Serum Pepsinogen Levels Are Correlated With Age, Sex and the Level of Helicobacter pylori Infection in Healthy Individuals.

BACKGROUND: To explore the relationship between age, sex, the level of Helicobacter pylori (HP) infection and serum pepsinogen (PG) in healthy people undergoing a medical examination. METHODS: A total of 6,596 "healthy" individuals undergoing a medical examination were selected as subjects in this study. The concentrations of serum pepsinogen I (PGI) and serum pepsinogen II (PGII) were tested for each of the subjects using time-resolved fluorescence immunoassay characterized with high sensitivity and wide measuring range. The infection ratio and level of HP were tested using a 13C-urea breath test to analyze the relationship between age, sex, HP infection, and serum PGs. RESULTS: The PGI, PGII and PGI-to-PGII ratio (x¯±S) were higher in males than in females. The serum PGI and PGII levels gradually increased with age. HP infection rate was 48.83%, and the serum PGI, PGII and PGI-to-PGII ratio (x¯±S) were 187.05 ± 73.50µg/L, 18.09 ± 8.68µg/L and 11.67 ± 5.44, respectively in the HP-positive group and 150.39 ± 67.04µg/L, 11.50 ± 7.45µg/L and 15.67 ± 8.19, respectively in the HP-negative group. There was significant difference in the detection rate of an abnormal PG between the 2 groups as with the worsening of HP infection, 13C-urea breath test and serum PGI and PGII levels increased, but the PGI-to-PGII ratio decreased significantly. CONCLUSIONS: Serum PGI and PGII levels were correlated with age, sex and the level of HP infection. Therefore, the influencing factors of age, sex and the level of HP infection should be considered when screening stomach diseases using PG.

[XPS characterization of TiN layer on bearing steel surface treated by plasma immersion ion implantation and deposition technique].

Titanium nitride (TIN) hard protective films were fabricated on AISI52100 bearing steel surface employing plasma immersion ion implantation and deposition (PIIID) technique. The TiN films were characterized using a variety of test methods. Atomic force microscope (AFM) revealed that the titanium nitride film has extremely smooth surface, very high uniformity and efficiency of space filling over large areas. X-ray diffraction (XRD) result indicated that (200) crystal face of titanium nitride phase is the preferred orientation and three kinds of titanium components exist in the surface modified layer. Tailor fitting analysis of X-ray photoelectron spectroscopy (XPS) combined with Ar ion etching proved that Ti2p(1/2) and Ti2p(3/2) have two peaks in the titanium nitride film layer, respectively. It is shown that different chemical state exists in titanium compound. N(1s) bond energy of XPS has also three fitting peaks at 396.51, 397. 22 and 399.01 eV, corresponding to the nitrogen atom in TiNxOy, TiN and N--N, respectively. Combined with the XPS Tailor fitting analysis results of O(1s) bond energy, it was shown that there is a large amount of titanium nitride phase in addition to a small amount of simple substance nitrogen and oxide of titanium in the surface layer. The whole film system is made up of TiN, TiO2, N--N and Ti--O--N compound.