms of dermatomal height. The mean SBP and mean arterial pressure values of Group I were significantly lower than in Group II in the initial 14 min. Diastolic BP was also significantly lower in Group I. Heart rate was found to be lower in Group II, especially after 30 min (P < 0.05). Conclusion: Maintaining plasma levels of the physiological burst of vasopressin helps to avoid hypotension following neuraxial blockade. Continuous infusion of vasopressin at 1–3 U/h can prevent hypotension following neuraxial blockade. PMID:27746553

  13. 19 CFR 18.27 - Port marks.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Port marks. 18.27 Section 18.27 Customs Duties U.S... Port marks. Port marks may be added by authority of the port director and under the supervision of a Customs officer. The original marks and the port marks shall appear in all papers pertaining to...

  14. 19 CFR 18.27 - Port marks.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Port marks. 18.27 Section 18.27 Customs Duties U.S... Port marks. Port marks may be added by authority of the port director and under the supervision of a Customs officer. The original marks and the port marks shall appear in all papers pertaining to...

  15. Marking Errors: A Simple Strategy

    ERIC Educational Resources Information Center

    Timmons, Theresa Cullen

    1987-01-01

    Indicates that using highlighters to mark errors produced a 76% class improvement in removing comma errors and a 95.5% improvement in removing apostrophe errors. Outlines two teaching procedures, to be followed before introducing this tool to the class, that enable students to remove errors at this effective rate. (JD)

  16. Early-Modern "Speech" Marks

    ERIC Educational Resources Information Center

    Blackburn, Nick

    2011-01-01

    This essay presents a revised history of the punctuation mark ["], drawn from the earliest communities who made it their own. By situating the development of ["] in its historical context, from first uses of the diple [diple] by the Greek scholar Aristarchus, it explains how it was the general applications which persisted into the sixteenth…

  17. EP Profiles Inventor Mark Sherron

    ERIC Educational Resources Information Center

    Williams, John M.

    2006-01-01

    This article profiles Mark Jerome Sherron, inventor of the ALLIES Line of electronic sensors for blind and visually-impaired people. Featuring the American Liquid Level Indicator electronic sensor (ALLI), Sherron's ALLIES product line also includes the Light Intensity Level Indicator (LILI), a multi-function electronic light sensor for electronic…

  18. 40 CFR 761.40 - Marking requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... dielectric fluid with a PCB concentration of ≥500 ppm must be marked individually with the ML mark as... of dielectric fluid with a PCB concentration of ≥500 ppm shall be marked as follows: The vault...

  19. 40 CFR 761.40 - Marking requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... dielectric fluid with a PCB concentration of ≥ 500 ppm must be marked individually with the ML mark as... of dielectric fluid with a PCB concentration of ≥ 500 ppm shall be marked as follows: The vault...

  20. 40 CFR 761.40 - Marking requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... dielectric fluid with a PCB concentration of ≥ 500 ppm must be marked individually with the ML mark as... of dielectric fluid with a PCB concentration of ≥ 500 ppm shall be marked as follows: The vault...

  1. 40 CFR 761.40 - Marking requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... dielectric fluid with a PCB concentration of ≥ 500 ppm must be marked individually with the ML mark as... of dielectric fluid with a PCB concentration of ≥ 500 ppm shall be marked as follows: The vault...

  2. 40 CFR 761.40 - Marking requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... dielectric fluid with a PCB concentration of ≥ 500 ppm must be marked individually with the ML mark as... of dielectric fluid with a PCB concentration of ≥ 500 ppm shall be marked as follows: The vault...

  3. 46 CFR 164.023-15 - Marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... permanently and clearly marked in a color which contrasts with the color of the surface on which the marking is applied. Each label must be marked with— (1) The manufacturer's or supplier's name, trade name,...

  4. Sonography and hypotension: a change to critical problem solving in undergraduate medical education

    PubMed Central

    Amini, Richard; Stolz, Lori A; Hernandez, Nicholas C; Gaskin, Kevin; Baker, Nicola; Sanders, Arthur Barry; Adhikari, Srikar

    2016-01-01

    Study objectives Multiple curricula have been designed to teach medical students the basics of ultrasound; however, few focus on critical problem-solving. The objective of this study is to determine whether a theme-based ultrasound teaching session, dedicated to the use of ultrasound in the management of the hypotensive patient, can impact medical students’ ultrasound education and provide critical problem-solving exercises. Methods This was a cross-sectional study using an innovative approach to train 3rd year medical students during a 1-day ultrasound training session. The students received a 1-hour didactic session on basic ultrasound physics and knobology and were also provided with YouTube hyperlinks, and links to smart phone educational applications, which demonstrated a variety of bedside ultrasound techniques. In small group sessions, students learned how to evaluate patients for pathology associated with hypotension. A knowledge assessment questionnaire was administered at the end of the session and again 3 months later. Student knowledge was also assessed using different clinical scenarios with multiple-choice questions. Results One hundred and three 3rd year medical students participated in this study. Appropriate type of ultrasound was selected and accurate diagnosis was made in different hypotension clinical scenarios: pulmonary embolism, 81% (95% CI, 73%–89%); abdominal aortic aneurysm, 100%; and pneumothorax, 89% (95% CI, 82%–95%). The average confidence level in performing ultrasound-guided central line placement was 7/10, focused assessment with sonography for trauma was 8/10, inferior vena cava assessment was 8/10, evaluation for abdominal aortic aneurysm was 8/10, assessment for deep vein thrombus was 8/10, and cardiac ultrasound for contractility and overall function was 7/10. Student performance in the knowledge assessment portion of the questionnaire was an average of 74% (SD =11%) at the end of workshop and 74% (SD =12%) 3 months later

  5. The contribution of genetic and environmental factors to quantitative variability of erythrocyte membrane proteins in primary hypotension.

    PubMed

    Ivanov, V P; Polonikov, A V; Solodilova, M A

    2005-01-01

    Our previous studies have shown that, compared with healthy individuals, patients with primary arterial hypotension (PAH) have significant quantitative changes in erythrocyte membrane proteins. The purpose of the present study was to evaluate the contribution made by genetic and environmental factors to quantitative variation of erythrocyte membrane proteins in PAH. We studied 109 hypotensive patients, 124 normotensive subjects, 222 of their first-degree relatives and 24 twin pairs by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis. The decomposition of total phenotypic variance of erythrocyte membrane proteins to genetic and environmental components was performed on the basis of correlations among first-degree relatives by the least squares method. The genetic dominance and shared environmental factors were found to influence the variability of cytoskeletal membrane proteins whose contents were changed in PAH. Furthermore, variations in alpha-spectrin, actin and anion exchanger in hypotensives were substantially influenced by major gene and maternal effects. Ankyrin 2.1 and actin content was under the control of common underlying genes. Variations in membrane-associated glutathione-S-transferase and tropomyosin were predominantly affected by polygenes. These findings suggest that the putative major genes with pleiotropic effects appear to be involved in the control of quantitative disorders of erythrocyte membrane proteins in primary hypotension. PMID:15638825

  6. Carotid-cardiac baroreflex: Relation with orthostatic hypotension following simulated microgravity and implications for development of countermeasures

    NASA Technical Reports Server (NTRS)

    Convertino, Victor A.

    1991-01-01

    In a series of studies, we have examined the effects of exposure to simulated microgravity, varying states of vascular volume, and acute exercise on the function of the carotid-cardiac baroreflex in man. In the first study, exposure to simulated microgravity (6 degree headdown bedrest) reduced the sensitivity and buffer capacity of the vagal baroreceptor-cardiac reflex mechanisms and this impaired baroreflex function was associated with orthostatic hypotension. Since the reduction in plasma volume during BR was not correlated with impaired baroreflex function, a second study was conducted which demonstrated that the carotid-cardiac baroreflex response was not affected by either acute hypovolemia or hypervolemia. These results suggest that acute fluid replacement prior to reentry may not reverse impaired baroreflex function associated with postflight hypotension. In a third study, we demonstrated that one bout of maximal exercise increased baroreflex sensitivity and buffer capacity through 24 h post-exercise. These baroreflex changes were opposite to those observed following BR. Taken together, these data suggest that the contributions of reduced blood volume and impaired carotid-cardiac baroreflex function to orthostatic hypotension following exposure to microgravity are probably separate and additive; maximal exercise in addition to fluid replacement may provide an acute effective countermeasure against postflight hypotension.

  7. Carotid-cardiac baroreflex: Relation with orthostatic hypotension following simulated microgravity and implications for development of countermeasures

    NASA Astrophysics Data System (ADS)

    Convertino, Victor A.

    In a series of studies, we have examined the effects of exposure to simulated microgravity, varying states of vascular volume, and acute exercise on the function of the carotid-cardiac baroreflex in man. In the first study, exposure to simulated microgravity (6° headdown bedrest) reduced the sensitivity and buffer capacity of the vagal baroreceptor-cardiac reflex mechanisms and this impaired baroreflex function was associated with orthostatic hypotension. Since the reduction in plasma volume during BR was not correlated with impaired baroreflex function, a second study was conducted which demonstrated that the carotid-cardiac baroreflex response was not affected by either acute hypovolemia or hypervolemia. These results suggest that acute fluid replacement prior to reentry may not reverse impaired baroreflex function associated with postflight hypotension. In a third study, we demonstrated that one bout of maximal exercise increased baroreflex sensitivity and buffer capacity through 24 h post-exercise. These baroreflex changes were opposite to those observed following BR. Taken together, these data suggest that the contributions of reduced blood volume and impaired carotid-cardiac baroreflex function to orthostatic hypotension following exposure to microgravity are probably separate and additive; maximal exercise in addition to fluid replacement may provide an acute effective countermeasure against postflight hypotension.

  8. Permissive hypotension does not reduce regional organ perfusion compared to normotensive resuscitation: animal study with fluorescent microspheres

    PubMed Central

    2012-01-01

    Introduction The objective of this study was to investigate regional organ perfusion acutely following uncontrolled hemorrhage in an animal model that simulates a penetrating vascular injury and accounts for prehospital times in urban trauma. We set forth to determine if hypotensive resuscitation (permissive hypotension) would result in equivalent organ perfusion compared to normotensive resuscitation. Methods Twenty four (n=24) male rats randomized to 4 groups: Sham, No Fluid (NF), Permissive Hypotension (PH) (60% of baseline mean arterial pressure - MAP), Normotensive Resuscitation (NBP). Uncontrolled hemorrhage caused by a standardised injury to the abdominal aorta; MAP was monitored continuously and lactated Ringer’s was infused. Fluorimeter readings of regional blood flow of the brain, heart, lung, kidney, liver, and bowel were obtained at baseline and 85 minutes after hemorrhage, as well as, cardiac output, lactic acid, and laboratory tests; intra-abdominal blood loss was assessed. Analysis of variance was used for comparison. Results Intra-abdominal blood loss was higher in NBP group, as well as, lower hematocrit and hemoglobin levels. No statistical differences in perfusion of any organ between PH and NBP groups. No statistical difference in cardiac output between PH and NBP groups, as well as, in lactic acid levels between PH and NBP. NF group had significantly higher lactic acidosis and had significantly lower organ perfusion. Conclusions Hypotensive resuscitation causes less intra-abdominal bleeding than normotensive resuscitation and concurrently maintains equivalent organ perfusion. No fluid resuscitation reduces intra-abdominal bleeding but also significantly reduces organ perfusion. PMID:23531188

  9. The C-1021T polymorphism of dopamine β-hydroxylase is not associated with orthostatic hypotension in a Chinese population.

    PubMed

    Lu, N; Chen, J; Yuan, Y; Cong, X; Yang, Y; Meng, L; Sun, K; Hui, R; Zheng, Y

    2015-03-01

    To explore the association between the dopamine β-hydroxylase (DBH) gene C-1021T polymorphism and the occurrence of orthostatic hypotension (OH) in Chinese patients, the DBH C-1021T polymorphism was genotyped in 317 patients with OH and 664 age- and sex-matched controls with orthostatic normotension. All subjects underwent an upright posture study for the measurement of orthostatic blood pressure. OH was defined as a drop in blood pressure of 20/10 mm Hg or more within 3 min of assuming the upright posture. The allele frequency of the DBH C-1021T polymorphism in the orthostatic hypotensive group was similar to the orthostatic normotensive group (17.4 versus 14.9%, P>0.05). No statistical significant association was found between the distribution of the C-1021T genotypes and the risk of OH in both the orthostatic hypotensive and orthostatic normotensive groups even after adjustment for demographic parameters. Among the three different genotypes, blood pressure levels did not significantly differ in the general population in this study. The changes in orthostatic systolic or diastolic blood pressures among the different genotype groups were not detected (all P>0.05). The C-1021T polymorphism of the DBH was not associated with orthostatic hypotensive risk in a Chinese population. PMID:24990418

  10. Involvement of the histaminergic system in cytidine 5'-diphosphocholine-induced reversal of critical haemorrhagic hypotension in rats.

    PubMed

    Jochem, J; Savci, V; Filiz, N; Rybus-Kalinowska, B; Fogel, W A; Yalcin, M

    2010-02-01

    Cytidine 5'-diphosphocholine (CDP-choline) is an endogenously synthesized mononucleotide which exerts a variety of physiological effects by altering central cholinergic transmission. Administered intracerebroventricularly (i.c.v.) or intravenously, it reverses haemorrhagic hypotension in rats, apparently by the activation of central cholinergic receptors. The study was undertaken to investigate the involvement of the central histaminergic system in CDP-choline-mediated reversal of haemorrhagic hypotension. Experiments were carried out in male ketamine/xylazine-anaesthetised Wistar rats subjected to haemorrhagic hypotension of 20-26 mmHg. CDP-choline (2 micromol; i.c.v.) administered at 5 min of critical hypotension produced a long-lasting pressor effect with increases in mean arterial pressure (MAP), heart rate (HR), and renal, hindquarters and mesenteric blood flows, resulting in a 100% survival at 2 h. The action was accompanied by approximately a 26% increase in extracellular histamine concentration at the posterior hypothalamus, as measured by microdialysis. Cardiovascular effects mediated by CDP-choline were almost completely blocked by pretreatment with H(1) receptor antagonist chlorpheniramine (50 nmol; i.c.v.), but not with H(2) receptor blocker ranitidine (25 nmol; icv) or H(3)/H(4) receptor antagonist thioperamide (50 nmol; i.c.v.). In conclusion, the present results show that he central histaminergic system, through the activation of H(1) histaminergic receptors, is involved in CDP-choline-induced resuscitating effect in haemorrhage-shocked rats.

  11. Idiopathic orthostatic hypotension: Recent data (eleven cases) and review of the literature

    NASA Technical Reports Server (NTRS)

    Ninet, J.; Annat, G.; Boisson, D.; Holzhapfel, L.; Vincent, M.; Peyrin, L.; Michel, D.; Schott, B.; Devic, M.; Levrat, R.

    1981-01-01

    Eight cases of Shy-Drager syndrome and three of Bradbury-Eggleston idiopathic orthostatic hypotension were examined. In all cases, examination of circulatory reflexes showed major dysfunction of the sympathetic vasoconstrictor system. Anomalies in the vagal cardiomoderator system were less constant. Normal urinary elimination of catecholamines was recorded daily. Characteristically, no elevation of blood or urine norepinephrine levels were found in orthostatism. Insulin hypoglycemia normally raised urinary adrenalin elimination in three of ten patients. Plasma dopa-beta-hydroxylase activity was normal. Renin-angiotensin-aldosterone system showed variable activity at basal state but usually rose during orthostatism. On the average, very low homovanillic acid levels were found in cerebrospinal fluid before and after probenecid; hydroxyindolacetic acid was normal. Cerebral autoregulation had deteriorated in two of four cases. Physiopathologically the two clinical types are indistinguishable with or without central neurological signs.

  12. Megaloblastic anemia with hypotension and transient delirium as the primary symptoms: report of a case.

    PubMed

    Zhang, Qin; Lv, Xue-Ying; Yang, Yun-Mei

    2015-01-01

    The present study describes a case of an elderly patient that was hospitalized secondary to hypotension and delirium. Physical examination at admission revealed bilateral positive Babinski's sign. Laboratory examination revealed severe anemia. Bone marrow examination showed megaloblastic changes of the granulocyte and erythroid series, as well as other dyshaematopoiesis. The conditions of the patient rapidly improved after vitamin B12 treatments. Because the clinical manifestations of megaloblastic anemia are complex, this disease is often misdiagnosed in the geriatric population. Bone marrow examinations can aid in the diagnosis of anemia, but the results from these tests cannot always differentiate the type of anemia. Clinical management of the disorder is reliant upon proper classification of the type of anemia. The prognosis of megaloblastic anemia is typically good and a simple regimen of folic acid and/or vitamin B12 is effective. PMID:26770511

  13. [Sensitization of bradycardia during final hypotension induced by serotonin in rats: effect of lidocaine].

    PubMed

    Valle, L B; Oliveira-Filho, R M; Armonia, P L; Nassif, M; Saraceni, G

    1975-10-01

    It was studied the sensibilizing effect of lidocaine (8.5 mg/kg, i.v.) on the ECG (heart rate, P-R interval, QRS complex and Q-T interval) of both intact and bilaterally vagotomised rats, in the nadir of the final hypotension determined by serotonine (60 mug/kg, i.v.). The results showed (1) a certain degree of selectivity of the vagi, and (2) the effects of serotonine either isolated or associated to lidocaine on P-R interval and heart rate were reinforced when intact animals were used. Although no significant alterations of Q-T were elicited by the drugs, lidocaine surprisingly enlarged the QRS complex in a more significant fashion for the intact than for the vagotomised animals.

  14. Cactus alkaloids. XLVII. N alpha-dimethylhistamine, a hypotensive component of Echinocereus triglochidiatus.

    PubMed

    Ferrigni, N R; Nichols, D E; McLaughlin, J L; Bye, R A

    1982-05-01

    Echinocereus triglochidiatus Engelm. var. neomexicanus (Standley) Standley ex W. T. Marshall is believed to cause psychotropic effects when consumed by the Mexican Tarahumara Indians. A phytochemical study was initiated with E. triglochidiatus Engelm. var. paucispinus Engelm. ex W. T. Marshall, which is more abundant in Texas. In the fractionated extracts three compounds, detected by thin-layer chromatography, were positive to Ehrlich's reagent, indicating the possible presence of indole alkaloids; however, a non-Erhlich positive alkaloid was crystallized as the dihydrochloride and subsequently identified (spectrometrically and via synthesis as N alpha, N alpha-dimethylhistamine dihydrochloride. The same compound was then detected chromatographically in the neomexicanus variety. This compound has peripheral hypotensive effects similar to histamine, and this action may help to explain the alleged psychotrophic effects of the cactus.

  15. Differences in motor and cognitive function in patients with Parkinson's disease with and without orthostatic hypotension.

