Investigation of Scattered Radiation Reduction Effect by Use of Collimator Cover Covered with Leaded Sheet in Angiography Equipment.

The purpose of this study was to investigate the effect of scattered radiation reduction to medical staff by attaching the leaded sheet on the collimator cover of the angiography equipment. Ambient dose equivalent was measured to compare the rate of scattered radiation reduction between with and without the leaded sheet. Shielding effect was confirmed for scattered radiation in all directions, especially 27% of shielding ratio in the head and neck area when angiography equipment installed with small detector, and more than 40% of shielding ratio when adjusting a cut portion of leaded sheet to the field size. However, it decreased when the dose area product meter was not attached. Therefore, our proposed leaded sheet can reduce radiation dose to medical staff during angiographic and interventional procedures.

Insulin resistance and ß-cell function influence postprandial blood glucose levels in Japanese patients with gestational diabetes mellitus.

AIMS/INTRODUCTION: The aim of this study in patients with gestational diabetes mellitus (GDM) was to evaluate the relationship of insulin resistance and secretion to area-under-the-sensor glucose concentration-time curve from before to 120 min postmeal (CGM-AUC(0-120 min)) as determined with continuous glucose monitoring (CGM). MATERIALS AND METHODS: Immunoreactive insulin and HbA1c were determined in 22 Japanese patients with GDM undergoing a 75 g oral glucose tolerance test. Patients underwent CGM within 3 weeks of receiving a diagnosis of GDM. RESULTS: HbA1c (NGSP) was 5.5 ± 0.4%, BMI was 24.8 ± 5.3 kg/m(2), mean sensor glucose by CGM was 94.2 ± 10.3 mg/dL, standard deviation was 17.5 ± 4.4 mg/dL, and CGM-AUC(0-120 min) was 204.2 ± 23.8 h mg/dL. The insulin resistance indices the homeostasis model assessment ratio (HOMA-R), quantitative insulin sensitivity check index (QUICKI), and the Matsuda Index were correlated with CGM-AUC(0-120 min). The disposition index (DI), which was used to evaluate insulin secretion, was negatively correlated with CGM-AUC(0-120 min). CONCLUSIONS: Not only insulin resistance but also beta cell dysfunction contributes to postprandial hyperglycemia in Japanese patients with GDM.

[Significance of the regulation of hyperglucagonemia in type 2 diabetes mellitus].

Abstract Generally, pancreatic ß-cell dysfunction and hypoinsulinemia have been known as the cause of development of hyperglycemia in diabetes mellitus. Pancreatic α-cell dysfunction, particularly hyperglucagonemia is also serious problem to increase hepatic glucose production in type 2 diabetes mellitus (T2DM). ß-cell mass decrement and α-cell mass increment in T2DM have been reported in many reports inclusive of our study. Those might be the background to the pancreatic cells dysfunction in T2DM. Glucagon secretion from α-cells could not be suppressed by insufficient insulin, and hyperglucagonemia has been worsening in T2DM. Incretin, particularly glucagon like peptide-1 (GLP-1) could control both α- and ß-cell dysfunction, via the decrease of glucagon and the increase of insulin respectively. We believe that incretin therapy(GLP-1 receptor agonists and DPP-4 inhibitors) is the best strategy to control hyperglucagonemia caused by α-cell dysfunction in T2DM.

Effects of exenatide on metabolic parameters/control in obese Japanese patients with type 2 diabetes.

