BACKGROUND:Studies have shown that human telomerase reverse transcriptase (hTERT) has the ability to enhance cel proliferation, maintain telomere length, prolonged cel life cultured in vitro. OBJECTIVE:To observe the effect of hTERT gene-modified bone marrow mesechymal stem cel transplantation on neural function recovery of rats with cerebral infarction. METHODS:Rat models of middle cerebral artery occlusion were established and randomized into model group, cel transplantation group and hTERT-modified cel transplantation group, with 20 rats in each group. Rats in the three groups were respectively injected via tail vein with 1 mL PBS, passage 9 bone marrow mesenchymal stem cel suspension (2.5×107/L) and hTERT-modified passage 9 bone marrow mesenchymal stem cel suspension (2.5×107/L), respectively. Modified neurological severity scores were determined before and after transplantation; RT-PCR and western blot assay were used to measure hTERT expression at gene and protein levels; TUNEL method was adopted to detect cel apoptosis in the brain. RESULTS AND CONCLUSION:hTERT-modified bone marrow mesenchymal stem cels had prolonged cel cycle, and with the increase in passage number, the cels showed good growth with no changes in morphology. The expressions of hTERT mRNA and protein were superior in the hTERT-modified cel transplantation group than the cel transplantation group, and there was a significant difference (P < 0.05). Modified neurological severity scores and number of apoptotic cels were decreased significantly in the hTERT-modified cel transplantation group compared with the other two groups (P < 0.05). These findings indicate that hTERT-modified bone marrow mesenchymal stem cels can promote neural functional recovery of rats with cerebral infarction.

BACKGROUND:Numerous clinical studies have confirmed that the microenvironment at a spinal cord injury site can be obviously improved through hyperbaric oxygen therapy; however, what effect does hyperbaric oxygen have on the microenvironment of the injured brain? OBJECTIVE:To investigate the effect of hyperbaric oxygen therapy on nerve regeneration microenvironment and the recovery of rat nerve function after focal cerebral infarction. METHODS:Rat models of focal cerebral infarction were established by occlusion of the middle cerebral artery and subjected to hyperbaric oxygen therapy. Sham group and model group were established as comparison. In the sham group, rat models of focal cerebral infarction were established but did not receive any treatment. Rats in the model group were placed in a hyperbaric oxygen therapy chamber but the pressure and oxygen concentration were not administered. RESULTS AND CONCLUSION:Compared with the model group, the score of rat limb function at 16 days after treatment and the expression of growth associated protein 43 in the rat cerebral infarcted area at postoperative 14 days were significantly increased , but infarct volume at postoperative 24 hours was al significantly decreased in the hyperbaric oxygen therapy group (alP < 0.05). These results confirmed that hyperbaric oxygen therapy can improve nerve regeneration microenvironment and promote the recovery of rat nerve function after focal cerebral infarction.

Seventy-three patients with type 2 diabetes mellitus were divided into atheroselerosis(AS) group and non-AS group according to the intima-media thickness(IMT)of the carotid artery.The plasma visfatin level in AS group was higher than that in non-As group[(44.95±10.14 vs 34.52±9.08)μg/L,P<0.05],and both of them were higher than that of the control [(24.46±7.18)μg/L,both P<0.05 ].The visfatin level Was positively correlated with IMT,waist-to-hip ratio,visceral fat thickness,fasting insulin,and HOMA insulin resistance index.Age,duration of diabetes,HbA_(1C),and visfatin level were the major risk factors for IMT of the carotid artery.

Background Air pollution exposure has a significant impact on maternal and child health. However, the research on the association between ambient ozone (O₃) exposure during pregnancy and the risk of premature birth in newborns is limited, and the conclusions are inconsistent. Objective To investigate the association of ambient O₃ exposure during pregnancy with the risk of preterm birth in Guangdong Province. Methods Data of pregnant women in Guangzhou from 2013 to 2019 and Foshan from 2018 to 2023 were collected, and O₃ concentrations during different trimesters were assessed according to maternal residential addresses. Bilinear interpolation was used to evaluate the concentrations of air pollution. A cohort study design was adopted in our study. Restricted cubic spline curves were used to evaluate the exposure-response relationship between O₃ exposure and preterm birth risk and explore potential exposure threshold of O₃. Logistic regression models were used to evaluate the association of O₃ exposure with preterm birth. Results A total of 702 924 pregnant women were included in this study, of whom 43 051 (6.12%) were preterm. The average O₃ exposure concentrations of pregnant women during the first, second, third, and whole trimesters were 95.51, 97.51, 100.60, and 97.87 μg·m⁻³, respectively. We observed J-shaped associations between O₃ exposure and preterm birth risk during the second, third, and whole trimesters of pregnancy using restricted cubic spline curves. This study found that there were threshold concentrations between O₃ exposure and preterm birth risk during different gestational periods, and the threshold concentrations in the first, second, third, and whole trimesters were 112.32, 99.83, 111.74, and 112.46 μg·m⁻³, respectively. During the second, third, and whole trimesters of pregnancy, after adjusting for maternal age, baby sex, pre-pregnancy body mass index, mode of delivery, baby birth weight, gestational diabetes, and gestational hypertension, the odds ratios (OR) of preterm birth were 1.02 (95%CI: 1.01, 1.04), 1.02 (95%CI: 1.00, 1.03), and 1.17 (95%CI: 1.13, 1.21) for each 10 μg·m⁻³ increase in O₃ concentration above the O₃ threshold. No significant association was found between O₃ exposure and the risk of preterm birth during the first trimester. Conclusion There is a nonlinear association between the risk of preterm birth and O₃ exposure during pregnancy, and higher concentrations of O₃ exposure during pregnancy are associated with the risk of preterm birth. Above the O₃ threshold concentration during pregnancy, especially during the second, third, and whole trimesters, the risk of preterm birth elevates with the increase of O₃ exposure concentrations.