Matrix extracellular phosphoglycoprotein (MEPE): a putative phosphatonin

The introduction to the thesis discusses the control of phosphate balance and considers recent developments in the field. The concept of novel circulating substances which influence, and perhaps regulate, plasma phosphate (‘phosphatonins’), and which are important in tumour-induced hypophosphataemia, hereditary hypophosphataemias and, potentially, in normal phosphate physiology, is introduced. Finally, the isolation of the putative phosphatonin MEPE, and the current state of knowledge about this molecule, is described. The initial practical studies deal with the development and validation of a novel micromethod for measurement of phosphate and, simultaneously, other anions in biological fluids, using capillary electrophoresis. The accuracy and reproducibility of the method are demonstrated, and the method is compared with an established micromethod for measurement of individual ions. Finally, capillary electrophoresis is applied to the measurement of phosphate and other anions in urine, plasma and tubular fluid samples. In the next section, renal clearance experiments are performed in anaesthetized rats, in order to assess the effects of intravenously administered MEPE and to compare them with those of parathyroid hormone. MEPE is shown to be markedly phosphaturic. It does not alter glomerular filtration rate, blood pressure, plasma phosphate concentration or filtered phosphate load, but does cause large, dose-dependent increases in absolute and fractional phosphate excretion. The final series of experiments uses micropuncture methods in anaesthetized rats, in which fluid is collected from individual proximal convoluted tubules. The phosphaturic effect of MEPE is confirmed, and is shown to result, at least in part, from a reduction in fractional phosphate reabsorption in the proximal convoluted tubule, without a change in filtered phosphate load. The results obtained in these studies are discussed in relation to previous knowledge

Deficiencies in education and experience in the management of acute kidney injury among Malawian healthcare workers

Background Acute kidney injury (AKI) is a common but under-recognised disease process, which carries a high risk of mortality or chronic complications, such as chronic kidney disease and other organ dysfunction. Management of AKI, however, is suboptimal, both in developed settings and in Malawi. This is partly because of deficiencies in AKI education and training.Aim To establish current levels of AKI education in a range of healthcare workers in Malawi.Methods An AKI symposium was held in Blantyre in March 2015. Delegates were asked to complete a survey at the start of the symposium to assess their clinical experience and education in the management of AKI.Results From 100 delegates, 89 nurses, clinical officers, and physicians, originating from 11 different districts, responded to the survey. Twenty-two percent of healthcare workers (including 28% of district workers of the various cadres and 31% of nurses) had never received teaching on any aspect of renal disease, and 50% (including 63% of district workers and 61% of nurses) had never received teaching specifically on AKI. Forty-four percent did not feel confident managing AKI, and 98% wanted more support managing patients with renal disease. Thirty-four percent (including 55% of district workers) were unaware that haemodialysis was available at Queen Elizabeth Central Hospital (QECH) for the treatment of AKI and 53% (74% of district workers) were unaware that peritoneal dialysis was available for the treatment of AKI in children. Only 33% had ever referred a patient with AKI to QECH.Conclusions There are deficiencies in education about, and clinical experience in, the management of AKI among Malawian healthcare workers, in addition to limited awareness of the renal service available at QECH. Urgent action is required to address these issues in order to prevent morbidity and mortality from AKI in Malawi

Calibration of thickness-dependent k-factors for germanium X-ray lines to improve energy-dispersive X-ray spectroscopy of SiGe layers in analytical transmission electron microscopy

We show that the accuracy of energy-dispersive X-ray spectroscopy can be improved by analysing and comparing multiple lines from the same element. For each line, an effective k-factor can be defined that varies as a function of the intensity ratio of multiple lines (e.g. K/L) from the same element. This basically performs an internal self-consistency check in the quantification using differently absorbed X-ray lines, which is in principle equivalent to an absorption correction as a function of specimen thickness but has the practical advantage that the specimen thickness itself does not actually need to be measured

