Optimal blood glucose regulation of diabetic patients using single network adaptive critics

Diabetes is a long-term disease during which the body's production and use of insulin are impaired, causing glucose concentration level to increase in the bloodstream. Regulating blood glucose levels as close to normal as possible leads to a substantial decrease in long-term complications of diabetes. In this paper, an intelligent online feedback-treatment strategy is presented for the control of blood glucose levels in diabetic patients using single network adaptive critic (SNAC) neural networks (which is based on nonlinear optimal control theory). A recently developed mathematical model of the nonlinear dynamics of glucose and insulin interaction in the blood system has been revised and considered for synthesizing the neural network for feedback control. The idea is to replicate the function of pancreatic insulin, i.e. to have a fairly continuous measurement of blood glucose and a situation-dependent insulin injection to the body using an external device. Detailed studies are carried out to analyze the effectiveness of this adaptive critic-based feedback medication strategy. A comparison study with linear quadratic regulator (LQR) theory shows that the proposed nonlinear approach offers some important advantages such as quicker response, avoidance of hypoglycemia problems, etc. Robustness of the proposed approach is also demonstrated from a large number of simulations considering random initial conditions and parametric uncertainties. Copyright (C) 2009 John Wiley & Sons, Ltd.

Conformal Cytocompatible Ferrite Coatings Facilitate the Realization of a Nanovoyager in Human Blood

Controlled motion of artificial nanomotors in biological environments, such as blood, can lead to fascinating biomedical applications, ranging from targeted drug delivery to microsurgery and many more. In spite of the various strategies used in fabricating and actuating nanomotors, practical issues related to fuel requirement, corrosion, and liquid viscosity have limited the motion of nanomotors to model systems such as water, serum, or biofluids diluted with toxic chemical fuels, such as hydrogen peroxide. As we demonstrate here, integrating conformal ferrite coatings with magnetic nanohelices offer a promising combination of functionalities for having controlled motion in practical biological fluids, such as chemical stability, cytocompatibility, and the generated thrust. These coatings were found to be stable in various biofluids, including human blood, even after overnight incubation, and did not have significant influence on the propulsion efficiency of the magnetically driven nanohelices, thereby facilitating the first successful ``voyage'' of artificial nanomotors in human blood. The motion of the ``nanovoyager'' was found to show interesting stick-slip dynamics, an effect originating in the colloidal jamming of blood cells in the plasma. The system of magnetic ``nanovoyagers'' was found to be cytocompatible with C2C12 mouse myoblast cells, as confirmed using MTT assay and fluorescence microscopy observations of cell morphology. Taken together, the results presented in this work establish the suitability of the ``nanovoyager'' with conformal ferrite coatings toward biomedical applications.

The effect of replacement of soyabean meal with blood meal on the growth of mudfish Clarias anguillaris (L) fingerlings

Blood meal and full fat soyabean meal were mixed in different proportions to give 0%, 10%, 25%, 50%, 75%, 90% and 100% meal in the protein fraction of the diet and fed to Claria anguillaris fingerlings in floating hapas. The growth performance of the fingerlings were monitored for 84 days. At the end of the experiment the mean weight of the fingerlings increased in the level of blood meal up to 50% blood meal in the diet after which there was a decline in the mean weight of the fish. This same level of blood meal gave the best specific growth rate, feed conversion efficiency and protein efficiency ratio. Thus the nutritive value of blood meal was enhanced by the addition of an equal level of full fat soyabean meal in the diet

Genetic diversity of Yunnan local pig breeds inferred from blood protein electrophoresis

Protein electrophoresis was used to examine the blood protein polymorphism in Yunnan local pig breeds, i.e., the Saba pig, Dahe pig, and Diannan small-ear pig breeds, Of 38 genetic loci surveyed 9 were found to be polymorphic. The percentage of polymorphic loci (P) varies from 0.1875 to 0.2121, and the mean individual heterozygosity (H) varies front 0.0712 to 0.1027 in three pig breeds. The results indicate that blood protein polymorphism in Yunnan pig breeds is high. Yunnan local pig breeds have a wealth of genetic diversity at the level of blood proteins.

