Oral contraceptive use and abnormal glucose regulation in Swedish middle aged women

Aim

To investigate the association between oral contraceptive (OC) use and abnormal glucose regulation in Swedish middle aged women.

Methods

A prospective population-based study including 4794 women, aged 36-56 at baseline. None had previously diagnosed diabetes. At both baseline and follow-up 8 years later, the women were examined by oral glucose tolerance test. Information regarding lifestyle factors and anthropometric measurements were collected.

Results

At baseline, current use of OCs was associated with pre (Odds ratio, OR 4.1, 95%CI 2.2-7.8) but not with type 2 diabetes. The association to prediabetes was entirely linked to IGT (OR 7.1, 3.3-15.8) in current users of OCs and in former users (OR 2.1, 1.1-3.9). Women who used OC at baseline had a better cardiovascular disease risk profile; lower body mass index (BMI), more physically active and less smoking. At follow-up, the increased risk did not persist.

Conclusion

Current use of OC was associated with a four times increased risk of having prediabetes and seven times of having impaired glucose tolerance. No increased risk persisted at the follow-up, suggesting that the risk due to prior use of OC is decreasing with time. The healthier lifestyle in women who used OCs may have contributed to reduced long-term risk of prediabetes.     

Osteogenic growth peptide accelerates bone healing during distraction osteogenesis in rabbit tibia

Distraction osteogenesis is a valuable treatment method that allows limb lengthening or reconstruction of large bone defects. However, its major disadvantage is the long period required for the consolidation of a distraction callus. Osteogenic growth peptide (OGP) stimulates endochondral bone formation in fracture callus, but its capacity to promote regenerate ossification during distraction osteogenesis has not been evaluated. This study investigated whether intravenously administered OGP accelerated bone healing during distraction osteogenesis in 36 male New Zealand White rabbits, randomized into two groups. The treatment group received OGP (200 ng/kg body weight) in phosphate-buffered saline (PBS), intravenously, each day; the control group received PBS alone. A 15-mm lengthening of the right lower leg was performed using the method of Ilizarov. Evidence from biomechanical, histological and radiographic evaluations demonstrated that systemic OGP treatment promoted optimal new bone formation during distraction osteogenesis in this rabbit model.     

Human olfactory epithelial cells generated in vitro express diverse neuronal characteristics

The olfactory epithelium constitutes the sole source of regenerating neural cells that can be obtained from a living human. As such, primary cultures derived from human olfactory epithelial biopsies can be utilized to study neurobiological characteristics of individuals under different conditions and disease states. Here, using such human cultures, we report in vitro generation of cells that exhibit a complex neuronal phenotype, encompassing receptors and signaling pathways pertinent to both olfaction and other aspects of CNS function. Using in situ hybridization, we demonstrate for the first time the native expression of olfactory receptors in cultured cells derived from human olfactory epithelial tissue. We further establish the presence and function of olfactory transduction molecules in these cells using immunocytochemistry, calcium imaging and molecular methods. Western blot analysis revealed the expression of neurotransmitter receptors for dopamine (D2R), 5-HT (5HT2C) and NMDA subtypes 1 and 2A/2B. Stimulation with dopamine or 5-HT enhanced receptor G protein activation in a subtype specific manner, based on 35S-guanosine triphosphate incorporation assay. Functional characteristics of the cultured cells are demonstrated through enhanced tyrosine phosphorylation of NMDAR 2A/2B and recruitment of signaling partners in response to NMDA stimulation. The array of neuronal characteristics observed here establishes that proliferating cells derived from the human olfactory epithelium differentiate in vitro to express functional and molecular attributes of mature olfactory neurons. These cultured neural cells exhibit neurotransmitter pathways important in a number of neuropsychiatric disorders. Their ready availability from living humans thus provides a new tool to link functional and molecular features of neural cells with clinical characteristics of individual living patients.     

