scholarly journals Acute Glycemic Changes in Brain and Subcutaneous Tissue Measured by Continuous Glucose Monitoring System in Hereditary Hypertriglyceridemic Rat

2018 ◽  
pp. 127-131
Author(s):  
M. ŽOUREK ◽  
P. KYSELOVÁ ◽  
D. ČECHUROVÁ ◽  
Z. RUŠAVÝ
Keyword(s):  
Glucose Level ◽  
Subcutaneous Tissue ◽  
Time Lag ◽  
Glucose Monitoring ◽  
Time Shift ◽  
Sensor Calibration ◽  
Blood Brain ◽  
The Difference ◽  
Glucose Dynamics ◽  
The Brain

Parallel glucose measurements in blood and other different tissues give us knowledge about dynamics of glycemia changes, which depend on vascularization, distribution space and local utilization by tissues. Such information is important for the understanding of glucose homeostasis and regulation. The aim of our study was to determine the time-lag between blood, brain, and adipose tissue during rapid glucose changes in a male hHTG rat (n=15). The CGMS sensor Guardian RT (Minimed/Medtronic, USA) was inserted into the brain and into the abdominal subcutaneous tissue. Fixed insulin and variable rate of glucose infusion was used to maintain euglycemia during sensor calibration period. At 0 min, 0.5 g/kg of bolus of glucose was administered, and at 50 min, 5 IU/kg of bolus of insulin was administered. Further glucose and insulin infusion was stopped at this time. The experiment was finished at 130 min and animals were euthanized. The time-shift between glycemia changes in blood, brain, and subcutaneous tissue was calculated by identification of the ideal correlation function. Moreover, the time to achieve 90 % of the maximum glucose excursion after intervention (T90) was measured to compare our data with the literature. The time-lag blood vs. brain and blood vs. subcutaneous tissue was 10 (10; 15) min and 15 (15; 25) min, respectively. The difference was statistically significant (P=0.01). T90 after glucose bolus in brain and subcutaneous tissue was 10 min (8.75; 15) and 15 min (13.75; 21.25), respectively. T90 after insulin bolus in brain and subcutaneous tissue was 10 min (10; 15) and 20 min (20; 27.5), respectively. To the contrary, with literature, our results showed earlier glucose level changes in brain in comparison with subcutaneous tissue after glucose and insulin boluses. Our results suggest that glucose dynamics is different within monitored tissues under rapid changing glucose level and we can expect similar behavior in humans. Improved knowledge about glucose distribution and dynamics is important for avoiding hypoglycemia.

scholarly journals Enlarged glycemic variability in sulfonylurea-treated well-controlled type 2 diabetics identified using continuous glucose monitoring

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fumi Uemura ◽  
Yosuke Okada ◽  
Keiichi Torimoto ◽  
Yoshiya Tanaka
Keyword(s):  
Glucose Level ◽  
Continuous Glucose Monitoring ◽  
Glucose Monitoring ◽  
Glycemic Variability ◽  
High Dose ◽  
Type 2 Diabetics ◽  
Time In Range ◽  
The Difference ◽  
Glycated Hemoglobin Level

AbstractTime in range (TIR) is an index of glycemic control obtained from continuous glucose monitoring (CGM). The aim was to compare the glycemic variability of treatment with sulfonylureas (SUs) in type 2 diabetes mellitus (T2DM) with well-controlled glucose level (TIR > 70%). The study subjects were 123 patients selected T2DM who underwent CGM more than 24 h on admission without changing treatment. The primary endpoint was the difference in glycemic variability, while the secondary endpoint was the difference in time below range < 54 mg/dL; TBR < 54, between the SU (n = 63) and non-SU (n = 60) groups. The standard deviation, percentage coefficient of variation (%CV), and maximum glucose level were higher in the SU group than in the non-SU group, and TBR < 54 was longer in the high-dose SU patients. SU treatment was identified as a significant factor that affected %CV (β: 2.678, p = 0.034). High-dose SU use contributed to prolonged TBR < 54 (β: 0.487, p = 0.028). Our study identified enlarged glycemic variability in sulfonylurea-treated well-controlled T2DM patients and high-dose SU use was associated with TBR < 54. The results highlight the need for careful adjustment of the SU dose, irrespective of glycated hemoglobin level or TIR value.

