Nowadays, the risk of developing second primary cancers among women diagnosed with prior breast cancer represents a public health issue worldwide.Twenty-eight cases of the primary breast cancer with the multiple primary cancers (MPC) between 2008 and 2015 at our hospital were retrospectively analyzed in regards to age of patients, family history, interval time of the 2 cancers, and survival time of these patients.A total 28 cases were analyzed, at the mean age of 44.57 years at the diagnosis of the first primary cancer. The most common primary cancer in these breast cancer patients was contralateral breast cancer. Of 28 patients with breast cancer, 16 developed a second malignant tumor of the opposite breast, there were no significant difference both median age at first breast cancer and second breast cancer (P > .05). The difference of interval time of 2 cancers also had no statistical significance. There was no statistically significant difference in overall survival between the bilateral primary breast cancers (BPBC) group and the group of breast cancer patients who diagnosed with another cancer (P > .05). If we grouped patients age of diagnosed with the first cancer (<45, ≥45 years), no statistical different between 2 groups (P > .05). However, the survival time with positive-node patients was lower than in patients with node-negative, the difference had a notable significant difference (P < .01). And there are 3 cases had a positive family history for malignant tumor in the form of first-degree relative.Multiple primary carcinoma in patients with prior breast cancer is not the influencing factor of prognosis. It is crucial to detect, diagnose, and treat cancers at their early stage for improving the cure rate of cancer and the survival rate of patients.
Many receptors, including thermal receptors and mechanical receptors, are only activated by stimuli within a clearly defined range of intensities. Differences in the receptive ranges enable individual receptors and their sensory centers to precisely detect the intensity of the stimulus and changes in intensity. Baroreceptors are the sensory terminals of the baroreflex. It is well understood that an increasing number of baroreceptors are recruited to produce afferent action potentials as the blood pressure increases, indicating that individual baroreceptors have different pressure thresholds. The present study revealed that individual baroreceptors could stop their afferent signals when the blood pressure exceeds a certain level, indicating that individual baroreceptors are sensitive to a specific range of blood pressure. The receptive ranges of individual baroreceptors differ in terms of the total range, the lower threshold, and the upper threshold. Of 85 baroreceptors examined in this study, the upper thresholds for about half were within the physiological blood pressure range. These results indicate that supraphysiological blood pressure is unlikely to be encoded by the recruitment of more baroreceptors. Instead, supraphysiological blood pressure levels might be signaled by an increase in the frequency of action potentials or by other mechanisms. In conclusion, our results indicate that rabbit baroreceptors are activated by blood pressure levels within specific receptive ranges. These findings should encourage further studies to examine the role of population coding of blood pressure by baroreceptors in the baroreflex. The baroreflex is the major physiological mechanism involved in the rapid regulation of blood pressure. Stretching of the aorta following an increase in blood pressure activates baroreceptors located in the carotid sinus and aorta, causing stronger afferent signal to the blood pressure regulatory center. The reflex system lowers blood pressure by decreasing the heart rate and the peripheral resistance. This reflex is also known as the depressure reflex [1,2]. Baroreceptors, sensory nerve terminals located beneath the vascular adventitia, are the sensory components of the depressure reflex. Variations in blood pressure cause changes in vascular extension and thus the stress on baroreceptors. Afferent neural impulses generated by the baroreceptors then convey information regarding the changes in blood pressure to the central nervous system [3]. It is well established that, within the physiological range of blood pressure, the frequency of impulses generated by individual baroreceptors is positively correlated with vascular extension, with an S-shaped correlation between the frequency of afferent impulses and blood pressure [4][5][6][7]. As blood pressure increases, more baroreceptors are recruited and changes in blood pressure are coded by the frequency of action potentials derived from the individual afferent nerve fibers and the number of the recruited active fibers. These
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