    PubMed

    Hohler, Anna D; Zuzuárregui, José-Rafael P; Katz, Douglas I; Depiero, T Joy; Hehl, Christina L; Leonard, Alissa; Allen, Valerie; Dentino, Jill; Gardner, Maura; Phenix, Heidi; Saint-Hilaire, Marie; Ellis, Terry

    2012-05-01

    Patients with Parkinson's disease (PD) often present with orthostatic hypotension (OH) as a result of the dysautonomia associated with the disease or as a side effect of the dopaminergic medications used to treat the disease. The purpose of this study was to investigate differences in motor and cognitive function in patients with PD with and without OH. Forty-four patients with a diagnosis of PD were evaluated and stratified by the presence of OH based on orthostatic blood pressure recordings. Both groups underwent assessments of motor and cognitive function. OH was present in 17 of 44 patients (39%) with PD. These patients with OH had significantly lower scores in gross motor, balance, and cognitive function (p < .05). No significant difference between groups was found in the finger tapping scores. These results suggest that patients with PD should be routinely screened for OH as it commonly occurs and may negatively impact gross motor, balance, and cognitive function. PMID:22191544

  16. Caffeine ingestion and intense resistance training minimize postexercise hypotension in normotensive and prehypertensive men.

    PubMed

    Astorino, Todd Anthony; Martin, Brian J; Schachtsiek, Lena; Wong, Keau

    2013-01-01

    The primary aim of the study was to compare changes in blood pressure (BP) in normotensive and prehypertensive men completing resistance exercise following caffeine ingestion. Normotensive (n = 7) and hypertensive men (n = 7) ingested caffeine (6 mg x kg(-1)) or placebo 1 h preexercise, then completed four sets of bench press, leg press, lat pull-down, and shoulder press at 70%-80% one repetition maximum (1-RM). Heart rate (HR) and BP were measured preexercise, during exercise, and for 75 min postexercise. Caffeine increased (p < 0.05) resting, exercise, and recovery systolic BP, yet had no effect on HR (p = 0.16) or diastolic BP (p = 0.10). HR and BP were significantly higher (p < 0.05) in prehypertensive men versus normotensives. Postexercise hypotension did not occur in either treatment, suggesting that intense resistance training with or without caffeine intake may mitigate the BP-lowering effect of resistance exercise. PMID:23286422

  17. Hypotensive and toxicological study of citric acid and other constituents from Tagetes patula roots.

    PubMed

    Saleem, Rubeena; Ahmad, Mohammad; Naz, Aneela; Siddiqui, Humaira; Ahmad, Syed Iqbal; Faizi, Shaheen

    2004-10-01

    Study of the effects of the methanolic extract of Tagetes patula roots on blood pressure led to the isolation of well known citric (1) and malic acid (7) as hypotensive, and pyridine hydrochloride (4) as hypertensive constituents of the plant along with a new constituent, 2-hydroxy, 5-hydroxymethyl furan (9). Citric acid and malic acid caused 71% and 43% fall in Mean Arterial Blood Pressure (MABP) of rats at the doses of 15 mg/kg and 30 mg/kg respectively while pyridine hydrochloride produced 34% rise in the MABP of rats at the dose of 30 mg/kg. LD50 and LD100 of citric acid in mice have been determined as 545 mg/kg and 1000 mg/kg, respectively.

  18. Successful steroid treatment of coma induced by severe spontaneous intracranial hypotension

    PubMed Central

    Goto, Shunsaku; Ohshima, Tomotaka; Yamamoto, Taiki; Shimato, Shinji; Nishizawa, Toshihisa; Kato, Kyozo

    2016-01-01

    ABSTRACT Spontaneous intracranial hypotension (SIH) is a syndrome characterized by low cerebrospinal fluid (CSF) pressure and postural headaches. It is a rare condition which may sometimes present with severe symptoms such as stupor or coma. The standard treatment protocol includes conservative measures such as bed rest, hydration, and steroids. However, severe cases may require invasive measures such as epidural blood patch (EBP), continuous epidural saline infusion, epidural fibrin glue, or surgical repair of the dural defect. In this report, we describe a case of severe SIH resulting in coma that exhibited dramatic improvement on intravenous administration of steroids. This is the first report of severe SIH causing coma that was treated non-invasively by steroids only. PMID:27303109

  19. Successful steroid treatment of coma induced by severe spontaneous intracranial hypotension.

    PubMed

    Goto, Shunsaku; Ohshima, Tomotaka; Yamamoto, Taiki; Shimato, Shinji; Nishizawa, Toshihisa; Kato, Kyozo

    2016-05-01

    Spontaneous intracranial hypotension (SIH) is a syndrome characterized by low cerebrospinal fluid (CSF) pressure and postural headaches. It is a rare condition which may sometimes present with severe symptoms such as stupor or coma. The standard treatment protocol includes conservative measures such as bed rest, hydration, and steroids. However, severe cases may require invasive measures such as epidural blood patch (EBP), continuous epidural saline infusion, epidural fibrin glue, or surgical repair of the dural defect. In this report, we describe a case of severe SIH resulting in coma that exhibited dramatic improvement on intravenous administration of steroids. This is the first report of severe SIH causing coma that was treated non-invasively by steroids only. PMID:27303109

  20. Caffeine ingestion and intense resistance training minimize postexercise hypotension in normotensive and prehypertensive men.

    PubMed

    Astorino, Todd Anthony; Martin, Brian J; Schachtsiek, Lena; Wong, Keau

    2013-01-01

    The primary aim of the study was to compare changes in blood pressure (BP) in normotensive and prehypertensive men completing resistance exercise following caffeine ingestion. Normotensive (n = 7) and hypertensive men (n = 7) ingested caffeine (6 mg x kg(-1)) or placebo 1 h preexercise, then completed four sets of bench press, leg press, lat pull-down, and shoulder press at 70%-80% one repetition maximum (1-RM). Heart rate (HR) and BP were measured preexercise, during exercise, and for 75 min postexercise. Caffeine increased (p < 0.05) resting, exercise, and recovery systolic BP, yet had no effect on HR (p = 0.16) or diastolic BP (p = 0.10). HR and BP were significantly higher (p < 0.05) in prehypertensive men versus normotensives. Postexercise hypotension did not occur in either treatment, suggesting that intense resistance training with or without caffeine intake may mitigate the BP-lowering effect of resistance exercise.

  1. [Headhache secondary to intracranial hypotension in a Lumbar Spinal Stenosis Surgery].

    PubMed

    Hidalgo-Mendía, Begoña; Angulo-Taberno, Marina; Jaroid-Audes, Ricardo; Untoria-Agustín, Carmen; Rivero-Zelada, David

    2016-01-01

    Intracraneal hypotension headache is a well known syndrome in neurosurgery practice. In most cases cerebrospinal fluid leaks are caused by medical interventions, such as lumbar puncture, peridural anesthesia and surgical interventions on the spine. Clinical symptoms tipically show orthostatic headache that resolves in supine position, and other symptoms like neck tightness, vertigo and diplopia. RMI diagnostic confirms paquimeningeal enhancement and subdural hygromas. Conservative treatment usually includes bed resting, hydratation and administration of caffeine or glucocorticoids, resolving spontaneously in one to four months. The importance of the diagnosis lies in the differential diagnosis with other causes of headache, as symptomatic limiting factor in the rehabilitation of the patient and the same favorable prognosis. PMID:27420146

  2. Midodrine as a Countermeasure to Orthostatic Hypotension Immediately After Space Shuttle Landing

    NASA Technical Reports Server (NTRS)

    Platts, Steven H.; Stenger, Michael B.; Ribeiro, L. Christine; Lee, Stuart M. C.

    2010-01-01

    Midodrine prevents post-space flight orthostatic intolerance when testing is conducted in a controlled laboratory setting within 2-4 hours after Space Shuttle landing. It is unknown if midodrine is as effective during re-entry and immediately following landing. METHODS: Cardiovascular responses to 10 minutes of 80 head-up tilt in five male astronauts were compared before and immediately after Space Shuttle missions. Preflight tests were conducted in the Johnson Space Center Cardiovascular Laboratory without midodrine. Post-flight testing was performed in the Crew Transport Vehicle on the Space Shuttle runway within 60 minutes of landing; midodrine was self-administered before re-entry. Survival analysis was performed (Gehan-Breslow test) to compare presyncope rates pre- to post-flight. Cardiovascular responses (last minute standing minus supine) to tilt before and after space flight were compared using paired t-tests. RESULTS: Midodrine did not prevent post-flight orthostatic hypotension in two of the five astronauts, but the rate of presyncope across the group did not increase (p=0.17) from pre- to post-flight. Also, although the change in heart rate from supine to the last minute of standing was not affected by space flight, systolic blood pressure decreased more (p=0.05) and diastolic blood pressure tended to decrease (p=0.08) after space flight. CONCLUSIONS: Accurate interpretation of the current results requires that similar data be collected in control subjects (without midodrine) on the CTV. However, drug interaction concerns with commonly used anti-emetics and potentiation of prolonged QTc intervals observed in long duration astronauts make the routine use of midodrine for immediate post-flight orthostatic hypotension unlikely. 2

  3. 2-vessel occlusion/hypotension: a rat model of global brain ischemia.

    PubMed

    Sanderson, Thomas H; Wider, Joseph M

    2013-01-01

    Cardiac arrest followed by resuscitation often results in dramatic brain damage caused by ischemia and subsequent reperfusion of the brain. Global brain ischemia produces damage to specific brain regions shown to be highly sensitive to ischemia (1). Hippocampal neurons have higher sensitivity to ischemic insults compared to other cell populations, and specifically, the CA1 region of the hippocampus is particularly vulnerable to ischemia/reperfusion (2). The design of therapeutic interventions, or study of mechanisms involved in cerebral damage, requires a model that produces damage similar to the clinical condition and in a reproducible manner. Bilateral carotid vessel occlusion with hypotension (2VOH) is a model that produces reversible forebrain ischemia, emulating the cerebral events that can occur during cardiac arrest and resuscitation. We describe a model modified from Smith et al. (1984) (2), as first presented in its current form in Sanderson, et al. (2008) (3), which produces reproducible injury to selectively vulnerable brain regions (3-6). The reliability of this model is dictated by precise control of systemic blood pressure during applied hypotension, the duration of ischemia, close temperature control, a specific anesthesia regimen, and diligent post-operative care. An 8-minute ischemic insult produces cell death of CA1 hippocampal neurons that progresses over the course of 6 to 24 hr of reperfusion, while less vulnerable brain regions are spared. This progressive cell death is easily quantified after 7-14 days of reperfusion, as a near complete loss of CA1 neurons is evident at this time. In addition to this brain injury model, we present a method for CA1 damage quantification using a simple, yet thorough, methodology. Importantly, quantification can be accomplished using a simple camera-mounted microscope, and a free ImageJ (NIH) software plugin, obviating the need for cost-prohibitive stereology software programs and a motorized microscopic stage

  4. Renal responses of normal and preascitic broilers to systemic hypotension induced by unilateral pulmonary artery occlusion.

    PubMed

    Forman, M F; Wideman, R F

    1999-12-01

    During the pathophysiological progression of pulmonary hypertension syndrome (PHS; ascites), broilers concurrently develop systemic hypotension (low mean systemic arterial pressure) that may initiate renal retention of water and solute, contributing to fluid accumulation in the abdominal cavity (ascites). In male Single Comb White Leghorns, glomerular filtration is autoregulated over a systemic arterial pressure range of 110 to 60 mm Hg, and corresponding reductions in urine flow are attributed to a phenomenon known as pressure natriuresis. Acute unilateral pulmonary artery occlusion was used in the present study to reduce systemic arterial pressure toward the lower autoregulatory limit for glomerular filtration, and to evaluate kidney function in normal and preascitic broilers. Preascitic broilers characteristically exhibited lower (P < or = 0.05) values for mean systemic arterial pressure (91 vs 100 mm Hg) and percentage saturation of hemoglobin with oxygen (73 vs 84%), higher hematocrits (35 vs 30%), heavier right ventricles (3.44 vs 2.32 g), and higher right:total ventricular weight ratios (0.32 vs 0.24) than normal broilers. Body weights (2,445 vs 2,429 g, respectively), left ventricle plus septum weights (7.16 vs 7.19 g), and heart rates (349 vs 341 beats/min) were similar. Preascitic broilers exhibited larger (P < or = 0.05) dependent reductions in glomerular filtration, urine flow, osmolal clearance, and solute excretion and had a higher free water clearance than normal broilers in response to pulmonary artery occlusion. The differences observed between normal and preascitic broilers demonstrate that systemic hypotension can trigger renal mechanisms contributing to fluid and solute retention during development of PHS.

  5. Involvement of NMDA receptors in nicotine-mediated central control of hypotensive effects.

    PubMed

    Hong, Ling-Zong; Cheng, Pei-Wen; Cheng, Wen-Han; Chen, Siang-Ru; Wang, Ling-Lin; Tseng, Ching-Jiunn

    2012-10-31

    It is known that enrichment of glutamatergic transmission in the nucleus tractus solitarii (NTS) plays an important role in central cardiovascular regulation. Our previous study demonstrated that nicotine decreased blood pressure and heart rate in the NTS probably acting via the nicotinic acetylcholine receptors (nAChRs)-Ca²⁺-calmodulin-eNOS-NO signaling pathway. The possible relationship between glutamate and nicotine in the NTS for cardiovascular regulation is poorly understood. This study investigated the involvement of glutamate receptors in the cardiovascular effects of nicotine in the NTS. Nicotine (a non-selective nAChRs agonist), MK801 (a non-competitive NMDA receptor antagonist), APV (a competitive NMDA receptor antagonist), or NBQX (a selective AMPA receptor antagonist) was microinjected into the NTS of anesthetized Wistar-Kyoto rats. Microinjection of nicotine (1.5 pmol) into the NTS produced decreases in blood pressure and heart rate. The hypotensive and bradycardic effects of nicotine were abolished by prior administration of MK801 (1 nmol) and APV (10 nmol), but was completely restored after 60 min of recovery. In contrast, prior administration of NBQX (10 pmol) into the NTS did not alter the cardiovascular effects of nicotine. The nitrate (served as total NO) production in response to nicotine microinjection into the NTS was suppressed by prior administration of APV. These results suggest that the hypotensive and bradycardic effects of nicotine in the NTS might be mediated through NMDA receptors, and that the nAChRs-NMDA receptor-NO pathway could be involved.

  6. Evaluation of sodium nitroprusside for controlled hypotension in children during surgery

    PubMed Central

    Drover, David R.; Hammer, Gregory B.; Barrett, Jeffrey S.; Cohane, Carol A.; Reece, Tammy; Zajicek, Anne; Schulman, Scott R.

    2015-01-01

    Purpose: (1) To define the onset and offset of the blood-pressure-lowering effects of sodium nitroprusside (SNP) for use in developing instructions for dose titration in children undergoing a surgical or medical procedure, and (2) to assess the safety of SNP administration in pediatric patients requiring controlled reduction of blood pressure. Methods: We conducted a randomized, double-blind, parallel-group, dose-ranging, effect-controlled, multicenter study of intravenous (IV) infusions of SNP in pediatric patients <17 years, who required controlled hypotension for at least 2 h while undergoing a surgical or medical procedure. A blinded SNP dose of 0.3, 1, 2, or 3 μg/kg/min was infused for 30 min, followed by open-label administration for at least 90 min. Both infusions were titrated to effect. Results: The final intent-to-treat group comprised 203 patients. Significant reductions in mean arterial pressure (MAP) from baseline were observed for all four doses at 20 and 25 min after the start of infusion (p ≤ 0.009 and p ≤ 0.010 for each time, respectively). Overall, 98.5% of the patients achieved the target MAP; 72.9% first achieved the target MAP during the blinded infusion. The mean infusion rate at target MAP was 1.07 μg/kg/min. Conclusion: We determined that 0.3 μg/kg/m is a reasonable starting dose for SNP in pediatric patients requiring controlled hypotension. The infusion rate can then be increased to achieve the desired reduction in blood pressure. On the basis of our results, we found an average infusion rate of 1 μg/kg/min might be appropriate. Of note, no cyanide toxicity was reported, and no measureable cyanide levels were detected in any blood samples obtained during the study. http://clinicaltrials.gov/show/NCT00135668. PMID:26217225

  7. A diminished aortic-cardiac reflex during hypotension in aerobically fit young men.

    PubMed

    Shi, X; Crandall, C G; Potts, J T; Williamson, J W; Foresman, B H; Raven, P B

    1993-09-01

    We compared the aortic-cardiac baroreflex sensitivity in eight average fit (AF: VO2max = 44.7 +/- 1.3 ml.kg-1 x min-1) and seven high fit (HF: VO2max = 64.1 +/- 1.7 ml.min-1 x kg-1) healthy young men during hypotension elicited by steady state sodium nitroprusside (SN) infusion. During SN mean arterial pressure (MAP) was similarly decreased in AF (-12.6 +/- 1.0 mm Hg) and HF (-12.1 +/- 1.1 mm Hg). However, the increases in heart rate (HR) were less (P < 0.023) in HF (15 +/- 3 bpm) than AF (25 +/- 1 bpm). When sustained neck suction (NS, -22 +/- 1 torr in AF and -20 +/- 1 torr in HF, P > 0.05) was applied to counteract the decreased carotid sinus transmural pressure during SN, thereby isolating the aortic baroreceptors, the increased HR remained less (P < 0.021) in HF (8 +/- 2 bpm) than AF (16 +/- 2 bpm). During both SN infusion and SN+NS, the calculated gains (i.e., delta HR/delta MAP) were significantly greater in AF (2.1 +/- 0.3 and 1.3 +/- 0.2 bpm.mm Hg-1) than HF (1.2 +/- 0.2 and 0.6 +/- 0.2 bpm.mm Hg-1). However, the estimated carotid-cardiac baroreflex sensitivity (i.e., the gain difference between the stage SN and SN + NS) was not different between AF (0.7 +/- 0.2 bpm.mm Hg-1) and HF (0.6 +/- 0.1 bpm.mm Hg-1). These data indicated that the aortic-cardiac baroreflex sensitivity during hypotension was significantly diminished with endurance exercise training. PMID:8231770

  8. A diminished aortic-cardiac reflex during hypotension in aerobically fit young men

    NASA Technical Reports Server (NTRS)

    Shi, X.; Crandall, C. G.; Potts, J. T.; Williamson, J. W.; Foresman, B. H.; Raven, P. B.

    1993-01-01

    We compared the aortic-cardiac baroreflex sensitivity in eight average fit (AF: VO2max = 44.7 +/- 1.3 ml.kg-1 x min-1) and seven high fit (HF: VO2max = 64.1 +/- 1.7 ml.min-1 x kg-1) healthy young men during hypotension elicited by steady state sodium nitroprusside (SN) infusion. During SN mean arterial pressure (MAP) was similarly decreased in AF (-12.6 +/- 1.0 mm Hg) and HF (-12.1 +/- 1.1 mm Hg). However, the increases in heart rate (HR) were less (P < 0.023) in HF (15 +/- 3 bpm) than AF (25 +/- 1 bpm). When sustained neck suction (NS, -22 +/- 1 torr in AF and -20 +/- 1 torr in HF, P > 0.05) was applied to counteract the decreased carotid sinus transmural pressure during SN, thereby isolating the aortic baroreceptors, the increased HR remained less (P < 0.021) in HF (8 +/- 2 bpm) than AF (16 +/- 2 bpm). During both SN infusion and SN+NS, the calculated gains (i.e., delta HR/delta MAP) were significantly greater in AF (2.1 +/- 0.3 and 1.3 +/- 0.2 bpm.mm Hg-1) than HF (1.2 +/- 0.2 and 0.6 +/- 0.2 bpm.mm Hg-1). However, the estimated carotid-cardiac baroreflex sensitivity (i.e., the gain difference between the stage SN and SN + NS) was not different between AF (0.7 +/- 0.2 bpm.mm Hg-1) and HF (0.6 +/- 0.1 bpm.mm Hg-1). These data indicated that the aortic-cardiac baroreflex sensitivity during hypotension was significantly diminished with endurance exercise training.

