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Glucochecks are commonly used on admission to hospital to pinpoint patients who may have diabetes. This summary paper describes two clinical audits assessing action following glucocheck results and staff education to improve follow-up. The full audit paper can be accessed at nursingtimes.net.
A radiometric bioassay based on the continuous monitoring of 14CO2 released from labeled glucose in the presence of amniotic fluid or amniotic fluid with added phosphate has been employed to detect the presence of a phosphate-sensitive bacterial inhibitor in amniotic fluid near term. The time required for detection of the inhibitory activity is approximately 12 hours, in contrast to approximately 36 hours required for a previously reported technique. Application of this radiometric bioassay to demonstrate bacterial growth inhibition by amniotic fluid and physicochemical properties of the inhibitory activity yielded results comparable to those obtained with the older method of plate counts of viable bacteria. By the new technique it was possible to demonstrate that the inhibitory activity was phosephate sensitive, heat stable, inactivated by metal chelation, removed by bentonite, and present in a low-molecular-weight fraction of amniotic fluid.
The present study analyzed the actions of exogenous ATP on liver carbohydrate metabolism by using both isolated perfused rat livers and hepatocytes as model systems. The metabolic parameters measured in the perfused livers were glucose production, lactate production, oxygen consumption, and K+ movement. All parameters were monitored continuously during the perfusions in order to assess transient effects. ATP increased both glucose and lactate production in the isolated rat liver when perfused with either constant pressure or constant flow. ATP increased oxygen consumption in the perfused liver at a low concentration (10 microM) but was inhibitory at high concentrations (40 and 160 microM). ATP also increased K+ efflux in the isolated perfused liver. ATP did not alter basal glucose production in isolated hepatocytes; however, it did inhibit glucagon-stimulated glucose output by hepatocytes. ATP inhibited lactate production in the isolated hepatocytes. Extracellular ATP has the potential to modify basal as well as hormonal modulation of hepatic carbohydrate metabolism during shock.
To elucidate the potency of continuous vs. intermittent exposure to hormonal stimuli, hepatic glucose production of isolated perfused rat livers was monitored in response to glucagon and insulin infusion. Using a nonrecirculating perfusion system, continuous exposure to glucagon (35 pM) induced a rise in hepatic glucose production from basal 0.33 +/- 0.03 mmol/(96 min X 100 g BW) to 0.65 +/- 0.02 mmol/(96 min X 100 g BW), while intermittent exposure (3 min on/off intervals; total dose 50%) to the same glucagon concentration elicited an almost identical rise in hepatic glucose production to 0.59 +/- 0.12 mmol/(96 in X 100 g BW). Insulin (100 mU/liter) given continuously and intermittently (3 min on/off intervals) inhibited glucagon-stimulated (70 pM) hepatic glucose production to the same extent, i.e. by 37.4% and 41.1%, respectively. Doubling the off period to 6 min and thereby reducing the total hormone dose to 33% did not diminish insulin's suppressive effect on glucagon-stimulated hepatic glucose release (34.6%). When the latter infusion protocol was applied with insulin at 300 mU/liter, hepatic glucose production during the first 40 min of glucagon infusion was more restrained (P less than 0.01) than during continuous delivery of 100 mU/liter, although the same amount of insulin was infused per period of time. In parallel, glucagon-stimulated cAMP release was similarly suppressed by insulin in all experiments. From this we conclude that the effect on hepatic glucose production of pulsatile administration of glucagon as well as of insulin, depending on the applied time interval of hormone exposure, is equipotent or even superior to the respective hormones' continuous infusion even if the hormone load is significantly reduced.
OBJECTIVE: To study the hormonal and metabolic responses of fetal lamb during cardiopulmonary bypass. METHODS: Six pregnant ewes underwent fetal cardiopulmonary bypasses with artificial oxygenators and roller pumps for 30 minutes, which maintained the blood gas value at the fetal physiological level. The fetal blood pressure, heart rate, pH value and blood lactate levels were monitored. The levels of catecholamine, cortisol and insulin were measured pre-bypass and then again 30 minutes later. The blood glucose and free fatty acid levels were monitored continuously during the bypass. Fetal hepatic PAS staining was also carried out. RESULTS: There were no changes before and during the bypass in fetal blood pressure, heart rate and blood gas. However, pH values decreased and blood lactate levels increased (P < 0.05). The fetal catecholamine and cortisol levels increased significantly (P < 0.01), while the levels of insulin did not change. The blood glucose and free fatty acid levels increased at the beginning of the bypass (P < 0.01), and then gradually slowed down during the bypass. The fetal hepatic PAS staining showed that hepatic glycogen was consumed in large amounts. After 30 minutes of bypass, the fetal lamb would not survive more than 1 hour. CONCLUSION: The fetal lamb has a strong negative reaction to cardiopulmonary bypass.
