Anti-Diabetic Drugs: Cure or Risk Factors for Cancer?

Anti-diabetic drugs are an important group of therapeutics used worldwide. Different anti-diabetic drugs lower blood glucose level by different mechanisms. In recent years, numerous investigations have been performed based on both comparative and cohort studies, in order to establish the relationship between anti-diabetic pharmacotherapy and cancer incidence as well as mortality due to cancer. Some anti-diabetic drugs have been found to exhibit anti-cancer activity while others might increase the risk for cancer. The underlying cause for this disparity is likely to be the varying mechanisms of action of these drugs in controlling blood glucose level. This review discusses the various carcinogenic and/or anti-cancer effects of commonly used anti-diabetic drugs. The information is vital in view of the fact that diabetes mellitus is a commonly occurring disease with a rising incidence rate.     

Ultrasonic technique for imaging tissue vibrations: preliminary results

We propose an ultrasound (US)-based technique for imaging vibrations in the blood vessel walls and surrounding tissue caused by eddies produced during flow through narrowed or punctured arteries. Our approach is to utilize the clutter signal, normally suppressed in conventional color flow imaging, to detect and characterize local tissue vibrations. We demonstrate the feasibility of visualizing the origin and extent of vibrations relative to the underlying anatomy and blood flow in real-time and their quantitative assessment, including measurements of the amplitude, frequency and spatial distribution. We present two signal-processing algorithms, one based on phase decomposition and the other based on spectral estimation using eigen decomposition for isolating vibrations from clutter, blood flow and noise using an ensemble of US echoes. In simulation studies, the computationally efficient phase-decomposition method achieved 96% sensitivity and 98% specificity for vibration detection and was robust to broadband vibrations. Somewhat higher sensitivity (98%) and specificity (99%) could be achieved using the more computationally intensive eigen decomposition-based algorithm. Vibration amplitudes as low as 1 mum were measured accurately in phantom experiments. Real-time tissue vibration imaging at typical color-flow frame rates was implemented on a software-programmable US system. Vibrations were studied in vivo in a stenosed femoral bypass vein graft in a human subject and in a punctured femoral artery and incised spleen in an animal model.     

Head and neck squamous cell carcinoma: the role of post-operative adjuvant radiotherapy

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is one of the leading cancers in India. Since a large majority present in loco-regionally advanced stages, surgery followed by adjuvant post-operative radiotherapy (PORT) has been the mainstay of treatment for resectable HNSCC. AIM: To identify clinico-pathologic factors that could have an impact on outcome in HNSCC in the postoperative setting. MATERIALS AND METHODS: A retrospective review of 348 previously untreated patients with HNSCC who received PORT following curative surgery. The outcome measures were local control, loco-regional control, and disease free survival (DFS). RESULTS: With a median follow-up of 36 months (range: 2-127 months) for surviving patients, the 5-year local control, loco-regional control, and DFS was 79%, 63%, and 56%, respectively for all patients. On univariate analysis, site of primary was an independent prognostic factor for all the outcome measures (P = 0.005, 0.02, and 0.04, respectively) with oral cavity lesions faring the worst. Peri-nodal extension (PNE) affected loco-regional control (P = 0.002) and DFS (P = 0.0005), but was not predictive for local control (P = 0.9852). Cut margin positivity predicted for inferior local control alone (P = 0.03), the significance of which was lost on multivariate analysis. Cox regression analysis however confirmed the significance of primary site and PNE as independent prognostic factors. CONCLUSION: Primary site and PNE are independent factors predicting outcome in the postoperative radiotherapeutic management of HNSCC.     

Biocompatibility of polymethylmethacrylate resins used in dentistry

Biocompatibility or tissue compatibility describes the ability of a material to perform with an appropriate host response when applied as intended. Poly-methylmethacrylate (PMMA) based resins are most widely used resins in dentistry, especially in fabrication of dentures and orthodontic appliances. They are considered cytotoxic on account of leaching of various potential toxic substances, most common being residual monomer. Various in vitro and in vivo experiments and cell based studies conducted on acrylic based resins or their leached components have shown them to have cytotoxic effects. They can cause mucosal irritation and tissue sensitization. These studies are not only important to evaluate the long term clinical effect of these materials, but also help in further development of alternate resins. This article reviews information from scientific full articles, reviews, or abstracts published in dental literature, associated with biocompatibility of PMMA resins and it is leached out components. Published materials were searched in dental literature using general and specialist databases, like the PubMED database.