Near-Infrared Light Emitting Diode Based Non-Invasive Glucose Detection System.

Diabetes mellitus is a common disease that has affected people since antiquity. The complexity of diabetes mellitus lies in the fact that it requires continuous management in order to prevent serious complications. Various methods for managing diabetes mellitus through monitoring blood glucose levels have been studied and developed, and the most widely used method includes using an invasive blood glucose meter. Since the invasive blood glucose meter poses a major inconvenience for patients, in this study, we sought to develop a non-invasive blood glucose meter. We therefore proposed the development of a non-invasive blood glucose measurement system that is based on near-infrared spectroscopy. The system developed was composed of a light source for emitting different wavelengths, a light detector unit, and a computing system for recording signals. A prepared glucose solution was injected into a quartz cuvette and light at 780-1650 nm was emitted to pass through the cuvette. The degree of reaction was determined by recording the change in wavelength. The wavelength band used for the experiment was 780-1000 nm and the resolution was 20 nm. The glucose concentration was determined to be between 50 to 400 mg/dl compared to the normal range of 80 to 120 mg/dl. By examining which wavelength bands specifically reacted with glucose, we observed that the wavelength bands that decreased or increased in response to the glucose concentration were at 780 nm and 940 nm. For wavelength bands at 1000 nm or above, light was also absorbed by water and therefore it was difficult to distinguish the results. The most reliable wavelength band was at 940 nm with an R² of 0.9806. In conclusion, the near-infrared light emitting diode based non-invasive glucose detection system performed well and is expected to be a superior method for monitoring blood glucose levels in diabetes mellitus.

Anti-Inflammatory Effects of Step Electrical Stimulation on Complete Freund's Adjuvant (CFA) Induced Rheumatoid Arthritis Rats.

Rheumatoid arthritis is a chronic inflammatory disease that affects joints and induces pain and swelling. We evaluated the anti-inflammatory effects of step electrical stimulation (SES) in this study. SES was carried out by increasing the voltage (3 V/s) from 5 V to 100 V for 60 cycles. The viability of mouse embryonic fibroblasts (NIH-3T3) was evaluated after step-electrical stimulation. After the injection of complete Freund's adjuvant (CFA) on the right hind paw of Sprague Dawley (SD) rats (6 weeks old), the degree of swelling was measured using a digital plethysmometer and Vernier caliper. Histological changes in inflamed tissues were observed with hematoxylin and eosin (H&E) staining, while the degree of inflammation was evaluated from the expression level of inflammatory factors such as cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). As a result, we found no difference in cell viability after SES treatment between the control and SES-treated groups. On day 21 after CFA injection, the swelling of right hind paws decreased by 1.09 times in SES-treated group as compared with the untreated group. In addition, the levels of COX-2, TNF-α and IL-6 significantly decreased after SES treatment. Thus, SES treatment decreased paw swelling and alleviated inflammation.

Phosphorylation and inactivation of glycogen synthase kinase 3ß (GSK3ß) by dual-specificity tyrosine phosphorylation-regulated kinase 1A (Dyrk1A).

Glycogen synthase kinase 3ß (GSK3ß) participates in many cellular processes, and its dysregulation has been implicated in a wide range of diseases such as obesity, type 2 diabetes, cancer, and Alzheimer disease. Inactivation of GSK3ß by phosphorylation at specific residues is a primary mechanism by which this constitutively active kinase is controlled. However, the regulatory mechanism of GSK3ß is not fully understood. Dual-specificity tyrosine phosphorylation-regulated kinase 1A (Dyrk1A) has multiple biological functions that occur as the result of phosphorylation of diverse proteins that are involved in metabolism, synaptic function, and neurodegeneration. Here we show that GSK3ß directly interacts with and is phosphorylated by Dyrk1A. Dyrk1A-mediated phosphorylation at the Thr(356) residue inhibits GSK3ß activity. Dyrk1A transgenic (TG) mice are lean and resistant to diet-induced obesity because of reduced fat mass, which shows an inverse correlation with the effect of GSK3ß on obesity. This result suggests a potential in vivo association between GSK3ß and Dyrk1A regarding the mechanism underlying obesity. The level of Thr(P)(356)-GSK3ß was higher in the white adipose tissue of Dyrk1A TG mice compared with control mice. GSK3ß activity was differentially regulated by phosphorylation at different sites in adipose tissue depending on the type of diet the mice were fed. Furthermore, overexpression of Dyrk1A suppressed the expression of adipogenic proteins, including peroxisome proliferator-activated receptor γ, in 3T3-L1 cells and in young Dyrk1A TG mice fed a chow diet. Taken together, these results reveal a novel regulatory mechanism for GSK3ß activity and indicate that overexpression of Dyrk1A may contribute to the obesity-resistant phenotype through phosphorylation and inactivation of GSK3ß.