The effects of exenatide on glycemic control, lipid metabolism, blood pressure, and gastrointestinal symptoms were investigated in obese Japanese patients with type 2 diabetes mellitus. Twenty-six outpatients were enrolled and administered 5 µg of exenatide twice daily. If there was insufficient weight loss and/or insufficient improvement in glycemic control, the dose was increased to 10 µg twice daily. Follow-up was continued until the 12th week of administration. Hemoglobin A1c, glycoalbumin, fasting plasma glucose, body weight, fasting serum C-peptide, serum lipids, blood pressure, and pulse rate were measured before and after the observation period. In the initial phase of exenatide therapy, each patient received a diary to record gastrointestinal symptoms. During treatment with exenatide, hemoglobin A1c decreased significantly and serum C-peptide increased significantly. Body weight, low-density lipoprotein cholesterol, and systolic blood pressure decreased significantly. Nausea was the most frequent gastrointestinal symptom and occurred in 16 patients. Its onset was noted at a mean of 1.7 h after injection, the mean duration was 1.1 h, and it continued for a mean of 9.3 days after the initiation of administration. Patients with nausea showed a significant decrease in hemoglobin Alc, glycoalbumin, or body weight compared with those without nausea. These findings suggest that a more marked improvement in metabolic parameters by exenatide can be partly dependent on the manifestation of gastrointestinal symptoms.

New strategy for the treatment of type 2 diabetes mellitus with incretin-based therapy.

Incretin-based therapy was first made available for the treatment of type 2 diabetes mellitus (T2DM) in the US in 2006 and in Japan in 2009. Four DPP-4 inhibitors and two GLP-1 analog/receptor agonists are currently available. The effects of incretin-based therapy are assumed to be exerted mainly through the hormonal and neuronal actions of one of the incretins, GLP-1, which is secreted from L cells localized in the small intestine. The benefits of this therapy over conventional sulfonylureas or insulin injections, such as fewer hypoglycemic events and reduced body weight gain, derive from the glucose-dependent insulinotropic effect. The protective effects of this therapy on vulnerable pancreatic ß-cells and against micro/macroangiopathy in T2DM are also most welcome. Indications and/or contraindications for incretin-based therapy should be clarified by prospectively studying the experiences of Japanese T2DM patients undergoing this therapy in the clinical setting.

Add-on therapy with the DPP-4 inhibitor sitagliptin improves glycemic control in insulin-treated Japanese patients with type 2 diabetes mellitus.

The effect of add-on therapy with sitagliptin on glycemic control was prospectively investigated in patients with type 2 diabetes mellitus (T2DM) receiving insulin alone or insulin combined with oral antidiabetic drugs. Seventy-one patients were evaluated (38 men and 33 women aged 63.9 ± 10.2 years). They were divided into three groups, which were 45 patients receiving premixed insulin twice daily, 15 patients receiving multiple daily insulin injections, and 11 patients receiving basal insulin with oral antidiabetic drugs (basal insulin therapy). Concomitant oral drugs included sulfonylureas, α-glucosidase inhibitors and metformin. The hemoglobin A1c (HbA1c) of all patients improved significantly from 8.1 ± 1.2% to 7.6 ± 1.1% after 12 weeks of add-on therapy with sitagliptin (p<0.01), and the insulin dosage was reduced from 27.3 ± 15.8 U/day to 24.5 ± 16.5 U/day (p<0.001). Body weight did not change after the start of concomitant therapy and severe hypoglycemia was not observed. The baseline HbA1c and glycated albumin levels were identified as factors that predicted the response to add-on therapy with sitagliptin. These findings suggest that add-on therapy with sitagliptin can be expected to achieve improvement of poor glycemic control irrespective of a patient's demographic profile. Stratified analysis based on the insulin regimen revealed a stronger antidiabetic effect and a high efficacy of sitagliptin when it was added to basal insulin therapy. The results of this investigation confirmed that add-on therapy with sitagliptin to various insulin regimens could improve glycemic control without severe hypoglycemia and/or weight gain.

Effect of additional administration of acarbose on blood glucose fluctuations and postprandial hyperglycemia in patients with type 2 diabetes mellitus under treatment with alogliptin.

