In order to determine the suitable harvest time of Dendrobium officinale from different regions in Yunnan province, the drying rate, mannose and glucose peak area ratio, extract, contents of polysaccharide and mannose of D. officinale samples collected from six producing areas in Ynnnan province were determined. The results indicate that drying rate and the contents of polysaccharide and mannose arrived the peak from January to April, extract reached a higher content from September to December, and mannose and glucose peak area ratio from October to February of the coming met the requirment of the Chinese Pharmacopoeia. Hence, the suitable harvesting time of D. officinale in Yunnan province is from December to February of the coming year,according to the experimental results and the request of the Chinese Pharmacopoeia.
China ; Dendrobium ; chemistry ; growth & development ; metabolism ; Glucose ; analysis ; metabolism ; Mannose ; analysis ; metabolism ; Time Factors

Glycated haemoglobins are haemoglobins with an attached sugar moiety. They constitute the HbA1 fraction of the adult haemoglobin HbA. HbA1c is the predominant fraction of HbA1 and gives an estimate of the blood sugar levels of an individual over the last three months. It has been observed that an HbA1c value of less than seven percent reduces the microvascular complications in diabetic patients. However, HbA1c is not affected by blood sugar levels alone. Apart from blood sugar, there are other factors that affect HbA1c. This article reviews in detail the structure, formation, methods of measurement, factors affecting HbA1c levels and their clinical significance.
Blood Glucose ; metabolism ; Diabetes Mellitus ; metabolism ; physiopathology ; Glycated Hemoglobin A ; analysis ; metabolism ; Humans

OBJECTIVETo explore the changes of brain energy metabolism following acrylamide (ACR) poisoning.

METHODSCreatie kinase (CK), adenosine triphosphate (ATP), adenosine diphosphate(ADP), adenosine 5'-monophosphate(AMP) and glucose contents in brain were observed in O1a mice and 6J mice following ACR intoxication by enzyme analytical method.

RESULTSATP, CK and glucose levels decreased transiently in O1a mice, while ATP level in 6J mice was significantly decreased (1.76 mumol/g, P < 0.01), as compared to the control (2.53 mumol/g) but ADP and AMP were increased, glucose was decreased. The activity of CK in poisoned group (1.13 mumol/g, P < 0.01) was lower than that of control (3.16 mumol/g and lasted for 5 weeks).

CONCLUSIONThe influence of ACR on O1a mice was slight and reversible but on 6J mice was severe and lasting. There was severe damage to the potential energy supply compensation, which might be the biochemical basis of neuron damage induced by acrylamide.

Acrylamide ; poisoning ; Adenosine Triphosphate ; analysis ; Animals ; Brain ; drug effects ; metabolism ; Creatine Kinase ; analysis ; Energy Metabolism ; drug effects ; Glucose ; analysis ; Mice

BACKGROUND: Commutable reference materials (RMs) are suitable for end-users for evaluating the metrological traceability of values obtained using routine measurement systems. We assessed the performance of 6 routine measurement systems with validated secondary RMs. METHODS: We tested the homogeneity, stability, and commutability of 5 minimally processed human serum pools according to the standard guidelines. The serum pools were assigned values as per the reference procedure of the United States Centers for Disease Control and were used to evaluate the trueness of results from 6 commercial measurement systems based on enzymatic methods: 3 glucose oxidase (GOD) and 3 hexokinase (HK) methods. RESULTS: The prepared RMs were validated to be sufficiently homogenous, stable, and commutable with the patient samples. Method bias varied for different systems: GOD01, -0.17 to 2.88%; GOD02, 1.66 to 4.58%; GOD03, -0.17 to 3.14%; HK01, -3.48 to -0.85%; HK02, -3.83 to -0.11%, and HK03, -1.82 to -0.27%. CONCLUSIONS: We observed that the prepared serum glucose RMs were qualified for trueness assessment. Most of the measurement systems met the minimal quality specifications.
Blood Chemical Analysis/instrumentation/*standards ; Blood Glucose/*analysis ; Glucose Oxidase/metabolism ; Hexokinase/metabolism ; Humans ; Reagent Kits, Diagnostic ; Reference Standards ; Regression Analysis

BACKGROUNDThe delivery of glucose from the blood to the brain involves its passage across the endothelial cells of the blood-brain barrier (BBB), which is mediated by the facilitative glucose transporter protein 1 (GLUT(1)), and then across the neural cell membranes, which is mediated by GLUT(3). This study aimed to evaluate the dynamic influence of hyperglycemia on the expression of these GLUTs by measuring their expression in the brain at different blood glucose levels in a rat model of diabetes. This might help to determine the proper blood glucose threshold level in the treatment of diabetic apoplexy.

