Rimonabant has been shown to not only decrease the food intake and body weight but also to increase serum adiponectin levels. This increase of the serum adiponectin levels has been hypothesized to be related to the rimonabant-induced amelioration of insulin resistance linked to obesity, although experimental evidence to support this hypothesis is lacking. To test this hypothesis experimentally, we generated adiponectin knock-out (adipo(-/-))ob/ob mice.
View Article and Find Full Text PDFJ Periodontal Res
August 2008
Background And Objective: Obesity has been implicated as a risk factor for several chronic health conditions. Recent studies have reported a relationship between obesity and periodontitis, but few studies have investigated this relationship in adolescents. The purpose of the present study was to investigate the relationship between body composition (i.
View Article and Find Full Text PDFInsulin-like growth factor (IGF)-1 increases proliferation, inhibits apoptosis and promotes differentiation of oligodendrocytes and their precursor cells, indicating an important function for IGF-1 receptor (IGF-1R) signaling in myelin development. The insulin receptor substrates (IRS), IRS-1 and -2 serve as intracellular IGF-1R adaptor proteins and are expressed in neurons, oligodendrocytes and their precursors. To address the role of IRS-2 in myelination, we analyzed myelination in IRS-2 deficient (IRS-2(-/-)) mice and age-matched controls during postnatal development.
View Article and Find Full Text PDFEfficient reproduction using natural mating and reproduction technology [in vitro fertilization (IVF) and embryo transfer (ET)] was investigated in IRS2 deficient mice with C57BL/6JJcl genetic background (Irs2(-/-) mice) as a typical type 2 diabetes model. From the results using various combinations of Irs2(-/-) and Irs2(-/+) mice, the combination of female Irs2(-/+) x male Irs2(-/-) was found to be more efficient than other combinations. In applications of reproduction technology using IVF and ET, the combination of female Irs2(-/+) x male Irs2(-/-) involves the possibility of Irs2(-/-) production by repeats using female Irs2(-/+) mice.
View Article and Find Full Text PDFThe objective of this study was to characterise the fulminant type 1 diabetes mellitus (DM) accompanying abrupt hyperglycaemia and ketonuria observed in insulin receptor substrate 2 (IRS2)-deficient mice. IRS2-deficient mice backcrossed onto the original C57BL/6J:Jc1 background (B6J-IRS2(-/-) mice) for more than 10 generations were used. Eight male IRS2-deficient mice with ketonuria and abrupt increase in plasma glucose concentrations over 25 mmol/l were used as the fulminant type 1 diabetic mice (diabetic mice) and 8 male IRS2-deficient mice (8 weeks old) without glycosuria were used as the control mice.
View Article and Find Full Text PDFInsulin receptor substrate (Irs) mediates metabolic actions of insulin. Here, we show that hepatic Irs1 and Irs2 function in a distinct manner in the regulation of glucose homeostasis. The PI3K activity associated with Irs2 began to increase during fasting, reached its peak immediately after refeeding, and decreased rapidly thereafter.
View Article and Find Full Text PDFBackground: The activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) in pancreatic beta-cells has been thought to play a central role in Ca2+-mediated insulin secretion. However, the physiological and pathological significance of CaMKII activation in pancreatic beta-cells has never been investigated in vivo.
Methods: We generated transgenic (TG) mice overexpressing the constitutively active-type CaMKIIalpha (Thr286Asp) in beta-cells.
Obesity and metabolic syndrome are increasingly recognized as major risk factors for cardiovascular disease. Herein we show that Krüppel-like transcription factor 5 (KLF5) is a crucial regulator of energy metabolism. Klf5(+/-) mice were resistant to high fat-induced obesity, hypercholesterolemia and glucose intolerance, despite consuming more food than wild-type mice.
View Article and Find Full Text PDFWe show that, in the minimal supersymmetric standard model, the possibility for the lightest CP-even Higgs boson to be lighter than Z boson (as low as about 60 GeV) is, contrary to the usual belief, not yet excluded by the CERN LEP2 Higgs search nor any direct searches for supersymmetric particles at high energy colliders. The characteristic of the light Higgs boson scenario (LHS) is that the ZZh coupling and the decay branching ratio Br(h/A-->bb) are simultaneously suppressed as a result of generic supersymmetric loop corrections. Consequently, the W(+/-)H(-/+)h coupling has to be large due to the sum rule of Higgs couplings to weak gauge bosons.
View Article and Find Full Text PDFAim: The purpose of this study was to clarify the anatomical detail of the superior group of vessels in the falciform ligament in terms of the relationship with the internal thoracic vessels, inferior phrenic vessels, and the intrahepatic portal vein.
Materials And Methods: (1) Anatomical study: we dissected eight adult human cadavers (seven normal and one cirrhotic liver) to determine the relationship between the superior group of vessels in the falciform ligament, the internal thoracic vessels, and the inferior phrenic vessels. (2) Clinical study: we determined the origin and destination of the superior group of veins demonstrated in 8 of 4,006 patients with chronic liver disease who underwent the contrast enhanced CT scans.