Acarbose was administered at 300 mg/day to patients with type 2 diabetes mellitus (T2DM) who had been taking 25 mg/day of alogliptin, and levels of blood glucose were analyzed by continuous glucose monitoring (CGM) for 3 days. The mean blood glucose level with acarbose (136.4 ± 30.7 mg/dL) did not differ significantly from that without acarbose (141.7 ± 28.3 mg/dL). However, in the condition of the combination therapy, there were significant decreases in the standard deviation of the mean blood glucose levels for the 24-hour period (27.6 ± 9.1 vs. 16.2 ± 6.9 mg/dL, p<0.001) and mean amplitude of glycemic excursions (MAGE) (65.8 ± 26.1 vs. 38.8 ± 19.2 mg/dL, p=0.010). In addition, a meal tolerance test was conducted to monitor changes in insulin secretion and active GLP-1 and total GIP values. Ten subjects (5 males, 5 females) of 54.9 ± 6.9 years with BMI 25.9 ± 5.2 kg/m² and HbAlc 9.2 ± 1.2% were enrolled. In the meal tolerance test, active GLP-1 values before and after acarbose administration were 17.0 ± 5.8 and 24.1 ± 9.3 pmol·hr/mL (p=0.054), respectively, showing an increasing tendency, and total GIP(AUC0-180) values were 685.9 ± 209.7 and 404.4 ± 173.7 pmol·hr/mL, respectively, showing a significant decrease (p=0.010). The results indicate that the combined administration of both inhibitors is effective not only in decreasing blood glucose fluctuations and preventing postprandial insulin secretion. The beneficial effects may also protect the endocrine pancreas and inhibit body weight gain.

Optimal sampling devices for liquid-based procedure in screening for cervical cancer: comparison between cotton stick/Cytobrush and Cervex-Brush.

OBJECTIVE: To find an appropriate sampling device for a liquid-based procedure in the population screening for cervical cancer, focusing on bleeding at sampling and the amount of cells smeared. METHODS AND MATERIALS: 1,000 consecutive women who underwent primary screening were studied. The specimens were obtained with the cotton stick/Cytobrush® method in the first 500 cases or with the Cervex-Brush® in the following 500 subjects, and were processed using the Thinlayer Advanced Cytology Assay System (TACAS™) following the manufacturer's instructions. RESULTS: (1) Bleeding at cellular sampling using the cotton stick/Cytobrush and Cervex-Brush methods occurred in 1.2 and 8.8% of the cases, respectively (p < 0.0001). (2) The incidences of cells obtained with the two methods which covered the whole area, <1/2 and ≥1/4, and <1/4 of the observation fields were 55.4 versus 62.2% (p < 0.05), 14.6 versus 9.4% (p < 0.05), and 2.0 versus 4.0% (p < 0.05), respectively. (3) The incidences of endocervical or metaplastic cells obtained with ≥500 and <10 were 34.6 versus 20.0% (p < 0.01) and 9.4 versus 18.4% (p < 0.01), respectively. In cases of cells covering <1/4, incidences with <10 were 0 and 0.6% (n = 3), respectively. (4) Detection rates of abnormal cytology were 3.4 and 5.2% (n.s.), including atypical squamous cells of undetermined significance in 2.4 and 3.2%. CONCLUSIONS: The cotton stick/Cytobrush is superior to the Cervex-Brush as a cellular sampling device for the TACAS liquid-based procedure.

Lipid droplet accumulation in ß cells in patients with type 2 diabetes is associated with insulin resistance, hyperglycemia and ß cell dysfunction involving decreased insulin granules.

Background and objective: Pancreatic fat is a form of ectopic fat. Lipid droplets (LDs) are also observed in ß cells; however, the pathophysiological significance, especially for ß cell function, has not been elucidated. Our aim was to assess LD accumulation in ß cells in various stages of glucose intolerance and to clarify its relationship with clinical and histological parameters. Methods: We examined 42 Japanese patients who underwent pancreatectomy. The BODIPY493/503-positive (BODIPY-positive) area in ß cells was measured in pancreatic sections from 32 patients. The insulin granule numbers were counted in an additional 10 patients using electron microscopy. Results: The BODIPY-positive area in ß cells in preexisting type 2 diabetes patients was higher than that in normal glucose tolerance patients (p = 0.031). The BODIPY-positive area in ß cells was positively correlated with age (r = 0.45, p = 0.0097), HbA1c (r = 0.38, p = 0.0302), fasting plasma glucose (r = 0.37, p = 0.045), and homeostasis model assessment insulin resistance (r = 0.41, p = 0.049) and negatively correlated with an increase in the C-peptide immunoreactivity level by the glucagon test (r = -0.59, p = 0.018). The ratio of mature insulin granule number to total insulin granule number was reduced in the patients with rich LD accumulation in ß cells (p = 0.039). Conclusions: Type 2 diabetes patients had high LD accumulation in ß cells, which was associated with insulin resistance, hyperglycemia, aging and ß cell dysfunction involving decreased mature insulin granules.

