Increased glucose availability activates chicken thymocyte metabolism and survival

Glucose metabolism in mammalian thymocytes is coupled to their development and selection in the thymus. In chickens, thymocytes develop in a low glucose concentration in ovo and a high glucose concentration posthatch. To determine the effect of glucose concentration on thymocyte glucose metabolism, embryonic thymic lobes were cultured in media containing varying glucose concentrations and thymocytes were isolated for analysis. Glucose transporter-1 (Glut-1) and Glut-3 mRNA abundance was at least 2-fold higher in thymocytes incubated with 10 and 20 mmol/L glucose than in those incubated with 0 mmol/L glucose (P < 0.05) and glucose uptake was greatest in thymocytes incubated with 20 mmol/L glucose (P < 0.05). Thymocytes incubated with 0 and 20 mmol/L glucose had 185% greater hexokinase activity than in those incubated with 10 mmol/L glucose (P < 0.05). Consequently, thymocyte glucose utilization was dependent upon glucose availability. Increased glucose utilization resulted in a higher mitochondrial membrane potential in thymocytes incubated with 15 mmol/L glucose than in those incubated with 5 mmol/L glucose (P < 0.05), indicating enhanced thymocyte energy status in response to high glucose concentrations. Additionally, thymocyte viability was lower in thymocytes incubated with 5 mmol/L glucose than in those incubated with 10 and 15 mmol/L glucose (P < 0.05) and rates of thymocyte apoptosis were higher in thymocytes incubated with 5 mmol/L glucose than in those incubated with 15 mmol/L glucose (P < 0.05). Glucose availability induced metabolic changes in thymocytes that altered their energy status and survival. Consequently, these data indicate that glucose availability may influence the development of na?ve T cells in the chicken thymus.     

全自动生化分析仪与快速血糖仪的血糖检测结果分析

目的:探究全自动生化分析仪与快速血糖仪的血糖检测结果。方法:选取本院2019年1月~2019年5月收治的96例糖尿病患者作为研究对象。给予所有患者全自动生化分析仪及便携式血糖仪检测,对比患者快速血糖仪、全自动生化分析仪的血糖检测结果。结果:全自动生化分析仪空腹血糖、餐后2h血糖水平高于快速血糖仪检测,P<0.05,差异有统计学意义。全自动生化分析仪静脉血空腹血糖、餐后2h血糖水平高于快速血糖仪检测,P<0.05,差异有统计学意义。结论:相比于快速血糖仪,全自动生化分析仪在检测血糖上优势更为突出,且快速血糖仪受外界因素影响较多,在检测血糖上还无法取代全自动生化分析仪。因此,临床在检测患者血糖时,一定要进行全自动生化分析仪检测,以提高检测准确率。     

Endogenous glucose production after stomach resection

Endogenous glucose production was measured in eight patients after stomach resection to determine glucose requirement after elective surgery in five patients during infusion of 2.1 - 2.9 g glucose.kg/day (low glucose) and in three patients during infusion of 6.2 - 6.9 g glucose.kg/day (high glucose). Endogenous glucose production was defined as the difference between total glucose turnover measured by 2-3H-glucose and the glucose infusion rate. Endogenous glucose production was the same in both groups, respectively 0.010 +/- 0.002 and 0.009 +/- 0.002 mmol kg/min. It was concluded that a daily quantity of glucose equal to the endogenous production of 180 g. 70 kg/day should be the minimum given after stomach resection.     

