大兴安岭兴安落叶松森林不同林型AMF分布特性

为了初步了解内蒙古大兴安岭兴安落叶松森林生态系统丛枝菌根真菌(AMF)多样性状况, 调查了5种落叶松林型和火烧迹地土壤中AMF状况。从90份土样中共分离到AMF 4属53种, 其中无梗囊霉属Acaulospora 25种(47.17%), 球囊霉属Glomus 23种(43.40%), 此二属为优势属, 内养囊霉属Entrophospora 4种(7.55%), 巨孢囊霉属Gigaspora 1种(1.89%)。杜香落叶松林的优势种为浅窝无梗囊霉A. lacunosa; 草地落叶松林没有优势种, 最常见种为浅窝无梗囊霉A. lacunosa; 柴桦落叶松林的优势种为一种无梗囊霉Acaulospora sp. 3和缩球囊霉G. constrictum; 落叶松皆伐林的优势种为刺无梗囊霉A. spinosa; 落叶松渐伐林的优势种为一种球囊霉Glomus sp. 3; 火烧迹地的优势种为刺无梗囊霉A. spinosa。5种林型中以柴桦落叶松林的孢子密度(41.00个/50 g 风干土)、物种丰富度(12.66种/土样)、多样性指数(H = 2.12, D = 0.85)都为最高。孢子密度与有机质含量呈明显正相关(r = 0.956*), 物种丰富度与速效磷含量呈明显的负相关(r = -0.899*)。     

中国毛霉目的一个新纪录属—单囊霉属

单囊霉属(Haplosporangium)是被孢霉科(Mortierellaceae)内的一个小属,由Thaxter在1914年建立的。它的主要特征为孢囊梗从高度分化、通常分隔的菌丝上长出。本文首次在中国报道了两个种(极尖单囊霉Haplosporangium attenuatissima sp. nov.和单孢单囊霉H.decipens Thaxter),其中极尖单囊霉是新种,其特征为孢囊梗基部强烈膨大、顶端极细,孢子囊内含1-9个孢子。     

安徽茶区茶树丛枝菌根真菌多样性

调查了安徽茶区茶树丛枝菌根真菌(AMF)资源分布情况,为菌根生物技术在茶产业中的应用提供了具有应用价值的菌种资源.采用醋酸-墨水染色法观察茶树丛枝菌根(AM)的侵染率、侵染级数、侵染强度和菌根类型;采用湿筛法获得AMF孢子,进行形态学鉴定.结果表明: 在安徽茶区,AMF能够侵入茶树根系形成典型的共生体,侵染率在36%～95%,侵染级数均在3级以上,侵染强度大;从安徽茶树根际土中共鉴定出8属36种AMF,其中缩管柄囊霉是优势种,网状球囊霉、刺无梗囊霉、孔窝无梗囊霉、詹氏无梗囊霉、双网无梗囊霉和凹坑无梗囊霉是常见种,褐色管柄囊霉、疣突管柄囊霉、毛氏无梗囊霉、近明管柄囊霉、瑞氏无梗囊霉、空洞无梗囊霉、晕环球囊霉、细齿无梗囊霉、地管柄囊霉、幼套球囊霉、蜜色无梗囊霉、稀有内养囊霉是稀有种,其余17种为少见种;不同采样地茶树根际AMF群落相似性系数(0.14～0.55)较低,多属于低和中等水平;相关性分析表明,孢子密度与侵染率呈显著正相关,种的丰度与侵染率和总球囊霉素相关土壤蛋白呈显著正相关.安徽茶区茶树根系存在典型的AM结构,其根际AMF多样性丰富,为开发茶树专用AMF肥料提供了丰富的菌种资源.     

