Matrix metalloproteinase-9 (MMP-9) is an inducible enzyme. Oral potentially malignant disorders (OPMDs) are considered as the early tissue changes that happen due to various habits such as smoking tobacco, chewing tobacco or stress. This alteration in the tissues alters the expression of MMP-9. The rationale of the review is to know the expression of MMP-9 in OPMDs. Hand searching and electronic databases such as PubMed and ScienceDirect were done for mesh terms such as OPMDs and MMP-9. Eight articles were obtained, after applying inclusion and exclusion criteria. These articles were assessed with QUADAS and data were extracted and evaluated. The included eight studies were done in 182 oral squamous cell carcinoma cases, 430 OPMDs (146 oral lichen planus, 264 leukoplakia and 20 oral submucous fibrosis) and 352 healthy controls evaluated for MMP-9. MMP-9 expression was found to be elevated in tissue, serum and saliva samples of OPMDs than in healthy controls. There is only one study in each serum and saliva samples to evaluate MMP-9. Saliva being noninvasive and serum being minimally invasive, more studies need to be done in both serum and saliva to establish MMP-9 as an early diagnostic marker in OPMDs to know its potential in malignant transformation.

Oral potentially malignant disorders (OPMD) are oral mucosal disorders which have a high potential to turn into malignancy. A recent report suggests that 16%–62% of epithelial dysplasia cases of OPMD undergo malignant transformation, showing the need for early detection of malignancy in these disorders. Micro RNA (miRNA) plays an important role in cellular growth, differentiation, apoptosis, and immune response, and hence, deregulation of miRNA is considered a signature of oral carcinogenesis. A search was done using MeSH terms in the PubMed, ScienceDirect databases, hand search, and finally, six studies were included in this systematic review. A total of 167 patients with oral cancer, 78 with OPMDs, 147 healthy controls, and 20 disease controls were analyzed for the expression of salivary miRNAs. Quality assessment based on the Quality Assessment of Diagnostic Accuracy Studies 2 tool was used to obtain a risk of bias chart using Revman 5.3 software and it was proved that the study done by Zahran et al. in 2015 had a low risk of bias. The results of this study revealed upregulated miRNA 184 with an area under the curve (AUC) of 0.86 and miRNA 21 with an AUC of 0.73 and downregulated miRNA 145 with an AUC of 0.68, which proved that these miRNAs are significant in detecting early malignancy in OPMD and should be further analyzed in various populations. This systematic review explored the potential of expression of salivary miRNA in OPMD for future studies. This could pave the way to utilize saliva as a surrogate marker in diagnosing early malignant changes in OPMD.

Objectives A new radiotracer, 124I-epidepride, has been developed for the imaging of dopamine D2/3 receptors (D2/3Rs). 124I-epidepride (half-life of 124I = 4.2days) allows imaging over extended periods compared to 18F-fallypride (half-life of 18F = 0.076days) and may maximize visualization of D2/3Rs in the brain and pancreas (allowing clearance from adjacent organs). D2/3Rs are also present in pancreatic islets where they co-localize with insulin to produce granules and may serve as a surrogate marker for imaging diabetes. Methods 124I-Epidepride was synthesized using N-[[(2S)-1-ethylpyrrolidin-2-yl]methyl]-5-tributyltin-2,3-dimethoxybenzamide and 124I-iodide under no carrier added condition. Rats were used for in vitro and in vivo imaging. Brain slices were incubated with 124I-epidepride (0.75μCi/cc) and nonspecific binding measured with 10 μM haloperidol. Autoradiograms were analyzed by OptiQuant. 124I-Epidepride (0.2 to 0.3 mCi, iv) was administered to rats and brain uptake at 3 hours, 24 hours, and 48 hours post injection was evaluated. Results 124I-Epidepride was synthesized with 50% radiochemical yield and high radiochemical purity (>95%). 124I-Epidepride localized in the striatum with a striatum to cerebellum ratio of 10. Binding was displaced by dopamine and haloperidol. Brain slices demonstrated localization of 124I-epidepride up until 48 hr in the striatum. However, the extent of binding was reduced significantly. Conclusions 124I-Epidepride is a new radiotracer suitable for extended imaging of dopamine D2/3 receptors and may have applications in imaging of receptors in the brain and monitoring pancreatic islet cell grafting.

Background: A noninvasive method of monitoring the loss of islet cells can provide an earlier and improved diagnosis for therapeutics development of preclinical phases of diabetes. The use of [18 F]fallypride, a dopamine D2/D3 receptor radiotracer, has been developed as a surrogate marker to evaluate loss of pancreatic islet cells in a rodent model of type 1 diabetes. Materials and Methods: Healthy Sprague-Dawley rats were administered [18 F]fallypride and imaged for 2 h in a positron emission tomography (PET)/computed tomography (CT) scan. Diabetes was then induced in the same rats by administration of streptozotocin, and a PET/CT scan was performed 4 days after establishing diabetes. Pancreata of a separate set of rats were evaluated by insulin immunostaining for loss of islet cells by streptozotocin.Results: Blood glucose levels of 125 mg/dL and 550 mg/dL were established for those rats without and with diabetes, respectively. [

Background Micro-RNAs (miRNAs) have been reported as an emerging biomarker in many cancer types. They are used as diagnostic and prognostic biomarkers and could be considered therapeutic targets in treating the same. Main body Studies have proven that miRNAs play an essential role in molecular cancer pathophysiology, including oral squamous cell carcinoma. Distinct expression profiles of different miRNAs have been demonstrated in oral squamous cell carcinoma. Among the miRNAs, the miR-31 has strong potential as a unique biomarker in head and neck squamous cell carcinoma, and the increased expression was correlated to a poor clinical outcome with a likely contribution to oral carcinogenesis. Short conclusion The recent research on different aspects of miR-31 as a biomarker and also its potential application in the development of therapy for oral squamous cell carcinoma has been focused in this review. Graphical abstract