Activating adenosine A1 receptor accelerates PC12 cell injury via ADORA1/PKC/KATP pathway after intermittent hypoxia exposure.

Obstructive sleep apnea hypopnea syndrome (OSAHS) is associated with the neurocognitive deficits as a result of the neuronal cell injury. Previous studies have shown that adenosine A1 receptor (ADORA1) played an important role against hypoxia exposure, such as controlling the metabolic recovery in rat hippocampal slices and increasing the resistance in the combined effects of hypoxia and hypercapnia. However, little is known about whether ADORA1 takes part in the course of neuronal cell injury after intermittent hypoxia exposure which was the main pathological characteristic of OSAHS. The present study is performed to explore the underlying mechanism of neuronal cell injury which was induced by intermittent hypoxia exposure in PC12 cells. In our research, we find that the stimulation of the ADORA1 by CCPA accelerated the injury of PC12 cells as well as upregulated the expression of PKC, inwardly rectifying potassium channel 6.2(Kir6.2) and sulfonylurea receptor 1(SUR1) while inhibition of the ADORA1 by DPCPX alleviated the injury of PC12 cells as well as downregulated the expression of PKC, Kir6.2, and SUR1. Moreover, inhibition of the PKC by CHE, also mitigated the injury of PC12 cells, suppressed the Kir6.2 and SUR1 expressions induced by PKC. Taken together, our findings indicate that ADORA1 accelerated PC12 cells injury after intermittent hypoxia exposure via ADORA1/PKC/KATP signaling pathway.

Chronic intermittent hypoxia exposure induces kidney injury in growing rats.

OBJECTIVE: The objectives of this paper are to examine the effect of chronic intermittent hypoxia (CIH) on the morphological changes in the kidney of growing rats and to explore the mechanisms underlying the CIH-induced renal damage. METHODS: Forty Sprague-Dawley rats were randomly divided into two groups: 2 and 4 weeks CIH groups (2IH, 4IH), and in the control group 2 and 4 weeks air-stimulated groups (2C, 4C), with 10 rats in each group. Pathological changes of renal tissue were observed by HE staining, PAS staining, and Masson staining. Real-time PCR method was used to detect the mRNA expression of HIF-1α, CuZnSOD/ZnSOD, and MnSOD in renal tissue. RESULTS: (1) Intermittent hypoxia (IH) caused morphological damage in the kidney. Hypertrophy of epithelial cells in the kidney tubules and dilation in the glomeruli were observed under light microscope in HE and PAS stain, especially in 4IH group. Masson staining showed no significant fibrotic response in the IH groups. (2) Compared with the corresponding control groups, the levels of serum SOD were significantly lower in CIH groups, and especially in 4IH group. The mRNA expression of Cu/ZnSOD and MnSOD in CIH groups decreased significantly as compared to control groups. The mRNA levels of HIF-1α in the kidney were significantly higher in CIH groups than those in the corresponding control groups. CONCLUSION: Oxidative stress played a critical role in renal damage by up-regulating HIF-1α transcription and down-regulating Cu/ZnSOD and MnSOD transcription after chronic intermittent hypoxia exposure in growing rats.

A high-resolution summary of Cambrian to Early Triassic marine invertebrate biodiversity.

One great challenge in understanding the history of life is resolving the influence of environmental change on biodiversity. Simulated annealing and genetic algorithms were used to synthesize data from 11,000 marine fossil species, collected from more than 3000 stratigraphic sections, to generate a new Cambrian to Triassic biodiversity curve with an imputed temporal resolution of 26 ± 14.9 thousand years. This increased resolution clarifies the timing of known diversification and extinction events. Comparative analysis suggests that partial pressure of carbon dioxide (Pco2) is the only environmental factor that seems to display a secular pattern similar to that of biodiversity, but this similarity was not confirmed when autocorrelation within that time series was analyzed by detrending. These results demonstrate that fossil data can provide the temporal and taxonomic resolutions necessary to test (paleo)biological hypotheses at a level of detail approaching those of long-term ecological analyses.

[Cannulated screw internal fixation for sustentaculum tali fractures with articular surface].

OBJECTIVE: To explore clinical efficacy of cannulated screw internal fixation in treating sustentaculum tali fractures with articular surface. METHODS: From August 2012 to June 2017, 13 sustentaculum tali fracture patients with articular surface were treated by cannulated screw internal fixation, including 10 males and 3 females, aged from 26 to 58 years old. Joint plane flatness was evaluated by calcaneal width, clearance distance of middle-range and posterior talar articular surface on coronal position of CT scan before operation and 1 year after operation. AOFAS score at 1 year after operation was applied to evaluate clinical efficacy. RESULTS: All patients were followed up from 9 to 70 months. The fractures were healed well from 8 to 16 weeks. No subtalar arthritis and tenosynovitis occurred. Calcaneal width before operation was from 46.2 to 52.7 mm, and decreased from 35.2 to 39.2 mm after operation; clearance distance of middle-range before operation was from 4.5 to 4.8 mm, and decreased from 1.9 to 2.2 mm after operation; clearance distance of posterior talar articular surface before operation was from 2.4 to 2.8 before operation, and decreased from 1.9 to 2.3 mm after operation. AOFAS score at 1 year after operation ranged from 77 to 94, and 1 got excellent result and 12 moderate. CONCLUSIONS: The clinical efficacy of two cannulated screws with cross internal fixation for sustentaculum tali fractures with articular surface is satisfactory, sustentaculum tali fracture could obtain good reduction, recover smooth of middle talar articular surface, and the function of feet were improved.