Eluting characteristics of a platelet glycoprotein receptor antibody using a PLLA-coated stent

Drug-eluting stents (DES) have emerged as a recognized alternative to treat stent restenosis but many questions remain regarding the optimal type and eluting characteristics of both drug and stent. The first component of the study examines the extent of surface coating of PLLA (poly(L-lactic acid)) on a Nitinol stent. The second characterizes the adsorption and elution rates of monoclonal mouse anti-human platelet glycoprotein (GP) IIIa antibody SZ-21 from a PLLA-coated surface. The PLLA coating was examined by fluorescence staining and image analysis using the Image Processing Box of MATLAB. Stents exposed to the monoclonal mouse anti-human platelet GP IIIa antibody were tested for their adsorption characteristics by radioisotope technique with (125)I-labelled SZ-21. The elution rates were then measured in looped circuits at different velocities (10 or 20 ml/min) and durations (30 min up to 312 h). Results showed that the fluorescence staining and image analysis showed a striking difference in the extent of coating between PLLA-coated stents and SZ-21 eluting stents on the gray-scale distribution of Nitinol surfaces. The amount of SZ-21 adsorbed onto the PLLA-coated stents was dependent on the concentration and duration of immersion in the solution. The method of preparation the mAb eluting stent significantly influenced the elution characteristics for a continuous perfusion of more than 300 h. The eluting curve was biphasic with initial rapid elution for the first 24 h followed by a gradual slow elution. These results indicate that the Image Processing Box of MATLAB appears to be a useful method for semi-quantitative analysis of fluorescence images. Furthermore, SZ-21 can be passively adsorbed onto PLLA-coated stents and predictably influenced by the concentration and duration of immersion. These studies may pave the way to developing stent-based delivery of a potent anti-platelet agent.     

Epitope mapping of series of monoclonal antibodies against the hepatocellular carcinoma-associated antigen HAb18G/CD147

The hepatocellular carcinoma-associated antigen HAb18G/CD147, a member of CD147 family, could promote tumour invasion and metastasis via inducing the secretion of matrix metalloproteinases (MMP). Anti-CD147 monoclonal antibodies (MoAb) have exhibited obvious inhibitory effect on MMP induction. However, none of the epitopes of these MoAb has been reported. We previously prepared five MoAb against HAb18G/CD147, named HAb18, 3B3, 1B3, 5A5 and 4D2. To map the epitopes of these MoAb, a series of truncated fragments of extracellular region of HAb18G/CD147 was expressed in Escherichia coli and the MoAb-binding affinity to these fragments was examined with an enzyme-linked immunosorbent assay and Western blot. The residues (39)LTCSLNDSATEV(50), (36)KILLTCS(42) and (22)AAGTVFTTVEDL(33) were determined to be the epitopes of HAb18, 3B3 and 1B3, respectively, which were further proved by a dot-blot analysis with synthesized peptides and bioinformatics epitope prediction. The binding regions of MoAb 5A5 and 4D2 were located at residues E(120)-R(203). Then we constructed and expressed full-length HAb18G/CD147 and truncated HAb18G/CD147 without residues A(22)-V(50) in COS-7 cells. Gelatin zymography and Boyden chamber assay showed that the COS-7 cells expressing truncated HAb18G/CD147 failed to induce MMP production and enhance the cells' invasive potential, compared with the cells expressing full-length HAb18G/CD147. Taken together with the obviously inhibitory effects of HAb18 on the function of full-length HAb18G/CD147, these findings suggest that residues (22)AAGTVFTTVEDLGSKILLTCSLNDSATEV(50) may play a critical role in the functions of HAb18G/CD147 on MMP secretion and tumour invasion. These key residues can be used as potential drug target in cancer therapy.     

Performance evaluation of stereo endoscopic imaging system incorporating TFT-LCD

This paper presents a 3D endoscopic video system designed to improve visualization and enhance the ability of the surgeon to perform delicate endoscopic surgery. In a comparison of the polarized and electric shutter-type stereo imaging systems, the former was found to be superior in terms of both accuracy and speed for knot-tying and for the loop pass test. The results of our experiments show that the proposed 3D endoscopic system has a sufficiently wide viewing angle and zone for multi-viewing, and that it provides better image quality and more stable optical performance compared with the electric shutter-type.