The effect of acidosis on the labelling of urinary ammonia during infusion of [amide-15N]glutamine in human subjects

In three experiments [amide-15N]glutamine was infused intravenously in male volunteers. After 4-8 h of infusion acidosis was achieved by an oral dose of CaCl2 (1 mmol/kg). In one subject acidosis was maintained for 5 d. The acid load produced an approximately 3-fold increase in urinary NH3 excretion, with a small (approximately 20%) and transient increase in the isotope abundance of urinary NH3 Estimates of glutamine production rate (flux) were obtained in two experiments. There was no evidence that it was increased in acidosis. The extra NH3 production by the kidney represented only a very small part, about 3%, of the total glutamine production rat

Splanchnic metabolism of nutrients and hormones in steers fed alfalfa under conditions of increased absorption of ammonia and L-arginine supply across the portal-drained viscera

Effects of increased ammonia and/or arginine absorption on net splanchnic (portal-drained viscera [PDV] plus liver) metabolism of nonnitrogenous nutrients and hormones in cattle were examined. Six Hereford × Angus steers (501 ± 1 kg BW) prepared with vascular catheters for measurements of net flux across the splanchnic bed were fed a 75% alfalfa:25% (as-fed basis) corn and soybean meal diet (0.523 MJ of ME/[kg BW0.75.d]) every 2 h without (27.0 g of N/kg of DM) and with 20 g of urea/kg of DM (35.7 g of N/kg of DM) in a split-plot design. Net flux measurements were made immediately before and after a 72-h mesenteric vein infusion of L-arginine (15 mmol/h). There were no treatment effects onPDVor hepaticO2 consumption. Dietary urea had no effect on splanchnic metabolism of glucose or L-lactate, but arginine infusion decreased net hepatic removal of L-lactate when urea was fed (P < 0.01). Net PDV appearance of n-butyrate was increased by arginine infusion (P < 0.07), and both dietary urea (P < 0.09) and arginine infusion (P < 0.05) increased net hepatic removal of n-butyrate. Dietary urea also increased total splanchnic acetate output (P < 0.06), tended to increase arterial glucagon concentration (P < 0.11), and decreased arterial ST concentration (P < 0.03). Arginine infusion increased arterial concentration (P < 0.07) and net PDV release (P < 0.10) and tended to increase hepatic removal (P < 0.11) of insulin, as well as arterial concentration (P < 0.01) and total splanchnic output (P < 0.01) of glucagon. Despite changes in splanchnic N metabolism, increased ammonia and arginine absorption had little measurable effect on splanchnic metabolism of glucose and other nonnitrogenous components of splanchnic energy metabolism

An isotope dilution model for partitioning of phenylalanine and tyrosine uptake by the liver of lactating dairy cows

An isotope dilution model to describe the partitioning of phenylalanine (PHE) and tyrosine (TYR) in the bovine liver was developed. The model comprises four intracellular and six extracellular pools and various flows connecting these pools and external blood. Conservation of mass principles were applied to generate the fundamental equations describing the behaviour of the system in the steady state. The model was applied to datasets from multi-catheterised dairy cattle during a constant infusion of [1-13C] phenylalanine and [2,3,5,6-2H] tyrosine tracers. Model solutions described the extraction of PHE and TYR from the liver via the portal vein and hepatic artery. In addition, the exchange of free PHE and TYR between extracellular and intracellular pools was explained and the hydroxylation of PHE to TYR was estimated. The model was effective in providing information about the fates of PHE and TYR in the liver and could be used as part of a more complex system describing amino acid metabolism in the whole animal