Effectiveness of glycosylated hemoglobin, fasting plasma glucose, and a single post load plasma glucose level in population screening for glucose intolerance

Five shortcut methods of population screening for glucose intolerance (impaired glucose tolerance and non-insulin-dependent diabetes mellitus) were assessed for effectiveness: 1) glycosylated hemoglobin concentration (HbA1), 2) fasting plasma glucose level, 3) combinations of fasting plasma glucose and HbA1, 4) plasma glucose one hour post oral glucose load, and 5) plasma glucose two hour post oral glucose load. In a sample of the Israeli Jewish population aged 40-70 years, 2040 participants in the Israel Study of Glucose Intolerance, Obesity and Hypertension, who were not known to be diabetic, underwent an oral glucose tolerance test based on three blood samples (fasting, one hour, and two hour post oral glucose load). In 1058 of the subjects, HbA1 was also measured, and was found to increase significantly (P less than 0.001) with increasing glucose intolerance, but with extensive overlap of ranges, even between normals and newly found diabetics. Fasting plasma glucose was more effective than HbA1 in screening for both impaired glucose tolerance and diabetes by its higher specificity and predictive value of a positive test at comparable sensitivity levels. Combinations of HbA1 and fasting plasma glucose did not improve prediction over fasting plasma glucose alone. As observed in other studies, the screening effectiveness of fasting plasma glucose was also unsatisfactory, either post load glucose level being more effective. Plasma glucose level two hour post load was better for detection of diabetes alone. Plasma glucose level one hour post load was more effective at detecting the total group of glucose intolerance, but did not discriminate well between impaired tolerance and diabetes. A cost-risk-benefit evaluation suggests that a full three-sample oral glucose tolerance test is the best method in screening for both intolerance categories.     

Continuous glucose monitoring system, as a valuable tool in the care of children and adolescents with diabetes mellitus

INTRODUCTION: Good metabolic control of diabetic patients is mainly based on the results of self measured blood glucose levels. Important excursions of blood glucose may, however, be hidden in the usual case of 4-5 daily determinations. The aim of this paper was to give detailed information about this new diagnostic tool and to report the first Hungarian pediatric experiences with continuous glucose monitoring. METHOD: Continuous glucose monitoring system (Mini-Med) is able to monitor the changes of tissue glucose levels for up to 72 hours by measuring glucose concentration via a s.c. canula every 5 minutes. In its present form the results of continuous glucose monitoring cannot be observed real time by the patient, it provides useful information retrospectively mainly for the doctor. RESULTS: The sensor detected unexpectedly high fluctuation of glucose levels in several patients. It was possible to distinguish between nighttime hypoglycaemia (Somogyi-effect) or dawn phenomenon-induced morning hyperglycaemiae by the use of continuous glucose monitoring. Fever may influence peripheral circulation representing a limitation in the use (or evaluation) of continuous tissue glucose monitoring. The authors found good correlation between continuous glucose monitoring and self blood glucose monitoring results. The best correlation was observed in the low blood glucose range. CONCLUSIONS: The continuous glucose monitoring results provide useful information for the diabetologist in order to modify insulin treatment. Continuous glucose monitoring-based changes in insulin treatment are reported to result in better long term metabolic control. Continuous glucose monitoring in the near future will obviously play a primary role in insulin pump therapy where it will provide glucose result for the pump.     

血糖仪监测在老年糖尿病患者血糖管理中的应用效果

目的:对血糖仪监测在老年糖尿病患者血糖管理中的应用效果进行观察与分析。方法:本次实验研究的对象为老年糖尿病患者104例,其接受治疗的时间在2018年3月~2019年3月,根据其血糖管理方式的不同分为两组,运用血糖仪监测的52例患者作为试验组,给予常规血糖仪监测的52例患者作为常规组,对比分析两组患者的血糖管理效果。结果:试验组与常规组患者监测后空腹血糖与餐后2h血糖水平均有明显改善(P<0.05),且试验组患者的改善效果显著优于常规组患者(P<0.05),两组患者监测前空腹血糖与餐后2h血糖无明显差异(P>0.05);试验组患者对血糖管理的满意程度明显高于常规组患者(P<0.05)。结论:在为老年糖尿病患者进行血糖管理的过程中血糖仪监测的运用,可以将其空腹血糖与餐后2h血糖控制在更加合理的范围内,提高了患者对血糖管理的满意程度。     