scholarly journals Transport of D-Glucose and 2-Fluorodeoxyglucose across the Blood-Brain Barrier in Humans

1996 ◽  
Vol 16 (4) ◽  
pp. 659-666 ◽  
Author(s):  
Steen G. Hasselbalch ◽  
Gitte M. Knudsen ◽  
Søren Holm ◽  
L. Pinborg Hageman ◽  
Brunella Capaldo ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Initial Distribution ◽  
Brain Barrier ◽  
Transport Parameters ◽  
Indicator Method ◽  
Blood Brain ◽  
The Difference ◽  
Regional Cerebral Glucose Metabolism ◽  
The Brain

The deoxyglucose method for calculation of regional cerebral glucose metabolism by PET using 18F-2-fluoro-2-deoxy-d-glucose (FDG) requires knowledge of the lumped constant, which corrects for differences in the blood–brain barrier (BBB) transport and phosphorylation of FDG and glucose. The BBB transport rates of FDG and glucose have not previously been determined in humans. In the present study these transport rates were measured with the intravenous double-indicator method in 24 healthy subjects during normoglycemia (5.2 ± 0.7 m M). Nine subjects were restudied during moderate hypoglycemia (3.4 ± 0.4 m M) and five subjects were studied once during hyperglycemia (15.0 ± 0.7 m M). The global ratio between the unidirectional clearances of FDG and glucose (K1*/K1) was similar in normoglycemia (1.48 ± 0.22), moderate hypoglycemia (1.41 ± 0.23), and hyperglycemia (1.44 ± 0.20). This ratio is comparable to what has been obtained in rats. We argue that the global ratio is constant throughout the brain and may be applied for the regional determination of LC. We also determined the transport parameters of the two hexoses from brain back to blood and, assuming symmetrical transport across the BBB, we found evidence of a larger initial distribution volume of FDG in brain (0.329 ± 0.236) as compared with that of glucose (0.162 ± 0.098, p < 0.005). The difference can be explained by the very short experimental time, in which FDG may distribute both intra- and extracellularly, whereas glucose remains in a volume comparable to the interstitial fluid of the brain.

scholarly journals Virulence Factors of Meningitis-Causing Bacteria: Enabling Brain Entry across the Blood–Brain Barrier

2019 ◽  
Vol 20 (21) ◽  
pp. 5393 ◽  
Author(s):  
Herold ◽  
Schroten ◽  
Schwerk
Keyword(s):  
Blood Brain Barrier ◽  
Virulence Factors ◽  
Host Cells ◽  
Brain Barrier ◽  
Host Cell Signaling ◽  
Blood Brain ◽  
The Central Nervous System ◽  
The Difference ◽  
Multiple Pathogens ◽  
The Brain

Infections of the central nervous system (CNS) are still a major cause of morbidity and mortality worldwide. Traversal of the barriers protecting the brain by pathogens is a prerequisite for the development of meningitis. Bacteria have developed a variety of different strategies to cross these barriers and reach the CNS. To this end, they use a variety of different virulence factors that enable them to attach to and traverse these barriers. These virulence factors mediate adhesion to and invasion into host cells, intracellular survival, induction of host cell signaling and inflammatory response, and affect barrier function. While some of these mechanisms differ, others are shared by multiple pathogens. Further understanding of these processes, with special emphasis on the difference between the blood–brain barrier and the blood–cerebrospinal fluid barrier, as well as virulence factors used by the pathogens, is still needed.