  9. Hyperbaric oxygen reduces edema and necrosis of skeletal muscle in compartment syndromes associated with hemorrhagic hypotension

    SciTech Connect

    Skyhar, M.J.; Hargens, A.R.; Strauss, M.B.; Gershuni, D.H.; Hart, G.B.; Akeson, W.H.

    1986-10-01

    This study examined the effect of exposures to hyperbaric oxygen on the development of the edema and necrosis of muscle that are associated with compartment syndromes that are complicated by hemorrhagic hypotension. A compartment syndrome (twenty millimeters of mercury for six hours) was induced by infusion of autologous plasma in the anterolateral compartment of the left hind limb of seven anesthetized dogs while the mean arterial blood pressure was maintained at sixty-five millimeters of mercury after 30 per cent loss of blood volume. These dogs were treated with hyperbaric oxygen (two atmospheres of pure oxygen) and were compared with six dogs that had an identical compartment syndrome and hypotensive condition but were not exposed to hyperbaric oxygen. Forty-eight hours later, edema was quantified by measuring the weights of the muscles (the pressurized muscle compared with the contralateral muscle), and necrosis of muscle was evaluated by measuring the uptake of technetium-99m stannous pyrophosphate. The ratio for edema was significantly (p = 0.01) greater in dogs that had not been exposed to hyperbaric oxygen (1.15 +/- 0.01) than in the dogs that had been treated with hyperbaric oxygen (1.01 +/- 0.03), and the ratio for necrosis of muscle was also significantly (p = 0.04) greater in dogs that had not had hyperbaric oxygen (1.96 +/- 0.41) than in those that had been treated with hyperbaric oxygen (1.05 +/- 0.11). Comparisons were also made with the muscles of four normal control dogs and separately with the muscles of six normotensive dogs that had an identical compartment syndrome and normal blood pressure and were not treated with hyperbaric oxygen.

  10. Efficacy of prophylactic intramuscular ephedrine in prevention of hypotension during caesarean section under spinal anaesthesia: a comparative study.

    PubMed

    Bhar, Debasish; Bharati, Saswata; Halder, Partha Sarathi; Mondal, Subrata; Sarkar, Malay; Jana, Swapan

    2011-05-01

    Hypotension during caesarean section under spinal anaesthesia is a common complication. Several measures are used to reduce the incidence of hypotension but no method is fully effective. Prophylactic intramuscular ephedrine may be effective in reducing the incidence of hypotension in addition to conventional measures. To evaluate the efficacy of prophylactic intramuscular (IM) ephedrine (0.5 mg/kg, maximum up to 45 mg), given 10 minutes and 20 minutes before spinal anaesthesia to prevent hypotension, and to observe the adverse effects of IM ephedrine. A prospective, randomised, double-blind controlled study was undertaken where 150 pregnant mothers aged between 18 and 29 years and belonging to ASA physical status I, posted for elective caesarean section, were randomly allocated into one of the three groups. Group C received only preloading with 15 ml/kg of Ringer lactate (RL) solution, group E10 and group E20 received injection ephedrine 0.5 mg/kg IM 10 minutes and 20 minutes prior to performing spinal anaesthesia respectively along with 15 ml/kg RL preloading. The incidence of hypotension was significantly more in group C compared to other two groups. Mean arterial pressure and heart rate were significantly more in group E10 compared to group C. No significant increase in the incidence of hypertension and tachycardia in any group were observed. The findings of this study indicate that prophylactic IM ephedrine 0.5 mg/kg given 10 minutes before spinal anaesthesia gives better haemodynamic stability during intra-operative period without any significant increase in the incidence of adverse effects.

  11. Marked Initial Pitch in Questions Signals Marked Communicative Function.

    PubMed

    Sicoli, Mark A; Stivers, Tanya; Enfield, N J; Levinson, Stephen C

    2015-06-01

    In conversation, the initial pitch of an utterance can provide an early phonetic cue of the communicative function, the speech act, or the social action being implemented. We conducted quantitative acoustic measurements and statistical analyses of pitch in over 10,000 utterances, including 2512 questions, their responses, and about 5000 other utterances by 180 total speakers from a corpus of 70 natural conversations in 10 languages. We measured pitch at first prominence in a speaker's utterance and discriminated utterances by language, speaker, gender, question form, and what social action is achieved by the speaker's turn. Through applying multivariate logistic regression we found that initial pitch that significantly deviated from the speaker's median pitch level was predictive of the social action of the question. In questions designed to solicit agreement with an evaluation rather than information, pitch was divergent from a speaker's median predictably in the top 10% of a speakers range. This latter finding reveals a kind of iconicity in the relationship between prosody and social action in which a marked pitch correlates with a marked social action. Thus, we argue that speakers rely on pitch to provide an early signal for recipients that the question is not to be interpreted through its literal semantics but rather through an inference. PMID:26677643

  12. 49 CFR 221.14 - Marking devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Marking devices. 221.14 Section 221.14..., DEPARTMENT OF TRANSPORTATION REAR END MARKING DEVICE-PASSENGER, COMMUTER AND FREIGHT TRAINS Marking Devices § 221.14 Marking devices. (a) As prescribed in § 221.13, passenger, commuter and freight trains shall...

  13. 40 CFR 761.45 - Marking formats.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of PCBs and PCB Items § 761.45 Marking formats. The following formats shall be used for marking: (a) Large PCB Mark—M L. Mark ML shall be as shown in Figure 1, letters and striping on a white or yellow... the PCB Article, PCB Equipment, or PCB Container. The size of the mark shall be at least 15.25 cm...

  14. 40 CFR 761.45 - Marking formats.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of PCBs and PCB Items § 761.45 Marking formats. The following formats shall be used for marking: (a) Large PCB Mark—M L. Mark ML shall be as shown in Figure 1, letters and striping on a white or yellow... the PCB Article, PCB Equipment, or PCB Container. The size of the mark shall be at least 15.25 cm...

  15. 46 CFR 160.171-23 - Marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Immersion Suits § 160.171-23 Marking. (a) Each immersion suit must be marked with the words “IMMERSION SUIT—COMPLIES WITH SOLAS 74/83,” the name of the manufacturer... case must be marked with the words “immersion suit” and the size. (c) The markings for the child...

  16. Reading Skill, Textbook Marking, and Course Performance

    ERIC Educational Resources Information Center

    Bell, Kenneth E.; Limber, John E.

    2010-01-01

    We surveyed students enrolled in Introductory Psychology courses about their text marking preferences and analyzed the marking in their textbooks. Low-skill readers report more reliance on highlighting strategies and actually mark their texts more than better readers. In addition, low-skilled readers prefer to buy used, previously marked texts…

  17. 27 CFR 28.154 - Export marks.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.154..., for Exportation or Transfer to a Foreign-Trade Zone § 28.154 Export marks. In addition to the marks... provisions of part 19 of this chapter, the proprietor shall mark the word “Export” on the Government side...

  18. 27 CFR 28.103 - Export marks.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.103... Manufacturing Bonded Warehouse § 28.103 Export marks. (a) General. In addition to the marks and brands required... provisions of part 19 of this chapter, the proprietor shall mark the word “Export” on the Government side...

  19. 27 CFR 28.193 - Export marks.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.193... Drawback Filing of Notice and Removal § 28.193 Export marks. In addition to the marks and brands required... chapter, the exporter shall mark the word “Export” on the Government side of each case or Government...

  20. 27 CFR 28.144 - Export marks.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.144... § 28.144 Export marks. (a) General Requirement. In addition to the marks and brands required to be... brewer shall mark the word “Export” on each container or case of beer, or the words “Beer concentrate...

  1. 14 CFR 45.10 - Marking.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Marking. 45.10 Section 45.10 Aeronautics..., § 45.10 was added, effective Apr. 14, 2010. The effective date of this addition was subsequently... REGISTRATION MARKING Identification of Aircraft and Related Products § 45.10 Marking. No person may mark...

  2. Black anneal marking with pulsed fiber lasers

    NASA Astrophysics Data System (ADS)

    Murphy, T.; Harrison, P.; Norman, S.

    2015-07-01

    High contrast marking of metals is used in a wide range of industries. Fiber laser marking of these metals provides non-contact marking with no consumables, offering many advantages over traditional methods of metal marking. The laser creates a permanent mark on the material surface combining heat and oxygen with no noticeable ablation. The focussed beam of the fiber laser in combination with precision control of the heat input is able to treat small areas of the material surface evenly and consistently, which is critical for producing black anneal marks. The marks are highly legible which is ideal for marking serial numbers or small data matrices where traceability is required. This paper reports the experimental study for producing black anneal marks on various grades of stainless steel using fiber lasers. The influence of metal surface finish, beam quality, spot size diameter and pulse duration are investigated for producing both smooth and decorative anneal marks.

  3. The Mark III vertex chamber

    SciTech Connect

    Adler, J.; Bolton, T.; Bunnell, K.; Cassell, R.; Cheu, E.; Freese, T.; Grab, C.; Mazaheri, G.; Mir, R.; Odian, A.

    1987-07-01

    The design and construction of the new Mark III vertex chamber is described. Initial tests with cosmic rays prove the ability of track reconstruction and yield triplet resolutions below 50 ..mu..m at 3 atm using argon/ethane (50:50). Also performed are studies using a prototype of a pressurized wire vertex chamber with 8 mm diameter straw geometry. Spatial resolution of 35mm was obtained using dimethyl ether (DME) at 1 atm and 30 ..mu..m using argon/ethane (50/50 mixture) at 4 atm. Preliminary studies indicate the DME to adversely affect such materials as aluminized Mylar and Delrin.

  4. N sup G -methyl-L-arginine inhibits tumor necrosis factor-induced hypotension: Implications for the involvement of nitric oxide

    SciTech Connect

    Kilbourn, R.G.; Adams, J. ); Gross, S.S.; Griffith, O.W.; Levi, R. ); Jubran, A.; Lodato, R.F. )

    1990-05-01

    Clinical assessment of the activity of tumor necrosis factor (TNF) against human cancer has been limited by a dose-dependent cardiovascular toxicity, most frequently hypotension. TNF is also thought to mediate the vascular collapse resulting from bacterial endotoxin. The present studies address the mechanism by which TNF causes hypotension and provide evidence for elevated production of nitric oxide, a potent vasodilator initially characterized as endothelium-derived relaxing factor. Nitric oxide is synthesized by several cell types, including endothelial cells and macrophages, from the guanidino nitrogen of L-arginine; the enzymatic pathway is competitively inhibited by N{sup G}-methyl-L-arginine. The authors found that hypotension induced in pentobarbital-anesthetized dogs by TNF was completely reversed within 2 min following administration of N{sup G}-methyl-L-arginine. In contrast, N{sup G}-methyl-L-arginine failed to reverse the hypotensive response to an equivalent depressor dose of nitroglycerin, a compound that acts by forming nitric oxide by a monenzymatic, arginine-independent mechanism. The effect of N{sup G}-methyl-L-arginine on TNF-induced hypotension was antagonized, and the hypotension restored, by administration of excess L-arginine findings suggest that excessive nitric oxide production mediates the hypotensive effect of TNF.

  5. Interview with Professor Mark Wilcox.

    PubMed

    Wilcox, Mark

    2016-08-01

    Mark Wilcox speaks to Georgia Patey, Commissioning Editor: Professor Mark Wilcox is a Consultant Microbiologist and Head of Microbiology at the Leeds Teaching Hospitals (Leeds, UK), the Professor of Medical Microbiology at the University of Leeds (Leeds, UK), and is the Lead on Clostridium difficile and the Head of the UK C. difficile Reference Laboratory for Public Health England (PHE). He was the Director of Infection Prevention (4 years), Infection Control Doctor (8 years) and Clinical Director of Pathology (6 years) at the Leeds Teaching Hospitals. He is Chair of PHE's Rapid Review Panel (reviews utility of infection prevention and control products for National Health Service), Deputy Chair of the UK Department of Health's Antimicrobial Resistance and Healthcare Associated Infection Committee and a member of PHE's HCAI/AR Programme Board. He is a member of UK/European/US working groups on C. difficile infection. He has provided clinical advice as part of the FDA/EMA submissions for the approval of multiple novel antimicrobial agents. He heads a healthcare-associated infection research team at University of Leeds, comprising approximately 30 doctors, scientists and nurses; projects include multiple aspects of C. difficile infection, diagnostics, antimicrobial resistance and the clinical development of new antimicrobial agents. He has authored more than 400 publications, and is the coeditor of Antimicrobial Chemotherapy (5th/6th/7th Editions, 15 December 2007). PMID:27494150

  6. Urinary elimination kinetics of 3-hydroxybenzo(a)pyrene and 1-hydroxypyrene of workers in a prebake aluminum electrode production plant: Evaluation of diuresis correction methods for routine biological monitoring.

    PubMed

    Lutier, Simon; Maître, Anne; Bonneterre, Vincent; Bicout, Dominique J; Marques, Marie; Persoons, Renaud; Barbeau, Damien

    2016-05-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous carcinogenic pollutants emitted in complex mixtures in the ambient air and contribute to the incidence of human cancers. Taking into account all absorption routes, biomonitoring is more relevant than atmospheric measurements to health risk assessment, but knowledge about how to use biomarkers is essential. In this work, urinary elimination kinetic of 1-hydroxypyrene (1-OHP) and 3-hydroxybenzo(a)pyrene (3-OHBaP) were studied in six electrometallurgy workers after PAHs exposure. Spot samples were collected on pre- and post-shift of the last workday then the whole urinations were separately sampled during the weekend. Non-linear mixed effects models were built to study inter- and intra-individual variability of both urinary metabolites toxicokinetic and investigate diuresis correction ways. Comparison of models confirmed the diuresis correction requirement to perform urinary biomonitoring of pyrene and BaP exposure. Urinary creatinine was found as a better way than specific gravity to normalize urinary concentrations of 1-OHP and as a good compromise for 3-OHBaP. Maximum observed levels were 1.0 µmol/mol creatinine and 0.8nmol/mol creatinine for 1-OHP and 3-OHBaP, respectively. Urinary 1-OHP concentrations on post-shift were higher than pre-shift for each subject, while 3-OHBaP levels were steady or decreased, and maximum urinary excretion rates of 3-OHBaP was delayed compared to 1-OHP. These results were consistent with the sampling time previously proposed for 3-OHBaP analysis, the next morning after exposure. Apparent urinary half-life of 1-OHP and 3-OHBaP ranged from 12.0h to 18.2h and from 4.8h to 49.5h, respectively. Finally, inter-individual variability of 1-OHP half-life seemed linked with the cutaneous absorption extent during exposure, while calculation of 3-OHBaP half-life required the awareness of individual urinary background level. The toxicokinetic modeling described here is an efficient tool which

  7. Urinary elimination kinetics of 3-hydroxybenzo(a)pyrene and 1-hydroxypyrene of workers in a prebake aluminum electrode production plant: Evaluation of diuresis correction methods for routine biological monitoring.

    PubMed

    Lutier, Simon; Maître, Anne; Bonneterre, Vincent; Bicout, Dominique J; Marques, Marie; Persoons, Renaud; Barbeau, Damien

    2016-05-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous carcinogenic pollutants emitted in complex mixtures in the ambient air and contribute to the incidence of human cancers. Taking into account all absorption routes, biomonitoring is more relevant than atmospheric measurements to health risk assessment, but knowledge about how to use biomarkers is essential. In this work, urinary elimination kinetic of 1-hydroxypyrene (1-OHP) and 3-hydroxybenzo(a)pyrene (3-OHBaP) were studied in six electrometallurgy workers after PAHs exposure. Spot samples were collected on pre- and post-shift of the last workday then the whole urinations were separately sampled during the weekend. Non-linear mixed effects models were built to study inter- and intra-individual variability of both urinary metabolites toxicokinetic and investigate diuresis correction ways. Comparison of models confirmed the diuresis correction requirement to perform urinary biomonitoring of pyrene and BaP exposure. Urinary creatinine was found as a better way than specific gravity to normalize urinary concentrations of 1-OHP and as a good compromise for 3-OHBaP. Maximum observed levels were 1.0 µmol/mol creatinine and 0.8nmol/mol creatinine for 1-OHP and 3-OHBaP, respectively. Urinary 1-OHP concentrations on post-shift were higher than pre-shift for each subject, while 3-OHBaP levels were steady or decreased, and maximum urinary excretion rates of 3-OHBaP was delayed compared to 1-OHP. These results were consistent with the sampling time previously proposed for 3-OHBaP analysis, the next morning after exposure. Apparent urinary half-life of 1-OHP and 3-OHBaP ranged from 12.0h to 18.2h and from 4.8h to 49.5h, respectively. Finally, inter-individual variability of 1-OHP half-life seemed linked with the cutaneous absorption extent during exposure, while calculation of 3-OHBaP half-life required the awareness of individual urinary background level. The toxicokinetic modeling described here is an efficient tool which

  8. The research of laser marking control technology

    NASA Astrophysics Data System (ADS)

    Zhang, Qiue; Zhang, Rong

    2009-08-01

    In the area of Laser marking, the general control method is insert control card to computer's mother board, it can not support hot swap, it is difficult to assemble or it. Moreover, the one marking system must to equip one computer. In the system marking, the computer can not to do the other things except to transmit marking digital information. Otherwise it can affect marking precision. Based on traditional control methods existed some problems, introduced marking graphic editing and digital processing by the computer finish, high-speed digital signal processor (DSP) control marking the whole process. The laser marking controller is mainly contain DSP2812, digital memorizer, DAC (digital analog converting) transform unit circuit, USB interface control circuit, man-machine interface circuit, and other logic control circuit. Download the marking information which is processed by computer to U disk, DSP read the information by USB interface on time, then processing it, adopt the DSP inter timer control the marking time sequence, output the scanner control signal by D/A parts. Apply the technology can realize marking offline, thereby reduce the product cost, increase the product efficiency. The system have good effect in actual unit markings, the marking speed is more quickly than PCI control card to 20 percent. It has application value in practicality.

  9. Hypoglycaemic and hypotensive effects of Ficus exasperata vahl. (Moraceae) leaf aqueous extract in rats.

    PubMed

    Adewole, Stephen O; Adenowo, Tk; Naicker, Thajasvarie; Ojewole, John A O

    2011-01-01

    The hypotensive and hypoglycaemic effects of Ficus exasperata (Vahl) (family: Moraceae) leaf aqueous extract (FEE) were investigated in experimental rat models. In this study, spontaneously-hypertensive rats (SHR) (type 1 diabetes), obese Zucker (type 2 diabetes) and Wistar rats were used. Three (A, B and C) groups of rats, each group consisting of 10 rats, were used. Group A Wistar rats received distilled water in quantities equivalent to the volume of streptozotocin (STZ) and FEE administered intraperitoneally to treated rats. Diabetes mellitus was induced in the SHR group B rats by multiple low-dose (MLD) intraperitoneal injections of STZ (40 mg/kg body weight) to induce type 1 diabetes. The animals in group C were the obese Zucker rats with non-insulin-independent diabetes mellitus (NDDM) (type 2 diabetes) on genetic basis. F. exasperata leaf aqueous extract (FEE, 100 mg/kg/day p.o.) was administered orally by orogastric intubation to fasted Groups B and C rats. In groups B and C rats, administration of FEE commenced 4 weeks post STZ injection, and continued for the next 4 consecutive weeks. Group A rats gave normal biochemical and morphological findings. Group B rats exhibited pronounced polyuria, hypoinsulinaemia, hyperlipidaemia and hyperglycaemia. These findings were also observed in group C rats, except that there was hyperinsilinaemia. Histopathological study of the aortic blood vessels showed extensive collagen fiber formation as well as perivascular fibrosis in both groups B and C rats. Four weeks of oral administration of F. exasperata leaf aqueous extract to diabetic groups of rats decreased blood glucose, blood pressure and lipid profiles. Administration of FEE (100 mg/kg p.o.) also restored the microanatomy of the blood vessels to almost normal levels. The findings of this study suggest that F. exasperata leaf aqueous extract possesses hypoglycaemic, hypotensive and hypolipidaemic properties. These findings lend biomedical and pharmacological

  10. 46 CFR 160.016-4 - Marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Lamps, Safety, Flame, for Merchant Vessels § 160.016-4 Marking. (a) Flame safety lamps shall be permanently and legibly marked with the name and address of...

