Blood glucose monitors: a laboratory and patient assessment.

The four blood glucose monitors available in the United Kingdom were compared by asking the opinions of 24 patients who used each monitor for two weeks, by correlating their blood glucose results with those obtained in the laboratory, and by having the monitors examined by an electronics engineer. Of the battery-operated monitors, patients preferred the Hypocount (15) to the Glucochek (9). The mains-operated units were less popular, with little to choose between Eyetone and Reflomat. Under field conditions the blood glucose results obtained with the Glucochek correlated poorly with the standard reference method. In contrast the Hypocount, Eyetone, and Reflomat machines produced good correlations. Poor results with the Glucochek were mainly due to faulty timing systems. The patients'' preference for the Hypocount was supported by tests of performance under laboratory conditions and by the electronics engineer''s report.     

The uptake and release of water vapour by the foam seal of a diffusion porometer as a source of bias

Abstract. The apparent resistance to diffusion of water vapour presented by a set of holes in a calibration plate when measured by a commercial porometer depended on materials previously measured in the sensor head of the instrument. The data reported show the variation in apparent resistance of a set of holes with a specified value of 13.7 s cm⁻¹ after a leaf of small resistance, a set of holes with a specified resistance of 3.75 s cm⁻¹, or a hydrophobic membrane had been in the sensor head and the effect of covering the foam seal around the mouth of the cup with aluminium foil. It was concluded that the results were profoundly affected by the history of water vapour accumulation and release from the foam seal which could give rise to biased readings both during calibration and in measurements of leaf resistance and might also explain much of the scatter when calibration data obtained at different times were pooled for the calculation of a calibration equation. Reliable estimates of resistance over the effective range of the instrument cannot be expected unless this transfer of water vapour between the seal and the cup is prevented.     

Compact optical microfluidic uric acid analysis system

We designed, fabricated and tested a novel compact fluorescence analysis system for quantification of uric acid (UA) in clinical samples at the point-of-care. To perform an analysis, diluted saliva, urine or blood samples are simply placed in a disposable thin-film sample holder using a dropper. A new enzyme immobilization technique was developed to retain within the sample holder two enzymes and a molecule, which transforms into a fluorescer in amounts depending on the UA concentration. The small instrument (7.5 cm × 5 cm × 5 cm) into which the sample holder is placed for analysis contains an LED, a narrow-band filter and an amplified photodiode. The analysis time is 30s, and the dynamic range of the system is 4-400 μM of UA. The calibration curve for transparent saliva and urine was made using solutions of UA. The calibration curve for opaque blood was obtained with spiked samples of blood. The three different types of clinical samples were collected from three subjects and simply diluted before their measurements. Analysis with our instrument yielded UA concentrations within the expected concentration ranges. Development of instruments based on the current laboratory prototype is expected to result in products for clinical trials and point-of-care.     

Analysis of zinc in biological samples by flame atomic absorption spectrometry

The quantification of target analytes in complex matrices requires special calibration approaches to compensate for additional capacity or activity in the matrix samples. The standard addition is one of the most important calibration procedures for quantification of analytes in such matrices. However, this technique requires a great number of reagents and material, and it consumes a considerable amount of time throughout the analysis. In this work, a new calibration procedure to analyze biological samples is proposed. The proposed calibration, called the addition calibration technique, was used for the determination of zinc (Zn) in blood serum and erythrocyte samples. The results obtained were compared with those obtained using conventional calibration techniques (standard addition and standard calibration). The proposed addition calibration was validated by recovery tests using blood samples spiked with Zn. The range of recovery for blood serum and erythrocyte samples were 90-132% and 76-112%, respectively. Statistical studies among results obtained by the addition technique and conventional techniques, using a paired two-tailed Student's t-test and linear regression, demonstrated good agreement among them.     