To assess physiological and pathophysiological events that involve dynamic interplay between multiple cell types, real-time, in vivo analysis is necessary. We developed a technique based on confocal laser microscopy that enabled us to analyze and compare the 3-dimensional structures, cellular dynamics, and vascular function within mouse lean and obese adipose tissue in vivo with high spatiotemporal resolution. We found increased leukocyte-EC-platelet interaction in the microcirculation of obese visceral adipose tissue in ob/ob and high-fat diet-induced obese mice.
View Article and Find Full Text PDFAims: Despite the growing literature on workplace tobacco control policies, very few studies have evaluated the role of smoking cessation programme as one of these policies in a university setting. We aimed to investigate the efficacy of intensive cessation programme delivered in a group format using nicotine patch therapy and internet mailing supports for our university employees.
Methods: From January 2003, we conducted the group therapy programme for smoking cession seven times in Okayama University, Japan.
Bone mass and turnover are maintained by the coordinated balance between bone formation by osteoblasts and bone resorption by osteoclasts, under regulation of many systemic and local factors. Phosphoinositide-dependent serine-threonine protein kinase Akt is one of the key players in the signaling of potent bone anabolic factors. This study initially showed that the disruption of Akt1, a major Akt in osteoblasts and osteoclasts, in mice led to low-turnover osteopenia through dysfunctions of both cells.
View Article and Find Full Text PDFBackground: The whole blood interferon-gamma assay (QuantiFERON-TB-2G; QFT) has not been fully evaluated as a baseline tuberculosis screening test in Japanese healthcare students commencing clinical contact. The aim of this study was to compare the results from the QFT with those from the tuberculin skin test (TST) in a population deemed to be at a low risk for infection with Mycobacterium tuberculosis.
Methodology/principal Findings: Healthcare students recruited at Okayama University received both the TST and the QFT to assess the level of agreement between these two tests.
Adiponectin has been shown to stimulate fatty acid oxidation and enhance insulin sensitivity through the activation of AMP-activated protein kinase (AMPK) in the peripheral tissues. The effects of adiponectin in the central nervous system, however, are still poorly understood. Here, we show that adiponectin enhances AMPK activity in the arcuate hypothalamus (ARH) via its receptor AdipoR1 to stimulate food intake; this stimulation of food intake by adiponectin was attenuated by dominant-negative AMPK expression in the ARH.
View Article and Find Full Text PDFWe studied the impact of "IVF - ET" on the glucose tolerance test (GTT), insulin tolerance test (ITT) and adiponectin to investigate differences in the phenotypes of B6J- Irs2(-/-) mice. The B6J-Irs2(-/-) mice (KO-Nat group) were prepared by natural mating. Other mice were produced by IVF-ET used ICR strain recipients and surrogate mothers (KO-IVF group).
View Article and Find Full Text PDFObjective: The expansion of adipose tissue mass seen in obesity involves both hyperplasia and hypertrophy of adipocytes. However, little is known about how adipocytes, adipocyte precursors, blood vessels, and stromal cells interact with one another to achieve adipogenesis.
Research Design And Methods: We have developed a confocal microscopy-based method of three-dimensional visualization of intact living adipose tissue that enabled us to simultaneously evaluate angiogenesis and adipogenesis in db/db mice.
Purpose: Automatic Doppler flow signal detection systems can provide beat-to-beat information for large blood vessels. We have developed new equipment for automatic measurement of Doppler flow signals. The reliability of the system was examined, and the variability of aortic and pulmonary peak flow velocity was determined.
View Article and Find Full Text PDFA direct shunt between the inferior mesenteric vein and the inferior vena cava was detected in a patient with hepatic encephalopathy. The authors performed balloon-occluded retrograde transvenous obliteration (BRTO) for this shunt. Before the obliteration, the shunt was occluded by using a balloon catheter and it was confirmed that the portal venous flow was redirected to the liver.
View Article and Find Full Text PDFAdiponectin plays a central role as an antidiabetic and antiatherogenic adipokine. AdipoR1 and AdipoR2 serve as receptors for adiponectin in vitro, and their reduction in obesity seems to be correlated with reduced adiponectin sensitivity. Here we show that adenovirus-mediated expression of AdipoR1 and R2 in the liver of Lepr(-/-) mice increased AMP-activated protein kinase (AMPK) activation and peroxisome proliferator-activated receptor (PPAR)-alpha signaling pathways, respectively.
View Article and Find Full Text PDFEnvironmental sequencing has revealed unimagined diversity among eukaryotic picoplankton. A distinct picoplanktonic algal group, initially detected from 18S ribosomal DNA (rDNA) sequences, was hybridized with rRNA-targeted probes, detected by tyramide signal amplification-fluorescent in situ hybridization, and showed an organelle-like body with orange fluorescence indicative of phycobilins. Using this fluorescence signal, cells were sorted by flow cytometry and probed.
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