Evidence of host blood feeding by the monogenean, Ancyrocephalus mogurndae (Monogenea : Ancyrocephalidae) from the gills of the mandarin fish, Siniperca chuatsi

By examining iron contents, it is demonstrated that the monogenean Ancyrocephalus mogurndae (Yamaguti, 1940) feeds on the blood of its host, the mandarin fish Siniperca chuatsi (Basilewsky). The iron content and then the quantity of blood necessary to produce this amount of iron are found different in young and fully-matured worms. Young worms contain higher levels of iron and estimated amount of blood. It is suggested that A. mogurndae may start to feed on host blood as attached on gills, and the amount of blood ingested by young worms may vary from 0.01 to 1.00 mu l before reproduction. The difference between young and fully-matured worms may be accounted for by the elimination of haematin and change of food composition in matured worms and may also be affected by reproduction. Experimental infections of the monogenean may provide supportive information for explaining the difference, and further studies should also examine the effect of immune components in host blood ol mucus on the intestines of the parasite.

Comparison of the Lactate Pro and Analox GM7 blood lactate analysers

van Someren KA, Howatson G, Nunan D, Thatcher R, Shave R., Comparison of the Lactate Pro and Analox GM7 blood lactate analysers, Int J Sports Med. 2005 Oct;26(8):657-61. RAE2008

Giving and Receiving: Nuruddin Farah's Gifts, or, the Postcolonial Logic of Third World Aid

Woods, T. (2003). Giving and Receiving: Nuruddin Farah's Gifts, or, the Postcolonial Logic of Third World Aid. Journal of Commonwealth Literature, 38 (1), 91-112.

PARAMETERS AFFECTING THE IMAGING AND DETECTION OF MICROBUBBLES IN BLOOD

Stabilized micron-sized bubbles, known as contrast agents, are often injected into the body to enhance ultrasound imaging of blood flow. The ability to detect such bubbles in blood depends on the relative magnitude of the acoustic power backscattered from the microbubbles (‘signal’) to the power backscattered from the red blood cells (‘noise’). Erythrocytes are acoustically small (Rayleigh regime), weak scatterers, and therefore the backscatter coefficient (BSC) of blood increases as the fourth power of frequency throughout the diagnostic frequency range. Microbubbles, on the other hand, are either resonant or super-resonant in the range 5-30 MHz. Above resonance, their total scattering cross-section remains constant with increasing frequency. In the present thesis, a theoretical model of the BSC of a suspension of red blood cells is presented and compared to the BSC of Optison® contrast agent microbubbles. It is predicted that, as the frequency increases, the BSC of red blood cell suspensions eventually exceeds the BSC of the strong scattering microbubbles, leading to a dramatic reduction in signal-to-noise ratio (SNR). This decrease in SNR with increasing frequency was also confirmed experimentally by use of an active cavitation detector for different concentrations of Optison® microbubbles in erythrocyte suspensions of different hematocrits. The magnitude of the observed decrease in SNR correlated well with theoretical predictions in most cases, except for very dense suspensions of red blood cells, where it is hypothesized that the close proximity of erythrocytes inhibits the acoustic response of the microbubbles.

Differential expression of components of the cardiomyocyte adrenomedullin/intermedin receptor system following blood pressure reduction in nitric oxide-deficient hypertension.