Synthesis and application of Fmoc-hydrazine for the quantitative determination of saccharides by reversed-phase high-performance liquid chromatography in the low and subpicomole range

A new derivatization reagent, Fmoc-hydrazine, has been synthesized from the reaction of Fmoc-chloroformate with hydrazine as a precolumn fluorometric labeling reagent for reducing sugars such as glucose, galactose, mannose, fructose, fucose, ribose, xylose, arabinose, lactose, and maltose. The optimization of derivatization conditions was examined in detail. Using a reversed-phase high-performance C-8 column and a mobile phase consisting of acetonitrile-aqueous acetic acid, seven sugar derivatives were separated under either isocratic or gradient conditions within 20 min. The Fmoc-hydrazine and sugar Fmoc-hydrazone derivatives exhibit excellent stability. The extent of the hydrazone formation was 77 and 82% for mannose and fucose as assessed by Dionex high-performance anion-exchange chromatography with pulsed amperometric detection. Linear calibration graphs were established in the range from 0.5 to 2 pmol and 12 to 110 pmol for individual sugar derivatives. The determination limits were 0.05-0.09 pmol for mannose, galactose, and ribose; 0.1 pmol for maltose, xylose, and glucose; 0.2 pmol for fucose and lactose; 0.3 pmol for arabinose; and 0.4 pmol for fructose. The component monosaccharides of ultramicroquantities of two glycoproteins (e.g., from 7 ng fetuin and ovalbumin) were determined in the subpicomole range.     

A survival and reproduction trade-off is resolved in accordance with resource availability by virgin female mosquitoes

The first 2-4 days after an Anopheles gambiae female mosquito emerges are critical to her survival and reproductive success. Yet, the order of behavioural events (mating, sugar feeding, blood feeding) during this time has received little attention. We discovered that among female cohorts sampled from emergence, sugar feeding had a higher probability than blood feeding of occurring first, and mating rarely occurred before a meal was taken. The night after emergence, 48% of females fed on sugar in mesocosms, and 25% fed on human blood; in the absence of sugar, 49% of females fed on human blood. After 5 days, 39% of the sugar-supplied females had blood fed and mated, and were fructose negative, whereas only 8% of the sugar-denied females had both blood fed and mated by this time. The model that best explained the transitions suggests that females made use of two distinct behavioural pathways, the most common one being to sugar-feed, then mate, and then seek blood. Other females sought blood first, then mated, and forwent a sugar meal. Lipid levels were higher in females with access to sugar than in females without access to sugar, particularly for those in later gonotrophic stages, while glycogen levels in the sugar-supplied group were higher throughout. In single-night experiments with females having had access to sucrose since emergence, those given a blood meal 1 day before spending a night with males had higher insemination rates than those not receiving the blood meal. These results indicate that the trade-off between survival and immediate reproduction is resolved by young adult females in accordance with availability of resources and gonotrophic state.     

Dextrostix-Eyetone in the insulin hypoglycaemia test.

The Ames Dextrostix-Eyetone system was evaluated for monitoring the blood glucose concentration during insulin-induced hypoglycaemia. The results agreed well with laboratory values for plasma glucose, obtained by an orthotoluidine method, and the method was practicable as a bedside technique. In two cases quick results obtained with the Eyetone enabled the insulin tolerance test to be interrupted to prevent severe hypoglycaemia before the clinical indications were obvious. The extra time and effort required were minimal, and its value seems to far outweigh the disadvantage of the extra work entailed. Nevertheless, care in using the system was important, and the operator must familiarise himself with the system before the most reliable results can be obtained.     

塔里木盆地西北缘核桃坚果生化成分多样性分析

该研究收集新疆塔里木盆地西北缘44份核桃资源,其中树龄超过50 a的实生资源41份、主栽良种3个,并对其主要生化成分蛋白质、糖、脂肪、氨基酸、油酸、亚油酸、亚麻酸、棕榈酸、硬脂酸进行了多样性分析。结果表明:44份资源的生化成分变异幅度大,存在着丰富的多样性。各指标变异幅度由4.93%~30.93%,香农-维纳指数(H')变幅为1.38~2.02。17种氨基酸变异幅度由10.07%~35.71%,香农-维纳指数(H')变幅为1.85~2.20。主要生化成分主成分分析显示蛋白质、糖、脂肪三个主要成分的累计贡献率达81.67%。聚类分析表明,群组间生化成分存在显著差异,群组的聚类与地理分布有明显相关性,流域相同的资源的生化成分构成比例具有相似性。与主栽品种相比,实生资源在糖、蛋白质、脂肪等方面具有更高的变异幅度,因而具有一定的开发潜力。     

