Antidiabetic effect of free amino acids supplementation in human visceral adipocytes through adiponectin-dependent mechanism.

BACKGROUND & OBJECTIVES: : Amino acids are general nutrients having anti-diabetic property. The present study was undertaken to investigate the mechanism of anti-diabetic effects of amino acids in human visceral adipocyte cells in high glucose environment. METHODS: : Experiments were carried out in human visceral adipocytes. Adiponectin (APN) siRNAs were designed using Ambion tools. APN mRNA expression was quantified using real-time polymerase chain reaction, and protein level was studied using ELISA. AMP-activated kinase (AMPK) activity was measured and glucose uptake by 2-deoxyglucose uptake method. RESULTS: : Amino acids (proline and phenylalanine) exposure to adipocytes significantly (P <0.01) increased APN mRNA by 1.5-folds when compared to control whereas proline increased APN secretion by 10.6-folds (P <0.01), phenylalanine by 12.7-folds (P <0.001) and alanine by 6.3-folds (P <0.01). Free amino acid-induced AMPK activity and glucose uptake were decreased with the transient knockdown of APN. INTERPRETATION & CONCLUSIONS: : Antidiabetic effect of the tested amino acids was exhibited by increased glucose uptake through the AMPK pathway by an APN-dependent mechanism in human visceral adipocytes. This should be tested and confirmed in in vivo system. Newer treatment modalities with amino acids which can enhance glucose uptake and APN secretion can be developed as drug for treating both diabetes and obesity.

Expression of elastic fiber in esophageal squamous carcinoma tissue.

AIM: We studied the expression of elastic fiber in esophageal squamous cell carcinoma tissue in North-eastern Indian population. MATERIALS AND METHODS: Archival paraffin embedded 40 esophageal carcinoma specimens were retrieved for the study. Only smokers were included in the study. Verhoeff's stain for elastic fiber was performed to demonstrate elastic fiber with positive and negative control. RESULT: A total of 28 (70%) tissue specimens was found to be positive for elastic fiber. CONCLUSION: Elastosis in esophageal carcinoma may be due to smoking. Further studies are required to rule out the etiology.

Effect of adiponectin on expression of vascular endothelial growth factor and pigment epithelium-derived factor: an in vitro study.

AIM: This study was carried out to identify the role of adiponectin (APN) in modulating the expression of vascular endothelial growth factor (VEGF) and pigment epithelial-derived factor (PEDF) in relation to ocular angiogenesis. MATERIALS AND METHODS: Human retinal pigment epithelial cell lines (ARPE-19) were cultured in Dulbeco's minimum essential medium with 10% fetal bovine serum (FBS) and exposed to varying concentrations of recombinant adiponectin (5-5 ng/ml) for 1 h. Analysis of VEGF and PEDF mRNA was done by reverse transcriptase and further quantified by quantitative polymerase chain reaction. VEGF and PEDF protein expression were studied using enzyme-linked immune sorbent assay (ELISA). STATISTICAL ANALYSIS: Unpaired Student's t-test was used to analyze the significance. P < 0.05 was accepted as statistically significant. RESULTS: ARPE cells exposed to APN showed decreased expression of VEGF mRNA, protein whereas PEDF protein is unaltered and PEDF mRNA was increased. CONCLUSION: Our in vitro study on ARPE exposed to APN showed a negative correlation with VEGF levels. Thus indicating the protective role for APN in angiogenesis-related diseases.

Tear ascorbic acid levels and the total antioxidant status in contact lens wearers: a pilot study.

AIMS: The tear ascorbate owing to its high concentration, functions as an effective antioxidant against the oxidative damage of cornea. Contact lens wearers (CLW) are prone to oxidative stress due to the lens-induced hypoxic conditions. A pilot study was done to compare the tear ascorbic acid level and the total antioxidant capacity give as in normal and CLW. MATERIALS AND METHODS: In this study 21 CLW (Mean age 23 +/- 3 years ; M-2, F-19), who were daily wear users, with duration of wear not more than four years, along with age-matched 28 controls (Mean age 28 +/- 3 ; M-15, F-13) were recruited in the study for collection of reflex tears using Schirmer's strip. Ascorbic acid in tears was determined using high-performance liquid chromatography (HPLC), total antioxidant capacity (TAC) and total protein assay by spectrophotometric analysis. RESULTS: CLW showed no significant change in the tear ascorbic acid levels (0.4 +/- 0.26 mM) compared to the control subjects (0.61 +/- 0.59 mM). The amount of ascorbic acid in tears did not correlate with the TAC or the total protein of the tears. The mean TAC in CLW was 0.69 +/- 0.16 mM, with a total protein of 1.35 +/- 0.46 mg/ml while in controls it was 0.7 +/- 0.18 mM and 1.21 +/- 0.47 mg/ml respectively. CONCLUSIONS: Soft contact lens wear did not show any significant change in tear ascorbic acid, TAC and total protein levels compared to controls.

Solitary fibrous tumor of the pancreas: case report with cytologic and surgical pathology correlation and review of the literature.

CONTEXT: Solitary fibrous tumor is an uncommon spindle cell tumor which can occur in a variety of locations. Four cases of pancreatic solitary fibrous tumor have been reported in the literature. CASE REPORT: We report the fifth case of pancreatic solitary fibrous tumor in a 78-year-old woman who presented with back pain and weight loss. Imaging studies were suggestive of an endocrine tumor. Endoscopic ultrasound with fine needle aspiration was performed and revealed a benign mesenchymal tumor, which is the first successful report of cytology on a pancreatic solitary fibrous tumor. The patient underwent a distal pancreatectomy with resection of the mass which was diagnosed as solitary fibrous tumor, supported by immunohistochemical studies showing positivity for CD99, vimentin, bcl-2, and CD34. CONCLUSION: Diagnosing pancreatic solitary fibrous tumor is challenging due to its rarity, nonspecific clinical presentation, and difficulty to be radiologically distinguished from other pancreatic lesions. These issues as well as the prior four cases are discussed.