Adrenomedullin (AM) and intermedin (IMD; adrenomedulln-2) are vasodilator peptides related to calcitonin gene-related peptide (CGRP). The actions of these peptides are mediated by the calcitonin receptor-like receptor (CLR) in association with one of three receptor activity-modifying proteins. CGRP is selective for CLR/receptor activity modifying protein (RAMP)1, AM for CLR/RAMP2 and -3, and IMD acts at both CGRP and AM receptors. In a model of pressure overload induced by inhibition of nitric-oxide synthase, up-regulation of AM was observed previously in cardiomyocytes demonstrating a hypertrophic phenotype. The current objective was to examine the effects of blood pressure reduction on cardiomyocyte expression of AM and IMD and their receptor components. Nomega-nitro-L-arginine methyl ester (L-NAME) (35 mg/kg/day) was administered to rats for 8 weeks, with or without concurrent administration of hydralazine (50 mg/kg/day) and hydrochlorothiazide (7.5 mg/kg/day). In left ventricular cardiomyocytes from L-NAME-treated rats, increases (-fold) in mRNA expression were 1.6 (preproAM), 8.4 (preproIMD), 3.4 (CLR), 4.1 (RAMP1), 2.8 (RAMP2), and 4.4 (RAMP3). Hydralazine/hydrochlorothiazide normalized systolic blood pressure (BP) and abolished mRNA up-regulation of hypertrophic markers sk-alpha-actin and BNP and of preproAM, CLR, RAMP2, and RAMP3 but did not normalize cardiomyocyte width nor preproIMD or RAMP1 mRNA expression. The robust increase in IMD expression indicates an important role for this peptide in the cardiac pathology of this model but, unlike AM, IMD is not associated with pressure overload upon the myocardium. The concordance of IMD and RAMP1 up-regulation indicates a CGRP-type receptor action; considering also a lack of response to BP reduction, IMD may, like CGRP, have an anti-ischemic function.

Dried blood spot liquid chromatography assay for therapeutic drug monitoring of metformin

The use of blood spot collection cards is a simple way to obtain specimens for analysis of drugs for the purpose of therapeutic drug monitoring, assessing adherence to medications and preventing toxicity in routine clinical setting. We describe the development and validation of a microanalytical technique for the determination of metformin from dried blood spots. The method is based on reversed phase high-performance liquid chromatography with ultraviolet detection. Drug recovery in the developed method was found to be more than 84%. The limits of detection and quantification were calculated to be to be 90 and 150 ng/ml, respectively. The intraday and interday precision (measured by CV%) was always less than 9%. The accuracy (measured by relative error, %) was always less than 12%. Stability analysis showed that metformin is stable for at least 2 months when stored at -70 degrees C. The small volume of blood required (10 mu L), combined with the simplicity of the analytical technique makes this a useful procedure for monitoring metformin concentrations in routine clinical settings. The method is currently being applied to the analysis of blood spots taken from diabetic patients to assess adherence to medications and relationship between metformin level and metabolic control of diabetes. (c) 2006 Elsevier B.V. All rights reserved.

Blood levels of vitamin C, carotenoids and retinol are inversely associated with cataract in a north Indian population

PURPOSE. To examine the association of blood antioxidants with cataract.

An evaluation of a domiciliary blood transfusion serivce for palliative care patients in Northern Ireland

Marie Curie Cancer Care (MCCC) is a national charitable organisation which provides specialist palliative care services to patients with cancer and other life limiting illnesses. Marie Curie Nursing Service (MCNS) provides nursing services to patients in their own homes. The administration of blood transfusions to palliative care patients is required to improve symptom management and quality of life; however this procedure often results in unnecessary hospital admissions. Recognising that the majority of patients wish to be cared for and die in their own home, and with National Guidance recommending that specialist palliative care services should be provided to patients in their preferred place of care, a recent service initiative by MCNS was domiciliary blood transfusions. Whilst this is not a new service within domiciliary care, this pilot project aimed to capture patient views to evaluate this service initiative. Telephone interviews were conducted, using a questionnaire, with 11 patients who had received the service. Findings indicated positive evaluation of the service. Domiciliary blood transfusions helped to avoid unnecessary hospital admissions, the quality of life of patients and their families was improved in the palliative phase of illness and they received the service in their preferred place of care.