  11. 46 CFR 160.016-4 - Marking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Lamps, Safety, Flame, for Merchant Vessels § 160.016-4 Marking. (a) Flame safety lamps shall be permanently and legibly marked with the name and address of...

  12. 46 CFR 160.016-4 - Marking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Lamps, Safety, Flame, for Merchant Vessels § 160.016-4 Marking. (a) Flame safety lamps shall be permanently and legibly marked with the name and address of...

  13. 46 CFR 160.016-4 - Marking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Lamps, Safety, Flame, for Merchant Vessels § 160.016-4 Marking. (a) Flame safety lamps shall be permanently and legibly marked with the name and address of...

  14. 46 CFR 160.016-4 - Marking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Lamps, Safety, Flame, for Merchant Vessels § 160.016-4 Marking. (a) Flame safety lamps shall be permanently and legibly marked with the name and address of...

  15. 10 CFR 1045.40 - Marking requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... markings in paragraphs (b)(3) and (4) of this section. (b) Front Marking. In addition to the overall classification level of the document, the following notices shall appear on the front of the document,...

  16. 49 CFR 179.500-17 - Marking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500-17 Marking. (a) Each... of this specification. These marks shall be stamped into the metal of necked-down section of tank...

  17. 46 CFR 160.048-6 - Marking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Marking. (a) Each buoyant cushion must have the following information clearly marked in waterproof... waterproof so that after 72 hours submergence in water, it will withstand vigorous rubbing by hand while...

  18. 46 CFR 160.048-6 - Marking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Marking. (a) Each buoyant cushion must have the following information clearly marked in waterproof... waterproof so that after 72 hours submergence in water, it will withstand vigorous rubbing by hand while...

  19. 46 CFR 160.048-6 - Marking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Marking. (a) Each buoyant cushion must have the following information clearly marked in waterproof... waterproof so that after 72 hours submergence in water, it will withstand vigorous rubbing by hand while...

  20. 46 CFR 160.048-6 - Marking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Marking. (a) Each buoyant cushion must have the following information clearly marked in waterproof... waterproof so that after 72 hours submergence in water, it will withstand vigorous rubbing by hand while...

  1. 46 CFR 160.048-6 - Marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Marking. (a) Each buoyant cushion must have the following information clearly marked in waterproof... waterproof so that after 72 hours submergence in water, it will withstand vigorous rubbing by hand while...

  2. Orthostatic hypotension is associated with decreased cerebrospinal fluid levels of chromogranin A in early stage of Parkinson disease.

    PubMed

    Kaiserova, Michaela; Prikrylova Vranova, Hana; Galuszka, Jan; Stejskal, David; Mensikova, Katerina; Zapletalova, Jana; Mares, Jan; Kanovsky, Petr

    2015-10-01

    An association between the CSF chromogranin A (CgA) and orthostatic blood pressure changes was investigated in 20 patients in the early stage of Parkinson disease (PD). There was a positive correlation between the CSF CgA and diastolic blood pressure change, when CSF CgA levels were lower in patients with orthostatic hypotension (OH). Decreased CSF CgA may be useful in predicting OH in the early stage of PD.

  3. Tachykinin NK3 receptor contribution to systemic release of vasopressin and oxytocin in response to osmotic and hypotensive challenge.

    PubMed

    Haley, Gwendolen E; Flynn, Francis W

    2007-08-01

    Activation of the neurokinin 3 receptor (NK3R) by a receptor agonist, hypotension, and hyperosmolarity results in the internalization of NK3R expressed by magnocellular neurons and the release of vasopressin (VP) and oxytocin (OT) into the circulation. The contribution of NK3R activation to the release of VP and OT in response to hyperosmolarity and hypotension was evaluated by measuring the release of both hormones following pretreatment with a selective NK3R antagonist, SB-222200. Freely behaving male rats were given an intraventricular injection of either 0.15 M NaCl or 250, 500, or 1,000 pmol SB-222200, and then were administered an intravenous infusion of 2 M NaCl or 0.15 M NaCl (experiment 1), or a bolus intra injection of 0.15 M NaCl or hydralazine (HDZ), a hypotension-inducing drug (experiment 2). Blood samples were taken from indwelling arterial catheters at various time points for 1-2 h, both before and after treatments. Plasma VP and OT levels were determined by ELISA. Blockade of NK3R did not affect the baseline levels of either hormone. In contrast, pretreatment with SB-222200 significantly reduced ( approximately 60%) or abolished the release of VP and OT, respectively, to 2 M NaCl infusion. HDZ-induced VP and OT release was eliminated by pretreatment with 500 pmol SB-222200. Therefore, NK3R activation contributes significantly to the systemic release of both VP and OT in response to osmotic and hypotensive challenges.

  4. Respiratory failure and lethal hypotension due to blue-ringed octopus and tetrodotoxin envenomation observed and counteracted in animal models.

    PubMed

    Flachsenberger, W A

    The effects of crude blue-ringed octopus venom gland extract and tetrodotoxin (TTX) on anaesthetised rats and rabbits were studied. Paralysis of the respiratory musculature causing anoxia and cyanosis was overcome with positive, artificial respiration. The second lethal mechanism of the toxins: rapid and severe hypotension, had to be counteracted peripherally, since neural transmission had been drastically reduced by the toxins. Noradrenaline, d-amphetamine, phenylephrine and methoxamine, agonists acting on vascular adrenergic a-receptors, were tested. PMID:3573123

  5. 7 CFR 160.32 - Marking containers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Marking containers. 160.32 Section 160.32 Agriculture... STANDARDS FOR NAVAL STORES Analysis, Inspection, and Grading on Request § 160.32 Marking containers. The interested person shall provide any labor necessary for marking the containers, after the contents have...

  6. 14 CFR 25.1555 - Control markings.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Control markings. 25.1555 Section 25.1555....1555 Control markings. (a) Each cockpit control, other than primary flight controls and controls whose... aerodynamic control must be marked under the requirements of §§ 25.677 and 25.699. (c) For powerplant...

  7. 14 CFR 27.1555 - Control markings.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Control markings. 27.1555 Section 27.1555... Control markings. (a) Each cockpit control, other than primary flight controls or control whose function... fuel controls— (1) Each fuel tank selector control must be marked to indicate the...

  8. 14 CFR 25.1555 - Control markings.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Control markings. 25.1555 Section 25.1555....1555 Control markings. (a) Each cockpit control, other than primary flight controls and controls whose... aerodynamic control must be marked under the requirements of §§ 25.677 and 25.699. (c) For powerplant...

  9. 46 CFR 134.160 - Freeboard markings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Freeboard markings. 134.160 Section 134.160 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ADDED PROVISIONS FOR LIFTBOATS § 134.160 Freeboard markings. Freeboard markings required by § 174.260 of this subchapter must...

  10. 46 CFR 134.160 - Freeboard markings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Freeboard markings. 134.160 Section 134.160 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ADDED PROVISIONS FOR LIFTBOATS § 134.160 Freeboard markings. Freeboard markings required by § 174.260 of this subchapter must...

  11. 46 CFR 162.018-6 - Marking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Safety Relief Valves, Liquefied Compressed Gas § 162.018-6 Marking. (a) Each safety relief valve shall be plainly marked by the manufacturer with the required data... valve or stamped or cast on a plate securely fastened to the valve. The marking shall include...

  12. 46 CFR 162.018-6 - Marking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Safety Relief Valves, Liquefied Compressed Gas § 162.018-6 Marking. (a) Each safety relief valve shall be plainly marked by the manufacturer with the required data... valve or stamped or cast on a plate securely fastened to the valve. The marking shall include...

  13. 46 CFR 162.018-6 - Marking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Safety Relief Valves, Liquefied Compressed Gas § 162.018-6 Marking. (a) Each safety relief valve shall be plainly marked by the manufacturer with the required data... valve or stamped or cast on a plate securely fastened to the valve. The marking shall include...

  14. 46 CFR 162.018-6 - Marking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Safety Relief Valves, Liquefied Compressed Gas § 162.018-6 Marking. (a) Each safety relief valve shall be plainly marked by the manufacturer with the required data... valve or stamped or cast on a plate securely fastened to the valve. The marking shall include...

  15. 14 CFR 29.1555 - Control markings.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Control markings. 29.1555 Section 29.1555 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Operating Limitations and Information Markings and Placards § 29.1555 Control markings. (a)...

  16. 14 CFR 27.1555 - Control markings.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Control markings. 27.1555 Section 27.1555 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Operating Limitations and Information Markings and Placards § 27.1555 Control markings. (a) Each...

  17. 46 CFR 160.174-23 - Marking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-23 Marking. (a) Each thermal protective aid must be marked with the words “Thermal Protective Aid,” the name of the manufacturer, the... the Coast Guard approval number. (b) Each storage case must be marked with the words...

  18. 46 CFR 160.174-23 - Marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Thermal Protective Aids § 160.174-23 Marking. (a) Each thermal protective aid must be marked with the words “Thermal Protective Aid,” the name of the manufacturer, the... the Coast Guard approval number. (b) Each storage case must be marked with the words...

  19. 46 CFR 160.031-6 - Marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Line-Throwing Appliance, Shoulder Gun Type (and Equipment) § 160.031-6 Marking. (a) Gun. The gun shall be permanently and legibly marked on the barrel with the... prevent corrosion. After the proof test, the gun barrel shall be marked with the letters “P.T.” and...

  20. Classroom Mark-Recapture with Crickets

    ERIC Educational Resources Information Center

    Whiteley, Andrew R.; Woolfe, Jennifer; Kennedy, Kathleen; Oberbillig, David; Brewer, Carol

    2007-01-01

    Mark-recapture techniques are commonly used by ecologists to estimate abundance of naturally occurring animals and are an important component of ecology curricula. This investigation teaches a mark-recapture technique using store-bought crickets in 10-gallon aquaria and provides an inexpensive way to teach students about mark-recapture in a real…

  1. Marking Student Programs Using Graph Similarity

    ERIC Educational Resources Information Center

    Naude, Kevin A.; Greyling, Jean H.; Vogts, Dieter

    2010-01-01

    We present a novel approach to the automated marking of student programming assignments. Our technique quantifies the structural similarity between unmarked student submissions and marked solutions, and is the basis by which we assign marks. This is accomplished through an efficient novel graph similarity measure ("AssignSim"). Our experiments…

  2. 46 CFR 160.047-6 - Marking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... marked in waterproof lettering that can be read at a distance of 2 feet: Type II Personal Flotation....). (Name and address of manufacturer or distributor.). (Lot No.). (b) Waterproof marking tags. Marking for buoyant vests shall be sufficiently waterproof so that after 72 hours submergence in water, it...

  3. 46 CFR 160.047-6 - Marking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... marked in waterproof lettering that can be read at a distance of 2 feet: Type II Personal Flotation....). (Name and address of manufacturer or distributor.). (Lot No.). (b) Waterproof marking tags. Marking for buoyant vests shall be sufficiently waterproof so that after 72 hours submergence in water, it...

  4. 46 CFR 160.047-6 - Marking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... marked in waterproof lettering that can be read at a distance of 2 feet: Type II Personal Flotation....). (Name and address of manufacturer or distributor.). (Lot No.). (b) Waterproof marking tags. Marking for buoyant vests shall be sufficiently waterproof so that after 72 hours submergence in water, it...

  5. 27 CFR 28.223 - Export marks.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.223... Export marks. In addition to the marks and brands required to be placed on kegs, barrels, cases, crates... “Export” on each container or case before removal for export, for use on vessels or aircraft, or...

  6. 27 CFR 28.216 - Export marks.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.216... Export marks. In addition to the marks and brands required to be placed on packages or other bulk... “Export” on the Government side of each case or Government head of each container before removal...

  7. 27 CFR 28.123 - Export marks.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.123..., or Transportation to a Manufacturing Bonded Warehouse § 28.123 Export marks. (a) General. In addition... filled under the provisions of part 24 of this chapter, the proprietor shall mark the word “Export”...

  8. Prevention of hypotension associated with the induction dose of propofol: A randomized controlled trial comparing equipotent doses of phenylephrine and ephedrine

    PubMed Central

    Farhan, Muhammad; Hoda, Muhammad Qamarul; Ullah, Hameed

    2015-01-01

    Background and Aims: Propofol, the most commonly used intravenous (IV) anesthetic agent is associated with hypotension on induction of anesthesia. Different methods have been used to prevent hypotension but with variable results. The objective of this study was to evaluate efficacy of equipotent doses of phenylpehrine and ephedrine in preventing the hypotensive response to the induction dose of propofol. Material and Methods: One hundred thirty five adult patients were randomised to one of the study groups: propofol-saline (PS), propofol-phenylephrine (PP) or propofol-ephedrine (PE) by adding study drugs to propofol. Anesthesia was induced with a mixture of propofol and the study drug. Patients were manually mask-ventilated for 5 min using 40% oxygen in nitrous oxide and isoflurane at 1%. A baseline mean arterial pressure (MAP) was recorded prior to induction of anesthesia. Systolic, diastolic and mean blood pressure and heart rate were recorded every minute for up to 5 min after induction. Hypotension was defined as a 20% decrease from the baseline MAP. Results: There were no significant demographic differences between the groups. Overall incidence of hypotension in this study was 38.5% (52/135). Rate of hypotension was significantly higher in group PS than group PP (60% vs. 24.4% P = 0.001) and group PE (60% vs. 31.1% P = 0.005). In contrast, a significant difference in rate of hypotension was not observed between groups PP and group PE. Conclusion: In equipotent doses, phenylephrine is as good as ephedrine in preventing the hypotensive response to an induction dose of propofol. PMID:26702213

  9. Discrepancy between Bioavailability and Hypotensive Effect of Oral and Sublingual Nifedipine.

    PubMed

    Palma-Aguirre, J. A.; Montoya-Cabrera, M. A.; du Souich, P.; Hoyo-Vadillo, C.; Flores-Murrieta, F. J.; Castañeda-Hernández, G.

    1995-01-01

    Nifedipine, 10-mg capsules, were given orally and sublingually to six healthy volunteers according to a randomized crossover design. Nifedipine plasma levels, blood pressure, and heart rate were determined at several times after medication. C(max) was higher (134 plus minus 17 vs. 93 plus minus 2 ng ml(minus sign1), mean plus minus SD, P < 0.01) and occurred earlier (0.5 vs. 1 h) with oral than with sublingual nifedipine. However, there was no significant difference in AUC (268 plus minus 56 vs. 288 plus minus 35 ng h ml(minus sign1)) nor in t(1/2) (1.8 plus minus 0.2 vs. 1.9 plus minus 0.3 h), indicating that sublingual administration decreased the rate but not the extent of nifedipine absorption. Notwithstanding the difference in C(max), both routes yielded a similar reduction in diastolic blood pressure of 13 plus minus 1 mm Hg. Heart rate increase, which reflects the activation of homeostatic mechanisms, was greater with oral than with sublingual nifedipine, that is, 18 plus minus 1 vs. 13 plus minus 1 beats min(minus sign1), P < 0.01. It is concluded that slower absorption after sublingual administration increases nifedipine hypotensive efficiency by producing less counteracting homeostatic responses than the more rapidly absorbed oral nifedipine.

  10. Cervical CT scan-guided epidural blood patches for spontaneous intracranial hypotension.

    PubMed

    Maingard, Julian; Giles, Lauren; Marriott, Mark; Phal, Pramit M

    2015-12-01

    We describe two patients with spontaneous intracranial hypotension (SIH), presenting with postural headache due to C1-C2 cerebrospinal fluid (CSF) leak. Both patients were refractory to lumbar epidural blood patching (EBP), and subsequently underwent successful CT scan-guided cervical EBP. SIH affects approximately 1 in 50,000 patients, with females more frequently affected. Its associated features are variable, and as such, misdiagnosis is common. Therefore, imaging plays an important role in the diagnostic workup of SIH and can include MRI of the brain and spine, CT myelogram, and radionuclide cisternography. In patients with an established diagnosis and confirmed CSF leak, symptoms will usually resolve with conservative management. However, in a select subgroup of patients, the symptoms are refractory to medical management and require more invasive therapies. In patients with cervical leaks, EBP in the cervical region is an effective management approach, either in close proximity to, or directly targeting a dural defect. CT scan-guided cervical EBP is an effective treatment approach in refractory SIH, and should be considered in those patients who are refractory to conservative management. PMID:26209918

  11. Cervical CT scan-guided epidural blood patches for spontaneous intracranial hypotension.

    PubMed

    Maingard, Julian; Giles, Lauren; Marriott, Mark; Phal, Pramit M

    2015-12-01

    We describe two patients with spontaneous intracranial hypotension (SIH), presenting with postural headache due to C1-C2 cerebrospinal fluid (CSF) leak. Both patients were refractory to lumbar epidural blood patching (EBP), and subsequently underwent successful CT scan-guided cervical EBP. SIH affects approximately 1 in 50,000 patients, with females more frequently affected. Its associated features are variable, and as such, misdiagnosis is common. Therefore, imaging plays an important role in the diagnostic workup of SIH and can include MRI of the brain and spine, CT myelogram, and radionuclide cisternography. In patients with an established diagnosis and confirmed CSF leak, symptoms will usually resolve with conservative management. However, in a select subgroup of patients, the symptoms are refractory to medical management and require more invasive therapies. In patients with cervical leaks, EBP in the cervical region is an effective management approach, either in close proximity to, or directly targeting a dural defect. CT scan-guided cervical EBP is an effective treatment approach in refractory SIH, and should be considered in those patients who are refractory to conservative management.

