Downregulation of Rho associated coiled-coil forming protein kinase 1 in the process of delayed myocardialization of cardiac proximal outflow tract septum in connexin 43 knockout mice embryo / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The connexin43 knockout (Cx43 KO) mouse dies at birth with an enlarged conotruncal region, which leads to the obstruction of the right outflow tract (OFT). Since myocardialization of the proximal OFT septum is one of the key events during heart development, we investigated the process in the Cx43 KO embryo hearts. Rho associated coiled-coil forming protein kinase 1 (ROCK1), is a recently found key molecule to regulate the myocardialization of OFT, but its spatiotemporal expression pattern during myocardialization remains unknown. The objective of this study was to investigate the differentially expressed pattern of ROCK1 between Cx43 KO and wild type embryo hearts, and its relationship with the delayed myocardialization in Cx43 KO embryo hearts.</p><p><b>METHODS</b>Using immunohistochemistry, the processes of myocardiolization were investigated both in Cx43 KO and wild type embryo hearts. The differentially expressed pattern of ROCK1 between Cx43 KO and wildtype embryo hearts was evaluated both at the mRNA and protein level by real-time RT-PCR and immunohistochemistry.</p><p><b>RESULTS</b>The expression of α-sarcomeric actin (α-SCA) in the proximal OFT septum of Cx43 KO embryos was delayed. Meanwhile, it was shown that the downregulation of ROCK1 coincided with delayed myocardialization. The expression of ROCK1 protein was mainly limited to the proximal outflow tract septum from embryo day (E) E11.5 to E15.5. Its expression pattern was similar with that of α-SCA. Real-time RT-PCR found that the expression level of Rock-1 mRNA began at a low level on E11.5 and reached peak at E13.5 and E14.5.</p><p><b>CONCLUSIONS</b>ROCK1 may have an important role in the process of myocardialization of the proximal OFT septum. Downregulation of ROCK1 is likely to contribute to the aberrant myocardialization in Cx43 KO embryo hearts.</p>

Restraining effects of acupuncture on photoreceptor cell apoptosis in rats with retinitis pigmentosa induced by N-methyl-N-nitrosourea / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of acupuncture on photoreceptor cell apoptosis in rats with retinitis pigmentosa induced by N-methyl-N-nitrosourea (MNU).</p><p><b>METHODS</b>Fifty-day-old female SD rats were established into model of retinitis pigmentosa by once intraperitoneal injection of 50 mg/kg MNU, and randomly grouped to the acupuncture group and the model group for observing the cell apoptosis in rats and compared with that in normal rats at the corresponding time points.</p><p><b>RESULTS</b>Acupuncture showed no effect on cell apoptosis at its peak of occurring, apoptotic phenomena still could be seen on days 5 and 7, but it was significantly less in the acupuncture group than in the model group (P < 0.01). Moreover, acupuncture showed a restraining effect on the up-regulation of caspase-3 activity.</p><p><b>CONCLUSION</b>Acupuncture can restrain the MNU induced apoptosis of photoreceptor cells, the effect is correlated, to a certain degree, with the status of the apoptosis occurrence.</p>

Role of different oxygen concentration and different period of oxygen exposure in pathogenesis of retinopathy in neonatal mice / 中华儿科杂志

<p><b>OBJECTIVE</b>To evaluate the role of different oxygen concentration (FiO2) and different period of oxygen exposure on oxygen-induced retinopathy (OIR) in neonatal mice and to provide evidences for proper clinical oxygen therapy.</p><p><b>METHODS</b>Two hundred and four 7-day-old (P7) C57BL/6J mice were exposed to different FiO2 30%, 50% and 75% for 5, 7 and 9 days. The mice were divided into eight groups: groups 1 - 3 (n = 24 in each) were exposed to 30% oxygen for 5, 7 and 9 days, respectively; groups 4 - 6 (n = 24 in each) were exposed to 50% oxygen for 5, 7 and 9 days, respectively; group 7 (n = 30) was exposed to 75% hyperoxia for 5 days; group 8 (n = 30) was exposed to room air. Proliferative neovascular responses were estimated by observing vascular patterns in adenosine diphosphate-ase (ADPase) stained retina flat-mounts and quantitated by counting the number of new vascular cell nuclei extending into the internal limiting membrane in cross-sections.</p><p><b>RESULTS</b>(1) Vascular patterns in retina flat-mounts: a) When FiO2 was 30%, the entire vascular pattern was completely normal after 5 and 7 days exposure; although the deep vascular system seemed slightly constricted after 9 days exposure, it recovered 2 days later and matured at P21. b) When FiO2 was 50%, after 5 days exposure (group 4), the larger vessels constricted and central perfusion decreased moderately; after exposing to room air for 2 days, neovascularization was seen; however, the entire vascular pattern was almost normal at P17. After 7 days of exposure to 50% O2 (group 5), the vascular pattern recovered a bit, seemed to be better than that of group 4; after 9 days of exposure to 50% O2 (group 6), only slight constriction could be seen and it disappeared 2 days later and all vessels matured later. c) When FiO2 was 75%, after 5 days exposure to hyperoxia, the larger vessels became tortuous and constricted, central perfusion became decreased obviously; after exposing to room air for 2 days, neovascularization was seen; and this response was maximal at P17 - P21. However, the mortality of nurser mice and pups increased dramatically when the duration of hyperoxia was prolonged. (2) Quantitative results in cross-sections: neovascular nuclei extending into the vitreous reached (41.9 +/- 2.8) per section in 75% oxygen group, while less than 1 in every other groups, which was statistically different (P < 0.0001).</p><p><b>CONCLUSIONS</b>FiO2 and the duration of hyperoxia could affect retinal vascular development. Low and moderate FiO2 could induce reversible vessel changes, while high FiO2 induced irreversible changes which should be avoided in clinic.</p>