攀枝花地区野生番石榴叶水提取物降血糖作用研究

目的：研究攀枝花地区野生番石榴叶水提取物降血糖作用。方法：雄性昆明种小鼠，诱导葡萄糖性、肾上腺素性和链脲佐菌素性高血糖，受试物灌胃处理。测定处理后小鼠尾静脉血血糖，比较给予受试物前后血糖水平的变化。结果：番石榴叶水提取物不同程度降低外源性高血糖、拮抗应激性葡萄糖升高,明显降低糖尿病小鼠血糖水平，改善糖尿病小鼠糖耐量。结论：攀枝花地区野生番石榴叶水提取物能够抑制多种因素导致的血糖升高，具有明显的降血糖作用。     

Chronic alcohol consumption yields sex differences in whole-body glucose production in rats

AIMS: The effects of chronic alcohol consumption (8 weeks) on glucose kinetics, in the absence (water, 4 g/kg) and presence of an acute ethanol dose (4 g/kg), were examined in 48 h fasted male and female Wistar rats. METHODS: Primed continuous infusions of [6-3H]- and [U-14C]glucose were employed to assess rates of glucose appearance (Ra), glucose disappearance (Rd), and apparent glucose carbon recycling. RESULTS: After injecting the male and female controls with water, there were no significant alterations in glucose kinetics. Compared to controls, chronic alcohol-fed female animals (injected with water) demonstrated significantly lower: glucose Ra, blood glucose concentration, and apparent glucose carbon recycling for a majority of the experimental period. In separate groups injected with ethanol, the glucose Ra fell by 31% for male rats fed the control diet (MC), 43% for male rats fed the ethanol diet (ME), 29% for female rats fed the control diet (FC), and 42% for female rats fed the ethanol diet (FE). Further, compared to controls (MC and FC), the blood glucose concentration was significantly lower prior to and following the ethanol injection for FE. In addition, FE animals had significantly lower rates of glucose Ra and glucose carbon recycling compared to controls prior to and after the ethanol injection. ME animals demonstrated similar declines in glucose Ra (compared to FE), but only after the ethanol injection. Conversely, ME were able to match the decrease in glucose Ra with comparable declines in glucose Rd resulting in blood glucose concentrations that did not differ from controls. CONCLUSIONS: Chronic alcohol consumption results in sex differences in whole-body glucose production and glucose regulation.     

青春期多囊卵巢综合征患者糖代谢评估

目的　研究青春期多囊卵巢综合征 (PCOS)患者糖耐量异常的发生率 ,探讨糖代谢异常与胰岛素抵抗、体重的关系以及早期评估方法。　方法　 4 3例青春期PCOS患者 ,口服 75 g葡萄糖 ,行糖耐量及胰岛素释放实验。用稳态模型胰岛素抵抗指数 (HOMAIR)评价胰岛素抵抗。　结果　 (1)糖耐量低减发生率为 11 6 % (5 /43) ;(2 )糖耐量低减患者的体重指数、空腹血糖、空腹胰岛素及服糖后 6 0、 12 0min的血糖值、胰岛素值、HOMAIR均高于糖耐量正常患者 ,差异有显著性 (P <0 0 5 )。 (3)体重指数与服糖后 12 0min血糖值成正相关 (r =0 35 5 ,P <0 0 5 )。HOMAIR与服糖后 12 0min血糖值成正相关 (r=0 5 78,P <0 0 5 )。　结论　青春期PCOS患者存在糖代谢异常 ,肥胖和胰岛素抵抗是影响其糖耐量的重要因素 ,口服糖耐量试验是用于监测青春期PCOS患者糖代谢的较好指标。     