METHODSDiabetes mellitus was induced with streptozotocin (STZ) in 30 rats. The rats were randomly divided into 3 groups: diabetic group without blood glucose control (group DM1), diabetic rats treated with low dose insulin (group DM2), and diabetic rats treated with high dose insulin (group DM3). The mRNA and protein levels of GLUT(1) and GLUT(3) were assayed by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry, respectively.

RESULTSCompared with normal control rats, the GLUT(1) mRNA was reduced by 46.08%, 29.80%, 19.22% (P < 0.01) in DM1, DM2, and DM3 group, respectively; and the GLUT(3) mRNA was reduced by 75.00%, 46.75%, and 17.89% (P < 0.01) in DM1, DM2, and DM3 group, respectively. The abundance of GLUT(1) and GLUT(3) proteins had negative correlation with the blood glucose level (P < 0.01). The density of microvessels in the brain of diabetic rats did not change significantly compared with normal rats.

CONCLUSIONSChronic hyperglycemia downregulates GLUT(1) and GLUT(3) expression at both mRNA and protein levels in the rat brain, which is not due to the decrease of the density of microvessels. The downregulation of GLUT(1) and GLUT(3) expression might be the adaptive reaction of the body to prevent excessive glucose entering the cell that may lead to cell damage.

Animals ; Blood Glucose ; analysis ; Brain ; metabolism ; Diabetes Mellitus, Experimental ; metabolism ; Glucose Transporter Type 1 ; analysis ; genetics ; Glucose Transporter Type 3 ; analysis ; genetics ; Glycated Hemoglobin A ; analysis ; Male ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Streptozocin

BACKGROUNDThe hypothalamus plays a central role in the regulation of metabolism by sensing metabolic demands and releasing regulatory neurotransmitters. This study investigated the response of the hypothalamus to glucose ingestion in rats by blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI) and immunohistochemical techniques to determine the role of the hypothalamus in glyco-regulation during disturbances in carbohydrate metabolism.

METHODSThe signal intensity of the hypothalamus was monitored by fMRI for 60 minutes after oral glucose intake in 48 healthy rats (age 14 months), which included 24 normal weight rats (weighing (365 +/- 76.5) g) and 24 overweight rats (weighing (714 +/- 83.5) g). Then, 12 rats (6 normal, 6 overweight) underwent a repeat fMRI scan after consuming an equivalent amount of water without glucose on a separate day. The procedure for fMRI with water intake was the same as for glucose ingestion. fMRI data was processed using time cluster analysis and intensity averaging method. After fMRI, the expression of neuropeptide Y (NPY) and 5-hydroxytryptamine (5-HT) in the hypothalamus of all rats was determined by immunohistochemistry. Positive cells for NPY or 5-HT were counted.

RESULTSThere was a transient, but significant, decrease in fMRI signal intensity in all rats (mean (3.12 +/- 0.78)%) in the hypothalamus within 19.5 - 25.5 minutes of oral glucose ingestion. In overweight rats, the decrease in signal intensity in response to the glucose ingestion was more markedly attenuated than that observed in normal weight rats ((2.2 +/- 1.5)% vs (4.2 +/- 0.7)% inhibition, t = 2.12, P < 0.05). There was no significant response in the hypothalamus after oral water ingestion. The percentage of NPY positive cells in obese rats were slightly lower than those in control group (21% vs 23%, t = 0.71, P > 0.05); but there was no significant difference between the two groups; the percentage of 5-HT positive cells in obese rats were significantly lower than those in the control group (22% vs 31%, t = 3.25, P < 0.01).

CONCLUSIONSThere is a transient, but significant, decrease in BOLD signal intensity in the hypothalamus following glucose ingestion, which is similar to that observed in humans. The response of the hypothalamus to glucose ingestion was different in overweight and normal weight rats. The percentage of NPY positive cells in obese rats were lower than those in the control group, although this difference was not statistically significant. The percentage of 5-HT positive cells in obese rats was significantly lower than those in the control group.

Animals ; Glucose ; metabolism ; Hypothalamus ; physiology ; Immunohistochemistry ; Magnetic Resonance Imaging ; methods ; Neuropeptide Y ; analysis ; Obesity ; metabolism ; Oxygen ; blood ; Rats ; Serotonin ; analysis

OBJECTIVETo study the effect of mild hypothermia on glucose metabolism and glycerol of brain tissue in patients with severe traumatic brain injury (STBI) using clinical microdialysis.