Nature, change and agency in Aristotle's Physics

The concept of "nature as inner principle of change" is fundamental to Aristotle's theory of the physical world; it is the object of the present thesis to substantiate this claim by tracing the effects of this idea in Aristotle's rejection of materialism, in his doctrine of "natural places", in his definition of change and process in general, and (via the latter) in his notion of agency in general and the supreme Unmoved Mover in particular ((1)). Aristotle elucidates "natural" by . contrast with "artificial" ((2) - (3)), holding that natural substances not merely collectively ((4) - (5)) but as individuals each possess an 'innate impulse of change'. But this must be explained so as to allow for the fact that no change is entirely independent of external conditions ((6) - (7)). If, however, change were totally dependent on external conditions, its occurrence would be inexplicable ((8) - (9)), and the very concept of "change" would be incoherent. This latter conclusion emerges from an examination of the ancient paradox of becoming and Aristotle's treatment of it ((10) - (33)). The paradox is expounded ((11) -(14)). Aristotle answers it by showing that language assumes a continuing subject of change ((15) - (21)). But this assumption meets the problem only if the metaphysical category of substance is also assumed, and along with it some distinction between substance-constitutive and non-substance-constitutive characteristics ((22) - (27)). The former mark off their subject as a thing of a certain causal type; thus change, in presupposing a substantial subject (see also Appendix to Chapter 1), presupposes one that makes some causal contribution to its own changes ((28) - (33)). But Aristotle means more than this by 'nature as inner principle'. He holds a natural substance to be (like a craftsman) the autonomous determinant of certain changes; these therefore (by contrast with changes not so determined) are "natural", as manifesting the substantial nature ((34) - (36)). This problematic notion is taken for granted by Aristotle in the Vhys-ics ((37) - (39)), but can be seen to rest on his metaphysic of substance. It is a consequence of this that the natural change of a given substance be of one kind and display a unitary pattern reflecting the unity of the substance ((40)). This view cripples scientific method as we understand it ((41)), but Aristotle's idea of substance anyway cuts him off from the approaches successfully operated in later mechanics and chemistry ((42) - (45)). A summary of the ground so far covered ((46)) introduces a further sense in which Aristotle's natures are "inner" principles of change: the subject of change is not (as in artifice) external to the being which is the source of change ((47) - (54))

“It’s hard to tell”. The challenges of scoring patients on standardised outcome measures by multidisciplinary teams: a case study of Neurorehabilitation

Background Interest is increasing in the application of standardised outcome measures in clinical practice. Measures designed for use in research may not be sufficiently precise to be used in monitoring individual patients. However, little is known about how clinicians and in particular, multidisciplinary teams, score patients using these measures. This paper explores the challenges faced by multidisciplinary teams in allocating scores on standardised outcome measures in clinical practice. Methods Qualitative case study of an inpatient neurorehabilitation team who routinely collected standardised outcome measures on their patients. Data were collected using non participant observation, fieldnotes and tape recordings of 16 multidisciplinary team meetings during which the measures were recited and scored. Eleven clinicians from a range of different professions were also interviewed. Data were analysed used grounded theory techniques. Results We identified a number of instances where scoring the patient was 'problematic'. In 'problematic' scoring, the scores were uncertain and subject to revision and adjustment. They sometimes required negotiation to agree on a shared understanding of concepts to be measured and the guidelines for scoring. Several factors gave rise to this problematic scoring. Team members' knowledge about patients' problems changed over time so that initial scores had to be revised or dismissed, creating an impression of deterioration when none had occurred. Patients had complex problems which could not easily be distinguished from each other and patients themselves varied in their ability to perform tasks over time and across different settings. Team members from different professions worked with patients in different ways and had different perspectives on patients' problems. This was particularly an issue in the scoring of concepts such as anxiety, depression, orientation, social integration and cognitive problems. Conclusion From a psychometric perspective these problems would raise questions about the validity, reliability and responsiveness of the scores. However, from a clinical perspective, such characteristics are an inherent part of clinical judgement and reasoning. It is important to highlight the challenges faced by multidisciplinary teams in scoring patients on standardised outcome measures but it would be unwarranted to conclude that such challenges imply that these measures should not be used in clinical practice for decision making about individual patients. However, our findings do raise some concerns about the use of such measures for performance management

What Does Aristotle\u27s Prime Mover Do?

The Prime Mover of Metaphysics Lambda is the source, above all, of eternal motion in the first sphere. It may seem silly to ask \u27What (according to Lambda) does the Prime Mover do?\u27 The answer is obvious: \u27He — or it — gives rise to the motion of the first sphere\u27. But according to a widely accepted interpretation, this is not what the Prime Mover does first and foremost; instead, the Mover essentially contemplates. This contemplative conception is my target here. I shall adduce reasons for suspecting that the contemplative Prime Mover is not an Aristotelian postulate in Lambda, but an exegetical construct. I shall simultaneously make a case for holding that the actual Prime Mover in Lambda should be viewed as a kinetic agent (which is how the Prime Mover is generally presented elsewhere in the corpus). These arguments are founded on conceptual as well as textual considerations, and on reasonable assumptions concerning Aristotle\u27s aims in Lambda and his capacity for self-criticism especially in respect of absurdities for which he castigates other philosophers. I shall not, however, rely on debatable hypotheses about the development of his theology through several treatises, or about his journey towards or away from Platonism. I shall be concerned with the Prime Mover only in Metaphysics Lambda, and within Lambda I shall restrict the discussion to relations that may be thought to obtain between the Prime Mover, the first sphere, and the movement of that sphere. And as well as saying almost nothing about the other spheres and their movers, I shall touch only briefly on the celebrated doctrine in Ch. 9 that the Prime Mover\u27s activity is a thinking of thinking

Use of the new World Health Organization child growth standards to describe longitudinal growth of breastfed rural Bangladeshi infants and young children.