Intelligent Toilet System for Non-invasive Estimation of Blood-Sugar Level from Urine

Background and ObjectivesType-2 diabetes is one of the chronic diseases. This disease can be controlled by adjusting the dose of medicine, which is calculated from regular monitoring of blood sugar level. Blood glucose estimation methods are grouped into two categories direct and indirect. The direct method (invasive in nature) provides more accurate results; but people are not interested to test their blood several times in the day; because blood sample collection process is painful. On the other hand, indirect estimation methods are popular due to its non-invasive nature. The most widely used non-invasive blood glucose estimation method is based on urine sugar level estimation. Urine sugar level estimation is a chemical process requiring manual involvement. Human nature is very different; they dislike the repetitive work of testing urine regularly, although the process is not at all cumbersome. It will be very helpful if a system exists, which monitors urine sugar level automatically from the toilet.MethodsThis work describes an automatic technique to estimate blood sugar level from urine. The contribution of this work is as follows:

• •A complete customized mechanical unit, which controls the chemical process of urine sugar estimation.
• •An automatic technique to build the fuzzy membership functions from training data set.

This system includes a chemical process control along with a fuzzy logic based color estimation technique, where fuzzy membership functions are derived from training data set. One salient feature of this fuzzy membership functions generator is that it is tuneable, that means it allows calibration after constructing membership functions. From application point of view, it is an intelligent toilet to keep track of blood sugar level from urine.The system is divided into two sub sections named as a control section and a computation section. The control section includes the control of mechanical units and chemical process initiation. The activeness of chemical reagent changes over time, this system has the provision to handle such situation through volume adjustment chamber. The control section includes a lot of valve control, they are interdependent. Petri-net is used to synchronise them. Computation section is used for estimation of urine sugar level from the changed color of Benedict's Qualitative Solution.ResultFrom operational point of view, this system is a combination of sequential and parallel sub processes. It can be divided into 9 sub processes. The time required to complete all 9 processes is 660.5 second. This time includes sample collection time, chemical reaction time, result calculation and system cleaning time. The average Sensitivity, Specificity and error rate of the system are as follows 88.0225%, 95.95% and 5.765%. PIPEv4.3.0 is used to analysis the Petri-net. As per the analysis report, the system is safe (reliable).DiscussionThis system is efficient to estimate blood sugar level from urine. This system senses the urine sugar level indirectly using the color sensor. The color sensor is not directly in touch with the chemical of the reaction chamber. The normal toilet cleaning (acidic) solution can be used to clean the chambers. So, maintenance process is quite easy. The proposed system can reduce the probability of glaucoma, kidney problem etc. by assisting doctors to control high blood sugar level through regular monitoring of urine sugar level.     

Headspace solid-phase microextraction in combination with gas chromatography and tandem mass spectrometry for the determination of organochlorine and organophosphorus pesticides in whole numan blood

A method for the determination of several organochlorine and organophosphorus pesticides in human whole blood samples was developed. The combination of solid-phase microextraction in headspace mode with gas chromatography with tandem mass spectrometry allowed the determination of 11 selected pesticides at ppb levels, minimizing the sample treatment. Quantitation was carried out by means of calibration curves prepared in blood using labelled surrogate/internal standards. The method showed good linearity between 1 and 50 ng ml(-1) (0.5-25 ng ml(-1) for HCB) using second-order calibration curves. Precision was found to be better than 20% at the three concentration levels assayed in the range of ng ml(-1). The detection limits obtained were in the range 0.02-0.7 ng ml(-1), except for p,p'-DDT (3 ng ml(-1)). The developed procedure was applied to blood and serum samples obtained from agricultural workers. HCB. beta-HCH and p,p'-DDE were most frequently detected in the samples analyzed.     

Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood

There is the need for a clinical assay to determine the extent to which a patient''s blood is effectively anticoagulated by the low-molecular-weight-heparin (LMWH), enoxaparin. There are also urgent clinical situations where it would be important if this could be determined rapidly. The present assay is designed to accomplish this. We only assayed human blood samples that were spiked with known concentrations of enoxaparin. The essential feature of the present assay is the quantification of the efficacy of enoxaparin in a patient''s blood sample by degrading it to complete inactivity with heparinase. Two blood samples were drawn into Vacutainer tubes (Becton-Dickenson; Franklin Lakes, NJ) that were spiked with enoxaparin; one sample was digested with heparinase for 5 min at 37 °C, the other sample represented the patient''s baseline anticoagulated status. The percent shortening of clotting time in the heparinase-treated sample, as compared to the baseline state, yielded the anticoagulant contribution of enoxaparin. We used the portable, battery operated Hemochron 801 apparatus for measurements of clotting times (International Technidyne Corp., Edison, NJ). The apparatus has 2 thermostatically controlled (37 °C) assay tube wells. We conducted the assays in two types of assay cartridges that are available from the manufacturer of the instrument. One cartridge was modified to increase its sensitivity. We removed the kaolin from the FTK-ACT cartridge by extensive rinsing with distilled water, leaving only the glass surface of the tube, and perhaps the detection magnet, as activators. We called this our minimally activated assay (MAA). The use of a minimally activated assay has been studied by us and others. ^2-4 The second cartridge that was studied was an activated partial thromboplastin time (aPTT) assay (A104). This was used as supplied from the manufacturer. The thermostated wells of the instrument were used for both the heparinase digestion and coagulation assays. The assay can be completed within 10 min. The MAA assay showed robust changes in clotting time after heparinase digestion of enoxaparin over a typical clinical concentration range. At 0.2 anti-Xa I.U. of enoxaparin per ml of blood sample, heparinase digestion caused an average decrease of 9.8% (20.4 sec) in clotting time; at 1.0 I.U. per ml of enoxaparin there was a 41.4% decrease (148.8 sec). This report only presents the experimental application of the assay; its value in a clinical setting must still be established.     

A screen-printed, amperometric biosensor array incorporated into a novel automated system for the simultaneous determination of organophosphate pesticides

Organophosphate pesticides present serious risks to human and environmental health. A rapid reliable, economical and portable analytical system will be of great benefit in the detection and prevention of contamination. A biosensor array based on six acetylcholinesterase enzymes for use in a novel automated instrument incorporating a neural network program is described. Electrochemical analysis was carried out using chronoamperometry and the measurement was taken 10s after applying a potential of 0 V vs. Ag/AgCl. The total analysis time for the complete assay was less than 6 min. The array was used to produce calibration data with six organophosphate pesticides (OPs) in the concentration range of 10(-5) M to 10(-9) M to train a neural network. The output of the neural network was subsequently evaluated using different sample matrices. There were no detrimental matrix effects observed from water, phosphate buffer, food or vegetable extracts. Furthermore, the sensor system was not detrimentally affected by the contents of water samples taken from each stage of the water treatment process. The biosensor system successfully identified and quantified all samples where an OP was present in water, food and vegetable extracts containing different OPs. There were no false positives or false negatives observed during the evaluation of the analytical system. The biosensor arrays and automated instrument were evaluated in situ in field experiments where the instrument was successfully applied to the analysis of a range of environmental samples. It is envisaged that the analytical system could provide a rapid detection system for the early warning of contamination in water and food.     

A procedure to validate and correct the 13C chemical shift calibration of RNA datasets

Chemical shifts reflect the structural environment of a certain nucleus and can be used to extract structural and dynamic information. Proper calibration is indispensable to extract such information from chemical shifts. Whereas a variety of procedures exist to verify the chemical shift calibration for proteins, no such procedure is available for RNAs to date. We present here a procedure to analyze and correct the calibration of ¹³C NMR data of RNAs. Our procedure uses five ¹³C chemical shifts as a reference, each of them found in a narrow shift range in most datasets deposited in the Biological Magnetic Resonance Bank. In 49 datasets we could evaluate the ¹³C calibration and detect errors or inconsistencies in RNA ¹³C chemical shifts based on these chemical shift reference values. More than half of the datasets (27 out of those 49) were found to be improperly referenced or contained inconsistencies. This large inconsistency rate possibly explains that no clear structure–¹³C chemical shift relationship has emerged for RNA so far. We were able to recalibrate or correct 17 datasets resulting in 39 usable ¹³C datasets. 6 new datasets from our lab were used to verify our method increasing the database to 45 usable datasets. We can now search for structure–chemical shift relationships with this improved list of ¹³C chemical shift data. This is demonstrated by a clear relationship between ribose ¹³C shifts and the sugar pucker, which can be used to predict a C2′- or C3′-endo conformation of the ribose with high accuracy. The improved quality of the chemical shift data allows statistical analysis with the potential to facilitate assignment procedures, and the extraction of restraints for structure calculations of RNA.     

