The bidirectional association of C-peptide with cardiovascular risk in nondiabetic adults and patients with newly diagnosed type 2 diabetes mellitus: a retrospective cohort study.

BACKGROUND: Recent literature reported the biological role of C-peptide, but this role is still controversial and unclear. The primary aim of this study was to investigate associations between C-peptide and cardiovascular biomarkers as well as events. METHODS: A total of 55636 participants who had a health examination from 2017 to 2021 were included. Of them, 6727 participants visited the hospital at least twice. Cardiovascular biomarkers like high-sensitivity C-reactive protein (hs-CRP) and high-sensitivity cardiac troponin T (hs-cTnT) were measured and their relationships with fasting C-peptide were evaluated for all participants. Cardiovascular events were obtained during the last visit and their associations with C-peptide were evaluated for those participants who visited the hospital at least twice. RESULTS: Among the included participants, 11.1% had a previous type 2 diabetes mellitus (T2DM). In the participants without previous T2DM, the relationships between fasting C-peptide and hs-CRP and hs-cTnT were negative if the value of fasting C-peptide was < 1.4 ng/mL and positive if the value was ≥ 1.4 ng/mL. These relationships remained significant after adjusting for hemoglobin A1c, insulin resistance index, and its interaction with C-peptide, even if the participants were stratified by glucose metabolism status or levels of insulin resistance index. Hazard ratios of cardiovascular events were first decreased and then increased with the increasing of baseline C-peptide levels, though these associations became unsignificant using the multivariate Cox regression model. Unlike the participants without previous T2DM, the associations of C-peptide with cardiovascular biomarkers and events were not significant in the patients with previous T2DM. CONCLUSIONS: The associations of C-peptide with cardiovascular biomarkers and events were different between the participants without previous T2DM and those with previous T2DM. The effect of C-peptide on cardiovascular risk may be bidirectional, play a benefit role at a low level, and play a harmful role at a high level in the nondiabetic adults and the patients with newly diagnosed T2DM.

In vivo growth of subclones derived from Lewis lung carcinoma is determined by the tumor microenvironment.

Heterogeneity is a fundamental feature of human tumors and plays a major role in drug resistance and disease progression. In the present study, we selected single-cell-derived cell lines (SCDCLs) derived from Lewis lung carcinoma (LLC1) cells to investigate tumorigenesis and heterogeneity. SCDCLs were generated using limiting dilution. Five SCDCLs were subcutaneously injected into wild-type C57BL/6N mice; however, they displayed significant differences in tumor growth. Subclone SCC1 grew the fastest in vivo, whereas it grew slower in vitro. The growth pattern of SCC2 was the opposite to that of SCC1. Genetic differences in these two subclones showed marked differences in cell adhesion and proliferation. Pathway enrichment results indicate that signal transduction and immune system responses were the most significantly altered functional categories in SCC2 cells compared to those in SCC1 cells in vitro. The number and activation of CD3+ and CD8+ T cells and NK cells in the tumor tissue of tumor-bearing mice inoculated with SCC2 were significantly higher, whereas those of myeloid cells were significantly lower, than those in the SCC1 and LLC1 groups. Our results suggest that the in vivo growth of two subclones derived from LLC1 was determined by the tumor microenvironment rather than their intrinsic proliferative cell characteristics.

[The expression of O6-methylguanine DNA methyltransferase and p53 in non-small cell lung cancer and the association with the prognosis].