METHODSThirty-one patients with STBI(GCS less than or equal to 8) were randomly divided into hypothermic group(Group A) and control group(Group B). Microdialysis catheters were inserted into the cerebral cortex of perilesional and normal brain tissue. All samples were analyzed using CMA microdialysis analyzer.

RESULTSIn comparison with the control group, lactate/glucose ratio(L/G), lactate/pyruvate ratio(L/P) and glycerol(Gly) in perilensional tissue were significantly decreased; L/P in normal brain tissue was significantly decreased. In control group, L/G, L/P and Gly in perilensional tissue were higher than that in normal brain tissue. In the hypothermic group, L/P in perilensional tissue was higher than that in relative normal brain.

CONCLUSIONSMild hypothermia protects brain tissues by decreasing L/G, L/P and Gly in perilensional tissue and L/P in "normal brain" tissues. The energy crisis and membrane phospholipid degradation in perilensional tissue are easier to happen after traumatic brain injury, and mild hypothermia protects brain better in perilensional tissue than in normal brain tissue.

Adolescent ; Adult ; Brain ; metabolism ; Brain Injuries ; metabolism ; therapy ; Glucose ; metabolism ; Glycerol ; analysis ; Humans ; Hypothermia, Induced ; methods ; Microdialysis ; Middle Aged

OBJECTIVETo investigate the expression pattern of resistin (RSTN) in skeletal muscle tissue and its influence on glycometabolism in rats with traumatic brain injury (TBI).

METHODSSeventy-eight SD rats were randomly divided into traumatic group (n=36), RSTN group (n=36) and sham operation group (n=6). Fluid percussion TBI model was developed in traumatic and RSTN groups and the latter received additional 1 mg RSTN antibody treatment for each rat. At respectively 12 h, 24 h, 72 h, 1 w, 2 w, and 4 w after operation, venous blood was collected and the right hind leg skeletal muscle tissue was sampled. We used real-time PCR to determine mRNA expression of RSTN in skeletal muscles, western blot to determine RSTN protein expression and ELISA to assess serum insulin as well as fasting blood glucose (FBG) levels. Calculation of the quantitative insulin sensitivity check index (Q value) was also conducted. The above mentioned indicators and their correction were statistically analyzed.

RESULTSCompared with sham operation group, the RSTN expression in the skeletal muscle as well as serum insulin and FBG levels revealed significant elevation (P<0.05), and reduced Q value (P<0.05) in traumatic group. Single factor linear correlation analysis showed a significant negative correlation between RSTN expression and Q values (P<0.001) in traumatic group.

CONCLUSIONThe expression of RSTN has been greatly increased in the muscular tissue of TBI rats and it was closely related to the index of glycometabolism. RSTN may play an important role in the process of insulin resistance after TBI.

Animals ; Brain Injuries ; metabolism ; Glucose ; metabolism ; Insulin Resistance ; Male ; Muscle, Skeletal ; chemistry ; metabolism ; Rats, Sprague-Dawley ; Resistin ; analysis

To demonstrate the fructose metabolism pathway in Bifidobacterium Longum NCC2705 and to construct its fermentation model, we explored the comparative proteome cultivating the strain on glucose or fructose, based on a proteomic reference map of B. longum NCC2705 constructed earlier. Then, we used matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and electro-spray ionization tandem mass spectrometry (ESI-MS/MS) for differently expressed proteins identification. Furthermore, with semi-quantitative RT-PCR we determined the distinctively expressed proteins at the level of transcription. Proteomic comparison of glucose- and fructose-grown cells demonstrated much similarity. On the page of fructose there were all the enzymes and proteins that exist during the process of glucose degradation. We observed a greater variation of more than three-fold for the identified 9 spots representing 5 protein entries by MALDI-TOF MS. The sugar-binding protein specific to fructose (BL0033) and an ABC transporter ATP binding protein (BL0034) showed higher expression level from cells grown on fructose. It was also determined by semi-quantitative RT-PCR subsequently. BL0033 time course and concentration experiments showed that the induction time correlated to higher fructose concentration, and increased expression of BL0033. Fructose was catabolized via the same degradation pathway as glucose at the level of proteomics. BL0033 was induced by fructose. All results suggest that the uptake of fructose into the cell may be conducted by a specific ABC transport system, in which BL0033 and BL0034 as components might have played an important role.
Bifidobacterium ; chemistry ; genetics ; metabolism ; Culture Media ; Fermentation ; Fructose ; pharmacology ; Glucose ; pharmacology ; Proteome ; analysis ; genetics ; Proteomics ; methods

Blood Glucose ; analysis ; Capillaries ; metabolism ; Humans ; Hypoglycemia ; diagnosis ; Infant, Newborn ; Neonatal Screening ; methods ; Reference Standards