Mechanisms of the expression of exogenous genes injected via the mammary duct in rat mammary gland tissue / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the mechanisms of the expression of exogenous gene injected via the mammary duct in rat mammary gland tissue.</p><p><b>METHODS</b>Thirty-six SD rats were grouped according to the stages of mammary growth (9 weeks after birth, 7, 12 and 18 days of pregnancy, and 7 and 14 days post partum, 6 rats in each stage). pCE-29 plasmid for highly efficient expression of green fluorescent protein (GFP) and in vivo jetPEITM were mixed and injected into the 5th pair of the mammary glands via the mammary ducts in each rat. The mammary glands were taken to prepare freezing slices 48 h after the injection and observed under fluorescence microscope. HE staining was performed for slices with GFP expression to locate the site of GFP expression by comparison of the images before and after staining. Paraffin sections of the mammary glands with HE staining were also obtained from normal rats in different stages of mammary development.</p><p><b>RESULTS</b>After pCE-29 plasmid injection, GFP expression was observed in the mammary glands of 2 rats in pregnancy day 12 group and in postpartum day 7 group. The green spots shown by fluorescence microscopy were found in the mammary epithelial cells after image comparison. The gland cells undergoing cell division were more numerous in the two stages (pregnancy day 12 and postpartum day 7) than in other stages of mammary development.</p><p><b>CONCLUSIONS</b>In the two stages of pregnancy day 12 and postpartum day 7, exogenous genes injected via the mammary duct can be expressed in the mammary glands. In these stages, the stem cells in the mammary gland epithelia differentiate continuously and the mammary gland epithelial cells flourish under the regulation by hormones to allow better chance for exogenous gene acceptance in the context of active DNA replication in the gland cells. This finding provides important experimental evidence for further studies of mammary gland bioreactor in animals.</p>

Research and development on the dynamic system for detecting the force of acupuncture needle during the acupuncture process in the clinical practice of traditional Chinese medicine / 生物医学工程学杂志

Manipulations are essential to the acupuncture curative effect. With the technique limited, the researches on acupuncture manipulations can only be carried out with respect to the senses and experience of doctors and patients, thus seriously impeding the modernization and internationalization of acupuncture. Both the modern integration technology of transducer and the biomechanical principles are applied to develop a detection system that can measure the interaction force between the manipulator and the manipulated patient on the needle at each kind of manipulation. Through clinical practice, the force waveforms acting on needle with the manipulations of symmetrical twirling-rotating and symmetrical lifting-inserting were recorded so as to realize the quantitative, objective and real-time detection of the force during the acupuncture process, which provided a new experimentation means and analysis method for the improvement of clinical curative effect and quantitative research of acupuncture and meridians.