A provisional database for the silicon content of foods in the United Kingdom

Si may play an important role in bone formation and connective tissue metabolism. Although biological interest in this element has recently increased, limited literature exists on the Si content of foods. To further our knowledge and understanding of the relationship between dietary Si and human health, a reliable food composition database, relevant for the UK population, is required. A total of 207 foods and beverages, commonly consumed in the UK, were analysed for Si content. Composite samples were analysed using inductively coupled plasma&ndash;optical emission spectrometry following microwave-assisted digestion with nitric acid and H2O2. The highest concentrations of Si were found in cereals and cereal products, especially less refined cereals and oat-based products. Fruit and vegetables were highly variable sources of Si with substantial amounts present in Kenyan beans, French beans, runner beans, spinach, dried fruit, bananas and red lentils, but undetectable amounts in tomatoes, oranges and onions. Of the beverages, beer, a macerated whole-grain cereal product, contained the greatest level of Si, whilst drinking water was a variable source with some mineral waters relatively high in Si. The present study provides a provisional database for the Si content of UK foods, which will allow the estimation of dietary intakes of Si in the UK population and investigation into the role of dietary Si in human health.<br /

Rate and Volume of Intermittent Enteral Feeding

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141999/1/jpen0125.pd

The role of salt intake and salt sensitivity in the management of hypertension in South Asian people with chronic kidney disease: A randomized controlled trial

Background The effectiveness of salt restriction to lower blood pressure (BP) in Bangladeshi patients with chronic kidney disease (CKD) is uncertain. Objective To test the hypothesis that a tailored intervention intended to reduce salt intake in addition to standard care will achieve a greater reduction in BP in UK Bangladeshi patients with CKD than standard care alone. Design A randomised parallel-group controlled trial conducted over a 6 month period. Setting A tertiary renal unit based in acute care hospital in East London. Participants 56 adult participants of Bangladeshi origin with CKD and BP >130/80 mm Hg or on antihypertensive medication. Intervention Participants were randomly allocated to receive a tailored low-salt diet or the standard low-salt advice. BP medication, physical activity and weight were monitored. Main outcome measures The primary outcome was change in ambulatory BP. Adherence to dietary advice was assessed by measurement of 24 h urinary salt excretion. Results Of 56 participants randomised, six withdrew at the start of the study. During the study, one intervention group participant died, one control group participant moved to Bangladesh. Data were available for the primary endpoint on 48 participants. Compared with control group the intervention urinary sodium excretion fell from 260 mmol/d to 103 mmol/d (131 to 76, p<0.001) at 6 months and resulted in mean (95% CI) falls in 24 h systolic/diastolic BP of 8 mm Hg (11 to 5)/2 (?4 to 2) both p<0.001. Conclusions A tailored intervention can achieve moderate salt restriction in patients with CKD, resulting in clinically meaningful falls in BP independent of hypertensive medication

An origin behind Rashba spin splitting within inverted doped sGe heterostructures

In this paper, we demonstrate why cubic Rashba spin splitting is observed within inverted doped strained germanium (sGe) hetrostructures. Magnetotransport measurements showed beating within the SdH oscillation, with fast Fourier analysis revealing cubic Rashba spin splitting to be present. A cubic Rashba coefficient of β=7.97×10−29 eVm3β=7.97×10−29 eVm3 and a spin-splitting energy of Δ=1.17 meVΔ=1.17 meV were determined. The source of the cubic Rashba spin splitting was identified from a combination of ultra low energy secondary ion mass spectrometry analysis and subsequent band structure modelling using Nextnano3. Ultra-low eneIn this paper we demonstrate an origin for cubic Rashba spin splitting observed within inverted doped strained germanium (sGe) hetrostructures. Magnetotransport measurements showed beating within the SdH data, with ensuing Fast Fourier analysis revealing cubic Rashba spin splitting to be present. A spin orbit interaction value of and spin splitting energy were determined. The source of the cubic Rashba spin splitting was identified from a combination of ultra low energy secondary ion mass spectrometry analysis and subsequent band structure modelling using Nextnao3. Ultra low energy secondary ion mass spectrometry revealed an unintentional, highly B doped near surface region to be present. By incorporating this information into the Nextnano3 modelling, two single subband triangular QWs were predicted, one at the upper and the other at the lower interface of the sGe QW. Moreover, these triangular wells are expected to be asymmetric due to the difference in B doping levels and spacer layer thicknesses, and it is this asymmetry which induces the cubic Rashba spin splitting observed