Effects of insulin resistance and insulin secretion on the efficacy of interventions to retard development of type 2 diabetes mellitus: the DA Qing IGT and Diabetes Study

OBJECTIVE: To investigate the effects of insulin resistance (IR) and insulin secretion (IS) on the development of diabetes mellitus in individuals with impaired glucose tolerance (IGT) who underwent lifestyle interventions. METHODS: 284 out of 577 individuals with IGT identified by population-based screening in Da Qing, China, who were randomized to undergo diet change and/or increased physical activity had baseline fasting and 2 h post-load insulin determinations. They were followed for 6 years for the development of diabetes. IR and IS were assessed using calculated indices based on fasting plasma insulin and glucose. The interactions of IR, IS, obesity and plasma glucose and the effects of the lifestyle interventions were evaluated using Cox Proportional Hazards analysis. RESULTS: Both IR and IS were significantly associated with the development of diabetes. Lifestyle interventions were more effective in those with lower IT and higher IS at baseline. Diet plus exercise interventions resulted in significantly lower incidence of diabetes, even after controlling for IR, IS, BMI and 2hrPG. CONCLUSION: Both IR and beta-cell function were predictors of diabetes in Chinese with IGT. Lifestyle intervention reduced the incidence of DM and these interventions were more effective in those with less IR.     

Scanning Electron Microscopic Characterization of Healing and Normal Rat Ligament Microstructure Under Slack and Loaded Conditions

The objective of this study was to observe and compare behavior of the collagen fiber microstructure in normal and healing ligaments, both in situ and ex vivo, in order to add insight into the structure-function relationship in normal and healing ligaments. Fifty-two ligaments from 26 male rats were investigated. Eleven animals underwent surgical transection of both medial collateral ligaments (MCLs) (22 ligaments), which were allowed to heal for a period of 2 weeks. An additional 15 animals (30 ligaments) were used as normals. Ligaments were placed into six groups: Slack ( n = 6 control, n = 6 healing), Reference ( n = 4 control, n = 4 healing), Loaded ( n = 4 control, n = 4 healing), 15° Flexion ( n = 4 control, n = 4 healing), 120° Flexion ( n = 4 control, n = 4 healing), and Tissue Strain vs. Flexion Angle ( n = 8 normals). All ligaments, except those in the Tissue Strain vs. Flexion Angle group, were prepared for scanning electron microscopy. Tissues were harvested, mounted in a load frame, and chemically fixed in one of five states: (1) slack, (2) reference (onset of loading), (3) loaded, (4) 15° knee flexion, or (5) 120° knee flexion. After fixation the tissues were prepared for electron microscopy (SEM). The micrographs from the slack, reference, and loaded groups show fiber straightening with loading in normal ligaments as well as in both scar and "retracted" regions of healing ligaments. Collagen fibers' diameter and crimp patterns were dramatically changed in the scar region of healing ligaments: Width decreased from 19.4 &#45 1.7 &#119 m to 6.5 &#45 2.1 &#119 m ( p < .000001), period from 51.4 &#45 15.1 &#119 m to 11.0 &#45 2.4 &#119 m ( p < .000001), and amplitude from 9.8 &#45 0.8 &#119 m to 3.9 &#45 0.8 &#119 m ( p < .000001). Normal ligaments fixed in situ show wavy regions at 120° but less so at 15° flexion. Healing ligaments fixed in situ show regions of fiber waviness in the scar region at 120° and also at 15° flexion, indicating ligament laxity persists toward both extremes of the range of motion. The data suggest that straightening of crimped fibers is a functionally relevant phenomenon, not only in normal but also in healing ligaments.     

Distribution of sodium hypochlorite throughout the mesial root canal system of mandibular molars after adjunctive irrigant activation procedures: a micro-computed tomographic study

Clinical Oral Investigations - To evaluate and compare irrigant distribution throughout the root canal system of mesial roots of mandibular molars after application of distinct adjunctive irrigant...     

Interleukin-11 stimulates multilineage progenitors, but not stem cells, in murine and human long-term marrow cultures

Interleukin-11 (IL-11) is a bone marrow microenvironment-derived growth factor with pleiotropic effects on a variety of hematopoietic cells. To more accurately assess the effects of IL-11 on stem and progenitor compartments within the hematopoietic microenvironment (HM), we added recombinant human (rh) IL-11 to human and murine long-term bone marrow cultures (LTMC) and analyzed primitive (high proliferative potential- colony forming cells [HPP-CFC], long-term culture-initiating cells [LTC- IC], and long-term reconstituting stem cells) and progenitor (day 12 colony forming unit-spleen [CFU-S12], colony forming unit-megakaryocyte [CFU-Mk] and colony forming unit-granulocyte/macrophage [CFU-GM]) compartments throughout the duration of the cultures. rhIL-11 (100 ng/mL) added twice weekly resulted in significantly increased nonadherent (NA) cellularity, CFU-GM, and CFU-Mk production in human LTMC. Addition of rhIL-11 to murine LTMC was associated with a 5- to 40- fold increase in CFU-GM and a four- to 20-fold increase in day 12 CFU-S in NA cells. However, IL-11 had no significant effect on total HPP-CFC concentration and decreased the size of the more primitive stem/progenitor compartment as evidenced by both decreased LTC-IC frequency in human LTMC and decreased frequency of long-term reconstituting stem cells in murine LTMC. These data suggest that IL-11 may increase commitment of stem cells into a multipotential progenitor compartment.     

Mechanisms of Fibrosis in Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a frequent cause of cirrhosis and may lead to liver-related mortality. In Western countries, NASH is the most common liver disease and may progress to advanced fibrosis or cirrhosis in a significant portion of cases. Moreover, NASH, even in the absence of cirrhosis, is associated with the development of hepatocellular carcinoma. An increased risk of cardiovascular events and/or diabetes represents another major problem in these patients. In this review, we discuss recent data on the basic mechanisms leading to the development of fibrosis in nonalcoholic steatohepatitis, in particular those which may identify novel approaches to treatment.     

Cross-sectional analysis of the implant-abutment interface

The purpose of this study was to develop a technique to evaluate the implant-abutment gap of an external hexagon implant system as a function of radius. Six implants of 3.75 mm in diameter (Conexao Sistema de Protese Ltda, Sao Paulo, Brazil) and their respective abutments were screw connected and torqued to 20 N cm(-1). The implants were mounted in epoxy assuring an implant long-axis position perpendicular to the vertical axis. Each implant was grounded through its thickness parallel to implant long-axis at six different distance interval. Implant-abutment gap distances were recorded along the implant-abutment region for each section. Individual measurements were related to their radial position through trigonometric inferences. A sixth degree polynomial line fit approach determined radial adaptation patterns for each implant. Micrographs along implant sections showed a approximately 300 mum length implant-abutment engagement region. All implants presented communication between external and internal regions through connection gaps and inaccurate implant-abutment alignment. Average gap distances were not significantly different between implants (P > 0.086). Polynomial lines showed implant-abutment gap values below 10 mum from 0 mum to approximately 250 mum of the implant-abutment engagement region. Gap distances significantly increased from approximately 250 mum to the outer radius of the implant-abutment engagement region. The technique described provided a broader scenario of the implant-abutment gap adaptation compared with previous work concerning implant-abutment gap determination, and should be considered for better understanding mechanical aspects or biological effects of implant-abutment adaptation on peri-implant tissues.