ABSTRACT
Epidemiology is a discipline integrating methodology and applied science, whose mission is to prevent and control diseases and promote health. This review introduces the new progress of epidemiology from five aspects: communicable diseases, chronic diseases, systems epidemiology, implementation research and big data of health care. New projects and constantly emerging technologies in the field of infectious diseases are inspiring, while more attention should be paid to the environmental factors of pathogen variation. In the field of chronic diseases, there is an urgent need to study the multimorbidity of the elderly. The role of infectious inducers and human microbiota in the occurrence and development of chronic diseases has been gradually revealed. Systems epidemiology, which is of great significance to achieve precision prevention is a new branch and an important supplement of modern epidemiology. Implementation research, is a bridge connecting basic scientific research and public health practice and will provide evidence to support the effective implementation of the Health China Action Plan. The development of health care big data is based on digital public health, which provides a broad research platform and abundant data resources for epidemiology, and will promote the fundamental transformation of the service and management mode of public health.
ABSTRACT
BACKGROUND: Technetium-99m or (99m)Tc is widely used for labeling peptide in nuclear medicine. Somatostatin and its analog can inhibit tumor cell growth after binding with its receptor. This research was to study the preclinical effect of a new (99m)Tc-6-hydrazinopyridine-3-carboxylic acid (HYNIC)-depreotide, indirect (99m)Tc labeling of depreotide using HYNIC as a bifunctional chelator. METHODS: The cyclopeptide, cyclo-[(N-Me) Phe-Tyr-D-Trp-Lys-Val-Hcy], the linear peptide, and [ClCH(2)-CO×b-Dap-Lys- Cys-Lys×amide] were synthesized by Fmoc solid-phase synthesis. The cyclopeptide and the linear peptide were linked by liquid-phase synthesis. The product depreotide was isolated and purified by high performance liquid chromatography and was confirmed by mass spectrography. Depreotide was labeled with (99m)Tc through a direct labeling method, using HYNIC as a bifunctional chelator. Paper chromatography method was used to calculate the labeling rate, and through the comparative analysis selected the best mark conditions. The new (99m)Tc-HYNIC-depreotide was tested by high-performance liquid chromatography (HPLC). The internalization and externalization rates of the new (99m)Tc-HYNIC-depreotide were studied in A549 cells. Furthermore, biodistribution of the radiopeptide was studied in nude mice, bearing tumors from human lung carcinoma cells SPC-A1. RESULTS: The molecular of synthesize depreotide was 1358, and the purity of it was 95.29%. The labeling efficiency of (99m)Tc-HYNIC-depreotide was highest at pH 6.0 and 15°C, about (70.95 ± 0.84)%. The labeling rate of the new (99m)Tc-HYNIC-depreotide rose to a peak of (20.75 ± 0.48)% at 60 minutes in A549 cells at 37°C and decreased slightly later, while it elevated gradually during the time course at 4°C and 25°C. The internalization rate of the new (99m)Tc-HYNIC-depreotide at 37°C increased gradually and reached the peak of 84.4% in 120 minutes, while the externalization rate of the new (99m)Tc-HYNIC-depreotide was always less than 20%. In mice bearing the experimental SPC-A1 tumor, the new (99m)Tc-HYNIC-depreotide demonstrated a high tumor uptake of (4.05 ± 0.04)% ID/g at 1.5 hpi and remained high ((2.51 ± 0.06)% ID/g) at 4 hpi. The tumor-to-lung activity concentration ratio (T/Lu) was very high for the new (99m)Tc-HYNIC-depreotide at all time points. So did the tumor-to-muscle activity (T/Mu) and tumor-to-blood activity concentration ratios (T/Bl). CONCLUSION: The findings suggested that the new (99m)Tc-HYNIC-depreotide might be a promising candidate radiopharmaceutical for imaging somatostatin receptor positive lung cancer.
Subject(s)
Hydrazines/chemistry , Lung Neoplasms/pathology , Nicotinic Acids/chemistry , Technetium/chemistry , Animals , Cell Line, Tumor , Humans , Lung Neoplasms/metabolism , Male , Mice , Mice, Nude , Receptors, Somatostatin/metabolismABSTRACT
This paper introduces the current application of various kinds of implantable neuro-stimulator at home and abroad, and also analyzes its development trend.