Impact of Several Types of Stresses on Short-term Memory and Apoptosis in the Hippocampus of Rats.

PURPOSE: Stress has a deteriorating effect on hippocampal function. It also contributes to symptom exacerbation in many disease states, including overactive bladder and interstitial cystitis/bladder pain syndrome. We investigated the effects of various types of stresses (restraint, noise, and cold) on short-term memory and apoptosis in relation with corticotropin-releasing factor (CRF) expression. METHODS: Rats in the restraint stress group were restrained in a transparent Plexiglas cylinder for 60 minutes twice daily. Rats in the noise stress group were exposed to the 120 dB supersonic machine sound for 60 minutes twice daily. Rats in the cold stress group were placed in a cold chamber at 4℃ for 60 minutes twice daily. Each stress was applied for 10 days. A step-down avoidance test for short-term memory, immunohistochemistry for caspase-3 expression, and western blot analysis for Bax and Bcl-2 expressions were conducted. RESULTS: Latency time was decreased and CRF expression in the hippocampal dentate gyrus and hypothalamic paraventricular nucleus were increased in all of the stress groups. The number of caspase-3-positive cells in the hippocampal dentate gyrus was increased and the expressions of Bax and Bcl2 in the hippocampus were decreased in all of the stress groups. CONCLUSIONS: All of the stress groups experienced short-term memory impairment induced by apoptosis in the hippocampus. The present results suggest the possibility that these stresses affecting the impairment of short-term memory may also induce functional lower urinary tract disorders.

Dyrk1A-mediated phosphorylation of RCAN1 promotes the formation of insoluble RCAN1 aggregates.

The mechanisms underlying aggregate formation in age-related neurodegenerative diseases remain not well understood. Here we investigated whether dual-specificity tyrosine-(Y)-phosphorylation-regulated kinase 1A (Dyrk1A) is involved in the formation of regulator of calcineurin 1 (RCAN1) aggregates. We show that RCAN1 self-associates and forms multimers, and that this process is promoted by the Dyrk1A-mediated phosphorylation of RCAN1 at the Thr(192) residue. Transgenic mice that overexpress the Dyrk1A exhibited lower levels of phospho-Thr(192)-RCAN1 in 10-month-old-group compared to littermate controls, when analyzed with soluble hippocampus lysates. These results suggest that the phosphorylation of RCAN1 by Dyrk1A stimulates the formation of insoluble aggregates upon aging.

Depression-like state in maternal rats induced by repeated separation of pups is accompanied by a decrease of cell proliferation and an increase of apoptosis in the hippocampus.

Stressful experiences, such as an unsatisfactory mother-infant relationship after delivery, can induce depressive disorders, and it is well-known that stressors impair memory function. The hippocampus plays a crucial role in memory processes. In the present study, we determined whether a depressed-like state induced by repeated separation of pups affects the memory capability of the maternal rats. We also determined the effects of repeated separation from pups on cell proliferation, apoptosis, and serotonin expression in the brains of maternal rats. In the present results, the immobility time in the forced swim test was increased and the climbing time was decreased in the mothers separated from their pups. The latency in the step-down avoidance task was increased in the mothers separated from their pups. Also, the expressions of serotonin (5-hydroxytryptamine) and tryptophan hydroxylase in the dorsal raphe were decreased in the mothers separated from their pups. The number of Ki-67-positive cells was decreased, while the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells in the hippocampal dentate gyrus was increased in the mothers separated from their pups. Based on the present results, it is suggested that separation of pups might induce a depressed-like state in the maternal rats with reduced cell proliferation and increased apoptosis in the hippocampus, resulting in memory impairment of maternal rats.

Differential effects of 5-fluorouracil on glucose transport and expressions of glucose transporter proteins in gastric cancer cells.