Intraoperative Cone Beam CT in Hybrid Operation Room for Pediatric Scoliosis Patients: Comparison of Pedicle Screw Violation Rate at Normal and Low Radiation Doses.

STUDY DESIGN: Retrospective observational study. OBJECTIVE: This study aimed to determine the effect of reducing the radiation dose of intraoperative cone beam computed tomography (CBCT) during posterior spinal fusion (PSF) for pediatric scoliosis on the rate of pedicle screw (PS) violation. SUMMARY OF BACKGROUND DATA: Intraoperative CBCT for pediatric scoliosis improves the accuracy of PS insertion in PSF. However, few reports have addressed the PS perforation rate from reduced radiation doses in hybrid navigation. METHODS: We evaluated 855 PSs inserted into 58 pediatric scoliosis patients (11 male and 47 female, mean age: 16.6 yr) who underwent PSF using CBCT. A radiation dose of 1/3 or 1/5 of the normal dose (ND) was defined as a low dose (LD). After PS insertion, intraoperative CBCT images were reviewed to assess the degree of PS perforation. G2-3 (i.e., perforations of 4 mm or more) was defined as a violation. The PS violation rate was compared between the groups, and factors associated with violations were examined. RESULTS: A total of 567 and 288 screws were inserted in the ND group and LD group, respectively. The PS violation rate was comparable at 1.8% in the ND group and 1.7% in the LD group. Multiple logistic regression analysis showed that distance from the upper instrumented vertebra (UIV) was an independently associated factor of PS violation (+1 vertebra, operation room 0.73, P   =  0.038). In addition, the mean height of patients with PS violations (148.8 ±â€Š3.6 cm) was significantly shorter than that of patients without violations (157.9 ±â€Š1.2 cm) ( P  = 0.034). CONCLUSION: There was no increase in PS violation rate with lower doses of radiation for intraoperative navigation CBCT. Extra care is warranted for vertebrae close to the UIV and patients of shorter stature.Level of Evidence: 3.

Effects of miglitol in combination with intensive insulin therapy on blood glucose control with special reference to incretin responses in type 1 diabetes mellitus.

To determine whether miglitol administration improves glycemic control and reduces the frequency of hypoglycemia in type 1 diabetes mellitus (T1DM) patients treated with intensive insulin therapy, we analyzed the effect of miglitol on daily insulin doses, body weight, hypoglycemia, and incretin hormone responses during meal tolerance tests (MTT). Eleven T1DM subjects (21-77 years) undergoing intensive insulin therapy, took 25 mg (weeks 0-4) and 50 mg miglitol (weeks 4-12) thrice daily, immediately before meals. At weeks 0 and 12, 9 of 11 subjects underwent MTT. In present study, mean HbA1c, glycoalbumin, and 1,5-anhydroglucitol levels were significantly improved. The blood glucose level 1 h after dinner was significantly lower at week 12 than at week 0 (p = 0.008). From week 0 to 12, there was a significant decrease in the body mass index (BMI; p = 0.0051), frequency of preprandial hypoglycemic events (p = 0.012), and daily bolus insulin dosage (p = 0.018). The change in active glucagon-like peptide-1 (GLP-1) at 120 min significantly increased at week 12 (p = 0.015). The change in total glucose-dependent insulinotropic peptide (GIP) significantly decreased in the MTT at week 12. These results demonstrate that addition of miglitol on intensive insulin therapy in T1DM patients has beneficial effects on reducing BMI, bolus and total insulin dosage, and frequency of preprandial hypoglycemic events. MTT findings suggest that this combination therapy improves blood glucose control by delaying carbohydrate absorption and modifying the responses of incretins, GIP, and GLP-1.