福建、浙江、江苏、上海疫霉种的研究

1985—1986年,从福建漳州,浙江杭州,上海,江苏南京,苏州,扬州,常州等地采集100多种植物进行分离,在雪松(Cedrus deodara),倒挂仙人鞭(Cereus flagelliformis),冬青卫茅(Euonymus japonieus),构树(Broussonetia papyrifera),蓖麻(Ricinus communis),柑桔(Citrus reticulata),带叶兜兰(Paphiopedilum hirsutissimum),芋(Colocasia esculenta),鳄梨(Persea americana),山茶(Camellia sp.),珊瑚樱(Solanum pseudo-capsicum),百合(Lilium brownii var.viridulum),蔓常春花(Vinca major),西瓜(Citrullus lanatus)等14种寄主植物上分离到51个疫霉菌株,鉴定为9个种:烟草疫霉(=寄生疫霉)Phytophthora nicotianae B.de Haan(=P.parasitica Dast.),掘氏疫霉P.drechsleri Tucker,樟疫霉 P.ciunamomi Rands,棕榈疫霉P.palmivora(Butl.)Butl.,柑桔褐腐疫霉P.citrophthora(R.et E.Smith) Leon.,苎麻疫霉P.bochmeriae Saw.,蜜色疫霉P.meadii McRae,簇囊疫霉P.botryosa Chee,隐地疫霉P.cryptogea Pethyb.et Laff.。其中,烟草疫霉,掘氏疫霉,樟疫霉出现频率较高,分布较广,初步认为是上述地区植物疫病的主要病原菌。簇囊疫霉、蜜色疫霉是国内新记录。     

红壤中VA菌根真菌(球囊霉目)的种类和生态分布

本文报道了发育于第四纪红色粘土母质上的红壤中的4属13种VA菌根真菌(球囊霉目):1.细齿无梗囊霉 Acaulospora denticulata Sieverding & Toro;2.丽孢无梗囊霉Acaulospora elegans Trappe & Gerdemann:3.光壁无梗囊霉Acaulospora laevis Gerdeman D & Trappe:4.巨大巨孢囊霉Gigaspora gigantea(Nicol.& Gerd.)Gerdemann & Trappe;5.珍珠巨孢囊霉Gigaspora margarita Becket & Hall;6.聚球囊霉Glomus aggregatum Schenck & Smith;7.明球囊霉Glomus clarum Nicolson & Schenck;8.集球囊霉Glomus fasiculatum(Thaxter)Gerdemann & Trappe;9.地球囊霉Glomus geosporum(Nicol.& Gerd.)Walker;10.木薯球囊霉Glomus manihot Howeler,Sieverding & Schenck;11.变形球囊霉Glomus versiforme(Karsten)Berch;12.美丽盾孢囊霉Scutellospora calospora(Nicol.& Gerd.)Walker & Sanders;13.异配盾孢囊霉Scutellospora heterogama(Nicol.& Gerd.)Walker & Sanders。其中细齿无梗囊霉(Acaulospora denticulata)、巨大巨孢囊霉(Gigaspora gigantea)、木薯球囊霉(Glomus manihot)和异配盾孢囊霉(Scutellospora heterogama)4种为国内新记录种。对这13种VA菌根真菌的形态进行了描述讨论,并对这些种群的出现频度、不同利用方式     

荒漠生境油蒿根围AM真菌多样性

为了阐明荒漠生境主要植被油蒿(Artemisia ordosica)根围AM真菌多样性, 2007年8月从毛乌素沙地和腾格里沙漠选取榆林、盐池、研究站和沙坡头4个样地, 按0–10、10–20、20–30、30–40、40–50 cm 5个土层采集油蒿根围土壤样品, 研究了油蒿根围AM真菌物种多样性和生态分布。在分离的4属28种AM真菌中, 球囊霉属(Glomus)16种, 无梗囊霉属(Acaulospora)7种, 盾巨孢囊霉属(Scutellospora)4种, 多孢囊霉属(Diversispora)1种。4个样地的共同优势种为摩西球囊霉(G. mosseae), 共同常见种为双网无梗囊霉(A. bireticulata)和网状球囊霉(G. reticulatum), 共同稀有种为缩球囊霉(G. constrictum)。地球囊霉(G. geosporum)仅出现在盐池, 蜜色无梗囊霉(A. mellea)、帚状球囊霉(G. coremioides)、浅窝无梗囊霉(A. lacunosa)和宽柄球囊霉(G. magnicaule)仅出现在研究站, 黑球囊霉(G. melanosporum)仅出现在榆林。盐池与研究站样地AM真菌种类最多, 榆林样地孢子密度最大, 沙坡头样地种类和孢子密度显著偏低。总体上, 孢子密度、分离频度、相对多度和重要值依Glomus >Acaulospora > Scutellospora> Diversispora呈现显著减小趋势。结果表明, 油蒿与AM真菌之间有良好共生性, 这对进一步利用菌根生物技术维护荒漠生态系统结构的完整性具有重要意义。     

