Adiponectin and thiazolidinedione targets CRTC2 to regulate hepatic gluconeogenesis

During fasting periods, hepatic glucose production is enhanced by glucagon to provide fuels for other organs. This process is mediated via cAMP-dependent induction of the CREB regulated transcriptional coactivator (CRTC) 2, a critical transcriptional activator for hepatic gluconeogenesis. We have previously shown that CRTC2 activity is regulated by AMP activated protein kinase (AMPK) family members. Here we show that adiponectin and thiazolidinedione directly regulate AMPK to modulate CRTC2 activity in hepatocytes. Adiponectin or thiazolidinedione lowered glucose production from primary hepatocytes. Treatment of both reagents reduced gluconeogenic gene expression as well as cAMP-mediated induction of CRE reporter, suggesting that these reagents directly affect CREB/CRTC2- dependent transcription. Furthermore, adiponectin or thiazolidinedione mediated repression of CRE activity is largely blunted by co-expression of phosphorylation defective mutant CRTC2, underscoring the importance of serine 171 residue of this factor. Taken together, we propose that adiponectin and thiazolidinedione promote the modulation of AMPK-dependent CRTC2 activity to influence hepatic gluconeogenesis.

Management of Prolapsed Silicone Tube Inserted for Treatment of Nasolacrimal Duct Obstruction

PURPOSE: To introduce a new surgical management for the prolapsed silicone tube into the ocular surface which was inserted for treatment of nasolacrimal duct obstruction. METHODS: Five eyes of 179 eyes treated with silicone tube intubation for nasolacrimal duct obstruction from May to December 2003 had a prolapsed silicone tube during the follow-up period. After local anesthesia, a Ritleng probe was inserted into the nasolacrimal duct. A polypropylene thread was passed into the Ritleng probe, and after removal of the probe, the thread was tied to a prolapsed silicone tube near a punctum and was pulled through the nose. The silicone tube was repositioned in the nasolacrimal duct. RESULTS: All the prolapsed silicone tubes were successfully repositioned without any significant complications. CONCLUSIONS: It is difficult to reposition a prolapsed silicone tube after silicone tube intubation for the treatment of nasolacrimal duct obstruction. We introduced an easy and effective method to reposition the prolapsed silicone tube.

The Differences of Visual Field Defects in Three Types of Primary Glaucoma

PURPOSE: To compare the characteristics of visual field defect in primary open-angle glaucoma (HTG), normal-tension glaucoma (NTG) and primary angle-closure glaucoma (ACG). METHODS: We investigated the visual field defect of HTG (n=75), NTG (n=58), ACG (n=150) patients from March 2000 to November 2002. We compared the severity and asymmetry of the visual field defect in both eyes, the asymmetry of a more severely affected hemifield between both eyes, and the frequency of an early visual field defect with equivalently affected superior and inferior hemifield. RESULTS: The visual field defect was the severest in HTG, and the mildest in ACG. Asymmetry in severity of visual field defect between both eyes was the severest in HTG, and the mildest in NTG. The asymmetry of the affected hemifield between both eyes in terms of superior and inferior hemifields was most frequent in NTG. The frequency of the early visual field defect with equivalently affected superior and inferior hemifields occured mostly in NTG. ACG without an attack history had a more severe visual field defect than that with an attack history. CONCLUSIONS: The topographical pattern of the visual field defect was different in HTG, NTG, and ACG. There may be different pathophysiological mechanisms in the three types of primary glaucoma.

Comparison of Clinical Features in Three Types of Primary Glaucoma

PURPOSE: To compare the clinical characteristics of primary open-angle glaucoma (HTG), normal-tension glaucoma (NTG) and primary angle-closure glaucoma (ACG) patients. METHODS: We investigated the clinical characteristics of HTG (n=75), NTG (n=58), and ACG (n=150) patients from March 2000 to November 2002. We compared the age at initial glaucoma diagnosis, sex, family history, systemic diseases, refractive errors, and corneal curvature among the three groups. RESULTS: HTG was younger than the others at initial glaucoma diagnosis. In ACG, the incidence rate was higher in women, but it was in HTG, higher in men. Family history of glaucoma was significantly more prevalent in HTG than in the others. NTG showed higher prevalence of cardiovascular disease and hypotension than the others. In refractive errors, there was statistically significant difference among the three groups and HTG had more severe myopia than the others. ACG had the steepest cornea curvature. CONCLUSIONS: Three types of primary glaucoma (HTG, NTG and ACG) differed somewhat in clinical feature. This finding will be helpful in the early diagnosis and treatment of glaucoma.

Humphrey SITA and Octopus TOP Perimetry on Normal Korean Subjects

PURPOSE: To evaluate and compare the inter-individual variability and normal limits of Humphrey SITA and Octopus TOP which were recently developed for shortening test time and decreasing the patient's fatigue. METHODS: Humphrey SITA and Octopus TOP tests were performed on 100 normal Korean subjects and their test results were analyzed. RESULTS: The average test duration was 294.02+/-29.61 seconds in SITA and 147.93+/-9.78 seconds in TOP. There was no significant difference between the two perimetric tests in MD (mean deviation), but PSD (pattern standard deviation) of TOP program was significantly higher than that of SITA (P< 0.01). Mean sensitivity of SITA was 30.15+/-1.00 dB and that of TOP was 26.79+/-1.11 dB, so mean sensitivity of SITA was about 3 dB higher than that of TOP. In topographical map, averaged threshold sensitivity decreased with the eccentricity in both perimetries. Topographically, SITA showed the more regularly increasing standard deviation of threshold sensitivity toward periphery of visual field, but TOP showed the irregular pattern of distribution of the standard deviation. Most of the subjects (88.8%) replied that they were more comfortable with the TOP than the SITA program because of the shorter test time. CONCLUSION: Inter-individual variability in the normal Korean subjects was smaller in Humphrey SITA than Octopus TOP program, but Octopus TOP had the advantage of shorter duration of the test and lower fatigue.