  12. Ocular hypotension, ocular toxicity, and neurotoxicity in response to marihuana extract and cannabidiol.

    PubMed

    Colasanti, B K; Brown, R E; Craig, C R

    1984-01-01

    Marihuana extract containing 21.3% delta-9-tetrahydrocannabinol (100 micrograms/hr), delta-9-tetrahydrocannabinol (20 micrograms/hr), cannabidiol (20 micrograms/hr), or the polyethylene glycol vehicle (1 microliter/hr) was delivered topically to cat eyes via osmotic minipumps over a 9-day period. Intraocular pressure differences between treated and untreated eyes of cats receiving marihuana extract remained 3-4 mmHg lower than those for vehicle controls, while differential values for the delta 9-THC-treated group remained reduced by 3-5 mmHg; data for these two groups did not differ statistically. Pressure differences between treated and untreated eyes of cats receiving cannabidiol were likewise 3-4 mmHg lower than values for controls. Ocular toxicity after delta 9-THC, consisting of conjunctival erythema and chemosis as well as corneal opacification, was quite severe. Although these changes also occurred after marihuana extract, their intensity was much reduced. In contrast, no ocular toxicity became apparent during administration of cannabidiol. While marihuana extract and delta 9-THC produced a dose-related increase in the appearance of 8-13 Hz polyspike discharges in the electrocorticograms of rats, both polyethylene glycol and cannabidiol lacked this effect. These results indicate that the ocular and central effects of marihuana extract and delta 9-THC are qualitatively similar. In addition, it appears that the ocular hypotensive effect produced by cannabidiol is relatively dissociable from both the ocular toxicity and the neurotoxicity associated with marihuana extract.

  13. Chronic Subdural Hematoma Associated with Spontaneous Intracranial Hypotension: Therapeutic Strategies and Outcomes of 55 Cases

    PubMed Central

    TAKAHASHI, Koichi; MIMA, Tatsuo; AKIBA, Yoichi

    2016-01-01

    Spontaneous intracranial hypotension (SIH) has increasingly been recognized, and it is well known that SIH is sometimes complicated by chronic subdural hematoma (SDH). In this study, 55 cases of SIH with SDH were retrospectively analyzed, focusing on therapeutic strategies and outcomes. Of 169 SIH cases (75 males, 84 females), 55 (36 males, 19 females) were complicated by SDH. SIH was diagnosed based on clinical symptoms, neuroimaging, and/or low cerebrospinal fluid pressure. Presence of orthostatic headache and diffuse meningeal enhancement on magnetic resonance imaging were regarded as the most important criteria. Among 55 SIH with SDH cases, 13 improved with conservative treatment, 25 initially received an epidural blood patch (EBP), and 17 initially underwent irrigation of the hematomas. Of the 25 initially treated with EBP, 7 (28.0%) needed SDH surgery and 18 (72.0%) recovered fully without surgery. Of 17 SDH cases initially treated with surgery, 6 (35.7%) required no EBP therapy and the other 11 (64.3%) needed EBP and/or additional SDH operations. In the latter group, 2 cases had transient severe complications during and after the procedures. One of these 2 cases developed a hoarse voice complication. Despite this single, non-severe complication, all enrolled in this study achieved good outcomes. The present study suggests that patients initially receiving SDH surgery may need additional treatments and may occasionally have complications. If conservative treatment is insufficient, EBP should be performed prior to hematoma irrigation. PMID:26489406

  14. [Severe orthostatic hypotension and intramedullary tumor: a case report and review of the literature].

    PubMed

    Derrey, S; Maltête, D; Ahtoy, P; Fregey, P; Proust, F

    2009-12-01

    A 55-year-old woman presented with bilateral neuropathic pain of the upper limbs, motor palsy of the right arm, urinary dysfunction, and postural dizziness. MRI showed an intramedullary cervical tumor with a solid portion extended from C1 to C3 surrounded by a cystic portion. A macroscopic complete resection was performed and histological examination confirmed the diagnosis of ependymoma. Postoperatively, the patient's neuropathic pain and postural dizziness worsened, with syncopal attack while upright because of severe orthostatic hypotension (OH). On physical examination, her supine systolic blood pressure was 130 mmHg and fell to 80 mmHg while sitting with no change in heart rate. We found motor palsy of the left arm, bilateral ataxia, and urinary retention. Three months later, the patient was still bedridden, notably because of the OH. After 6 months, with the association of preventative measures of OH and high doses of a direct alpha1-adrenoreceptor agonist, a vasoconstricting agent, the patient recovered an independent gait permitting her to walk unassisted. The main causes of OH include medication, nonneurogenic causes such as cardiac insufficiency, and central or peripheral neurogenic causes such as diabetic insufficiency. Brainstem tumors are known to provide severe OH but this symptom has been seldom described in a purely spinal cord lesion. We report an interesting case of severe OH that had complicated the surgical treatment of a high cervical spinal cord ependymoma and we review the literature. PMID:19592056

  15. Predictors of the Treatment Response of Spontaneous Intracranial Hypotension to an Epidural Blood Patch

    PubMed Central

    Karm, Myong-Hwan; Choi, Jae-Hyung; Kim, Doohwan; Park, Jun Young; Yun, Hye Joo; Suh, Jeong Hun

    2016-01-01

    Abstract Spontaneous intracranial hypotension (SIH) is characterized by postural headache because of low cerebrospinal fluid (CSF) pressure. Brain magnetic resonance imaging (MRI) and radioisotope (RI) cisternography can be used to identify the site of a CSF leakage. Although autologous epidural blood patch (EBP) is a very effective treatment modality, some patients require a repeat autologous EBP. We investigated whether autologous EBP responses correlate with surrogate markers of quantitative findings. All cases of autologous EBP for SIH from January 2006 to December 2014 were enrolled. The demographic variables, number of EBPs, pain scores, RI cisternography (early visualization of bladder activity), and MRI findings (subdural fluid collections, pachymeningeal enhancement, engorgement of venous structures, pituitary hyperemia, and sagging of the brain) were reviewed. Patients with early bladder activity on RI cisternography had a tendency to need a higher number of autologous EBPs. Only sagging of the brain and no other variables showed a statistically significant negative correlation with the number of autologous EBPs. The response to autologous EBP may be related to the radiologic findings of early bladder activity on RI cisternography and sagging of the brain on MRI. PMID:27149484

  16. Life-Threatening Intracranial Hypotension after Skull Base Surgery with Lumbar Drainage

    PubMed Central

    Hirono, Seiichiro; Kawauchi, Daisuke; Higuchi, Yoshinori; Setoguchi, Taiki; Kihara, Kazunori; Horiguchi, Kentaro; Kado, Ken; Sato, Motoki; Fukuda, Kazumasa; Nakamura, Takao; Saeki, Naokatsu; Yamakami, Iwao

    2015-01-01

    Although lumbar drainage (LD) is widely used in skull base surgery (SBS), no cases with intracranial hypotension (IH) following LD-assisted SBS have been reported, and skull base surgeons lack awareness of this potentially life-threatening condition. We report two cases of IH after LD-assisted SBS, a spheno-orbital meningioma and an osteosarcoma in the orbit. Despite a minimal amount of cerebrospinal fluid (CSF) drainage and early LD removal, severe postural headache and even a deteriorating consciousness level were observed in the early postoperative course. Neuroimages demonstrated epidural fluid collections, severe midline shift, and tonsillar sag compatible with IH. Epidural blood patch (EBP) immediately and completely reversed the clinical and radiologic findings in both patients. IH should be included in the differential diagnosis of postural headache after LD-assisted SBS that can be managed successfully with EBP. Persistent leakage of CSF at the LD-inserted site leads to IH. Broad dural dissection and wide removal of bony structure may be involved in the midline shift. EBP should be performed soon after conservative management fails. Further reports will determine the risk factors for IH development following LD-assisted SBS. PMID:26251819

  17. Sulfide toxicity: Mechanical ventilation and hypotension determine survival rate and brain necrosis

    SciTech Connect

    Baldelli, R.J.; Green, F.H.Y.; Auer, R.N. )

    1993-09-01

    Occupational exposure to hydrogen sulfide is one of the leading causes of sudden death in the workplace, especially in the oil and gas industry. High-dose exposure causes immediate neurogenic apnea and death; lower doses cause [open quotes]knockdown[close quotes] (transient loss of consciousness, with apnea). Because permanent neurological sequelae have been reported, the authors sought to determine whether sulfide can directly kill central nervous system neurons. Ventilated and unventilated rats were studied to allow administration of higher doses of sulfide and to facilitate physiological monitoring. It was extremely difficult to produce cerebral necrosis with sulfide. Only one of eight surviving unventilated rats given high-dose sulfide (a dose that was lethal in [ge]50% of animals) showed cerebral necrosis. Mechanical ventilation shifted the dose that was lethal in 50% of the animals to 190 mg/kg from 94 mg/kg in the unventilated rats. Sulfide was found to potently depress blood pressure. Cerebral necrosis was absent in the ventilated rats (n = 11), except in one rat that showed profound and sustained hypotension to [le]35 Torr. Electroencephalogram activity ceased during exposure but recovered when the animals regained consciousness. The authors conclude that very-high-dose sulfide is incapable of producing cerebral necrosis by a direct histotoxic effect. 32 refs., 5 figs.

  18. Prediction of orthostatic hypotension in multiple system atrophy and Parkinson disease

    PubMed Central

    Sun, Zhanfang; Jia, Dandan; Shi, Yuting; Hou, Xuan; Yang, Xiaosu; Guo, Jifeng; Li, Nan; Wang, Junling; Sun, Qiying; Zhang, Hainan; Lei, Lifang; Shen, Lu; Yan, Xinxiang; Xia, Kun; Jiang, Hong; Tang, Beisha

    2016-01-01

    Orthostatic hypotension (OH) is common in multiple system atrophy (MSA) and Parkinson disease (PD), generally assessed through a lying-to-standing orthostatic test. However, standing blood pressure may not be available due to orthostatic intolerance or immobilization for such patients. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were successively measured in supine, sitting, and standing positions in patients with MSA and PD. Receiver operating characteristic analysis was used to evaluate diagnostic performance of the drops of sitting SBP or DBP. OH and severe OH were respectively regarded as “gold standard”. The drops of SBP in standing position were associated with increased disease severity for MSA and correlated with age for PD. In MSA group, drops in sitting SBP ≥ 14 mmHg or DBP ≥ 6 mmHg had highest validity for prediction of OH, and drops in sitting SBP ≥ 18 mmHg or DBP ≥ 8 mmHg for severe OH. In PD group, drops in sitting SBP ≥ 10 mmHg or DBP ≥ 6 mmHg had highest validity for prediction of OH. The lying-to-sitting orthostatic test is an alternative method for detection of OH in MSA and PD, especially when standing BP could not be validly measured due to various reasons. PMID:26867507

  19. Refractory Orthostatic Hypotension Caused by a Recurrent Hemangioblastoma: Case Report and Review of the Literature

    PubMed Central

    Nangunoori, Raj; Singh, Anil; Aziz, Khaled

    2016-01-01

    Refractory orthostatic hypotension (OH) has been described following surgery for posterior fossa tumors. We present the case of a patient with refractory OH following attempted surgical resection. We also reviewed the available literature to describe pathophysiologic mechanisms for this rare entity. A 58-year-old female was found to have a hemangioblastoma at the cervicomedullary junction following workup for dysphagia and coordination difficulties. She underwent successful suboccipital craniotomy and gross total resection. However, the patient’s symptoms returned several years later and a magnetic resonance imaging (MRI) showed tumor recurrence. A surgical resection was attempted but could not be performed due to significant scarring. Following discharge, she returned to our care with severe syncopal episodes, refractory OH, and an inability to ambulate. Aggressive medical therapy resulted in a gradual improvement in her ability to ambulate and a reduction in her orthostatic episodes. Unfortunately she died due to sepsis from aspiration pneumonia several months later. A survey of the literature yielded a total of 10 reports (14 patients) with refractory OH as a result of tumors in the cervicomedullary region. Five of fourteen patients died from complications related to OH and brainstem compression while the remainder had some improvement and were discharged. Refractory OH can rarely be a presenting sign of a tumor in the cervicomedullary junction or can manifest following surgical resection of tumors in this region. Recognition of OH and the institution of medical therapy (sodium and fluid replacement) and pharmacotherapy may curb the significant morbidity associated with this condition. PMID:27158570

  20. Robotic tilt table reduces the occurrence of orthostatic hypotension over time in vegetative states.

    PubMed

    Taveggia, Giovanni; Ragusa, Ivana; Trani, Vincenzo; Cuva, Daniele; Angeretti, Cristina; Fontanella, Marco; Panciani, Pier Paolo; Borboni, Alberto

    2015-06-01

    The aim of this study is to evaluate the effects of verticalization with or without combined movement of the lower limbs in patients in a vegetative state or a minimally conscious state. In particular, we aimed to study whether, in the group with combined movement, there was better tolerance to verticalization. This was a randomized trial conducted in a neurorehabilitation hospital. Twelve patients with vegetative state and minimally conscious state 3-18 months after acute acquired brain injuries were included. Patients were randomized into A and B treatment groups. Study group A underwent verticalization with a tilt table at 65° and movimentation of the lower limbs with a robotic system for 30 min three times a week for 24 sessions. Control group B underwent the same rehabilitation treatment, with a robotic verticalization system, but an inactive lower-limb movement system. Systolic and diastolic blood pressure and heart rate were determined. Robotic movement of the lower limbs can reduce the occurrence of orthostatic hypotension in hemodynamically unstable patients. Despite the small number of patients involved (only eight patients completed the trial), our results indicate that blood pressures and heart rate can be stabilized better (with) by treatment with passive leg movements in hemodynamically unstable patients. PMID:25591054

  1. Robotic tilt table reduces the occurrence of orthostatic hypotension over time in vegetative states.

    PubMed

    Taveggia, Giovanni; Ragusa, Ivana; Trani, Vincenzo; Cuva, Daniele; Angeretti, Cristina; Fontanella, Marco; Panciani, Pier Paolo; Borboni, Alberto

    2015-06-01

    The aim of this study is to evaluate the effects of verticalization with or without combined movement of the lower limbs in patients in a vegetative state or a minimally conscious state. In particular, we aimed to study whether, in the group with combined movement, there was better tolerance to verticalization. This was a randomized trial conducted in a neurorehabilitation hospital. Twelve patients with vegetative state and minimally conscious state 3-18 months after acute acquired brain injuries were included. Patients were randomized into A and B treatment groups. Study group A underwent verticalization with a tilt table at 65° and movimentation of the lower limbs with a robotic system for 30 min three times a week for 24 sessions. Control group B underwent the same rehabilitation treatment, with a robotic verticalization system, but an inactive lower-limb movement system. Systolic and diastolic blood pressure and heart rate were determined. Robotic movement of the lower limbs can reduce the occurrence of orthostatic hypotension in hemodynamically unstable patients. Despite the small number of patients involved (only eight patients completed the trial), our results indicate that blood pressures and heart rate can be stabilized better (with) by treatment with passive leg movements in hemodynamically unstable patients.

  2. Orthostatic Hypotension and Mortality in Elderly Frail Patients: A Retrospective Cross-Sectional Study.

    PubMed

    Freud, Tamar; Punchik, Boris; Press, Yan; Yan, Press

    2015-06-01

    Orthostatic hypotension (OH) is a common problem in the elderly age group, and some studies have reported an association between OH and increased mortality. We evaluated possible associations between OH and mortality in a retrospective study of frail elderly patients who came for a comprehensive geriatric assessment. The study included all patients ≥ 65 years who were assessed in the outpatient Comprehensive Geriatric Assessment Unit. Data were collected from the computerized medical record, including blood pressure, sociodemographic data, lifestyle, falls, pulse rate, body mass index, functional and cognitive status, and comorbidity. Data on mortality were also collected. The study population consisted of 571 patients who underwent assessment over a 9-year study period. The mean age was 83.7 ± 6.1, 35.9% were males, and 183 (32.1%) were diagnosed with OH. Systolic OH (OHS) was more common than diastolic OH (25.2% vs 15.6%). In univariate analyses, OHS was associated with increased overall mortality. Over the follow-up period, 30.2% of the OHS patients died compared with 22.3% (P = 0.037), but in the Cox models there was no statistically significant associations between OHS and overall mortality. In contrast, age, burden of comorbidity, a low high-density lipoprotein level, and low creatinine clearance were independent predictors of increased overall mortality. In a population of frail elderly patients with a high burden of comorbidity, OH was not an independent risk factor for overall mortality.

  3. Orthostatic hypotension: prevalence and associated risk factors among the ambulatory elderly in an Asian population

    PubMed Central

    Zhu, Qing Olivia; Tan, Choon Seng Gilbert; Tan, Hwee Leong; Wong, Ruining Geraldine; Joshi, Chinmaya Shrikant; Cuttilan, Ravi Amran; Sng, Gek Khim Judy; Tan, Ngiap Chuan

    2016-01-01

    INTRODUCTION The prevalence of orthostatic hypotension (OH) among the elderly population in Singapore, as defined by a decline in blood pressure upon a change in position, is not well-established. Studies associate OH with clinically significant outcomes such as falls. This study aims to determine the prevalence of OH among elderly patients attending a public primary care clinic (polyclinic) for chronic disease management, and examine the relationships between postulated risk factors and OH. METHODS Patients aged ≥ 65 years attending a typical polyclinic in Geylang were identified and targeted for recruitment at the study site. A questionnaire on symptoms and postulated risk factors was administered, followed by supine and standing blood pressure measurements. Cross-sectional analysis was performed with independent sample t-test for continuous data and chi-square test for categorical data. Prevalence rate ratios with 95% confidence interval were calculated for the latter. RESULTS A total of 364 multiethnic patients participated in the study. The prevalence of OH was 11.0%. Older age, comorbidities such as cardiac failure and kidney disease, being physically inactive at work, fatigue, self-reported dizziness in the past year, and the use of loop diuretics were found to be significantly associated with OH. CONCLUSION About one in ten elderly patients at a local polyclinic was affected by OH, which was associated with multiple factors. Some of these factors are modifiable and can be addressed to reduce the incidence of OH. PMID:27549316

  4. Indomethacin attenuates post-suspension hypotension in Sprague-Dawley rats

    NASA Technical Reports Server (NTRS)

    Bayorh, M. A.; Eatman, D.; Wang, M.; Socci, R. R.; Emmett, N.; Thierry-Palmer, M.

    2001-01-01

    Orthostatic hypotension is a serious condition that is sometimes manifested in astronauts during standing postflight. These observations may be related to impairment of autonomic function and/or excessive production of endothelium-dependent relaxing factors. To evaluate the role of the cyclooxygenase inhibitor indomethacin as a countermeasure against the post-suspension reduction in mean arterial pressure (MAP), we examined the cardiovascular responses to 7-day 30 degrees tail-suspension and a subsequent 6-hr post-suspension period in conscious male Sprague-Dawley rats. Indomethacin (2 mg/kg) or saline were administered intravenously prior to release from suspension and at 2 and 4 hrs post-suspension. Direct MAP and heart rate were determined prior to suspension, daily and every 2 hrs post-suspension. During suspension, MAP did not change, in contrast, during post-suspension; it decreased compared to parallel non-suspended, untreated animals. There were no significant changes in heart rate. The reduction in MAP post-suspension was associated with significant increases in plasma prostacyclin. Indomethacin attenuated the observed post-suspension reduction in MAP and reduced plasma prostacyclin levels. Also, the baroreflex sensitivity for heart rate was modified by indomethacin--the MAP threshold for baroreflex activation was raised and the effective MAP range expanded. Thus, the post suspension reduction in mean arterial pressure may be due to overproduction of vasodilatory prostaglandins and/or other endothelium-dependent relaxing factors and alteration in baroreflex activity.

  5. Post-suspension hypotension is attenuated in Sprague-Dawley rats by prostacyclin synthase inhibition

    NASA Technical Reports Server (NTRS)

    Bayorh, M. A.; Eatman, D.; Walton, M.; Socci, R. R.; Emmett, N.