Effects of different oxygen inhalation modes on retinal vessels development in neonatal mice / 中国当代儿科杂志

<p><b>OBJECTIVE</b>This study was designed to investigate the effects of different oxygen inhalation modes on retinal vessels development in neonatal mice in order to provide experimental data for proper oxygen therapy for premature infants.</p><p><b>METHODS</b>A total of 144 postnatal day (P) 7 C57BL/6J mice were randomly assigned into 6 groups according to different oxygen inhalation modes (n=24). Experimental group 1 was exposed to 30%, 40%, 50%, 60% and 75% oxygen in turn for one day respectively, followed by room air exposure for 5 days. Experimental group 2 was exposed to 75%, 60%, 50%, 40% and 30% oxygen in turn for one day respectively, followed by room air exposure for 5 days. Experimental group 3 was exposed to 75% oxygen for 5 days, followed by room air exposure for 5 days. Experimental group 4 was exposed to 75% oxygen for 5 days, 50% oxygen for 2 days and 30% oxygen for 2 days, then room air exposure for 6 days. The supplemental 75% oxygen and room air recovering was performed alternately for the mice in Experimental group 5 for 3 times and then room air exposure for 5 days. The Control group was exposed to room air for consecutive 10 days. The retinal vascular development and proliferation were evaluated by the retinal flat-mounts (ADPase stained retina) and cross-section.</p><p><b>RESULTS</b>The peripheral vascular pattern was clear, and a few avascular areas were seen in the Control group at P12. At P14 the avascular area disappeared. At P17, the entire vascular pattern became completely normal. In the Experimental groups 1, 3 and 5, the central vessels became tortuous and constricted and the central avascular area increased at P12. At P14, neovascularization was seen peaking at P17 in the Experimental groups 1, 3 and 5. In the Experimental group 4, the central avascular area increased and neovascularization was seen at P14, but the central avascular area was reduced and abnormal neovascularization disappeared, with slight constriction of the deep vessels, at P17. Five days later the vascular pattern became almost normal in the Experimental group 4. The retinal vascular form of the Experimental group 2 was similar to that of the Control group. The average number of neovascular nuclei extending into the vitreous per cross-section in the Experimental groups 1, 2, 3, 4, and 5 and the Control group was 49.50 +/- 1.36, 5.17 +/- 0.67, 47.68 +/- 4.70, 5.74 +/- 2.37, 29.15 +/- 2.48, and 1.22 +/- 0.20 respectively. There were significant differences between the Experimental groups 1, 3, 5 and the Control group (P < 0.05).</p><p><b>CONCLUSIONS</b>The effects of different oxygen inhalation modes on the retinal vessels development in neonatal mice were different. The obvious fluctuation of inhaled oxygen concentration and abrupt stop of supplemental oxygen after high levels of supplemental oxygen may severely affect the development of retina vascular, leading to the pathologic changes similar to retinopathy of prematurity.</p>

Decreased hippocampal neurogenesis is involved in cognitive dysfunction induced by thiamine deficiency / 中华神经科杂志

Objective To investigate the influence of thiamine deficiency(TD)at early pre- pathological lesion stage on cognitive function and the correlation between cognitive dysfunction and hippocampal neurogenesis.Methods TD mouse model was prepared by feeding a thiamine-depleted diet. Learning and memory functions of TD mice were tested with Y-maze.Hippoeampal neurogenesis was studied with bromodeoxyuridine(BrdU),proliferative cell nuclear antigen(PCNA),and Doublecortin(Dcx) immunohistochemical staining on the 7th(TD7),9th,14th and TD25th day.Results TD9 mice without pathological impairment and cholinergic nerve degeneration needed more times of training(22.3?2.2)in the learning test of Y maze compared with the controls(13.5?3.5).Correspondingly,the numbers of BrdU-positive ceils and the immunoreactivity of Dcx decreased significantly in the TD9 mice(19.8?0.4, 1537.2?50.2 vs 23.9?0.3,2688.9?127.9 pixels/mm~2).Thiamine re-administration reversed the declined hippocampal neurogenesis:the number of BrdU-positive cells was 23.6?1.9 and Dcx immunoreactivity was 2052.3?269.6 pixels/mm~2:the impaired learning ability was simultaneously restored,with the number of total training trial being 16.8?0.5.Conclusion The decreased hippocampal neurogenesis contributes to retarded learning ability at early pre-pathological lesion stage of TD.