Regulative effects of vessel active drugs on extremital skin temperature of experimental animals exposed to cold / 中国应用生理学杂志

<p><b>OBJECTIVE</b>Using an experimental model of animals exposed to cold to evaluate the regulative effects of prazosin hydrochloride (Pra) and racanisodamine (Ani) on extremital skin temperature of rats and mice.</p><p><b>METHODS</b>Eighty animals were randomly divided into eight groups according to the drug dosage. After been administered with drugs by intragastric at room temperature for 60 min, the animals were moved into specified temperature (5 degrees C,18 degrees C) environment and the skin temperatures at the 1/3 site at the proximal end of tail were measured by infrared camera on 180 min and 300 min. Effects of drug were evaluated by changes in tail skin temperatures.</p><p><b>RESULTS</b>Pra and Ani combination raised the extremital skin temperature of experimental animals significantly in a dose-dependent manner, while single use of Pra was not potent to rats and less potent to mice, and single use of Ani could not raise extremital skin temperature of both rats and mice. Change of rectal temperature in mice showed that Pra and Ani combination did not affect core temperature.</p><p><b>CONCLUSION</b>Pra and Ani combination could significantly raise extremital skin temperature of rats and mice exposed to cold, and would not affect their core (rectal) temperature.</p>

The damage effects of hypothermia combined with hypoxia on rat pulmonary microvascular endothelial cells / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the synergistic effects of hypothermia and hypoxia on the damage of pulmonary microvascular endothelial cells (PMVEC) in rat.</p><p><b>METHODS</b>Primary PMVECs were obtained by complex phosphoesterasum digesting from isolated lung tissues of Wistar rats, the PMVECs were identified by phase contrast microscope and immunofluorescence studies for CD31 antigen and bandeiraea simplicifolia isolectin (BSI) binding test. Factorial design was adopted in trial according to hypothermia and hypoxia existing or not. Using corresponding kit measured the levels of lactate dehydrogenase (LDH) activity in cell medium. Level of nitric oxide (NO) concentration was measured by Griess Assay. RT-PCR was used to examine the expression of vascular endothelial growth factor (VEGF), endothelin-1 (ET-1) mRNA in PMVECs.</p><p><b>RESULTS</b>The monolayer of cultured PMVECs displayed the shape of pavingstone. CD31 antigen and binding BSI results by fluorescence microscope identified the cultured cells were PMVECs. Compared to the control group, LDH activity and VEGF, ET-1 expression levels were significantly increased in hypothermia group, hypoxia group and hypoxia combined with hypothermia group. And the levels of NO concentration were reduced in these three groups. The results of One-way ANOVA showed that there was a synergistic effect between hypothermia and hypoxia.</p><p><b>CONCLUSION</b>Hypothermia and hypoxia both have an effect on PMVECs whether in altering the cell permeability or in releasing of vasoactive substances including NO and ET-1. In addition, there is a synergistic effect between hypothermia and hypoxia.</p>

Effects of low temperature exposure on dermal microvascular endothelial cells function / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the damage effects and expression of vascular endothelial growth factor (VEGF) exposed with different low-temperatures on rat dermal microvascular endothelial cells (DMVECs).</p><p><b>METHODS</b>Primary DMVECs were obtained by discontinuous Percoll gradient centrifugation. The DMVECs were identified by phase contrast microscope and immunofluorescence studies for CD31 antigen. Applied 28 degrees C, 12 degrees C and 0 degrees C to interfere with rat DMVECs as cold-exposure model. The changes of cells morphology were observed under invert microscope. The membrane integrity was determined by lactate dehydrogenase (LDH) activity. RT-PCR was used to examine the expression of vascular endothelial growth factor mRNA in cells.</p><p><b>RESULTS</b>The monolayer of cultured PMVECs displayed the shape of pavingstone. CD31 antigen and binding BSI results by fluorescence microscope identified the cultured cells were DMVECs. After 24 h cold exposure, the cell morphology of 0 degrees C group was shrunken, the other groups were "Fibroblast-like". The LDH activity (U/L) in the medium of 28 degrees C, 12 degrees C and 0 degrees C groups was 54.17 +/- 3.02, 64.66 +/- 3.03, 82.13 +/- 10.91 respectively, which was significantly higher than that of 37 degrees C group (12.23 +/- 3.0, P < 0.01). The VEGF mRNA expression level was up-regulated in 28 degrees C group and 12 degrees C group versus control group (P < 0.05), but unchanged in 0 degrees C group.</p><p><b>CONCLUSION</b>The rat DMVECs injury severity are deteriorated with temperature decreasing, and VEGF might be involved in the regulation of membrane permeability in this period.</p>

Relationship between reduced expression of surfactant protein B and neonatal respiratory distress syndrome in twenty Han ethnic group neonates in China / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate possible relationship between expression of surfactant protein B (SP-B) gene product and neonatal respiratory distress syndrome (NRDS) in Han ethnic group.</p><p><b>METHOD</b>Unrelated 20 cases with NRDS of Han ethnic group were selected as NRDS group while unrelated 20 diseases cases of Han ethnic group with diseases were selected as control group. The cases in the control group had congenital heart disease or bronchopulmonary dysplasia or persistent pulmonary hypertension. Blood sample was taken from every case. Lung tissues were taken from the patients who died half an hour after death in the two groups. Expression of SP-B in lung tissue was determined with immunohistochemical tecnique. Genetic deficiency variant of SP-B intron IV was screened with polymerase chain reaction (PCR).</p><p><b>RESULTS</b>Two cases at gestational age 26 weeks and one case at gestational age 34 weeks and two cases at gestational age 42 weeks of NRDS groups had lower level expression of SP-B in lung tissue than those at the same age of NRDS. Expression of SP-B in lung tissue of control group increased with gestational age, but no such phenomenon was found in NRDS group. Further, two cases at gestational age 42 weeks of NRDS group had genetic deficiency variant of SP-B intron IV with gene analysis of five cases who had lower expression of SP-B. Clinical data suggest that patients at 42 weeks of gestational age had severe illness.</p><p><b>CONCLUSIONS</b>Decrease of SP-B expression may participate in occurrence of NRDS, genetic deficiency variant of SP-B intron IV exists in the NRDS cases of Han ethnic group of China.</p>

Developmental Characters of Neural Stem Cells in Occipital of Cortex from Human Fetal Brain at Different Ages / 实用儿科临床杂志

Objective To investigate the developmental characters of neural stem cells(NSCs) in occipital of cortex from human fetal brain at different age.Methods Ninety cases of embryoes at gestational age 16-32 weeks and by induction of labor with water bag were collected for determining distribution,shapes,growth modes and the number of NSCs in the occipital of cortex with immunohisto- chemical method under light microscope.Results It was noted that NSCs existed in the occipital of cortex from human fetal brain at different ages.NSCs mainly distributed in layers of cone cells and inner granule cells.NSCs existed in the occipital of cortex of different fetal age included middling round cells,NSCs had enations from 0 to 1.Nucli were larger than plasm.Each NSC had nucleoli from 2-4 and rarefaction chromatin.Most of NSCs distributed in three growth modes including crowd,cluster and clone,occasionally with a single growth mode among other nerve cells.There were no differences including distribution,shapes,growth modes and the number of NSCs in the occipital of cortex between groups,but,NSCs gradually decreased with increasing of age.Conclusion NSCs exists in the occipital of cortex from different gestational age,and the number of NSCs decreases with increasing of age.