    2002-01-01

    Cardiovascular deconditioning, sometimes manifested in astronauts during standing postflight, may be related to the impairment of autonomic function and/or excessive production of endothelium-dependent relaxing factors. In the present study, we examined the cardiovascular responses to 7-day 30 degrees tail-suspension and a subsequent 6-h post-suspension period in conscious male Sprague-Dawley rats to determine the role of prostacyclin in the observed post-suspension reduction in mean arterial pressure (MAP). The specific prostacyclin synthase inhibitor U-51605 (0.3 mg/kg), or saline, was administered intravenously prior to release from suspension and at 2 and 4 h post-suspension. During 7 days of suspension, MAP did not change, however, there was a post-suspension reduction in MAP which was associated with significant increases in plasma prostacyclin and nitric oxide. U-51605 attenuated the observed post-suspension hypotension and reduced plasma prostacyclin levels, but not nitric oxide levels. The baroreflex sensitivity for heart rate was modified by U-51605: increased MAP threshold and effective MAP range. Thus, the post-suspension reduction in mean arterial pressure may be due to overproduction of prostacyclin and/or other endothelium-dependent relaxing factors and alteration in baroreflex activity.

  6. [Severe orthostatic hypotension and intramedullary tumor: a case report and review of the literature].

    PubMed

    Derrey, S; Maltête, D; Ahtoy, P; Fregey, P; Proust, F

    2009-12-01

    A 55-year-old woman presented with bilateral neuropathic pain of the upper limbs, motor palsy of the right arm, urinary dysfunction, and postural dizziness. MRI showed an intramedullary cervical tumor with a solid portion extended from C1 to C3 surrounded by a cystic portion. A macroscopic complete resection was performed and histological examination confirmed the diagnosis of ependymoma. Postoperatively, the patient's neuropathic pain and postural dizziness worsened, with syncopal attack while upright because of severe orthostatic hypotension (OH). On physical examination, her supine systolic blood pressure was 130 mmHg and fell to 80 mmHg while sitting with no change in heart rate. We found motor palsy of the left arm, bilateral ataxia, and urinary retention. Three months later, the patient was still bedridden, notably because of the OH. After 6 months, with the association of preventative measures of OH and high doses of a direct alpha1-adrenoreceptor agonist, a vasoconstricting agent, the patient recovered an independent gait permitting her to walk unassisted. The main causes of OH include medication, nonneurogenic causes such as cardiac insufficiency, and central or peripheral neurogenic causes such as diabetic insufficiency. Brainstem tumors are known to provide severe OH but this symptom has been seldom described in a purely spinal cord lesion. We report an interesting case of severe OH that had complicated the surgical treatment of a high cervical spinal cord ependymoma and we review the literature.

  7. Reporting of 'hypotension' after epidural analgesia during labour. Effect of choice of arm and timing of baseline readings.

    PubMed

    Kinsella, S M; Black, A M

    1998-02-01

    We studied 20 women in labour to see how reporting 'hypotension' after obstetric epidural analgesia is affected by position of the blood pressure cuff and baseline definition. Blood pressure was recorded from both arms simultaneously while the woman was semirecumbent and then in the left lateral position. Three readings were then taken after epidural bupivacaine, one left lateral and the remainder right lateral. Before the epidural, blood pressure in the dependent arm in the lateral position was similar to blood pressure in either arm in the semirecumbent position and an average of 10 mmHg (systolic) and 14 mmHg (diastolic) higher than blood pressure in the uppermost arm (p < or = 0.00005). This difference persisted in both lateral positions as epidural analgesia became established. Choosing different definitions of hypotension, baselines and arm to measure blood pressure resulted in 'hypotension rates' between 0% and 75%. For blood pressure measurement in the lateral position, the blood pressure cuff should be placed on the dependent arm.

  8. Intraoperative hypotension - a neglected causative factor in hospital-acquired acute kidney injury; a Mayo Clinic Health System experience revisited.

    PubMed

    Onuigbo, Macaulay Amechi Chukwukadibia; Agbasi, Nneoma

    2015-01-01

    Acute kidney injury (AKI) is a relatively common complication of cardiothoracic surgery and has both short- and long-term survival implications, even when AKI does not progress to severe renal failure. Given that currently, there are no active effective treatments for AKI, other than renal replacement therapy when indicated, the focus of clinicians ought to be on prevention and risk factor management. In the AKI-surgery literature, there exists this general consensus that intraoperative hypotension (IH) following hypotensive anesthesia (HA) or controlled hypotension (CH) in the operating room has no significant short-term and long-term impacts on renal function. In this review, we examine the basis for this consensus, exposing some of the flaws of the clinical study data upon which this prevailing consensus is based. We then describe our experiences in the last decade at the Mayo Clinic Health System, Eau Claire, in Northwestern Wisconsin, USA, with two selected case presentations to highlight the contribution of IH as a potent yet preventable cause of post-operative AKI. We further highlight the causative although neglected role of IH in precipitating postoperative AKI in chronic kidney disease (CKD) patients. We show additional risk factors associated with this syndrome and further make a strong case for the elimination of IH as an achievable mechanism to reduce overall, the incidence of hospital acquired AKI. We finally posit that as the old saying goes, prevention is indeed better than cure. PMID:26468476

  9. Intraoperative hypotension - a neglected causative factor in hospital-acquired acute kidney injury; a Mayo Clinic Health System experience revisited

    PubMed Central

    Onuigbo, Macaulay Amechi Chukwukadibia; Agbasi, Nneoma

    2015-01-01

    Acute kidney injury (AKI) is a relatively common complication of cardiothoracic surgery and has both short- and long-term survival implications, even when AKI does not progress to severe renal failure. Given that currently, there are no active effective treatments for AKI, other than renal replacement therapy when indicated, the focus of clinicians ought to be on prevention and risk factor management. In the AKI-surgery literature, there exists this general consensus that intraoperative hypotension (IH) following hypotensive anesthesia (HA) or controlled hypotension (CH) in the operating room has no significant short-term and long-term impacts on renal function. In this review, we examine the basis for this consensus, exposing some of the flaws of the clinical study data upon which this prevailing consensus is based. We then describe our experiences in the last decade at the Mayo Clinic Health System, Eau Claire, in Northwestern Wisconsin, USA, with two selected case presentations to highlight the contribution of IH as a potent yet preventable cause of post-operative AKI. We further highlight the causative although neglected role of IH in precipitating postoperative AKI in chronic kidney disease (CKD) patients. We show additional risk factors associated with this syndrome and further make a strong case for the elimination of IH as an achievable mechanism to reduce overall, the incidence of hospital acquired AKI. We finally posit that as the old saying goes, prevention is indeed better than cure. PMID:26468476

  10. The Role of Lumbar Sympathetic Nerves in Regulation of Blood Flow to Skeletal Muscle during Anaphylactic Hypotension in Anesthetized Rats.

    PubMed

    Song, Jie; Tanida, Mamoru; Shibamoto, Toshishige; Zhang, Tao; Wang, Mofei; Kuda, Yuhichi; Kurata, Yasutaka

    2016-01-01

    During hypovolemic shock, skeletal muscle blood flow could be redistributed to vital organs via vasoconstriction in part evoked by activation of the innervating sympathetic nerve activity. However, it is not well known whether this mechanism operates during anaphylactic shock. We determined the femoral artery blood flow (FBF) and lumbar sympathetic nerve activity (LSNA) mainly regulating the hindquater muscle blood flow during anaphylactic hypotension in anesthetized rats. Anesthetized Sprague-Dawley rats were randomly allocated to the following groups (n = 7/group): (1) non-sensitized, (2) anaphylaxis, (3) anaphylaxis-lumbar sympathectomy (LS) and (4) anaphylaxis-sinoaortic denervation (SAD) groups. Anaphylaxis was induced by an intravenous injection of the ovalbumin antigen to the sensitized rats. The systemic arterial pressure (SAP), heart rate (HR), central venous pressure (CVP), FBF and LSNA were continuously measured. In the anaphylaxis group, LSNA and HR increased, while SAP and FBF decreased after antigen injection. In the anaphylaxis-SAD group, LSNA did not significantly change during the early phase, but the responses of SAP and FBF were similar to those in the anaphylaxis group. In the anaphylaxis-LS group, both FBF and SAP decreased similarly to the anaphylaxis group during anaphylactic hypotension. These results indicated that LSNA increased via baroreceptor reflex, but this sympathoexcitation or LS did not affect antigen-induced decreases in FBF or SAP. Lumbar sympathetic nerves are not involved in regulation of the blood flow to the hindlimb or systemic blood pressure during anaphylactic hypotension in anesthetized rats. PMID:26998924

  11. Reporting of 'hypotension' after epidural analgesia during labour. Effect of choice of arm and timing of baseline readings.

    PubMed

    Kinsella, S M; Black, A M

    1998-02-01

    We studied 20 women in labour to see how reporting 'hypotension' after obstetric epidural analgesia is affected by position of the blood pressure cuff and baseline definition. Blood pressure was recorded from both arms simultaneously while the woman was semirecumbent and then in the left lateral position. Three readings were then taken after epidural bupivacaine, one left lateral and the remainder right lateral. Before the epidural, blood pressure in the dependent arm in the lateral position was similar to blood pressure in either arm in the semirecumbent position and an average of 10 mmHg (systolic) and 14 mmHg (diastolic) higher than blood pressure in the uppermost arm (p < or = 0.00005). This difference persisted in both lateral positions as epidural analgesia became established. Choosing different definitions of hypotension, baselines and arm to measure blood pressure resulted in 'hypotension rates' between 0% and 75%. For blood pressure measurement in the lateral position, the blood pressure cuff should be placed on the dependent arm. PMID:9534634

  12. [Management of transient radicular pain after receiving an epidural blood patch for headaches due to spontaneous intracranial hypotension].

    PubMed

    Melo, M C; Revuelta, M E; Santeularia, T; Genové, M; Català, E

    2015-11-01

    Spontaneous intracranial hypotension headache is an uncommon disease that resolves spontaneously in most of the cases and in a short period of time. The initial treatment should be symptomatic. In some patients the symptomatology is extremely disabling, and in these cases both the diagnosis and treatment may be performed by an epidural blood patch. A 49-year-old Caucasian woman, with no previous record of epidural or intrathecal puncture, consulted in the Emergency Department complaining of a 9-day history of frontal headache and diplopia, along with nausea and vomiting. The patient was diagnosed with spontaneous intracranial hypotension headache. Considering the symptomatology and the uncontrolled pain, the Pain Unit of our hospital performed an epidural blood patch. In the first 24h the patient reported a remarkable relief of both headache and diplopia but developed a left lumbar radiculopathy that was treated successfully with supportive measures. Transient lumbar radiculopathy is a common and acceptable event secondary to the use of epidural blood patch as a treatment for spontaneous intracranial hypotension headache.

  13. Sonography in Hypotension and Cardiac Arrest (SHoC): Rates of Abnormal Findings in Undifferentiated Hypotension and During Cardiac Arrest as a Basis for Consensus on a Hierarchical Point of Care Ultrasound Protocol

    PubMed Central

    Milne, James; Lewis, David; Fraser, Jacqueline; Diegelmann, Laura; Olszynski, Paul; Stander, Melanie; Lamprecht, Hein

    2016-01-01

    Introduction Point of care ultrasound (PoCUS) has become an established tool in the initial management of patients with undifferentiated hypotension. Current established protocols (RUSH and ACES) were developed by expert user opinion, rather than objective, prospective data. PoCUS also provides invaluable information during resuscitation efforts in cardiac arrest by determining presence/absence of cardiac activity and identifying reversible causes such as pericardial tamponade. There is no agreed guideline on how to safely and effectively incorporate PoCUS into the advanced cardiac life support (ACLS) algorithm. We wished to report disease incidence as a basis to develop a hierarchical approach to PoCUS in hypotension and during cardiac arrest. Methods We summarized the recorded incidence of PoCUS findings from the initial cohort during the interim analysis of two prospective studies. We propose that this will form the basis for developing a modified Delphi approach incorporating this data to obtain the input of a panel of international experts associated with five professional organizations led by the International Federation of Emergency Medicine (IFEM). The modified Delphi tool will be developed to reach an international consensus on how to integrate PoCUS for hypotensive emergency department patients as well as into cardiac arrest algorithms. Results Rates of abnormal PoCUS findings from 151 patients with undifferentiated hypotension included left ventricular dynamic changes (43%), IVC abnormalities (27%), pericardial effusion (16%), and pleural fluid (8%). Abdominal pathology was rare (fluid 5%, AAA 2%). During cardiac arrest there were no pericardial effusions, however abnormalities of ventricular contraction (45%) and valvular motion (39%) were common among the 43 patients included. Conclusions A prospectively collected disease incidence-based hierarchy of scanning can be developed based on the reported findings. This will inform an international consensus

  14. Predialysis hypotension is not a predictor for mortality in long-term hemodialysis patients: insight from a single-center observational study

    PubMed Central

    Huang, Wen-Hung; Hsu, Ching-Wei; Hu, Ching-Chih; Yen, Tzung-Hai; Weng, Cheng-Hao

    2016-01-01

    Introduction Predialysis hypotension has been noted to be a predictor of mortality in hemodialysis (HD) patients. Previous studies evaluating the impact of predialysis hypotension on the mortality of HD patients did not exclude patients with diabetes mellitus (DM) or cardiovascular disease. Methods Eight hundred and sixty-six patients on maintenance HD were recruited. Clinical parameters were recorded and subjected to the analysis of predictors of predialysis hypotension and mortality. Results Multivariate logistic regression analyses indicated that DM (odds ratio [OR]: 0.439, P=0.002), hypertension history (OR: 0.634, P=0.022), Kt/V Daugirdas (OR: 2.545, P=0.001), anuria (OR: 2.313, P=0.002), serum phosphate (OR: 0.833, P=0.010), and serum triglyceride (OR: 1.002, P=0.012) were associated with predialysis hypotension. Multivariate Cox regression analysis showed that age (P<0.001), male sex (P=0.029), anuria (P=0.004), and DM (P=0.011) were associated with higher probability of 24- and 36-month mortality. Predialysis hypotension was not associated with higher probability of 12-, 24-, and 36-month mortality. Conclusion Predialysis hypotension is not a predictor of 12-, 24-, and 36-month survival in patients without DM and with higher dialysis adequacy. PMID:27601912

  15. Autonomic Nervous System Mediates the Hypotensive Effects of Aqueous and Residual Methanolic Extracts of Syzygium polyanthum (Wight) Walp. var. polyanthum Leaves in Anaesthetized Rats

    PubMed Central

    Ismail, A.; Mohamed, M.; Sulaiman, S. A.; Wan Ahmad, W. A. N.

    2013-01-01

    Syzygium polyanthum (Wight) Walp. var. polyanthum leaves are consumed as a traditional Malay treatment of hypertension. This study investigates hypotensive potential of aqueous (AESP) and residual methanolic (met-AESP) extracts of S. polyanthum leaves and possible involvement of autonomic receptors. AESP and met-AESP (20 to 100 mg/kg) were intravenously administered into anaesthetized Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Blood pressure and heart were monitored for 20 min. AESP and met-AESP induced significant dose-dependent hypotension, but only 100 mg/kg AESP caused mild bradycardia (n = 5). AESP-induced hypotension was more potent than that of met-AESP in WKY. AESP has a faster onset time than that of met-AESP in both WKY and SHR. However, met-AESP-induced hypotension was more sustained than that of AESP in SHR. Blockages of autonomic ganglion and α-adrenergic receptors using hexamethonium and phentolamine (n = 5 for each group) partially attenuated AESP-induced hypotension, suggesting involvement of α-adrenergic receptors. Blockages of autonomic ganglion, β-adrenergic, cholinergic receptors, and nitric oxide production using hexamethonium, propranolol, atropine, and N-ω-nitro-l arginine methyl ester (L-NAME) (n = 5 for each group) partially attenuated met-AESP-induced hypotension, suggesting involvement of β-adrenergic and cholinergic receptors via nitric oxide production. PMID:24454508

  16. Predialysis hypotension is not a predictor for mortality in long-term hemodialysis patients: insight from a single-center observational study

    PubMed Central

    Huang, Wen-Hung; Hsu, Ching-Wei; Hu, Ching-Chih; Yen, Tzung-Hai; Weng, Cheng-Hao

    2016-01-01

    Introduction Predialysis hypotension has been noted to be a predictor of mortality in hemodialysis (HD) patients. Previous studies evaluating the impact of predialysis hypotension on the mortality of HD patients did not exclude patients with diabetes mellitus (DM) or cardiovascular disease. Methods Eight hundred and sixty-six patients on maintenance HD were recruited. Clinical parameters were recorded and subjected to the analysis of predictors of predialysis hypotension and mortality. Results Multivariate logistic regression analyses indicated that DM (odds ratio [OR]: 0.439, P=0.002), hypertension history (OR: 0.634, P=0.022), Kt/V Daugirdas (OR: 2.545, P=0.001), anuria (OR: 2.313, P=0.002), serum phosphate (OR: 0.833, P=0.010), and serum triglyceride (OR: 1.002, P=0.012) were associated with predialysis hypotension. Multivariate Cox regression analysis showed that age (P<0.001), male sex (P=0.029), anuria (P=0.004), and DM (P=0.011) were associated with higher probability of 24- and 36-month mortality. Predialysis hypotension was not associated with higher probability of 12-, 24-, and 36-month mortality. Conclusion Predialysis hypotension is not a predictor of 12-, 24-, and 36-month survival in patients without DM and with higher dialysis adequacy.

  17. Effects of fluid preload (crystalloid or colloid) compared with crystalloid co-load plus ephedrine infusion on hypotension and neonatal outcome during spinal anaesthesia for caesarean delivery.

    PubMed

    Gunusen, I; Karaman, S; Ertugrul, V; Firat, V

    2010-07-01

    Preload with crystalloid or colloid solution is widely recommended for the prevention of maternal hypotension during spinal anaesthesia. A combination of simultaneous rapid crystalloid infusion with vasopressor has also been suggested. This study tested the hypothesis that ephedrine infusion with crystalloid loading at spinal anaesthesia would reduce hypotension and alter neonatal outcome compared with fluid preloading. One hundred and twenty women undergoing elective caesarean delivery were randomly allocated to one of three groups to receive rapid infusion of lactated Ringer's solution (20 ml.kg(-1), n=40) or 4% succinylated gelatin solution (500 ml, n =40) before spinal anaesthesia or an ephedrine infusion (1.25 mg.minute(-1)) plus lactated Ringer's solution (1000 ml, n=40) after spinal anaesthesia. The incidence of hypotension (moderate and severe) and the ephedrine dose used to treat hypotension were compared. Neonatal outcome was assessed using Apgar scores and umblical venous and arterial blood gas analysis. The frequency of moderate or severe hypotension was lower in the ephedrine group than in the crystalloid or colloid preload group (10% vs. 51% and 38%; 5% vs. 21% and 23% respectively, P < 0.05). The incidence of nausea was significantly different between the crystalloid preload and ephedrine group. Umbilical blood gas analysis and Apgar scores were similar in all groups. A combination of an ephedrine infusion at 1.25 mg.minute(-1) with a crystalloid co-load was more effective than fluid preloading with crystalloid or colloid in the prevention of moderate and severe hypotension.

  18. The Mark 5 VLBI Data System

    NASA Astrophysics Data System (ADS)

    Whitney, A. R.