The artificial endocrine pancreas (AEP) is a controlled glucose and/or insulin infusion system in which continuously monitored blood sugar values are fed to a computerised analyser that uses predetermined algorithms to establish the doses to be administered. Since its first appearance in clinical practice and diabetological research during the Sixties, the AEP has been modified in various ways to overcome technical problems associated with the gluco-sensor and algorithms so as to make better use of the glucose-insulin feedback mechanism, and hence obtain a closer correspondence to physiological islet cell activity. As a result of these changes, the AEP can be employed in accordance with the physiopathological principles of insulin secretion in a variety of clinical conditions to secure the short-term control of metabolic alterations in the diabetic. Surgery is one field in which the AEP is used to great advantage, since this and its accompanying anaesthetics are the source of stress, which in turn may result in a rapid and sometimes serious postoperative metabolic derangement, including an increased secretion of anti-insulin hormones. The AEP has also been proposed for diabetic pregnancy and for the treatment of subjects in diabetic coma. It has proved useful in the diagnosis and management of hypoglycaemia due to organic hyperinsulinism, in diabetics with renal failure, in the honeymoon period, and in cases of unstable diabetes. The versatility of its application and its underlying physiopathological principles have enabled the AEP to be predominantly employed in research.(ABSTRACT TRUNCATED AT 250 WORDS)
There continues to be controversy regarding the role of blood glucose in the management of pregnant women with gestational diabetes mellitus (GDM), specifically with regard to the use of capillary versus venous samples, as well as the frequency and timing of blood glucose determinations. At the Third International Workshop Conference it was noted that "self-monitoring of capillary blood glucose has been useful in allowing the woman to participate in her own management," but its utility "in the mild GDM not requiring insulin, although reasonable and logical, has not been formally proved." This article reviews the existing evidence in the literature regarding the impact of self-monitoring of blood glucose on outcomes in pregnancies complicated by gestational diabetes. Data regarding the optimal timing, accuracy, costs, and psychosocial effects of self-monitored glucose determinations will also be explored.
A perfusion cell culture is characterised by the continuous addition of fresh nutrient medium and the withdrawal of an equal volume of used medium, allowing the realisation of cell cultivation conditions that are approximated as closely as possible to the in vivo situation. The combination of a perfusion cell culture with an enzyme glucose biosensor allows the glucose consumption of the cell culture to be monitored continuously. The resulting biosensor-controlled perfusion cell culture is a complex biomonitoring system that is useful for checking the metabolic state of a perfusion cell culture continuously and non-invasively over several days. With this experimental setup, it has been possible to test detrimental external effects on living systems at early stages, in vitro, but under in vivo-like conditions.
The simultaneous on-line determination of glucose and lactate using a microdevice that consisted of a dialysis sampling system incorporated to the flow-through cell of a microfabricated biosensor array is presented. The fluidic connections between the different device's components were realized by subsequent processing of stacked dry resist layers on a plastic support that provided also the means for electric connections. The performance of the device was evaluated in vitro. The cross-talk effect on the downstream sensor was investigated and found to be negligible. Recoveries of over 95% for both analytes were achieved when flow rates of the perfusion fluid </=0.5 microl/min were used. At this flow rate, the response time of the device was 2.4 min, which is acceptable for on-line analysis. The linear response concentration range extended up to 30 mM for glucose and 15 mM for lactate. Interference from electroactive species such as ascorbic acid, 2-acetamidophenol and uric acid, was minimal (less than 5% increase in biosensors signal for all substances tested). In addition, the device presented long-term run stability both in buffer and serum samples.
Type I diabetes mellitus requires an exogenous supply of insulin that ideally mimics physiological insulin secretion. The treatment goal is to achieve normoglycaemia in order to prevent or delay chronic complications, while limiting the risk of hypoglycaemia. Numerous advances have been performed in the last 10 years, as far as nature of insulin formulations, home blood glucose monitoring devices and modes of insulin delivery. Among the latter, continuous subcutaneous insulin infusion (CSII) using portable pumps represents the most sophisticated treatment capable of best mimicking normal insulin secretion. Such treatment provides better glucose control and glucose stability as compared to conventional multiple injection insulin therapy. However, it is essential to respect well defined indications and to organize a structured management by a multidisciplinary team in order to get the best metabolic results. The present paper describes recommendations, advantages and limits as well as cost of CSII with portable pumps in type 1 diabetic patients.