纳米二氧化钛与葡萄糖亚急性联合经口染毒对幼年大鼠血糖稳态的影响

目的探讨纳米二氧化钛(titanium dioxide nanoparticles,TiO₂ NPs)与葡萄糖联合染毒对幼年大鼠血糖稳态的影响。方法 80只4周龄清洁级SD大鼠按体重随机分为8组(每组10只,雌雄各半)。每天灌胃给予0、2、10和50 mg/kg TiO₂ NPs,分别加或不加1.8 g/kg葡萄糖。实验期间每周监测大鼠血糖变化。亚急性染毒30天后进行口服糖耐量试验(oral glucose tolerance test,OGTT),并检测血糖稳态相关指标,包括血液中糖化血清蛋白(glycosylated serum protein,GSP)、糖化血红蛋白(glycosylated hemoglobin,HbA1c)、胰岛素、C肽和胰高血糖素的含量,同时观察大鼠胰腺病理改变。结果 TiO₂ NPs晶型为锐钛矿,近球形,粒径为(24±5)nm。TiO₂ NPs单独染毒对血糖稳态的影响较小,仅雄性大鼠10 mg/kg染毒组第16天时血糖降低,2和50 mg/kg染毒组30天后餐后2 h血...     

血液病患者激素治疗后的血糖变化特点及意义

目的：观察不同血糖基础的血液病患者使用糖皮质激素（GC）治疗前后的血糖变化特点,探讨其临床意义。方法：65例血液病患者按OGTT分组为糖调节正常（NGT）、糖耐量异常（IGT）和糖尿病（DM）三组,观察各组患者使用GC治疗前后的血糖变化特点。结果：GC治疗后所有患者日平均血糖升高,且餐后血糖升高明显,GC治疗后三组间三餐前后各点血糖值比较差异有统计学意义（P〈0.05）。结论：GC治疗后大部分患者的血糖都会升高,且GC所致血糖变化具有其自身特点,大部分患者表现为午后至睡前严重高血糖,部分患者可出现夜间低血糖。     

农村居民空腹血糖与餐后血糖检测对照研究

目的:探讨餐后1 h血糖与空腹血糖的相关性及餐后1 h血糖的诊断价值。方法:随机抽取健康体检的农村成年居民222名,除5人外,其中的217人为对照组,61例2型糖尿病患者为观察组,测定空腹血糖与早餐后1 h的血糖。结果:222名农村成年居民中有5人空腹血糖升高,其中2人为糖尿病人,3人为空腹血糖受损,其余217人为健康人。糖尿病组餐后1 h血糖升至9.70±1.95 mmol/L,与空腹血糖呈正相关。结论:餐后1 h血糖可作为糖尿病的诊断指标。     

Oral glucose tolerance is unaltered in vitamin D-deficient rat

Vitamin D deficiency has been reported to result in impaired glucose tolerance and decreased insulin secretion when glucose is administered either intravenously or intraperitoneally. The aim of the present study was to study oral glucose tolerance and glucose absorption in a vitamin D-deficient rat model. Oral glucose tolerance tests were carried out in vitamin D-deficient and control rats, and this was found to be unaltered in the deficient state. Intestinal absorption of glucose was drastically reduced in the deficient animal and was found to be due to a reduction in the sodium-dependent component of glucose transport. Thus the unaltered oral glucose tolerance in the vitamin D-deficient rat is probably due to impaired absorption of glucose.     

Low glucokinase activity and high rates of gluconeogenesis contribute to hyperglycemia in barn owls (Tyto alba) after a glucose challenge.

Barn owls (Tyto alba) and leghorn chickens were fed a low protein high glucose (33.44% protein, 23.67% glucose) or a high protein low glucose (55.35% protein, 1.5% glucose) diet. After an intravenous glucose infusion, the peak in plasma glucose was not affected by diet in either species and was 22.6 and 39.4 mmol/L in chickens and barn owls, respectively. Glucose levels returned to normal within 30 min in chickens, but remained elevated for 3.5 h in barn owls. An oral glucose challenge also resulted in greater and longer hyperglycemia in barn owls than in chickens. The activities of hepatic glucokinase, malic enzyme and phosphoenolpyruvate carboxykinase of barn owls were 16, 35, and 333% of the levels in chickens. Malic enzyme (P = 0.024) was less affected by dietary glucose level in barn owls than in chickens. Cultured hepatocytes from chickens produced 43% more glucose from lactate than hepatocytes from barn owls and, conversely, barn owl hepatocytes produced 87% more glucose from threonine than chickens (P = 0.001). Gluconeogenesis from lactate was greatly suppressed by high media glucose in chicken hepatocytes but not in those of barn owls (P = 0.0001 for species by glucose level interaction). When threonine was the substrate, gluconeogenesis was suppressed by increased glucose in both species but to a greater relative extent in chickens (P = 0.007 for species by glucose level interaction). Owls were glucose intolerant at least in part because of low hepatic glucokinase activity and an inadequate suppression of gluconeogenesis in the presence of exogenous glucose, apparently because they evolved with large excesses of amino acids and limited glucose in their normal diet.     