[Incretin-based therapy in patients with type 1 diabetes mellitus].

GLP-1 has multiple physiological functions including glucose-dependent insulin secretion and glucagon suppression, delay of gastic emptying, suppression of hepatic glucose production, stimulation of beta cell replication and neogenesis, inhibition of beta cell apoptosis. All of these actions are beneficial for the treatment of diabetes. Therefore, incretin-based therapy may be still worthwhile as evidenced by studies demonstrating that beta cell mass may be preserved or expand in animals and that residual insulin secretion may be elevated to reduce the risk of hypoglycemia in patients treated with intensive insulin therapy, although the effect of GLP-1R agonists and DPP-4 inhibitors(DPP-4is) on beta cells may be small because destruction of beta cells leads to absolute insulin deficiency by cell-mediated autoimmune attack. Recent report also showed that DPP-4i might ameliorate an autoimmune attack against beta cells by restoring or increasing the number of regulatory T lymphocytes. Furthermore, GLP-1R-mediated signals might suppress the expression of chemokine ligand CXCL10 which binds to newly identified receptor TLR4 (Toll-like receptor 4), and impairs beta cell function and viability in diabetes. Taken together, incretin-based therapy may be worth testing in patients with type 1 diabetes.

Preoperative Arterial Embolization to Avoid Intraoperative Bleeding during Endoscopic Sinus Surgery for Organized Hematoma of the Maxillary Sinus: A Case Series and Literature Review.

Purpose: This study aimed to evaluate the safety and efficacy of preoperative arterial embolization of organized hematoma of the maxillary sinus. Material and Methods: Seven patients who were pathologically diagnosed with an organized hematoma of the maxillary sinus and who underwent endoscopic sinus surgery following preoperative arterial embolization for the same from July 2013 to April 2020 at our hospital were included. A literature review of the PubMed database was performed to identify 13 cases on organized hematomas of the maxillary sinuses. The embolization and nonembolization groups comprised patients who underwent preoperative embolization (n = 10, seven from this study and three from literature) and those who did not undergo preoperative embolization (n = 10, from literature), respectively. Outcomes of embolization including embolization-related complications and postoperative bleeding were assessed, and volumes of intraoperative blood loss and duration of surgery were compared between the groups. Results: No preoperative embolization-related complications were observed in our cases. The volume of surgical blood loss in the seven cases varied from 0 to 100 mL with a median of 30 mL, and the duration of surgery ranged from 45 to 166 minutes with a median of 112 minutes. The volume of blood loss was significantly lower for the embolization group than that for the nonembolization group (p = 0.0031). There was no statistically significant difference regarding duration of surgery between the groups (p > 0.10). Conclusions: Preoperative embolization of an organized hematoma of the maxillary sinus is a safe and effective method that helps prevent serious intraoperative hemorrhage.

Benefit of Early Add-on of Linagliptin to Insulin in Japanese Patients With Type 2 Diabetes Mellitus: Randomized-Controlled Open-Label Trial (TRUST2).

INTRODUCTION: This trial was conducted to assess the long-term safety, efficacy, and benefit of early add-on of linagliptin to insulin in patients with type 2 diabetes mellitus (T2DM). METHODS: This trial enrolled 246 subjects. The subjects were randomized to the linagliptin group or the control group and were observed for 156 weeks. After week 16, subjects in the control group were also allowed to add linagliptin to evaluate the benefit of early add-on of linagliptin to insulin. The primary end point was a change in HbA1c from baseline to week 16. Secondary end points included fasting plasma glucose, daily insulin dose, and frequency of adverse events. RESULTS: HbA1c and fasting plasma glucose levels significantly decreased from baseline to week 16 in the linagliptin group compared with the control group. The significant improvement in HbA1c continued until week 52. The daily insulin dose significantly decreased in the linagliptin group compared with the control group. The frequency of hypoglycemia and adverse events was comparable in both groups. CONCLUSIONS: Add-on of linagliptin to insulin was tolerated, improved glycemic control, and reduced the daily insulin dose. This study demonstrates the long-term safety, efficacy and benefit of early add-on of linagliptin to insulin in Japanese T2DM patients.

