Vitamin D3 administration increases the membrane fluidity of intestinal mitochondria

The fluorescence anisotropy in the mitochondria from vitamin D-treated chicks is significantly lower than that from the vitamin D-deficient animals with the inner core probe DPH. Surface membrane fluidity, measured with the probe TMA-DPH, shows no differences between the organelles of both groups. The fluorescence studies performed in mitochondrial subfractions revealed that cholecalciferol treatment induces a decrease of lipid order parameter S (DPH) in the mitochondrial inner membrane. These results pose the question of whether vitamin D3 participates in the regulation of physiological function of the intestinal mitochondria through changes in the physical properties of the membranes.     

Phospholipid and fatty acid changes produced by cholecalciferol on intestinal mitochondrial membranes

Cholecalciferol administration to vitamin D-deficient chicks produces, 24 h after treatment, a specific increase of the phosphatidylcholine content in the intestinal mitochondrial inner membrane plus matrix fraction without changes in its proportion in the outer membrane. The ratio of unsaturated/saturated fatty acids in the outer membrane phosphatidylcholine was increased by that treatment. The inner membrane plus matrix presents a decrease of 16:1 in phosphatidylethanolamine and 18:0 in the phosphatidylcholine fraction. Cardiolipin shows the largest change in the ratio of unsaturated/saturated fatty acids predominantly by an increase in the linoleic acid. The present data suggest that phosphatidylcholine and fatty acids modifications in both mitochondrial subfractions caused by vitamin D3 might have some role in the intestinal mitochondrial Ca transport.     

The early life history of two sympatric New Zealand octopuses: eggs and paralarvae of Octopus huttoni and Pinnoctopus cordiformis

This study combined morphological and morphometric information on egg clutches, egg capsules and paralarvae of two sympatric coastal octopuses from New Zealand waters, Octopus huttoni and Pinnoctopus cordiformis, to provide species-specific traits to identify their early life stages obtained from field surveys. Eggs of O. huttoni (2.5 mm length; 1 mm width) were entwined with one another forming strings that ranged from 11 to 25.8 mm in length. Eggs of P. cordiformis (6.4 mm length; 1.5 mm width) were significantly bigger than those of O. huttoni and were grouped in small clusters of about seven eggs. Paralarvae O. huttoni and P. cordiformis differed in hatching size (1.4 mm versus 3.1 mm mantle length), number of suckers per arm (four versus eight), number of lamellae per outer demibranch (five versus ten) and arrangements of chromatophores in the body surface (29 to 59 versus 91 to 179), respectively. The morphological traits described in hatchlings from the laboratory allowed comparisons with field-collected paralarvae, suggesting that such characters were reliable species-specific patterns to enable a consistent differentiation between the early life stages of these two sympatric species, even in the absence of the brooding female.     

蒙古高原岩黄芪属植物的分支分类学研究

以蒙古高原岩黄芪属植物为对象, 应用徐克学的最大同步法, 探讨了蒙古高原岩黄芪属(豆科)植物的系统演化, 并根据分支分类结果对蒙古高原岩黄芪属进行了系统学处理。作者首次将蒙古高原岩黄芪属分为岩黄芪亚属、半灌木岩黄芪亚属(新拟)和无刺岩黄芪组、丛枝岩黄芪组、无茎岩黄芪组、半灌木岩黄芪组等4 个组。本文对蒙古高原岩黄芪组的划分符合苏联植物志(1945)中的观点。     

非酒精性脂肪肝大鼠PPARα基因表达及脂代谢和胰岛素水平的变化

目的观察非酒精性脂肪肝（NAFLD）大鼠肝组织中PPARα基因的表达,并用PPARct激动剂进行干预,探讨其与胰岛素抵抗、脂代谢紊乱的关系。方法大鼠随机分为①正常对照组、②高脂模型组、③PPARα激动剂干预组,利用高脂饮食建立大鼠非酒精性脂肪肝模型。12周后,检测大鼠血脂、肝功能、血糖、胰岛素水平及胰岛素抵抗指数;RT-PCR法分析PPARα基因的表达;观察肝脏的形态学改变。结果PPARa激动剂可降低NAFLD大鼠转氨酶、血脂水平及胰岛素抵抗指数,可促进NAFLD大鼠中PPARa基因的表达;肝脏形态学明显改善。结论PPARα激动剂能改善NAFLD大鼠脂质代谢紊乱,有明显的保肝降酶作用,具有适度的胰岛素增敏作用。PPARα及其配体在NAFLD发病机制及治疗中的进一步深入研究,将为临床防治NAFLD提供新的思路。     

