Objective To detect and compare the pH value of different locations in esophagus and trachea of mice.Methods 40 male Kunming mice of clean grade were randomly divided into two groups,of which the esophagus(esophageal group) and trachea(windpipe group) were measured,before the experiment two groups kept 12 hours abrosia.The esophagus and trachea of the rats in two groups were dissected and separated out,the distance from the central incisors were 0.3 cm,0.5 cm,0.7 cm,the incision was like 'T'.The sensitive grade of pH test paper was used for the determination,and the data was recorded in each group and analyzed.Results All the mice were measured successfully.The pH of the esophagus group were (6.10±0.17),(5.84±0.11),(5.44±0.11),and the pH value of the trachea group were(7.44±0.11),(7.19±0.11),(6.97±0.07),respectively.There was a significant difference in the same segment between the two groups(P<0.05).Conclusion The results showed that the differences in the pH values of trachea and esophagus and the pH values of different segments,which provides a theoretical basis for the design of model mice by intragastric administration of pH to identify the value of trachea and esophagus.

Pressure overload can result in heart hypertrophy, and induce apoptosis, but the phenomenon of apoptosis during the forepart of cardiomyocyte hypertrophy remains unclear. The aim of this study was to inquire into the process of cardiomyocyte apoptosis during the forepart of cardiomyocyte hypertrophy. We constructed the hypertrophy model by transverse aortic constriction of male SD rat. The apoptosis ratio was detected by TUNEL method and FCM. The result demonstrated that hypertrophy indexes increased with the time of constriction, reached the highest level at day 7, maintained that level, and then decreased at day 91. The apoptosis ratio of cardiomyocyte at day 4 was higher than that at day 0 detected by FCM method, and the ratio at day 7 was markedly lower than that at day 4. After day 28, the apoptosis ratio of cardiomyocyte went up again with the time of constriction after surgery. TUNEL method revealed that positive nuclei were observed in cardiomyocytes exclusively in the left ventricle; the apoptosis ratio increased when constriction continued. TUNEL method confirmed the result of FCM. These data indicate that cardiac hypertrophy is initiated by apoptosis of cardiomyocyte, these two factors(hypertrophy and apoptosis) maintain the balance between growth and death during the early short period of aortic constriction, and when aortic constriction goes on they are involved in the pathogenesis of heart remodeling.

In order to understand the electricity frequency specialties of blood, we have developed a wide frequency electricity characteristic testing system and used it to test the amplitude frequency property and phase frequency property of the blood in different states and constituents at 1 Hz to 20 MHz. Further analysis on the results of tests helped us know some important properties of blood at even more microcosmic levels from a new angle. Meanwhile, some problems and considerations on the improvement of the electricity model of biotic tissue and blood were pointed out. (1) From 1 Hz to 5 KHz, the impedance of blood descended 99%. (2) Simple equivalent circuit of resistance and capacitance must be used in series equivalent but not in usual parallel connection equivalent. (3) Experiment indicated, equivalent circuits of blood need more analysis, because simple equivalent circuit of resistance and capacitance is liable to gross error. (4) When the three element model is used for measuring the resistance of inside liquid, capacitance of cell membrane and the resistance of outside liquid of blood, the three testing frequencies must be very similar.
Blood ; Blood Physiological Phenomena ; Electric Impedance ; Electrophysiology ; Humans ; Models, Biological