The HNF-1 target collectrin controls insulin exocytosis by SNARE complex formation.

Defective glucose-stimulated insulin secretion is the main cause of hyperglycemia in type 2 diabetes mellitus. Mutations in HNF-1alpha cause a monogenic form of type 2 diabetes, maturity-onset diabetes of the young (MODY), characterized by impaired insulin secretion. Here we report that collectrin, a recently cloned kidney-specific gene of unknown function, is a target of HNF-1alpha in pancreatic beta cells. Expression of collectrin was decreased in the islets of HNF-1alpha (-/-) mice, but was increased in obese hyperglycemic mice. Overexpression of collectrin in rat insulinoma INS-1 cells or in the beta cells of transgenic mice enhanced glucose-stimulated insulin exocytosis, without affecting Ca(2+) influx. Conversely, suppression of collectrin attenuated insulin secretion. Collectrin bound to SNARE complexes by interacting with snapin, a SNAP-25 binding protein, and facilitated SNARE complex formation. Therefore, collectrin is a regulator of SNARE complex function, which thereby controls insulin exocytosis.

The tetraspanin CD9 modulates epidermal growth factor receptor signaling in cancer cells.

CD9 is a member of the tetraspanins, and has been shown to be involved in a variety of cellular activities such as migration, proliferation, and adhesion. In addition, it has been known that CD9 can associate with other proteins. Here we demonstrated the physical and functional association of CD9 with epidermal growth factor receptor (EGFR) on MKN-28 cells. Double-immunofluorescent staining and immunoprecipitation demonstrated the complex formation of CD9-EGFR and CD9-beta(1) integrin, and that both complexes are colocalized on the cell surface especially at the cell-cell contact site. Anti-CD9 monoclonal antibody ALB6 induced a dotted or patch-like aggregation pattern of both CD9-EGFR and CD9-beta(1) integrin. The internalization of EGFR after EGF-stimulation was significantly enhanced by the treatment with ALB6. CD9 can associate with EGFR in hepatocellular carcinoma cells (HepG2/CD9) and Chinese hamster ovary cancer cells (CHO-HER/CD9), which were transfected with pTJ/human EGFR/CD9. Furthermore expression of CD9 specifically attenuated EGFR signaling in CHO-HER/CD9 cells through the down regulation of surface expression of EGFR. These results suggest that CD9 might have an important role that attenuates EGFR signaling. Therefore, CD9 not only associates EGFR but also a new regulator, which may affect EGF-induced signaling in cancer cells.

Expression of HNF-4alpha (MODY1), HNF-1beta (MODY5), and HNF-1alpha (MODY3) proteins in the developing mouse pancreas.