MICROCHEMICAL ASSAYS OF GLUCOSE AND GLUCOSE-6-PHOSPHATE IN MAMMALIAN PANCREATIC β-CELLS

1968 ◽  
Vol 59 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Lars-Ake Idahl ◽  
Bo Hellman
Keyword(s):  
Glucose Level ◽  
Exocrine Pancreas ◽  
The Other ◽  
Wide Concentration Range ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Enzymatic Cycling ◽  
Glucose Diffusion ◽  
Significant Barrier ◽  
The Brain

ABSTRACT The combination of enzymatic cycling and fluorometry was used for measuring glucose and glucose-6-phosphate in pancreatic β-cells from obese-hyperglycaemic mice. The glucose level of the β-cells corresponded to that of serum over a wide concentration range. In the exocrine pancreas, on the other hand, a significant barrier to glucose diffusion across the cell membranes was demonstrated. During 5 min of ischaemia, the glucose level remained practically unchanged in the β-cells while it increased in the liver and decreased in the brain. The observation that the pancreatic β-cells are characterized by a relatively low ratio of glucose-6-phosphate to glucose may be attributed to the presence of a specific glucose-6-phosphatase.

PENGENDALIAN KADAR GLUKOSA DARAH OLEH TEH HIJAU DAN ATAU TEH DAUN MURBEI PADA TIKUS DIABETES

2010 ◽  
Vol 5 (2) ◽  
pp. 87
Author(s):  
Rusman Efendi ◽  
Evy Damayanthi ◽  
Lilik Kustiyah ◽  
Nastiti Kusumorini
Keyword(s):  
Blood Glucose ◽  
Blood Glucose Level ◽  
Green Tea ◽  
Glucose Level ◽  
Diabetic Rats ◽  
Feed Consumption ◽  
Font Size ◽  
High Prevalence ◽  
The Difference ◽  
Control Diabetes

<p class="MsoNormal" style="margin: 0cm 7.1pt 6pt 14.2pt; text-align: justify; text-indent: 1cm;"><span style="font-size: 10pt;">Diabetes mellitus is degeneratif disease with high prevalence that happens in many countries. Several studies had been done to control diabetes by using green tea, mullberry leaf  tea, and their mixture. The aim of this research was to analyze the influence of the administration green tea, mullbery leaf tea, and their mixtures to blood glucose level of diabetic rats both during 120 minutes after administration. This research had four phases, first to determine the best mullberry leaf tea, second to fourth phases respectively, determine turnover of blood glucose level on normal rats; attempt during 120 minutes on diabetic rats.  The result of research during 120 minutes have showed that blood glucose level on diabetic rats which were administered by green tea, mullberry leaf tea and their mixture is significantly difference with diabetic rats which were administered by water. Blood glucose level at baseline increased at 30<sup>th </sup>minutes and showed the difference significantly and then until 60<sup>th</sup> and 120<sup>th</sup> minutes and relatively stable. During 120 minutes after feed consumption, inhibition of blood glucose level occured increasingly on diabetic rats which were administered by green tea, mullberry leaf tea, and their mixture compared to diabetic rats which were administered by water.</span></p>

Ligand and Structure-based Modeling of Passive Diffusion through the Blood-Brain Barrier

2018 ◽  
Vol 25 (9) ◽  
pp. 1073-1089 ◽  
Author(s):  
Santiago Vilar ◽  
Eduardo Sobarzo-Sanchez ◽  
Lourdes Santana ◽  
Eugenio Uriarte
Keyword(s):  
Blood Brain Barrier ◽  
In Silico ◽  
Passive Diffusion ◽  
Brain Barrier ◽  
Barrier Permeability ◽  
Blood Brain Barrier Permeability ◽  
Blood Brain ◽  
Brain Barrier Permeability ◽  
Different Types ◽  
The Brain