Although 5-fluorouracil (5-FU) is a widely used chemotherapeutic agent in the treatment of gastric cancer, the underlying mechanism for 5-FU resistant phenotype, has yet to be elucidated. We hypothesized that the sensitivity of gastric cancer to 5-FU treatment might be related to the rate of glucose transport (GLUT), and investigated the expressions of GLUT1, 2, 3, and 4 in two different gastric cancer cells (SNU-216, moderately differentiated gastric adenocarcinoma; and SNU-668, signet ring cell gastric carcinoma). Immunohistochemistry of GLUT1 and GLUT4 and immunoblot analysis of glycogen synthase kinase 3 were also performed. Hexokinase activity was measured. We found that 5-FU suppressed glucose uptake in SNU-216, while it stimulated GLUT in SNU-668. Further analysis revealed that 5-FU decreased the expression levels of GLUT1, 2, and 4 in SNU-216 cells and increased the expression levels of GLUT1, 2, and 4 in SNU-668 cells. Consistent with GLUT expression levels, immunohistochemistry analysis showed that 5-FU increased GLUT1 and GLUT4 levels in SNU-216 and decreased GLUT1 and GLUT4 levels in SNU-668. We also observed that glycogen synthase kinase 3 activity was decreased in SNU-216 and increased in SNU-668 with 5-FU treatment. No significant difference in hexokinase activities was observed with 5-FU treatment. Taken together, these results suggest that 5-FU exerts differential effects on GLUT depending on gastric cancer cell types, which may indicate a possible explanation, at least in part, for the differing responses to 5-FU chemotherapy in gastric cancer.

Suppressive effect by Hizikia fusiforme on the production of tumor necrosis factor in BV2 murine microglial cells.

BACKGROUND: Hizikia fusiforme has been commonly used as food in Korea. Antioxidant effect of Hizikia fusiforme, however, was recently reported. Thus, herein, we investigated the effect of Hizikia fusiforme on the production and expression of tumor necrosis factor (TNF), a major proinflammatory mediator, in lipopolysaccharide (LPS)-activated BV2 microglial cells. METHODS: Cells were pre-treated with 5 or 50 mug/ml Hizikia fusiforme and treated with 1 mug/ml LPS. The production of TNF was measured by enzyme-linked immunosorbent assay (ELISA). The effect of Hizikia fusiforme on the expression of TNF was also performed by immunoblot analysis and reverse transcription-polymerase chain reaction (RT-PCR). Activation of nuclear factor kappab (NFkappab) was determined by electrophoretic mobility shift assay (EMSA). RESULTS: We observed that Hizikia fusiforme decreased the production of TNF. The inhibitory effect of the Hizikia fusiforme on the expression of TNF was confirmed by immunoblot and RT-PCR analyses. In addition, EMSA experiment revealed that Hizikia fusiforme blocked the LPS-induced activation of NFkappab. CONCLUSION: The present study suggests that Hizikia fusiforme may suppress LPS-stimulated TNF production via inhibition of NFkappab in murine microglial cells.

1,2-bis(2-aminophenoxy)ethane-N,N,N'N'-tetraacetic acid (BAPTA-AM) inhibits caffeine-induced apoptosis in human neuroblastoma cells.

In the present study, it was investigated whether 1,2-bis(2-aminophenoxy)ethane-N,N,N'N'-tetraacetic acid (BAPTA-AM), an intracellular Ca(2+) chelator, possesses protective effect against caffeine-induced apoptosis in the central nervous system. Through morphological and biochemical analyses, cells treated with caffeine exhibited several apoptotic features. On the other hand, cells treated with caffeine and BAPTA-AM, showed decreased occurrence of apoptotic features. In addition, it was shown that BAPTA-AM treatment inhibits caffeine-induced increase of caspase-3 enzyme activity. These results show that caffeine induces apoptotic death in human SK-N-MC neuroblastoma cells and BAPTA-AM prevents apoptosis by attenuating caffeine-induced caspase-3 activation.

Caffeine induces apoptosis in human neuroblastoma cell line SK-N-MC.

Caffeine is one of the most widely consumed neuroactive drugs, coming mostly from everyday beverages such as coffee and tea. To investigate whether caffeine induces apoptosis in the central nervous system, 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, flow cytometric analysis, DNA fragmentation assay, and caspase-3 enzyme assay were performed on SK-N-MC human neuroblastoma cells. Cells treated with caffeine at concentrations as high as 10 mM exhibited several characteristics of apoptosis. In addition, caffeine was shown to increase the caspase-3 activity. These results suggest that high-dose of caffeine induces apoptosis in human neuroblastoma cells, probably by increasing the caspase-3 enzyme activity.