OBJECTIVE: To investigate the expression and role of O(6)-methylguanine DNA methyltransferase (MGMT) and p53 in non-small cell lung cancer (NSCLC) and the association with prognosis. METHODS: Immunohistochemical method was used to investigate the expression of MGMT and p53 in NSCLC specimens from 110 cases and in 20 cases of benign lung diseases as the control. The association of their expression with the prognosis of the 110 patients was evaluated. RESULTS: The positive expression of MGMT in NSCLC and benign lung diseases was 41.8% (46/110) and 80% (16/20) (χ(2) = 9.89, P < 0.05), respectively. The positive expression of p53 in NSCLC and benign lung diseases were 56.4% (62/110) and 0% (0/20) (χ(2) = 21.551, P < 0.05), respectively. There was a significant association between expression of MGMT with smoking, and lymph node metastasis (χ(2) = 12.107, P < 0.05; χ(2) = 6.512P < 0.05). There was also a significant association between expression of p53 with smoking and lymph node metastasis (χ(2) = 6.330, P < 0.05; χ(2) = 7.909, P < 0.05). A negative correlation was observed between the expression of MGMT and that of p53 protein in NSCLC (R(S) = -0.592, P < 0.05). The 5-year survival rate and median survival time of 110 cases was 10.9% (12/110), and (30.4 ± 0.6) months. In 46 cases with positive expression of MGMT the 5-year survival rate was 0% (0/110) and median survival was (25.9 ± 0.4) months, which were lower than those in the 64 patients with negative expression of MGMT [18.8% (12/64), (32.4 ± 0.7) months], Log rank test χ(2) = 23.569, P < 0.05. In the 62 patients with positive expression of p53, the 5-year survival rate and median survival were 4.8% (3/62) and (30.4 ± 1.2) months, which were lower than those in the 48 cases with negative expression of p53 [18.8% (9/48), (30.5 ± 1.1) months], Log rank test χ(2) = 5.521, P < 0.05. CONCLUSION: The loss of expression of MGMT may lead to activation of the wild-type p53. They may participate in lung carcinomatosis, and may predict prognosis in patients with NSCLC.

[Correlation analysis of serum calcium levels and risks of diabetes mellitus in middle-aged and elderly men].

OBJECTIVE: To investigate the correlation of serum calcium levels and the risks of diabetes mellitus (DM) in middle-aged elderly men. METHODS: A total of 3386 male subjects aged 40-79 years were selected from two local communities of Beijing using stratified random sampling for this cross-sectional survey. The survey was conducted using questionnaires, and all the subjects underwent physical examination and blood tests of serum calcium, vitamin D and other biochemical parameters. The subjects were divided into normal glucose group, prediabetic group and diabetic group to compare their blood biochemical parameters and analyze the risk factors of diabetes. RESULTS: The prevalence of diabetes and pre-diabetes was 32.31% in the 3386 subjects surveyed. Serum calcium, vitamin D and Creatinine (Cr) levels were significantly higher in pre-diabetic and diabetic groups than in the non-diabetic group (P/0.05), and age, body mass index, serum calcium, vitamin D, and Cr levels differed significantly between the former two groups (P/0.05). The prevalence of diabetes increased significantly with serum calcium level (P/0.05). Logistic regression analysis showed that age, body mass index, serum calcium, and serum vitamin D levels were independent risk factors for diabetes (P/0.05). CONCLUSION: Male diabetic patients have abnormal serum calcium levels. An increased age and increased serum calcium levels are associated with higher risks of diabetes, and age, serum calcium, serum vitamin D, Cr, and body mass index are all risk factors of diabetes in men.

[Practicability study on a group of vigilant chemical compounds including chlorheridine diacetate].

OBJECTIVES: To test in vitro the spermatozocidine drug which can also prevent sex transmitting diseases (STD) pathogens. METHODS: Chlorheridine diacetate and other three chemical compounds were applied in vitro spermatozocidine and sperm inhibitting tests. RESULTS: The lowest concentrations of chlorheridine diacetate and p-nitrophenol which can inhibit human sperm in 20 seconds were 1.25 mg/ml. The minimal inhibitory concentration and minimal bactericidal concentration of chlorheridine diacetate and p-nitrophenol on Streptococcus albus Stemberg were 0.125 to 0.50 mg/ml and 0.25 to 1.00 mg/ml. CONCLUSIONS: Chlorheridine diacetate and p-uitrophenol have strong spermatozocidine and antibacteria effects.

[CDNA cloning of human leptin and its expression].

To clone cDNA of human leptin gene and obtain leptin protein for future study on leptin binding proteins. The cDNA of human leptin with 6 x his-tag was cloned by over-hang extension PCR protocol using human genomic DNA as template, and subcloned into in vitro expression vector pIVEX2.3MCS, and the fusion protein was expressed in vitro by Rapid Translation System (RTS) (RTS500 cycle primer Kit and RTS500 ProteoMaster of Roche company). The apparent molecular weight(19.46 kD) and the immuno-specificity of the fusion protein were confirmed by SDS-PAGE and Western blot, and the expressed fusion protein stayed mainly in the supernatant of the reaction mixture in soluble form. This work provides us solid basis for further study on new leptin-associated proteins.