去铁酮联合去铁胺治疗重型地中海贫血患儿的疗效及对血糖代谢和铁代谢的影响

目的:探讨去铁酮联合去铁胺治疗重型地中海贫血患儿的疗效及对血糖代谢和铁代谢的影响。方法:选取2015年3月～2017年12月期间海南省妇女儿童医学中心儿科收治的127例重型地中海贫血患儿,根据数表法将患儿随机分为对照组(n=63)和研究组(n=64),其中对照组在基础治疗的基础上给予去铁胺治疗,研究组在对照组的基础上联合去铁酮治疗。比较两组患儿临床疗效、治疗前后的血糖代谢和铁代谢情况,记录两组患儿治疗期间不良反应发生情况。结果:研究组患儿治疗后临床总有效率为73.44%(47/64),高于对照组患儿的55.56%(35/63)(P0.05)。两组患儿治疗后血糖代谢正常率均升高,且研究组高于对照组(P0.05)。两组患儿治疗后血清铁蛋白(SF)降低,尿铁排泄量(UIE)升高(P0.05);研究组治疗后SF低于对照组,UIE高于对照组(P0.05)。两组不良反应发生率比较无统计学差异(P0.05)。结论:去铁酮联合去铁胺治疗重型地中海贫血患儿,安全有效,可改善机体铁代谢,提高血糖代谢正常比例,具有一定的临床应用价值。     

Dual polarity accurate mass calibration for electrospray ionization and matrix-assisted laser desorption/ionization mass spectrometry using maltooligosaccharides

In view of the fact that memory effects associated with instrument calibration hinder the use of many mass-to-charge (m/z) ratios and tuning standards, identification of robust, comprehensive, inexpensive, and memory-free calibration standards is of particular interest to the mass spectrometry community. Glucose and its isomers are known to have a residue mass of 162.05282 Da; therefore, both linear and branched forms of polyhexose oligosaccharides possess well-defined masses, making them ideal candidates for mass calibration. Using a wide range of maltooligosaccharides (MOSs) derived from commercially available beers, ions with m/z ratios from approximately 500 to 2500 Da or more have been observed using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and time-of-flight mass spectrometry (TOF-MS). The MOS mixtures were further characterized using infrared multiphoton dissociation (IRMPD) and nano-liquid chromatography/mass spectrometry (nano-LC/MS). In addition to providing well-defined series of positive and negative calibrant ions using either electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI), the MOSs are not encumbered by memory effects and, thus, are well-suited mass calibration and instrument tuning standards for carbohydrate analysis.     

Sensitive determination of pethidine in body fluids by gas chromatography-tandem mass spectrometry

We have presented a simple and sensitive method for determining pethidine, a narcotic analgesic drug in body fluids by gas chromatography-tandem mass spectrometry (GC-MS/MS). Pethidine and 4'-piperidinoacetophenone (internal standard) were extracted from body fluids with Bond Elut C(18) columns; the recoveries were above 85% for both compounds. The calibration curves for blood and urine showed good linearities in the range of 1.25-40 ng/ml. Its detection limits (signal-to-noise ratio=3) were estimated to be approximately 0.5 ng/ml of whole blood and urine.     

Near-infrared spectroscopy for bioprocess monitoring and control.

This article describes the calibration of a spectroscopic scanning instrument for the measurement of selected contaminants in a complex biological process stream. Its use is for the monitoring of a process in which contaminants are to be removed selectively by flocculation from yeast cell homogenate. The main contaminants are cell debris, protein, and RNA. A low-cost instrument has been developed for sensitivity in the region of the NIR spectrum (from 1900 to 2500 nm) where preliminary work found NIR signatures from cell debris, protein, and RNA. Calibration models have been derived using a multivariate method for concentrations of these contaminants, such as would be found after the flocculation process. Two strategies were compared for calibrating the NIR instrument. In one case, samples were prepared by adding materials representative of the contaminants to clarified yeast homogenate so the contaminant levels were well known but outside the range of interest. In the other case, where samples were like those from the process stream after flocculation and floc removal, there was uncertainty of analysis of contaminant level, but the calibration was in the range of interest. Calibration using process stream samples gave results close to those derived from traditional assays. When the calibration models were used to predict the contaminant concentrations in previously unseen samples, the correlation coefficients between measurements and predictions were above 90% in all cases but one. The prediction errors were similar to the errors in the traditional assays.     

