Noninvasive blood glucose monitoring with optical coherence tomography: a pilot study in human subjects

OBJECTIVE: To study the feasibility of noninvasive blood glucose monitoring using optical coherence tomography (OCT) technique in healthy volunteers. RESEARCH DESIGN AND METHODS: An OCT system with the wavelength of 1,300 nm was used in 15 healthy subjects in 18 clinical experiments. Standard oral glucose tolerance tests were performed to induce changes in blood glucose concentration. Blood samples were taken from the right arm vein every 5 or 15 min. OCT images were taken every 10-20 s from the left forearm over a total period of 3 h. The slope of the signals was calculated at the depth of 200-600 micro m from the skin surface. RESULTS: A total of 426 blood samples and 8,437 OCT images and signals were collected and analyzed in these experiments. There was a good correlation between changes in the slope of noninvasively measured OCT signals and blood glucose concentrations throughout the duration of the experiments. The slope of OCT signals changed significantly (up to 2.8% per 10 mg/dl) with variation of plasma glucose values. The good correlation obtained between the OCT signal slope and blood glucose concentration is due to the coherent detection of backscattered photons, which allows measurements of OCT signal from a specific tissue layer without unwanted signal from other tissue layers. CONCLUSIONS: This pilot study demonstrated the capability of the OCT technique to monitor blood glucose concentration noninvasively in human subjects. Further studies with a larger number of subjects including diabetic subjects are planned to validate these preliminary results.     

Intravascular ultrasound of normal left main arteries: Insights for stent optimization and standardization

• Left main (LM) lumen diameters >4 mm are the norm and diameter >4.5 mm is present in almost 50% of patients by intravascular ultrasound (IVUS).
• Normal LM minimum lumen area averages 14.1 mm² for women and 16.2 mm² for men, requiring an area stenosis of 57–63% for LM lesion to be hemodynamically significant using the prevailing criterion of 6 mm² as a cut‐off for revascularization.
• Incomplete LM visualization with IVUS is common (68%) without dedicated and specific LM IVUS techniques.

     

Resolution of hereditary hemorrhagic telangiectasia and anemia with prolonged alpha-interferon therapy for chronic hepatitis C

Hereditary hemorrhagic telangiectasia is a group of autosomal dominant disorders, characterized by telangiectases that develop in the skin, mucous membranes, and visceral organs. Currently, there is no satisfactory treatment of hereditary hemorrhagic telangiectasia. Interferon has never been used for the treatment of hereditary hemorrhagic telangiectasia. In this case, we report disappearance of hereditary hemorrhagic telangiectasia lesions after 12 months of treatment with interferon-alpha for chronic hepatitis C. Further studies are warranted to evaluate its role and potential use in the treatment of hereditary hemorrhagic telangiectasia.     

Back to the Future: How Biology and Technology Could Change the Role of PTFE Grafts in Vascular Access Management

Although the arteriovenous fistula (AVF) is the preferred mode of dialysis vascular access, AVF maturation failure remains a huge clinical problem, often resulting in a prolonged duration of use of tunneled dialysis catheters. In contrast, polytetrafluoroethylene (PTFE) grafts do not suffer from early failure, but have significant problems with later stenosis and thrombosis. This review will initially summarize the pathology and pathogenesis of PTFE graft dysfunction and will then use this as a basis for describing some novel therapies, which may have the potential to reduce PTFE graft dysfunction. Finally, we will emphasize that the introduction of such therapies could be an important first step toward individualizing overall vascular access care.     

Functionalized Magnetonanoparticles in Visualization of Intracranial Tumors on MRI

Purpose

The development of nonradioactive and targeted magnetonanoparticles (MNP) capable of crossing the blood–brain barrier (BBB) and of concentrating in and enhancing the contrast of intracranial tumors on magnetic resonance imaging (MRI).

Procedure

Nonradioactive 2-deoxy-d-glucose (2DG) was covalently attached to magnetonanoparticles composed of iron oxide and dextran and prepared for intravenous (tail) injection in the naïve rats and mouse models of glioma. MR images were acquired at 3 and 7 T.

Results

2DG-MNP increased tumor visibility and improved delineation of tumor margins. Histopathology confirmed that 2DG-MNP crossed the BBB and accumulated within brain parenchyma.

Conclusion

Nonradioactive 2DG-MNP can cross an intact BBB on and improve visualization of tumor and tumor margins on MRI.