The type 1, 3, and 5 forms of maturity-onset diabetes of the young (MODY) are caused by mutations of the genes encoding hepatocyte nuclear factor (HNF)-4alpha, HNF-1alpha, and HNF-1beta, respectively [Yamagata, K., Oda, N., Kaisaki, P.J., Menzel, S., Furuta, H., Vaxillaire, M., et al., 1996a. Mutations in the hepatocyte nuclear factor-1alpha gene in maturity-onset diabetes of the young (MODY3). Nature 384, 455-458; Yamagata, K., Furuta, H., Oda, N., Kaisaki, P.J., Menzel, S., Cox, N.J., et al., 1996b. Mutations in the hepatocyte nuclear factor-4alpha gene in maturity-onset diabetes of the young (MODY1). Nature 384, 458-460; Horikawa, Y., Iwasaki, N., Hara, M., Furuta, H., Hinokio, Y., Cockburn, B.N. et al., 1997. Mutation in hepatocyte nuclear factor-1beta gene (TCF2) associated with MODY. Nat. Genet. 17, 384-385]. Among these transcription factors, the pattern of HNF-4alpha expression during pancreatic differentiation remains largely unknown. We performed an immunohistochemical study to investigate its expression in comparison with the expression of HNF-1alpha and HNF-1beta. We found considerable variation in the level of HNF-4alpha expression by the individual epithelial cells in the pancreatic buds on E9.5. HNF-4alpha and HNF-1beta were initially expressed by Pdx1(+) common progenitor cells and neurogenin3(+) (Ngn3(+)) endocrine precursor cells during the first transition, but expression of HNF-1beta and either HNF-4alpha or HNF-1alpha became complementary around the end of the second transition (E15.5). In the mature pancreas, HNF-4alpha was expressed by glucagon-positive alpha-cells, insulin-positive beta-cells, somatostatin-positive delta-cells, and pancreatic polypeptide-positive PP-cells, as well as by pancreatic exocrine cells and ductal cells. Most of the HNF-4alpha(+) cells were also positive for HNF-1alpha, but HNF-4alpha expression in some non-beta-cells was remarkably high, and this was not paralleled by high HNF-1alpha expression. These results indicate that the expression of MODY proteins in each of the pancreatic cell types is strictly regulated in accordance with the status of differentiation during pancreatic organogenesis.

The -1535 promoter variant of the visfatin gene is associated with serum triglyceride and HDL-cholesterol levels in Japanese subjects.

Visfatin is a novel adipocytokine that is expressed by the visceral fat cells. We investigated the role of genetic variation in the visfatin gene in the pathophysiology of type 2 diabetes and clinical variables in Japanese subjects. The 11 exons, and the promoter region of the visfatin gene were screened for single nucleotide polymorphisms (SNPs) by PCR-direct sequencing. We found SNPs in the promoter region (SNP - 1535T>C), exon 2 (SNP + 131C>G, Thr44Arg), and exon 7 (SNP + 903G>A). The allele and genotype frequencies of these SNPs showed no significant differences between 200-448 diabetic and 200-333 control subjects. However, the -1535T/T genotype was associated with lower serum triglyceride levels (T/T vs. T/C + C/C (p = 0.015) and T/T vs. C/C (p = 0.043)) and higher HDL-cholesterol levels (T/T vs. C/C, p = 0.0496) in the nondiabetic subjects. Reporter gene assay of 3T3-L1 adipocytes revealed that the promoter activity of -1535T and -1535C was similar, suggesting that the observed association may reflect linkage disequilibrium between -1535T>C and causative variations of the visfatin gene.

Paracrine regulation of fat cell formation in bone marrow cultures via adiponectin and prostaglandins.

Adiponectin, an adipocyte-derived hormone, was recently shown to have potential therapeutic applications in diabetes and obesity because of its influence on glucose and lipid metabolism. We found that brown fat in normal human bone marrow contains this protein and used marrow-derived preadipocyte lines and long-term cultures to explore potential roles in hematopoiesis. Recombinant adiponectin blocked fat cell formation in long-term bone marrow cultures and inhibited the differentiation of cloned stromal preadipocytes. Adiponectin also caused elevated expression of cyclooxygenase-2 (COX-2) by these stromal cells and induced release of prostaglandin E(2) (PGE(2)). The COX-2 inhibitor Dup-697 prevented the inhibitory action of adiponectin on preadipocyte differentiation, suggesting involvement of stromal cell-derived prostanoids. Furthermore, adiponectin failed to block fat cell generation when bone marrow cells were derived from B6,129S(Ptgs2tm1Jed) (COX-2(+/-)) mice. These observations show that preadipocytes represent direct targets for adiponectin action, establishing a paracrine negative feedback loop for fat regulation. They also link adiponectin to the COX-2-dependent PGs that are critical in this process.