The fabrication of a microdevice for continuous sampling and on-line monitoring of glucose is described. The device comprised a microdialysis sampling system integrated on the flow through channel of a microfabricated enzyme sensor. The sensor was produced by thin film technology and was assembled to a printed circuit board (PCB) that provided the means for both electrical and fluidic connections. A polyacrilonitrile fibre, with a cut-off of 50 kDa, was used in the fabrication of the sampling probe. The performance of the device was evaluated in-vitro. High sampling efficiency of the microdialysis probe was achieved by appropriate selection of the perfusion fluid flow rate. Response times varying from 1.5 to 3.0 min were determined for flow rates ranging between 1 and 0.2 micro l/min. The linear response range was up to 30 mM glucose and interference from other electroactive substances was almost negligible. The device showed excellent stability under continuous operation for at least 5 days and sensitivity variation less than 3% over a period of 15 days.
Some features of diabetes care and diabetes treatment regimen which may have an impact on health-related quality of life (HRQOL) in people with diabetes were studied cross-sectionally using the SF-20 questionnaire. Of the 381 subjects with Type 2 diabetes aged under 65 years, 260 (68%) participated in the study. On univariate analysis, HRQOL was associated with regular clinical review (check-up at least twice a year) and continuity of care (the same GP for at least 2 years), education by a diabetes nurse, and satisfaction with diabetes education. No associations were found between the HRQOL dimensions and home glucose monitoring, participation in educational courses, or satisfaction with care. On logistic regression analysis only good continuity of care was significantly associated with the better well-being dimensions of the SF 20 (ORs 2.5-6.0). However, good continuity of care was also associated with less satisfactory glucose control (HbA(1c) 8.9 +/- 2.0 (+/- SD) vs 8.3 +/- 2.0%, P=0.04). It is concluded that a permanent physician-patient relationship may improve HRQOL in subjects with Type 2 diabetes, but further prospective studies are needed to confirm this finding.
The diurnal blood glucose profiles of 15 unstable diabetics were continuously monitored by the artificial endocrine pancreas (AEP, Biostator). Then, feedback control (FC) with the AEP was performed on each subject for 24-32 hr. Based on the data obtained from FC, the patients received an intensified conventional insulin therapy (ICIT) consisting of two daily mixed injections, 45-60 min prior to meals. There was a negative correlation between the MAGE and the sum of serum CPR in a 50 g OGTT, before FC. The M-value, MBG and MAGE decreased significantly during FC and remained lower one month later, compared with those values obtained before FC. The ICIT caused a noticeable decrease in HbA1 levels one to four months after FC. The ICIT was characterized by an increase in the proportion of short-acting insulin in the daily insulin dosage to 40. 3 +/- 11.5%. The proportion of daily insulin dosage to body weight also increased to 0.73 +/- 0.17 U/kg. These results suggest that the AEP, Biostator, could be useful in the clinical management of unstable diabetics by providing a more precise estimate of patients insulin requirements, especially those of short-acting insulin, leading to a better long-term control of blood glucose.
A widely applicable cultivation strategy, which reduces the costs of expensive isotopes, is designed for maximal (98-100%) incorporation of [13C] and [15N] into labelled recombinant protein expressed in Escherichia coli, allowing better assignment of the resonances for NMR studies. Isotope labelling of the culture was performed throughout the complete process, starting from preculture. Sufficient biomass is first generated in a batch phase. Upon consumption of glucose, identified by a sharp drop of on-line monitored oxygen consumption, expression is induced and cultivation is continued under glucose-limited conditions as fed-batch process. Thereby a quantitative utilisation of the most expensive component [13C]-glucose is achieved, while the approximate amount of the [15N]-ammonium chloride to be incorporated is calculated from the scheduled biomass. The usefulness of the strategy is demonstrated with production of uniformly [13C/15N]-labelled tryparedoxin of Crithidia fasciculata. Ideal isotope incorporation and product quality is documented by MALDI-TOF mass spectrometry and two- and three-dimensional NMR spectra.