Clinical and economic impact of contaminated blood cultures within the hospital setting

Blood cultures have an important role in the diagnosis of serious infections, although contamination of blood cultures (i.e. false-positive blood cultures) is a common problem within the hospital setting. The objective of the present investigation was to determine the impact of the false-positive blood culture results on the following outcomes: length of stay, hotel costs, antimicrobial costs, and costs of laboratory and radiological investigation. A retrospective case-control study design was used in which 142 false-positive blood culture cases were matched with suitable controls (patients for whom cultures were reported as true negatives). The matching criteria included age, comorbidity score and month of admission to the hospital. The research covered a 13-month period (July 2007 to July 2008). The findings indicated that differences in means, between cases and controls, for the length of hospital stay and the total costs were 5.4 days [95% CI (confidence interval): 2.8-8.1 days; P

Blood pressure lowering in patients without prior cerebrovascular disease for prevention of cognitive impairment and dementia

Background: This is an update of a previous review (McGuinness 2006). Hypertension and cognitive impairment are prevalent in older people. Hypertension is a direct risk factor for vascular dementia (VaD) and recent studies have suggested hypertension impacts upon prevalence of Alzheimer's disease (AD). Therefore does treatment of hypertension prevent cognitive decline?
Objectives: To assess the effects of blood pressure lowering treatments for the prevention of dementia and cognitive decline in patients with hypertension but no history of cerebrovascular disease.
Search strategy: The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group, The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS as well as many trials databases and grey literature sources were searched on 13 February 2008 using the terms: hypertens$ OR anti-hypertens$. Selection criteria: Randomized, double-blind, placebo controlled trials in which pharmacological or non-pharmacological interventions to lower blood pressure were given for at least six months.
Data collection and analysis: Two independent reviewers assessed trial quality and extracted data. The following outcomes were assessed: incidence of dementia, cognitive change from baseline, blood pressure level, incidence and severity of side effects and quality of life.
Main results: Four trials including 15,936 hypertensive subjects were identified. Average age was 75.4 years. Mean blood pressure at entry across the studies was 171/86 mmHg. The combined result of the four trials reporting incidence of dementia indicated no significant difference between treatment and placebo (236/7767 versus 259/7660, Odds Ratio (OR) = 0.89, 95% CI 0.74, 1.07) and there was considerable heterogeneity between the trials. The combined results from the three trials reporting change in Mini Mental State Examination (MMSE) did not indicate a benefit from treatment (Weighted Mean Difference (WMD) = 0.42, 95%CI 0.30, 0.53). Both systolic and diastolic blood pressure levels were reduced significantly in the three trials assessing this outcome (WMD = -10.22, 95% CI -10.78, -9.66 for systolic blood pressure, WMD = -4.28, 95% CI -4.58, -3.98 for diastolic blood pressure). Three trials reported adverse effects requiring discontinuation of treatment and the combined results indicated no significant difference (OR = 1.01, 95% CI 0.92, 1.11). When analysed separately, however, more patients on placebo in Syst Eur 1997 were likely to discontinue treatment due to side effects; the converse was true in SHEP 1991. Quality of life data could not be analysed in the four studies. Analysis of the included studies in this review was problematic as many of the control subjects received antihypertensive treatment because their blood pressures exceeded pre-set values. In most cases the study became a comparison between the study drug against a usual antihypertensive regimen.
Authors' conclusions: There is no convincing evidence fromthe trials identified that blood pressure lowering in late-life prevents the development of dementia or cognitive impairment in hypertensive patients with no apparent prior cerebrovascular disease. There were significant problems identified with analysing the data, however, due to the number of patients lost to follow-up and the number of placebo patients who received active treatment. This introduced bias. More robust results may be obtained by conducting a meta-analysis using individual patient data.

Development and validation of a dried blood spot LC-MS/MS assay to quantify ranitidine in paediatric samples.

A novel approach has been developed to determine ranitidine in paediatric samples using dried blood spots (DBS) on Guthrie cards (Whatman 903). A selective and sensitive HPLC-MS/MS assay has been developed and validated using small volumes of blood (30µl). A 6mm disc was punched from each DBS and extracted with methanolic solution of the internal standard (IS) nizatidine. This was further subjected to solid phase extraction (SPE), followed by reversed phase HPLC separation, using a XBridge™ C18 column and mobile phase 10mM ammonium acetate/methanol (98:2 v/v) with a flow rate of 0.3mL/min. This was combined with multiple reaction monitoring (MRM) mass detection using electrospray ionisation (ESI). The calibration curve for ranitidine was found linear over the range 10-500ng/mL (r=0.996). The limit of quantification (LOQ) of the method was validated at 10ng/mL. Accuracy and precision values for within and between days were