Clinical Studies of Tolazamide and Tolbutamide: Comparative Effectiveness of Control of Diabetes Mellitus

Tolazamide, a new oral hypoglycemic agent, was compared with tolbutamide, a related chemical compound, for stability of control of 12 patients suffering from maturity-onset diabetes mellitus. A short 12-week study was conducted which incorporated a cross-over design and the results were examined by variance analysis after dosage was individualized to the patient''s requirements. Greater stability of fasting blood sugar was found on tolazamide; patients also had less glycosuria and lower fasting blood sugar on tolazamide. Tolazamide appeared to be between five and six times as potent as tolbutamide, mg. for mg.No hepatic, renal, hematologic or symptomatic toxic reactions were observed during the total of 72 person-weeks of tolazamide therapy.     

Pyrolysis of olive residue and sugar cane bagasse: non-isothermal thermogravimetric kinetic analysis

Thermal degradation and kinetics for olive residue and sugar cane bagasse have been evaluated under dynamic conditions in the presence of nitrogen atmosphere, using a non-isothermal thermogravimetric method (TGA). The effect of heating rate was evaluated in the range of 2-50 K min(-1) providing significant parameters for the fingerprinting of the biomass. The DTG plot for the olive residue and sugar cane bagasse clearly shows that the bagasse begins to degrade at 473 K and exhibits two major peaks. The initial mass-loss was associated with hemicellulose pyrolysis and responsible for the first peak (538-543 K) whereas cellulose pyrolysis was initiated at higher temperatures and responsible for the second peak (600-607 K). The two biomass mainly devolatilized around 473-673 K, with total volatile yield of about 70-75%. The char in final residue was about 19-26%. Mass loss and mass loss rates were strongly affected by heating rate. It was found that an increase in heating rate resulted in a shift of thermograms to higher temperatures. Ozawa-Flynn-Wall and Vyazovkin methods were applied to determine apparent activation energy to the olive residue and sugar cane bagasse. Two different steps were detected with apparent activation energies in the 10-40% conversion range have a value of 153-162 kJ mol(-1) and 168-180 kJ mol(-1) for the hemicellulose degradation of olive residue and sugar cane bagasse, respectively. In the 50-80% conversion range, this value is 204-215 kJ mol(-1) and 231-240 kJ mol(-1) for the cellulose degradation of olive residue and sugar cane bagasse, respectively.     

Lifetime exposure to environmental lead and children's intelligence at 11-13 years: the Port Pirie cohort study.

OBJECTIVE--To examine the association between environmental exposure to lead and children''s intelligence at age 11-13 years, and to assess the implications of exposure in the first seven years of life for later childhood development. DESIGN--Prospective cohort study. SUBJECTS--375 children born in or around the lead smelting town of Port Pirie, Australia, between 1979 and 1982. MAIN OUTCOME MEASURE--Children''s intelligence quotient (IQ) measured at 11-13 years of age. RESULTS--IQ was inversely associated with both antenatal and postnatal blood lead concentrations. Verbal, performance, and full scale IQ were inversely related to blood lead concentration with no apparent threshold. Multivariate analyses indicated that after adjustment for a wide range of confounders, the postnatal blood lead concentrations (particularly within the age range 15 months to 7 years) exhibited inverse associations with IQ. Strong associations with IQ were observed for lifetime average blood lead concentrations at various ages. The expected mean full scale IQ declined by 3.0 points (95% confidence interval 0.07 to 5.93) for an increase in lifetime average blood lead concentration from 0.48 to 0.96 mumol/l (10 to 20 micrograms/dl). CONCLUSION--Exposure to environmental lead during the first seven years of life is associated with cognitive deficits that seem to persist into later childhood.