The role of urine sugar in diabetic management

Synthetic Protocell as Efficient Bioreactor: Enzymatic Superactivity and Ultrasensitive Glucose Sensing in Urine

It is believed that membraneless cellular condensates play a critical role in accelerating various slow and thermodynamically unfavorable biochemical processes. However, the exact mechanisms behind the enhanced activity within biocondensates remain poorly understood. Here, we report the fabrication of a high-performance integrated cascade bioplatform based on synthetic droplets for ultrasensitive glucose sensing. Using a horseradish peroxidase (HRP) and glucose oxidase (GOx) cascade pair, we report an unprecedented enhancement in the catalytic activity of HRP inside the synthetic membraneless droplet. Liquidlike membraneless droplets have been prepared via multivalent electrostatic interactions between adenosine triphosphate (ATP) and poly(diallyldimethylammonium chloride) (PDADMAC) in an aqueous medium. Compartmentalized enzymes (GOx/HRP@Droplet) exhibit high encapsulation efficiency, low leakage, prolong retention of activity, and exceptional stability toward protease digestion. Using an HRP@Droplet composite, we have shown that the enzymatic reaction within the droplet follows the classical Michaelis-Menten model. Our findings reveal remarkable enhancement in the catalytic activity of up to 100- and 51-fold for HRP@Droplet and GOx/HRP@Droplet, respectively. These enhanced activities have been explained on the basis of increased local concentrations of enzymes and substrates, along with altered conformations of sequestered enzymes. Furthermore, we have utilized highly efficient and recyclable GOx/HRP@Droplet composite to demonstrate ultrasensitive glucose sensing with a limit of detection of 228 nM. Finally, the composite platform has been exploited to detect glucose in spiked urine samples in solution and filter paper. Our present study illustrates the unprecedented activity of the compartmentalized enzymes and paves the way for next-generation composite bioreactors for a wide range of applications.

Overview of Biofluids and Flow Sensing Techniques Applied in Clinical Practice

This review summarizes the current knowledge on biofluids and the main flow sensing techniques applied in healthcare today. Since the very beginning of the history of medicine, one of the most important assets for evaluating various human diseases has been the analysis of the conditions of the biofluids within the human body. Hence, extensive research on sensors intended to evaluate the flow of many of these fluids in different tissues and organs has been published and, indeed, continues to be published very frequently. The purpose of this review is to provide researchers interested in venturing into biofluid flow sensing with a concise description of the physiological characteristics of the most important body fluids that are likely to be altered by diverse medical conditions. Similarly, a reported compilation of well-established sensors and techniques currently applied in healthcare regarding flow sensing is aimed at serving as a starting point for understanding the theoretical principles involved in the existing methodologies, allowing researchers to determine the most suitable approach to adopt according to their own objectives in this broad field.

The limited clinical value of home urine testing by diabetic patients

To investigate the value of home urine glucose testing in assessing chronic diabetic glucose control, the authors compared patients' glycosuria patterns with their mean blood glucose (MBG) levels calculated from glycosylated hemoglobin (Hb Alc). One hundred and twenty-one patients who regularly checked their urines reported on the frequencies of glycosuria over the preceding ten weeks. There was substantial overlap in the glycosuria patterns of patients at different levels of MBG. Glycosuria was not detectable in only 44% of patients with good control (MBG less than or equal to 150 mg/dl). The probability of such good control given no glycosuria was only 26%. Similarly, frequent glycosuria was reported by only 27% of patients with poor control (MGB greater than 250 mg/dl). The probability of such poor control given frequent glycosuria was only 34%. Because home urine testing cannot reliably identify good or poor control, it has a very limited role in assessing patients' chronic glucose control.

The effects of targeting improvements in urine glucose on metabolic control in children with insulin dependent diabetes

A treatment program designed to increase the percentage of negative urine tests was implemented using a multiple-baseline across groups design in a sample of 19 families of children with insulin dependent diabetes. The treatment involved instruction in insulin adjustment, decrease in intake of simple sugars and saturated fats, and increase in exercise, along with teaching the parents to support improvements in children's self-regulatory behaviors using a point economy and praise. New procedures designed to measure and reinforce adherence to the urine testing regimen were developed. Results showed significant increases in percentage of negative urines consistent with implementation of treatment across the three treatment groups, which were maintained over the follow-up period. Metabolic measures of control, including glycosylated hemoglobin and serum glucose did not show improvements even though the relationship between the percentage of negative urine tests and glycosylated hemoglobin was very high during treatment.

Relevance of colour vision and diabetic retinopathy to self-monitoring of blood glucose

A study was performed to determine the effect of colour vision defects and diabetic retinopathy on diabetic patients' ability to use a visual method of measuring their own blood glucose concentrations. Forty-eight diabetics whose colour vision and retinal status was assessed by an ophthalmologist carried out 311 blood glucose estimations using oxidase-peroxidase test strips which were then compared with laboratory values. There was a trend towards poor performance with advancing age but neither colour vision nor diabetic retinopathy had a significant effect on patients' ability to use this visual method of estimating blood glucose concentrations. The vast majority of diabetics who will benefit from being able to monitor their own blood glucose control should have no difficulty in using a visual method of testing, even if they do have defects of colour vision.

24-hour metabolic profiles in diabetic children

15 metabolic profiles were performed on 10 diabetic children who were on once-daily injections of insulin. Blood and urine glucose concentrations were high throughout much of the day and night, and were associated with abnormal levels of blood ketones, lactate, and pyruvate. The plasma free-insulin profiles gave a characteristic pattern for each type of insulin. The investigation gives valuable information for the clinical management of such children.