Background: Blood-brain barrier transport is an important process to be considered in drug candidates. The blood-brain barrier protects the brain from toxicological agents and, therefore, also establishes a restrictive mechanism for the delivery of drugs into the brain. Although there are different and complex mechanisms implicated in drug transport, in this review we focused on the prediction of passive diffusion through the blood-brain barrier. Methods: We elaborated on ligand-based and structure-based models that have been described to predict the blood-brain barrier permeability. Results: Multiple 2D and 3D QSPR/QSAR models and integrative approaches have been published to establish quantitative and qualitative relationships with the blood-brain barrier permeability. We explained different types of descriptors that correlate with passive diffusion along with data analysis methods. Moreover, we discussed the applicability of other types of molecular structure-based simulations, such as molecular dynamics, and their implications in the prediction of passive diffusion. Challenges and limitations of experimental measurements of permeability and in silico predictive methods were also described. Conclusion: Improvements in the prediction of blood-brain barrier permeability from different types of in silico models are crucial to optimize the process of Central Nervous System drug discovery and development.

Liposomes: Novel Drug Delivery Approach for Targeting Parkinson’s Disease

2020 ◽  
Vol 26 (37) ◽  
pp. 4721-4737 ◽  
Author(s):  
Bhumika Kumar ◽  
Mukesh Pandey ◽  
Faheem H. Pottoo ◽  
Faizana Fayaz ◽  
Anjali Sharma ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Drug Delivery ◽  
Parkinson's Disease ◽  
Side Effects ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Brain Targeting ◽  
Neural Cells ◽  
Blood Brain ◽  
The Brain

Parkinson’s disease is one of the most severe progressive neurodegenerative disorders, having a mortifying effect on the health of millions of people around the globe. The neural cells producing dopamine in the substantia nigra of the brain die out. This leads to symptoms like hypokinesia, rigidity, bradykinesia, and rest tremor. Parkinsonism cannot be cured, but the symptoms can be reduced with the intervention of medicinal drugs, surgical treatments, and physical therapies. Delivering drugs to the brain for treating Parkinson’s disease is very challenging. The blood-brain barrier acts as a highly selective semi-permeable barrier, which refrains the drug from reaching the brain. Conventional drug delivery systems used for Parkinson’s disease do not readily cross the blood barrier and further lead to several side-effects. Recent advancements in drug delivery technologies have facilitated drug delivery to the brain without flooding the bloodstream and by directly targeting the neurons. In the era of Nanotherapeutics, liposomes are an efficient drug delivery option for brain targeting. Liposomes facilitate the passage of drugs across the blood-brain barrier, enhances the efficacy of the drugs, and minimize the side effects related to it. The review aims at providing a broad updated view of the liposomes, which can be used for targeting Parkinson’s disease.

Brain Drug Delivery: Overcoming the Blood-brain Barrier to Treat Tauopathies

2020 ◽  
Vol 26 (13) ◽  
pp. 1448-1465 ◽  
Author(s):  
Jozef Hanes ◽  
Eva Dobakova ◽  
Petra Majerova
Keyword(s):  
Drug Delivery ◽  
Blood Brain Barrier ◽  
Neurodegenerative Disorders ◽  
Brain Barrier ◽  
Neuronal Function ◽  
Brain Drug Delivery ◽  
Naturally Occurring ◽  
Blood Brain ◽  
Traditional Approaches ◽  
The Brain

Tauopathies are neurodegenerative disorders characterized by the deposition of abnormal tau protein in the brain. The application of potentially effective therapeutics for their successful treatment is hampered by the presence of a naturally occurring brain protection layer called the blood-brain barrier (BBB). BBB represents one of the biggest challenges in the development of therapeutics for central nervous system (CNS) disorders, where sufficient BBB penetration is inevitable. BBB is a heavily restricting barrier regulating the movement of molecules, ions, and cells between the blood and the CNS to secure proper neuronal function and protect the CNS from dangerous substances and processes. Yet, these natural functions possessed by BBB represent a great hurdle for brain drug delivery. This review is concentrated on summarizing the available methods and approaches for effective therapeutics’ delivery through the BBB to treat neurodegenerative disorders with a focus on tauopathies. It describes the traditional approaches but also new nanotechnology strategies emerging with advanced medical techniques. Their limitations and benefits are discussed.

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