Reproductive condition of Akodon montensis Thomas and Bolomys lasiurus (Lund) (Rodentia, Muridae) based on histological and histometric analyses of testes and external characteristics of gonads

The reproductive activity of two species of wild rodents was studied in the Serra do Rola‐Moça State Park (PERM), in the state of Minas Gerais, Brazil. From October 1998 to October 1999 specimens of Akodon montensis (Thomas 1913) were captured in an area of seasonal semi‐deciduous forest, while specimens of Bolomys lasiurus (Lund 1840) were captured in a cerrado area (a savannah‐like grassland). The determination of the reproductive condition was based on histological and histometric analyses of testes and external characteristics of gonads. The volume of the testes, diameter of the seminiferous tubules and depth of the seminiferous epithelium were measured. Akodon montensis showed a seasonal annual reproductive cycle divided into four stages (recrudescence, activity or proliferation, regression and rest) with the reproductive activity mainly occurring during the rainy season. In contrast, B. lasiurus presented reproductive activity during almost the whole year. For both species the volume of the testes was an effective indicator of their reproductive condition. We suggest that the histological and histometric analysis of the gonads of males, together with the observations of external characteristics of gonads of males and females, may assist in identifying the reproductive condition of these animals.     

Production of endothelial progenitor cells obtained from human Wharton's jelly using different culture conditions

Endothelial progenitor cells (EPC) participate in revascularization and angiogenesis. EPC can be cultured in vitro from mononuclear cells of peripheral blood, umbilical cord blood or bone marrow; they also can be transdifferentiated from mesenchymal stem cells (MSC). We isolated EPCs from Wharton's jelly (WJ) using two methods. The first method was by obtaining MSC from WJ and characterizing them by flow cytometry and their adipogenic and osteogenic differentiation, then applying endothelial growth differentiating media. The second method was by direct culture of cells derived from WJ into endothelial differentiating media. EPCs were characterized by morphology, Dil-LDL uptake/UEA-1 immunostaining and testing the expression of endothelial markers by flow cytometry and RT-PCR. We found that MSC derived from WJ differentiated into endothelial-like cells using simple culture conditions with endothelium induction agents in the medium.     

实验动物皮肤病原真菌检测方法的改良

目的对实验动物皮肤病原真菌2种培养方法进行了比较。方法将采集到的3只皮肤真菌感染病兔样品经由沙氏平皿法和沙氏试管斜面培养法分别进行培养。结果在3只真菌感染病兔中应用试管斜面法我们只检测到1例皮肤病原真菌阳性,而采用沙氏平皿法3例阳性全部检出。结论结合临床检测经验,我们认为本研究的沙氏平皿法优于沙氏试管斜面法,在实验动物皮肤病原真菌常规检测中具有推广应用价值。     

Basolateral plasma membrane localization of ouabain-sensitive sodium transport sites in the secretory epithelium of the avian salt gland

The distribution of Na+ pump sites (Na+-K+-ATPase) in the secretory epithelium of the avian salt gland was demonstrated by freeze-dry autoradiographic analysis of [(3)H] ouabain binding sites. Kinetic studies indicated that near saturation of tissue binding sites occurred when slices of salt glands from salt-stressed ducks were exposed to 2.2 μM ouabain (containing 5 μCi/ml [(3)H]ouabain) for 90 min. Washing with label-free Ringer's solution for 90 min extracted only 10% of the inhibitor, an amount which corresponded to ouabain present in the tissue spaces labeled by [(14)C]insulin. Increasing the KCl concentration of the incubation medium reduced the rate of ouabain binding but not the maximal amount bound. In contrast to the low level of ouabain binding to salt glands of ducks maintained on a freshwater regimen, exposure to a salt water diet led to a more than threefold increase in binding within 9-11 days. This increase paralleled the similar increment in Na+-K+-ATPase activity described previously. [(3)H]ouabain binding sites were localized autoradiographically to the folded basolateral plasma membrane of the principal secretory cells. The luminal surfaces of these cells were unlabeled. Mitotically active peripheral cells were also unlabeled. The cell-specific pattern of [(3)H]ouabain binding to principal secretory cells and the membrane-specific localization of binding sites to the nonluminal surfaces of these cells were identical to the distribution of Na+-K+-ATPase as reflected by the cytochemical localization of ouabain-sensitive and K+-dependent nitrophenyl phosphatase activity. The relationship between the nonluminal localization of Na+-K+-ATPase and the possible role of the enzyme n NaCl secretion is considered in the light of physiological data on electrolyte transport in salt glands and other secretory epithelia.