BACKGROUND: Although the National Center for Health Statistics (NCHS) reference has been widely used, in 2006 the World Health Organization (WHO) released new standards for assessing growth of infants and children worldwide. OBJECTIVE: To assess and compare the growth of breastfed rural Bangladeshi infants and young children based on the new WHO child growth standards and the NCHS reference. METHODS: We followed 1343 children in the Maternal and Infant Nutrition Intervention in Matlab (MINIMat) study from birth to 24 months of age. Weights and lengths of the children were measured monthly during infancy and quarterly in the second year of life. Anthropometric indices were calculated using both WHO standards and the NCHS reference. The growth pattern and estimates of undernutrition based on the WHO standards and the NCHS reference were compared. RESULTS: The mean birthweight was 2697 +/- 401 g, with 30% weighing <2500 g. The growth pattern of the MINIMat children more closely tracked the WHO standards than it did the NCHS reference. The rates of stunting based on the WHO standards were higher than the rates based on the NCHS reference throughout the first 24 months. The rates of underweight and wasting based on the WHO standards were significantly different from those based on the NCHS reference. CONCLUSIONS: This comparison confirms that use of the NCHS reference misidentifies undernutrition and the timing of growth faltering in infants and young children, which was a key rationale for constructing the new WHO standards. The new WHO child growth standards provide a benchmark for assessing the growth of breastfed infants and children

Prophylactic dressing to minimize sacral pressure injuries in high-risk hospitalized patients: A pilot study

Aim: In this paper, we describe a trial protocol used to assess feasibility related to: study administration (recruitment, randomization, retention, compliance, eligibility criteria, suitability of protocol instructions and data collection questionnaires); resource and data management (suitability of site, time and budget allocation, management of personnel and data); intervention fidelity (treatment dose, violations); and effect size. Background: Pressure injury can lead to increases in hospital length of stay and cost. The sacrum is identified as one of the most common anatomical pressure injury sites for hospitalized patients. Silicone foam border dressings have been proposed as one strategy to reduce pressure injury incidence; however, rigorous testing of benefit in a general medical-surgical population is required. Design: Randomized controlled trial. Methods: Eighty patients will be recruited after assessment of high risk of pressure injury in a large tertiary hospital in south-east Queensland, Australia. Eligible, consenting participants will be randomly allocated to either a control group (routine care) or an intervention group (routine care and a sacral prophylactic dressing). The primary outcomes comprise feasibility criteria as identified above. The secondary measure is the presence and severity of sacral pressure injury via blind assessment of digital photographs. Research ethics approval was received in October 2013. Discussion: Prophylactic dressings applied to the sacrum may be an effective method for reducing pressure injury in high-risk general medical-surgical patients. However, more rigorous studies to confirm benefit are required. This pilot study will determine the feasibility and effect size to inform a larger randomized controlled trial

Pain, agitation, and behavioural problems in people with dementia admitted to general hospital wards

Pain is underdetected and undertreated in people with dementia. We aimed to investigate the prevalence of pain in people with dementia admitted to general hospitals and explore the association between pain and behavioural and psychiatric symptoms of dementia (BPSD). We conducted a longitudinal cohort study of 230 people, aged above 70, with dementia and unplanned medical admissions to 2 UK hospitals. Participants were assessed at baseline and every 4 days for self-reported pain (yes/no question and FACES scale) and observed pain (Pain Assessment in Advanced Dementia scale [PAINAD]) at movement and at rest, for agitation (Cohen–Mansfield Agitating Inventory [CMAI]) and BPSD (Behavioural Pathology in Alzheimer Disease Scale [BEHAVE-AD]). On admission, 27% of participants self-reported pain rising to 39% on at least 1 occasion during admission. Half of them were able to complete the FACES scale, this proportion decreasing with more severe dementia. Using the PAINAD, 19% had pain at rest and 57% had pain on movement on at least 1 occasion (in 16%, this was persistent throughout the admission). In controlled analyses, pain was not associated with CMAI scores but was strongly associated with total BEHAVE-AD scores, both when pain was assessed on movement (b 5 0.20, 95% confidence interval [CI] 5 0.07- 0.32, P 5 0.002) and at rest (b 5 0.41, 95% CI 5 0.14-0.69, P 5 0.003). The association was the strongest for aggression and anxiety. Pain was common in people with dementia admitted to the acute hospital and associated with BPSD. Improved pain management may reduce distressing behaviours and improve the quality of hospital care for people with dementia