The incidence of low nocturnal blood glucose values (i.e., less than 65 mg/dl) was assessed in 20 insulin-dependent diabetic patients treated with continuous subcutaneous insulin infusion supported by capillary blood glucose monitoring before each meal and the evening snack. Patients were randomly assigned to a control or experimental group. Both groups followed an identical protocol for the first part of the study (baseline). Patients were instructed to determine capillary blood glucose measurements five times during the night for three consecutive nights. The same procedure was repeated one week later, but this time the subjects in the experimental group were instructed to have an extra snack if capillary blood glucose levels at 10:30 P.M. were 120 mg/dl or less. The control group continued with the usual routine of one evening snack at 9 P.M. At baseline, the incidence of capillary blood glucose values of less than 65 mg/dl was 13 percent. The ingestion of an extra snack at bedtime resulted in the absence of capillary blood glucose values of less than 65 mg/dl in the experimental group, whereas the incidence of capillary blood glucose values of less than 65 mg/dl in the control group remained 13 percent (p = 0.038). The capillary blood glucose concentration at 10:30 P.M. was highly predictive of the risk of nocturnal blood glucose values below 65 mg/dl (p = 0.015) and fasting capillary blood glucose values above 140 mg/dl (p = 0.0001). These data show that nocturnal hypoglycemia may be a considerable problem during continuous subcutaneous insulin infusion therapy even if the basal infusion rate is adjusted in the hospital on the basis of nocturnal blood glucose concentrations. The ingestion of an extra snack at bedtime for capillary blood glucose values below 120 mg/dl has the potential to minimize this risk. The capillary blood glucose concentration at 10:30 P.M. is a significant predictor of nocturnal hypoglycemia.
CONTEXT: Adequacy of glucose infusion may be monitored via the glycosuria levels, as there is a relationship between glycemia and glycosuria regulated by the renal glucose threshold. In the neonatal period, however, this relationship is not so clear. OBJECTIVE: To evaluate the occurrence of glycosuria in preferm infants submitted to glucose infusion and to verify the relationship between glycosuria and blood glucose level. DESIGN: Accuracy study. SETTING: Neonatal intensive care unit of General Maternity Hospital. PATIENTS: 40 Preterm newborns receiving glucose infusion. PROCEDURES: 511 concomitant determinations of glycemia and glycosuria were performed. These 511 pairs were divided into stable and unstable, according to the clinical status of the newborn at the time of data collection, and they were studied in relation to the gestational age, birth weight and glucose infusion rate. RESULTS: The results revealed a greater frequency of glycosuria in gestational age < or = 30 weeks, birth weight < 1500 g and glucose infusion rate > 6 mg/kg/min. Eight (25.8%) episodes of positive glycosuria occurred in the absence of hyperglycemia, indicating only a moderate concordance between them. CONCLUSION: Glycosuria alone is an unreliable marker of blood glucose concentration and adequacy of glucose infusion rate. It is therefore necessary to monitor blood glucose levels in infants submitted to continuous glucose infusion.
Intensification of insulin therapy which maintains long-term near-normoglycaemia (HbA1c<7.0%) strongly protects against onset and/or progression of diabetic microangiopathy in Type 1 diabetes mellitus of adults. Similar intensification of insulin therapy is needed in diabetic children as well, in order to prevent complications a few years after diabetes onset, ie very often in young age. Provided adequate psychosocial support and education are available, children should be treated with multiple daily injections of insulin or, when necessary, with continuous subcutaneous insulin infusion, along with blood glucose monitoring. Insulin regimens may differ from child to child and vary from day to day in the same child, depending on lifestyle and considering all the available insulin preparations. These include the short-acting insulin (both human regular and short-acting insulin analogues), the intermediate-acting insulin (NPH and Lente), as well as the new long-acting insulin analogue glargine. The latter seems a promising candidate to substitute of basal insulin. The concern that intensified insulin therapy increases the risk of hypoglycaemia, as indicated by the Diabetes Control and Complications Trial (DCCT), is no longer tenable. On the contrary, a physiological, flexible insulin regimen better than a fixed insulin regimen, usually the twice daily split-mixed regimen, protects against the risk of hypoglycaemia in relation to food ingestion, physical exercise and sleep. Thus, appropriate education should be delivered at diabetes onset to the child and parents in order to start the strategy of intensified insulin therapy as early as possible.
An extracorporeal glucose monitor (EGM) has been used in a patient with an insulinoma. This system, which continuously measures blood glucose, can be used in combination with a feedback-controlled glucose infusion to maintain glycaemia at any preselected level. It prevents the risk of severe hypoglycaemia during diagnostic tests (total fast, tolbutamide and insulin tolerance tests) as well as during surgery. It also helps in determining whether all the insulin-secreting tumour tissue has been removed. The EGM is thus helpful in the diagnosis and surgical treatment of insulinomas.