    2007-07-01

    The Mark 5 VLBI data system is a disk-based data-recording and playback system for high-data-rate VLBI observations, and has been adopted worldwide for VLBI observations. Approximately 150 Mark 5A systems, capable of recording/playback at 1024 Mbps, are now deployed around the world, directly replacing the Mark 4/VLBA tape-based systems which were prevalent for over 25 years. The Mark 5A system records to an 8-disk removable module which is normally transported to a central correlator facility for processing. The Mark 5B VLBI data system is designed to support the VSI-H international specification and is now being deployed. It is based on the same physical platform and uses the same disk-modules as the Mark 5A; it also supports the same maximum data rate of 1024 Mbps. Data formatting and timetagging is done internally within the Mark 5B, eliminating the need for external formatters. Backwards playback compatibility with Mark 5A is accomplished by an upgrade to the Mark 5A. An upgrade of the Mark 5B system, dubbed Mark 5B+, is now also available and capable of sustained recording at 2 Gbps. The Mark 5C system, currently in development, accepts sampled data through a standard 10 Gigabit Ethernet OSI Layer 2 interface and will support sustained recording up to 4 Gbps. The Mark 5C will support a recording mode which is backwards compatible with the Mark 5B system for playback; Mark 5C is expected to be available in early 2008.

  19. Standards and practices for bite mark photography.

    PubMed

    Golden, G S

    2011-12-01

    In most crimes where bite marks are discovered, photographic accuracy is crucial to the investigative process since in many instances the bite mark(s) may be the only evidence linking a particular suspect to the crime. Therefore, the rationale for employing superior photographic principles is mandatory for the investigation team. This paper will discuss current standards, best practice, and armamentaria for digital photography of bite mark injuries on skin. Full spectrum protocols will be described including Alternate Light Imaging, Reflective Ultra-violet, and Infrared techniques for photo-documentation of images of bite marks and other bruise patterns that have been inflicted on human skin. PMID:22717911

  20. The Mark 5C VLBI Data System

    NASA Astrophysics Data System (ADS)

    Whitney, Alan; Ruszczyk, Chet; Romney, Jon; Owens, Kenneth

    2010-12-01

    The Mark 5C disk-based VLBI data system is being developed as the third-generation Mark 5 disk-based system, increasing the sustained data-recording rate capability to 4 Gbps. It is built on the same basic platform as the Mark 5A, Mark 5B and Mark 5B+ systems and will use the same 8-disk modules as earlier Mark 5 systems, although two 8-disk modules will be necessary to support the 4 Gbps rate. Unlike its earlier brethren, which use proprietary data interfaces, the Mark 5C will accept data from a standard 10 Gigabit Ethernet connection and be compatible with the emerging VLBI Data Interchange Format (VDIF) standard. Data sources for the Mark 5C system will be based on new digital backends now being developed, specifically the RDBE in the U.S. and the dBBC in Europe, as well as others. The Mark 5C system is being planned for use with the VLBI2010 system and will also be used by NRAO as part of the VLBA sensitivity upgrade program; it will also be available to the global VLBI community from Conduant. Mark 5C system specification and development is supported by Haystack Observatory, NRAO, and Conduant Corporation. Prototype Mark 5C systems are expected in early 2010.

  1. Sphenoid Sinus Expansion: A Radiographic Sign of Intracranial Hypotension and The Sunken Eyes, Sagging Brain Syndrome (An American Ophthalmological Society Thesis)

    PubMed Central

    McCulley, Timothy J.

    2013-01-01

    Purpose: To test the hypothesis that in patient with sunken eyes, sagging brain syndrome, bone remodeling is not limited to the orbits. Volumetric analysis of the sphenoid sinus is performed in this study. Methods: In this university-based retrospective case-control study, the dimensions of the sphenoid sinus were measured in four patients (2 males, 2 females; mean age 26.3 years, range 16–38 years) out of five individuals identified with sunken eyes, sagging brain syndrome. Three measurements were taken: the distance between the orbital apices, the posterior extension of the sphenoid sinus posterior to the orbital apices, and the maximal horizontal width. The mean of each was determined and compared to that of the control group (5 males, 5 females; mean age 35.6 years, range 23–45 years). Results: Posterior extension and width of the sphenoid sinus were markedly larger in the enophthalmic patients than in the control group: posterior extension (26.3±4.1 mm vs 13.4±6.3 mm, P=.0015, Student’s t test), width (39.2±8.7 mm vs 25.1±6.9 mm, P=.0035, Student’s t test). Mean distance between the orbital apices was slightly greater (36.3±1.7 mm vs 34.1±2.1 mm, P=.047, Student’s t test). Conclusions: Skull remodeling occurring in association with intracranial hypotension after ventriculoperitoneal shunting is not limited to the orbits. In this study we have demonstrated expansion of the sphenoid sinus. This finding adds to our knowledge and understanding of the scope of the sunken eyes, sagging brain syndrome and elucidates a clinically useful radiographic sign. PMID:24167328

  2. A New Orally Active, Aminothiol Radioprotector-Free of Nausea and Hypotension Side Effects at Its Highest Radioprotective Doses

    SciTech Connect

    Soref, Cheryl M.; Hacker, Timothy A.; Fahl, William E.

    2012-04-01

    Purpose: A new aminothiol, PrC-210, was tested for orally conferred radioprotection (rats, mice; 9.0 Gy whole-body, which was otherwise lethal to 100% of the animals) and presence of the debilitating side effects (nausea/vomiting, hypotension/fainting) that restrict use of the current aminothiol, amifostine (Ethyol, WR-2721). Methods and Materials: PrC-210 in water was administered to rats and mice at times before irradiation, and percent-survival was recorded for 60 days. Subcutaneous (SC) amifostine (positive control) or SC PrC-210 was administered to ferrets (Mustela putorius furo) and retching/emesis responses were recorded. Intraperitoneal amifostine (positive control) or PrC-210 was administered to arterial cannulated rats to score drug-induced hypotension. Results: Oral PrC-210 conferred 100% survival in rat and mouse models against an otherwise 100% lethal whole-body radiation dose (9.0 Gy). Oral PrC-210, administered by gavage 30-90 min before irradiation, conferred a broad window of radioprotection. The comparison of PrC-210 and amifostine side effects was striking because there was no retching or emesis in 10 ferrets treated with PrC-210 and no induced hypotension in arterial cannulated rats treated with PrC-210. The tested PrC-210 doses were the ferret and rat equivalent doses of the 0.5 maximum tolerated dose (MTD) PrC-210 dose in mice. The human equivalent of this mouse 0.5 MTD PrC-210 dose would likely be the highest PrC-210 dose used in humans. By comparison, the mouse 0.5 MTD amifostine dose, 400 {mu}g/g body weight (equivalent to the human amifostine dose of 910 mg/m{sup 2}), when tested at equivalent ferret and rat doses in the above models produced 100% retching/vomiting in ferrets and 100% incidence of significant, progressive hypotension in rats. Conclusions: The PrC-210 aminothiol, with no detectable nausea/vomiting or hypotension side effects in these preclinical models, is a logical candidate for human drug development to use in healthy

  3. Nitroglycerine, esmolol and dexmedetomidine for induced hypotension during functional endoscopic sinus surgery: A comparative evaluation

    PubMed Central

    Bajwa, Sukhminder Jit Singh; Kaur, Jasleen; Kulshrestha, Ashish; Haldar, Rudrashish; Sethi, Rakesh; Singh, Amarjit

    2016-01-01

    Background and Aim: Induced hypotension limits intra-operative blood loss to provide better visibility of the surgical field and diminishes the incidence of major complications during functional endoscopic sinus surgery (FESS). We aimed at comparing nitroglycerine, esmolol and dexmedetomidine for inducing controlled hypotension in patients undergoing FESS. Material and Methods: One hundred and fifty American Society of Anesthesiologists physical status I or II adult patients undergoing FESS under general anesthesia were randomly allocated to three groups of 50 patients each. Group E received esmolol in a loading and maintenance dose of 1 mg/kg over 1 min and 0.5-1.0 mg/kg/h, respectively. Group D received a loading dose of dexmedetomidine 1 μg/kg over 10 min followed by an infusion 0.5-1.0 μg/kg/h, and group N received nitroglycerine infusion at a dose of 0.5-2 μg/kg/min so as to maintain mean arterial pressure (MAP) between 60 and 70 mmHg in all the groups. The visibility of the surgical field was assessed by surgeon using Fromme and Boezaart scoring system. Hemodynamic variables, total intra-operative fentanyl consumption, emergence time and time to first analgesic request were recorded. Any side-effects were noted. The postoperative sedation was assessed using Ramsay Sedation Score. Result: The desired MAP (60-70 mmHg) could be achieved in all the three study groups albeit with titration of study drugs during intra-operative period. No significant intergroup difference was observed in Fromme's score during the intra-operative period. The mean total dose of fentanyl (μg/kg) used was found to be significantly lower in group D compared to groups E and N (1.2 ± 0.75 vs. 3.6 ± 1.3 and 2.9 ± 1.1 respectively). The mean heart rate was significantly lower in group D compared to groups E and N at all times of measurement (P < 0.05). The MAP was found to be significantly lower in group D compared to groups E and N after infusion of study drugs, after induction

  4. Efficacy of compression of different capacitance beds in the amelioration of orthostatic hypotension

    NASA Technical Reports Server (NTRS)

    Denq, J. C.; Opfer-Gehrking, T. L.; Giuliani, M.; Felten, J.; Convertino, V. A.; Low, P. A.

    1997-01-01

    Orthostatic hypotension (OH) is the most disabling and serious manifestation of adrenergic failure, occurring in the autonomic neuropathies, pure autonomic failure (PAF) and multiple system atrophy (MSA). No specific treatment is currently available for most etiologies of OH. A reduction in venous capacity, secondary to some physical counter maneuvers (e.g., squatting or leg crossing), or the use of compressive garments, can ameliorate OH. However, there is little information on the differential efficacy, or the mechanisms of improvement, engendered by compression of specific capacitance beds. We therefore evaluated the efficacy of compression of specific compartments (calves, thighs, low abdomen, calves and thighs, and all compartments combined), using a modified antigravity suit, on the end-points of orthostatic blood pressure, and symptoms of orthostatic intolerance. Fourteen patients (PAF, n = 9; MSA, n = 3; diabetic autonomic neuropathy, n = 2; five males and nine females) with clinical OH were studied. The mean age was 62 years (range 31-78). The mean +/- SEM orthostatic systolic blood pressure when all compartments were compressed was 115.9 +/- 7.4 mmHg, significantly improved (p < 0.001) over the head-up tilt value without compression of 89.6 +/- 7.0 mmHg. The abdomen was the only single compartment whose compression significantly reduced OH (p < 0.005). There was a significant increase of peripheral resistance index (PRI) with compression of abdomen (p < 0.001) or all compartments (p < 0.001); end-diastolic index and cardiac index did not change. We conclude that denervation increases vascular capacity, and that venous compression improves OH by reducing this capacity and increasing PRI. Compression of all compartments is the most efficacious, followed by abdominal compression, whereas leg compression alone was less effective, presumably reflecting the large capacity of the abdomen relative to the legs.

  5. The effect of exercise intensity on postresistance exercise hypotension in trained men.

    PubMed

    Duncan, Michael J; Birch, Samantha L; Oxford, Samuel W

    2014-06-01

    The occurrence of postresistance exercise hypotension (PEH) after resistance exercise remains unknown. This study examined blood pressure and heart rate (HR) responses to an acute bout of low- and high-intensity resistance exercise, matched for total work, in trained males. Sixteen resistance-trained males (23.1 ± 5.9 years) performed an acute bout of low- (40% of 1 repetition maximum [1RM]) and high-intensity resistance exercise (80% 1RM), matched for total work, separated by 7 days and performed in a counterbalanced order. Systolic blood pressure (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), and HR were assessed before exercise, after completion of each exercise resistance exercise (3 sets of back squat, bench press, and deadlift) and every 10 minutes after resistance exercise for a period of 60 minutes. Results indicated a significant intensity × time interaction for SBP (p = 0.034, partial η(2) = 0.122) and MAP (p = 0.047, partial η(2) = 0.116) whereby SBP and MAP at 50-minute recovery and 60-minute recovery were significantly lower after high-intensity exercise (p = 0.01 for SBP and p = 0.05 for MAP in both cases) compared with low-intensity exercise. There were no significant main effects or interactions in regard to DBP (all p > 0.05). Heart rate data indicated a significant main effect for time (F(9, 135) = 2.479, p = 0.0001, partial η(2) = 0.344). Post hoc multiple comparisons indicated that HR was significantly higher after squat, bench press, and deadlift exercise compared with resting HR and HR at 40-, 50-, and 60-minute recovery (all p = 0.03). The present findings suggest that an acute bout of high intensity, but not low intensity, resistance exercise using compound movements can promote PEH in trained men. PMID:24276299

  6. Vasorelaxant and hypotensive effects of Allium cepa peel hydroalcoholic extract in rat.

    PubMed

    Naseri, Mohammad Kazem Gharib; Arabian, Maedeh; Badavi, Mohammad; Ahangarpour, Akram

    2008-06-15

    The aim of present study was to investigate the effect of onion (Allium cepa) peel hydroalcoholic extract (OPE) on rat hypertension induced by high-fructose diet and aorta contractility. The OPE was prepared by maceration method using 70% ethanol. The thoracic aorta from male adult rat (Wistar) was dissected and suspended in Krebs-Henseleit solution under 1 g resting tension. Tissue preparation was contracted by KCl (80 mM) or phenylephrine (Phe, 1 microM) and then the extract was applied cumulatively (0.0625-2 mg mL(-1)). Hypertension was induced in negative control and three groups of rats by adding fructose (10% WN/V) in drinking water for 6 weeks but control group received tap water. Hypertensive groups received saline or OPE at 200, 400 and 800 mg kg(-1) daily for last 3 weeks by gavage. Results showed that OPE reduces aorta contractions induced by KCl or Phe in a concentration-dependent manner (p < 0.001). Removing aorta endothelium did not attenuate the OPE activity. Inhibition of nitric oxide, cGMP and prostaglandin synthesis by L-NAME (100 microM), methylene blue (10 microM) and indomethacin (10 microM), respectively, did not attenuate OPE activity. Atropine abolished ACh-induced relaxation in Phe precontracted aorta but not the OPE-induced relaxation. Although the extract did not change heart rate but after 3 weeks reduced the hypertension induced by fructose (p < 0.001). Present results indicated that OPE reduces aortic contractions possibly via inhibition of calcium influx but without involving NO, cGMP, endothelium and prostaglandins. The OPE hypotensive effect could be due to extract quercetin content, antioxidant activity and inhibiting vascular smooth muscle cells Ca2+ influx. PMID:18819643

  7. Initial Systolic Time Interval (ISTI) as a Predictor of Intradialytic Hypotension (IDH)

    NASA Astrophysics Data System (ADS)

    Biesheuvel, J. D.; Vervloet, M. G.; Verdaasdonk, R. M.; Meijer, J. H.

    2013-04-01

    In haemodialysis treatment the clearance and volume control by the kidneys of a patient are partially replaced by intermittent haemodialysis. Because this artificial process is performed on a limited time scale, unphysiological imbalances in the fluid compartments of the body occur, that can lead to intradialytic hypotensions (IDH). An IDH endangers the efficacy of the haemodialysis session and is associated with dismal clinical endpoints, including mortality. A diagnostic method that predicts the occurrence of these drops in blood pressure could facilitate timely measures for the prevention of IDH. The present study investigates whether the Initial Systolic Time Interval (ISTI) can provide such a diagnostic method. The ISTI is defined as the time difference between the R-peak in the electrocardiogram (ECG) and the C-wave in the impedance cardiogram (ICG) and is considered to be a non-invasive assessment of the time delay between the electrical and mechanical activity of the heart. This time delay has previously been found to depend on autonomic nervous function as well as preload of the heart. Therefore, it can be expected that ISTI may predict an imminent IDH caused by a low circulating blood volume. This ongoing observational clinical study investigates the relationship between changes in ISTI and subsequent drops in blood pressure during haemodialysis. A registration of a complicated dialysis showed a significant correlation between a drop in blood pressure, a decrease in relative blood volume and a substantial increase in ISTI. An uncomplicated dialysis, in which also a considerable amount of fluid was removed, showed no correlations. Both, blood pressure and ISTI remained stable. In conclusion, the preliminary results of the present study show a substantial response of ISTI to haemodynamic instability, indicating an application in optimization and individualisation of the dialysis process.

  8. A long-lasting hypotensive effect of topical diltiazem on the intraocular pressure in conscious rabbits.

    PubMed

    Santafé, J; Martínez de Ibarreta, M J; Segarra, J; Melena, J

    1997-05-01

    The effect of calcium channel blockers on intraocular pressure and aqueous humor dynamics remains still controversial, although preliminary evidence suggests that these drugs may be beneficial in the management of ocular hypertension and low-tension glaucoma. Having previously reported the ocular hypotensive effect of topical nifedipine and verapamil in albino rabbits, the original aim of the present work was to evaluate the effect of topical diltiazem on aqueous humor dynamics in this species. Intraocular pressure was measured with a manual applanation tonometer. The experiments examining the ocular actions of diltiazem were carried out in two stages. In the first one, short term effects of topical diltiazem on intraocular pressure were studied in groups of 13 albino rabbits receiving 8 different doses of the drug in order to obtain a dose-response curve. Tonographies were performed in 13 anaesthetized animals before and 90 min after drug instillation. In a second phase, the persistence of the effect of diltiazem on intraocular pressure was examined in 6 groups of 10 rabbits each receiving three different doses of the drug. Topical diltiazem was found to lower intraocular pressure in a dose-related fashion. The maximum response to diltiazem was greater and the ED50 lower than those previously reported for nifedipine and verapamil. In the tonographic study, diltiazem was shown to reduce the facility of aqueous humor outflow and inflow. Diltiazem exhibited a long lasting effect on intraocular pressure that was again dose-related. Depending on the dose administered, the calculated time necessary for the peak effect to be halved ranged from 0.6 to 7.0 days. Due to the intensity and the persistence of its intraocular pressure-lowering effect, diltiazem shows great potential for the treatment of glaucoma, since a daily or less frequent administration may be enough to control ocular hypertension.