Effects of maternal undernutrition and exercise on glucose kinetics in fetal sheep

Fetal glucose kinetics were measured using a combination of isotope-dilution and Fick-principle methodology in single-pregnant ewes which were either well-fed throughout, or fed at 0.3-0.4 predicted energy requirement for 7-21 d during late pregnancy. All ewes were studied while standing at rest and then while walking on a treadmill at 0.7 m/s on a 10 degree slope for 60 min. Underfed ewes suffered major decreases in fetal total disposal rate, fetal-placental transfer and umbilical net uptake of glucose, each of which were significantly related to declines in maternal and fetal blood glucose concentrations respectively. In well-fed ewes, fetal endogenous glucose production was negligible, as indicated by the similarity between fetal utilization rate (total glucose disposal rate minus placental uptake of fetal glucose) and umbilical net uptake of glucose, and by nearly identical fetal and maternal arterial blood specific radioactivities of maternally infused D-[2-3H]glucose. By contrast, in underfed ewes, fetal utilization rate greatly exceeded umbilical net uptake of glucose, and the fetal:maternal [3H]glucose specific activity ratio declined significantly, suggesting induction of a substantial rate of fetal endogenous glucogenesis. Exercise caused increases in fetal total glucose disposal rate and glycaemia in fed and underfed ewes. In underfed ewes only, this was accompanied by increased placental uptake of fetal glucose and umbilical net glucose uptake, unchanged fetal glucose utilization and decreased fetal endogenous glucose production. It is concluded that fetal gluconeogenesis makes a major contribution to fetal glucose requirements in undernourished ewes. Increased maternal supply of fetal glucose during exercise substitutes for rather than adds to fetal endogenous glucogenesis.     

Metabolism of intravenously administered maltose in renal tubules in humans

To investigate how urinary excretion rates (UERs) of maltose and glucose are determined after intravenous maltose infusion, maltose and glucose solutions were infused at various rates and the relationships between UERs of maltose and glucose and their plasma concentrations were examined. Results showed the existence of a threshold plasma maltose concentration for the urinary excretions of maltose and glucose and the existence of a maximum rate of urinary glucose excretion after maltose infusion. Elevation of plasma glucose concentration by simultaneous glucose infusion increased urinary glucose excretion but did not increase urinary maltose excretion; the relationship between plasma total sugar concentration and urinary total sugar excretion was unchanged. Results suggest that maltose administered intravenously is hydrolyzed to glucose by maltase in renal tubules and reabsorbed as glucose competitively with glucose derived from plasma and that the maximum utilization of intravenously infused maltose is determined by the tubular glucose reabsorption capacity.     

Insulin response to glucose and glucose tolerance following feeding in sheep

Sheep offered a roughage diet for 4 h daily were injected intravenously with glucose before and at various times after feeding. The insulin secretory response to glucose and the rate of disappearance of injected glucose were determined. While the basal concentration of plasma insulin was unchanged, the base-line plasma glucose concentration tended to decrease during the meal. The glucose load brought about an increase in the plasma insulin concentration at each injection, but the insulin response to glucose and the rate of glucose disposal were increased during the meal. On varying the time of feeding between 08.00 and 16.00 hours, the increase in the insulin response to glucose and in the rate of glucose disposal always appeared to be related to the giving of food, independent of the time food was offered. It is concluded that feeding increases the insulin response to an intravenous glucose load even when the increase in the basal level of plasma insulin on feeding is very modest in sheep given a roughage diet. The increased insulin response and glucose disposal rate following feeding did not appear to be related to diurnal rhythms in insulin secretory activity or glucose metabolism.     