  9. Improvement of Intradialytic Hypotension in Diabetic Hemodialysis Patients Using Vitamin E-Bonded Polysulfone Membrane Dialyzers

    PubMed Central

    Koremoto, Masahide; Takahara, Noriko; Takahashi, Masahiro; Okada, Yasuhiro; Satoh, Kouhei; Kimura, Tomoyoshi; Hirai, Tomoyuki; Ebihara, Itaru; Nagasaku, Daisuke; Miyata, Shigeo; Maniwa, Shunji; Kouzuma, Takuji; Arimura, Tetsurou; Kamei, Junzou

    2012-01-01

    Currently, there are no detailed reports on the effects of vitamin E-bonded polysulfone (PS) membrane dialyzers on intradialytic hypotension (IDH) in diabetic hemodialysis (HD) patients. This study was designed to evaluate changes in intradialytic systolic blood pressure (SBP) using “VPS-HA” vitamin E-bonded super high-flux PS membrane dialyzers. The subjects were 62 diabetic HD patients whose intradialytic SBP fell by more than 20%. Group A comprised patients who required vasopressors to be able to continue treatment or who had to discontinue therapy due to their lowest intradialytic SBP being observed at 210 min (28 patients). Group B comprised patients who showed no symptoms and required no vasopressors but showed a gradual reduction in blood pressure, with the lowest intradialytic SBP seen at the end of dialysis (34 patients). The primary outcome was defined as the lowest intradialytic SBP after 3 months using VPS-HA. Secondary outcomes included changes in the following: lowest intradialytic diastolic blood pressure, pulse pressure, pulse rate, plasma nitric oxide and peroxynitrite, serum albumin, and hemoglobin A1c. Group A's lowest intradialytic SBP had significantly improved at 3 months (128.0 ± 25.1 mm Hg vs. 117.1 ± 29.2 mm Hg; P = 0.017). Group B's lowest intradialytic SBP had significantly improved at 1 month (134.4 ± 13.2 mm Hg vs. 121.5 ± 25.8 mm Hg; P = 0.047) and 3 months (139.1 ± 20.9 mm Hg vs. 121.5 ± 25.8 mm Hg; P = 0.011). We conclude that VPS-HA may improve IDH in diabetic HD patients. PMID:22845774

  10. Are current recommendations to diagnose orthostatic hypotension in Parkinson's disease satisfactory?

    PubMed

    Jamnadas-Khoda, Jenny; Koshy, Suma; Mathias, Christopher J; Muthane, Uday B; Ragothaman, Mona; Dodaballapur, Subbakrishna K

    2009-09-15

    We interviewed 50 Parkinson's disease (PD) patients using a questionnaire to verify the reliability of orthostatic symptoms in warning the presence of orthostatic hypotension (OH). OH is defined as 20 mm Hg systolic or 10 mm Hg diastolic BP fall within 3 min of tilting or standing but if this fall occurs after 3 min we called it 'late OH' (L-OH). We compared if OH in Parkinson's disease (PD) was more frequent after head-up tilt or on standing and if the period of postural challenge matters in detecting OH. Twenty-one (42%) patients had OH that occurred twice more often after tilting (n = 20) than on standing (n = 10). OH occurred within 3 min of tilting in 9 patients (18%) and appeared beyond the currently recommended 3 min in 11 patients (55%) (L-OH). Ten of the 20 patients developing OH on tilting were symptomatic. The 10 patients who had OH on standing were asymptomatic. Reporting of symptoms was independent of age or severity of BP fall. Most (90%) patients reporting orthostatic symptoms on standing had OH on tilting for 3 min. Orthostatic symptoms in PD have a high specificity but low sensitivity in predicting OH. In Parkinson's disease OH occurs often after tilting than on standing and is delayed (after 3 min). As OH in PD is often asymptomatic and delayed it could contribute to falls and increase morbidity. We suggest routine evaluation of OH in PD by tilting them longer than the recommended 3 minutes to detect delayed OH.

  11. Hypovolemia Induced Orthostatic Hypotension in Presyncopal Astronauts and Normal Subjects Related to Hypoadrenergic Responsiveness

    NASA Technical Reports Server (NTRS)

    Meck, Janice V.; Platts, Steven H.; Waters, Wendy W.; Shi, Shang-Jin; Hayashi, Yuho; Perez, Sondra A.; Ziegler, Michael G.

    2006-01-01

    Circulating blood volume is reduced during spaceflight, making astronauts hemodynamically compromised. After landing, astronauts separate into two groups. One group compensates for the hypovolemia with a hyper-sympathetic response during upright tilt testing and can complete a tilt test with few symptoms. The other group is unable to mount a hyper-sympathetic response and experiences orthostatic hypotension and presyncope during upright tilt tests. We tested the hypothesis that hypovolemia alone, in the absence of spaceflight, also would cause subjects to separate into presyncopal and non-presyncopal groups according to their sympathetic responses during tilt. We studied 20 subjects, including 10 veteran astronauts, on three occasions. On Days 1 (normovolemia) and 3 (hypovolemia), plasma volume, tilt tolerance and supine and standing plasma norepinephrine levels were measured. Forty hours prior to Day 3, subjects were given intravenous furosemide, followed by 36 hours of a 10MEq Na diet. Statistical comparisons were made between normovolemia and hypovolemia responses. This protocol reproduced landing day tilt test outcomes with 100% fidelity in the astronauts. Similarly to patterns reported after flight, non-presyncopal subjects had greater norepinephrine responses to tilt during hypovolemia compared to normovolemia (580 plus or minus 79 vs. 298 plus or minus 37 pg/ml, P less than 0.05), but presyncopal subjects had no increase (180 plus or minus 44 vs. 145 plus or minus 32 pg/ml, P=NS). This model can be used to predict astronauts who will become presyncopal on landing day, so that prospective, individualized countermeasures can be developed. Within patient populations, it can be used to study the interaction of volemic state and the sympathetic nervous system.

  12. Spectral analysis of heart rate dynamics in elderly persons with postprandial hypotension

    NASA Technical Reports Server (NTRS)

    Ryan, S. M.; Goldberger, A. L.; Ruthazer, R.; Mietus, J.; Lipsitz, L. A.

    1992-01-01

    Prior studies suggest that postprandial hypotension in elderly persons may be due to defective sympathetic nervous system activation. We examined autonomic control of heart rate (HR) after a meal using spectral analysis of HR data in 13 old (89 +/- 6 years) and 7 young (24 +/- 4 years) subjects. Total spectral power, an index of overall HR variability, was calculated for the frequency band between 0.01 and 0.40 Hz. Relatively low-frequency power, associated with sympathetic nervous system and baroreflex activation, was calculated for the 0.01 to 0.15 Hz band. High-frequency power, representing parasympathetic influences on HR, was calculated for the 0.15 to 0.40 Hz band. Mean arterial blood pressure declined 27 +/- 8 mm Hg by 60 minutes after the meal in elderly subjects, compared with 9 +/- 8 mm Hg in young subjects (p less than or equal to 0.0001, young vs old). The mean change in low-frequency HR power from 30 to 50 minutes after the meal was +19.4 +/- 25.3 U in young subjects versus -0.1 +/- 1.5 U in old subjects (p less than or equal to 0.02). Mean change in total power was also greater in young (19.0 +/- 26.6 U) subjects compared with old subjects (0.0 +/- 1.6 U, p greater than or equal to 0.02). Mean ratio of low:high-frequency power increased 3.1 +/- 3.3 U in young subjects vs 0.5 +/- 2.7 U in old subjects (p less than or equal to 0.01). The increase in low-frequency HR power and in the low:high frequency band ratio in young subjects is consistent with sympathetic activation in the postprandial period.(ABSTRACT TRUNCATED AT 250 WORDS).

  13. RGB marking facilitates multicolor clonal cell tracking.

    PubMed

    Weber, Kristoffer; Thomaschewski, Michael; Warlich, Michael; Volz, Tassilo; Cornils, Kerstin; Niebuhr, Birte; Täger, Maike; Lütgehetmann, Marc; Pollok, Jörg-Matthias; Stocking, Carol; Dandri, Maura; Benten, Daniel; Fehse, Boris

    2011-04-01

    We simultaneously transduced cells with three lentiviral gene ontology (LeGO) vectors encoding red, green or blue fluorescent proteins. Individual cells were thereby marked by different combinations of inserted vectors, resulting in the generation of numerous mixed colors, a principle we named red-green-blue (RGB) marking. We show that lentiviral vector-mediated RGB marking remained stable after cell division, thus facilitating the analysis of clonal cell fates in vitro and in vivo. Particularly, we provide evidence that RGB marking allows assessment of clonality after regeneration of injured livers by transplanted primary hepatocytes. We also used RGB vectors to mark hematopoietic stem/progenitor cells that generated colored spleen colonies. Finally, based on limiting-dilution and serial transplantation assays with tumor cells, we found that clonal tumor cells retained their specific color-code over extensive periods of time. We conclude that RGB marking represents a useful tool for cell clonality studies in tissue regeneration and pathology. PMID:21441917

  14. Should dopamine be the first line inotrope in the treatment of neonatal hypotension? Review of the evidence

    PubMed Central

    Bhayat, Sadaf I; Gowda, Harsha M S; Eisenhut, Michael

    2016-01-01

    AIM: To determine if dopamine is effective in treating neonatal hypotension and safe to use comparing to other inotropes. METHODS: This is a review of evidence on inotropic treatment of neonatal hypotension. Databases searched were MEDLINE and the Cochrane Library, a total of 134 studies were identified. Only studies with high quality evidence (level 1a and b and 2a) were included. After review, only eight studies were included in the final analysis. Pooled risk ratios derived for each outcome [Mantel-Haenzel (M-H) fixed effect] with CI, as reported in the Cochrane reviews were plotted in forest plot form. RESULTS: Eight articles met inclusion criteria, which all included treatment in preterm infants. Dopamine increased mean arterial blood pressure (BP) (n = 163; r = 0.88, 95%CI: 0.76 to 0.94) and systolic BP (n = 142; r = 0.81, 95%CI: 0.42 to 0.94) comparing to placebo. Dopamine has been shown overall to be statistically more effective in increasing BP than dobutamine (n = 251, r = 0.26, 95%CI: 0.20-0.32). However there were no differences in short term outcomes (periventricular leucomalacia, periventricular haemorrhage) and mortality between both drugs. There is no statistical evidence of dopamine being more effective than adrenaline or corticosteroids. There was no difference in morbidity and mortality outcomes when dopamine was compared to hydrocortisone (RR 1.81, 95%CI: 0.18 to 18.39) or adrenaline. CONCLUSION: In preterms, dopamine is the most studied drug, and we suggest it could be used as first line treatment in hypotension. PMID:27170932

  15. Different preloading protocols with constant ephedrine infusion in the prevention of hypotension for elective cesarean section under spinal anesthesia.

    PubMed

    Faydaci, F; Gunaydin, B

    2011-01-01

    Ninety ASA I or II parturients were randomly allocated to three groups: group 10RL, 15RL and 20RL to receive 10, 15 and 20 mL/kg of Ringer's lactate (RL) respectively within 15 minutes (min) before the spinal block. Spinal anesthesia was performed with hyperbaric bupivacaine 12 mg, morphine 100 microg and fentanyl 10 microg. The operating table was tilted to the left and an IV infusion of ephedrine of 3 mg/min was immediately started and continued until umbilical cord clamping in all groups. Hypotension was defined as a drop in mean arterial pressure (MAP) of more than 20% from baseline : this was treated with 10 mg ephedrine IV. The incidence of hypotension was 60%, 36.7% and 13.4% in group 10RL, 15RL and 20RL, respectively (p<0.05). Additional ephedrine dose was the lowest in group 20RL compared to the other groups (p<0.05). The total amount of ephedrine was 49.9 +/- 13.5, 46.4 +/- 13.4 and 38.4 +/- 8.5 mg in group 10RL, 15RL and 20RL, respectively (p <0.05). The incidence of nausea and vomiting in group 20RL was significantly less than in group 10RL (p = 0.02). It was concluded that preloading with 20 mL/kg of RL prior to spinal anesthesia followed by constant ephedrine infusion 3 mg/min after spinal block reduced the incidence of hypotension and of nausea and vomiting and decreased the total amount of ephedrine.

  16. Oscillometric measure of blood pressure detects association between orthostatic hypotension and depression in population based study of older adults

    PubMed Central

    2013-01-01

    Background White matter hyperintensities may contribute to depression by disrupting neural connections among brain regions that regulate mood. Orthostatic hypotension (OH) may be a risk factor for white matter hyperintensities and accumulating evidence, although limited suggests it may play a role in the development of late-life depression. The aim of this study was to examine the relationship between an oscillometric measure of orthostatic hypotension and depression in population based sample of older adults. Methods We analysed data on adults aged 60 and over from the first wave of The Irish Longitudinal Study on Ageing (TILDA). Depression was assessed using the Center for Epidemiologic Studies – Depression (CES–D) scale and OH was assessed by a sit-to-stand orthostatic stress test; two seated blood pressure measurements were followed by a single standing blood pressure measurement. Participants self reported whether they felt dizzy, light-headed or unsteady on standing. Results Participants with symptomatic OH (SOH, n=20) had the highest mean CES-D score (mean 8.6, SE 1.6) when compared to participants with asymptomatic OH (AOH) (mean 5.6, SE .48) and participants with no OH (mean 5.2, SE .14) and this difference was significant for both comparisons (p<0.001). Linear regression analysis adjusted for socio-demographic and clinical characteristics showed that SOH was associated with higher CES-D scores (unstandardised B coefficient = 2.24; 95% CI .301 - 4.79; p =0.05) compared to participants without OH. AOH was not associated with higher CES-D scores (unstandardised B coefficient =.162; 95% CI -.681, 1.00; p= 0.70). Conclusions Symptomatic orthostatic hypotension is associated with depression in older adults and needs to be considered in studies examining the relationship between vascular disease and depression in older adults. PMID:24138959

  17. Comparison between nitroglycerin and remifentanil in acute hypervolemic hemodilution combined with controlled hypotension during intracranial aneurysm surgery

    PubMed Central

    Zhang, Xuekang; Hu, Qian; Liu, Zhiyi; Huang, Haijin; Zhang, Qin; Dai, Hanying

    2015-01-01

    Allogenetic transfusion has long been considered to be a relatively safe and extremely effective blood transfusion treatment. However, acute hypervolemic hemodilution (AHH) combined with the remifentanil-induced controlled hypotension (CH) have rarely been examined. Herein, 40 intracranial aneurysm surgery patients were randomly divided into nitroglycerin group (A group, n=20) and remifentanil group (B group, n=20). During intracranial aneurysm surgery, MAP, HR, Hb, and Hct were recorded. SjvO2, PjvO2, SaO2, PaO2 were measured, and CaO2, Da-jvO2, CjvO2, CERO2, VADL were calculated. In addition, The venous blood samples were collected for determining PT, TT, APTT, FBG, VIII, VWF and electrolytes. The results show that HR in nitroglycerin group dramatically accelerated and HR in remifentanil group slowed at 30 minutes after hypotension and 5 minutes after aneurysm occlusion (P<0.01) after hypotension. Compared with A group, the SjvO2 and CjvO2 of B group increased significantly and the Da-jvO2 and CERO2 decreased significantly at T3, T4. In addition, There were no significant differences between after AHH and before AHH in two groups (P>0.05) on TT, PT, APTT, FIB, VIII, VWF, Na+, Cl-, K+, Ca2+. These results suggest that AHH combined with remifentanil-based CH significantly lowered cerebral metabolic rate of oxygen and had effects on blood coagulation without clinical hemorrhagic signs increased and had important clinical significance for blood conservation. PMID:26770575

  18. 27 CFR 28.123 - Export marks.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Export marks. 28.123 Section 28.123 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT..., or Transportation to a Manufacturing Bonded Warehouse § 28.123 Export marks. (a) General. In...

  19. 46 CFR 162.161-8 - Marking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 6 2012-10-01 2012-10-01 false Marking. 162.161-8 Section 162.161-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Fixed Clean Agent Fire Extinguishing Systems § 162.161-8 Marking. The following information must be displayed...

  20. 46 CFR 58.16-35 - Markings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Markings. 58.16-35 Section 58.16-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-35 Markings. (a) The outside of...

  1. 46 CFR 58.16-35 - Markings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Markings. 58.16-35 Section 58.16-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-35 Markings. (a) The outside of...

  2. 46 CFR 58.16-35 - Markings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Markings. 58.16-35 Section 58.16-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-35 Markings. (a) The outside of...

  3. 46 CFR 58.16-35 - Markings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Markings. 58.16-35 Section 58.16-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-35 Markings. (a) The outside of...

  4. 46 CFR 58.16-35 - Markings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Markings. 58.16-35 Section 58.16-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-35 Markings. (a) The outside of...

  5. 30 CFR 7.90 - Approval marking.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Diesel Engines Intended for Use in Underground Coal Mines § 7.90 Approval marking. Each approved diesel engine shall be identified by a legible and... diesel engine. The marking shall also contain the following information: (a) Ventilation rate. (b)...

  6. 30 CFR 7.90 - Approval marking.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Diesel Engines Intended for Use in Underground Coal Mines § 7.90 Approval marking. Each approved diesel engine shall be identified by a legible and... diesel engine. The marking shall also contain the following information: (a) Ventilation rate. (b)...

  7. 30 CFR 7.90 - Approval marking.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Diesel Engines Intended for Use in Underground Coal Mines § 7.90 Approval marking. Each approved diesel engine shall be identified by a legible and... diesel engine. The marking shall also contain the following information: (a) Ventilation rate. (b)...

  8. 30 CFR 7.90 - Approval marking.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Diesel Engines Intended for Use in Underground Coal Mines § 7.90 Approval marking. Each approved diesel engine shall be identified by a legible and... diesel engine. The marking shall also contain the following information: (a) Ventilation rate. (b)...

  9. 30 CFR 7.90 - Approval marking.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Diesel Engines Intended for Use in Underground Coal Mines § 7.90 Approval marking. Each approved diesel engine shall be identified by a legible and... diesel engine. The marking shall also contain the following information: (a) Ventilation rate. (b)...

  10. 46 CFR 160.053-5 - Marking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 6 2014-10-01 2014-10-01 false Marking. 160.053-5 Section 160.053-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-5 Marking....

  11. 46 CFR 160.053-5 - Marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Marking. 160.053-5 Section 160.053-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-5 Marking....

  12. 46 CFR 160.053-5 - Marking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 6 2013-10-01 2013-10-01 false Marking. 160.053-5 Section 160.053-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-5 Marking....

  13. 7 CFR 956.162 - Container markings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Container markings. 956.162 Section 956.162... WALLA VALLEY OF SOUTHEAST WASHINGTON AND NORTHEAST OREGON Rules and Regulations § 956.162 Container markings. Effective April 15, 1997, no handler shall ship any container of Walla Walla Sweet Onions...

  14. 46 CFR 160.017-25 - Marking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Marking. 160.017-25 Section 160.017-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-25 Marking. (a) Each chain ladder...

  15. 46 CFR 163.003-25 - Marking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Marking. 163.003-25 Section 163.003-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-25 Marking. (a) Each pilot ladder...

  16. 46 CFR 163.003-25 - Marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Marking. 163.003-25 Section 163.003-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL CONSTRUCTION Pilot Ladder § 163.003-25 Marking. (a) Each pilot ladder...

  17. 46 CFR 160.017-25 - Marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Marking. 160.017-25 Section 160.017-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Chain Ladder § 160.017-25 Marking. (a) Each chain ladder...

  18. 46 CFR 160.036-5 - Marking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Hand-Held Rocket-Propelled Parachute Red Flare Distress Signals § 160.036-5 Marking. (a) General. Each hand-held rocket-propelled parachute red flare distress signal shall be legibly marked or labeled as follows: (Company brand or style designation) Hand-Held...

  19. 46 CFR 160.036-5 - Marking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Hand-Held Rocket-Propelled Parachute Red Flare Distress Signals § 160.036-5 Marking. (a) General. Each hand-held rocket-propelled parachute red flare distress signal shall be legibly marked or labeled as follows: (Company brand or style designation) Hand-Held...

  20. 46 CFR 160.036-5 - Marking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Hand-Held Rocket-Propelled Parachute Red Flare Distress Signals § 160.036-5 Marking. (a) General. Each hand-held rocket-propelled parachute red flare distress signal shall be legibly marked or labeled as follows: (Company brand or style designation) Hand-Held...