Screening for gestational diabetes mellitus: comparison of a glucose polymer and a glucose monomer test beverage.

BACKGROUND: The current test for gestational diabetes mellitus (GDM) uses a glucose monomer test beverage, which frequently causes gastrointestinal symptoms, and venipuncture. We investigated a simplified test using a beverage of glucose polymer and a capillary whole blood glucose measurement. METHODS: In a randomized, double-blind clinical trial, women at 24 to 28 weeks' gestation received a 50-g glucose monomer (n = 41) or glucose polymer (n = 35) beverage. Venous and capillary blood samples were obtained 1 hour later. The women then completed standardized questionnaires about their symptoms. RESULTS: The glucose polymer beverage was associated with significantly fewer symptoms than was the glucose monomer drink: the mean was 1.1 symptoms per test with the glucose monomer drink and 0.4 symptoms per test with the glucose polymer drink (P less than 0.05), 51 percent of the women developed symptoms after drinking the glucose monomer beverage, and 27 percent of the women developed symptoms after drinking the glucose polymer beverage (P less than 0.05). Glucose type did not affect the 1-hour plasma glucose level, mean 5.94 mmol/L (107 mg/dL) for the glucose monomer and 5.76 mmol/L (103.8 mg/dL) for the glucose polymer (P = 0.79). For the capillary test, sensitivity was 0.75 and specificity was 0.82 in detecting a screening test positive by the venous plasma glucose criterion. CONCLUSION: The results of this study indicate that a glucose polymer beverage is better tolerated than a glucose monomer beverage during GDM screening, but capillary glucose measurement might be of limited use in clinics where many personnel perform the capillary blood glucose testing.     

Glucose kinetics in protein depletion--effect of glucose infusion in the fasted rat

A primed constant infusion of [6-3H]glucose was used to determine glucose turnover in rats fasted for 48 h that had previously been pair-fed isoenergetic 4% and 14.4% protein diets for 6 wk. The protein-depleted rats had a low body weight and lower plasma glucose and plasma insulin concentrations compared with the 14.4% protein pair-fed control animals. The rate of appearance of glucose in plasma in the protein-depleted rats was significantly less than that in the pair-fed controls. During an intravenous infusion of unlabeled glucose (38.8 mumol.kg-1.min-1) plasma glucose concentrations and glucose appearance increased in both groups. Plasma insulin concentration remained lower in the 4% protein-fed group though the percentage of increase above basal was similar in both groups during glucose infusion. The clearance of glucose from the blood and suppression of endogenous glucose production during the exogenous glucose infusion were similar in both control and protein-depleted rats. Rats fed a 14.4% protein diet ad libitum consumed more diet than the pair-fed groups and their body weights were greater. However, fasting plasma glucose and insulin, concentrations were similar to the 14.4% protein pair-fed animals. This indicates that the observed changes in glucose metabolism in the 4% protein-fed animals were due to a reduced dietary ratio of protein to carbohydrate rather than reduced energy intake.     

A comparison of enteral and parenteral glucose after cholecystectomy

Twenty consecutive patients were randomised to receive either a glucose polymer by naso-duodenal tube or glucose by intravenous infusion as nutritional support for 24 h after elective cholecystectomy. Following identical amounts of glucose by the two routes, blood levels of glucose, insulin, C-peptide and pancreatic glucagon were similar except for higher glucose and C-peptide levels in the intravenous group at 4 and 10 h and 10 h after surgery, respectivel. Patients receiving enteral glucose did not have higher insulin and C-peptide levels than patients receiving intravenous glucose. It is concluded that nutritional support by the enteral route alone is feasible immediately following cholecystectomy. The relatively low glucose levels during enteral glucose infusion suggest improved utilisation of glucose as compared to intravenous glucose infusion.