接种AM真菌对喜树幼苗生长及光合特性的影响

 喜树(Camptotheca acuminata)是我国特有的多年生亚热带落叶阔叶树种, 因其次生代谢产物喜树碱具有良好的抗肿瘤活性而备受关注。通过温室盆栽接种试验, 观察了3属6种丛枝菌根(AM)真菌木薯球囊霉(Glomus manihot)、地表球囊霉(G. versiforme)、透光球囊霉(G. diaphanum)、蜜色无梗囊霉(Acaulospora mellea)、光壁无梗囊霉(A. laevis)和弯丝硬囊霉(Sclerocystis sinuosa)对喜树幼苗生长及光合特性的影响。结果表明, 除地表球囊霉外, 其余菌根幼苗生物量显著高于无菌根幼苗, 蜜色无梗囊霉、弯丝硬囊霉和透光球囊霉的菌根幼苗生物量分别达到无菌根幼苗的1.6倍、1.4倍和1.3倍。与无菌根幼苗相比, 蜜色无梗囊霉菌根幼苗叶片的净光合速率(P_n)、气孔导度(G_s)和蒸腾速率(T_r)均有显著提高, 而胞间CO₂浓度(C_i)与气孔限制值(L_s)则变化不明显。接种透光球囊霉、蜜色无梗囊霉、光壁无梗囊霉和弯丝硬囊霉的喜树幼苗叶片叶绿素a含量、总叶绿素含量、叶绿素a/b和类胡萝卜素含量均显著高于无菌根幼苗, 而叶绿素b含量只有木薯球囊霉和弯丝硬囊霉菌根幼苗显著高于无菌根幼苗。接种AM真菌对喜树幼苗叶片叶绿素荧光参数影响较小, 只有透光球囊霉菌根幼苗叶片的最大光能转换效率(F_v/F_m)显著高于无菌根幼苗, 接种木薯球囊霉和弯丝硬囊霉的喜树幼苗的PSⅡ有效光化学量子产量(EQY)显著高于无菌根幼苗, 弯丝硬囊霉菌根幼苗的光化学淬灭(qP)显著高于无菌根幼苗, 非光化学淬灭(NPQ)则显著低于无菌根幼苗。     

金沙江干热河谷(元谋段)丛枝菌根真菌多样性研究*

从金沙江干热河谷(元谋段)75种植物的根际土壤中分离鉴定了44种丛枝菌根真菌, 分属无梗囊霉属Acaulospora、古孢霉属Archaeospora、内养囊霉属Entrophospora、巨孢囊霉属Gigaspora、球囊霉属Glomus和盾巨孢囊霉属Scutellospora, 其中,球囊霉属和无梗囊霉属为金沙江干热河谷中丛枝菌根真菌的优势属。齿状无梗囊霉A. denticulata、刺状无梗囊霉A. spinosa、瘤状无梗囊A. tuberculata,近明球囊霉Glomus claroideum、明球囊霉G. clarum、根内球囊霉G. intraradices、单孢球囊霉G. monosporum、弯丝球囊霉G. sinuosa是金沙江干热河谷(元谋段)的优势种。金沙江干热河谷土壤中丛枝菌根真菌的孢子密度为5~6400个/100g土壤,平均1504;每个根际土壤中丛枝菌根真菌的物种丰富度1~18种,平均9种。     

金沙江干热河谷(元谋段)丛枝菌根真菌多样性研究

从金沙江干热河谷(元谋段)75种植物的根际土壤中分离鉴定了44种丛枝菌根真菌, 分属无梗囊霉属Acaulospora、古孢霉属Archaeospora、内养囊霉属Entrophospora、巨孢囊霉属Gigaspora、球囊霉属Glomus和盾巨孢囊霉属Scutellospora, 其中,球囊霉属和无梗囊霉属为金沙江干热河谷中丛枝菌根真菌的优势属。齿状无梗囊霉A. denticulata、刺状无梗囊霉A. spinosa、瘤状无梗囊A. tuberculata,近明球囊霉Glomus claroideum、明球囊霉G. clarum、根内球囊霉G. intraradices、单孢球囊霉G. monosporum、弯丝球囊霉G. sinuosa是金沙江干热河谷(元谋段)的优势种。金沙江干热河谷土壤中丛枝菌根真菌的孢子密度为5~6400个/100g土壤,平均1504;每个根际土壤中丛枝菌根真菌的物种丰富度1~18种,平均9种。     

Rare earth elements in soil and plant systems - A review

The rare earth elements (REEs) form a chemically uniform group and include yttrium (Y), lanthanum (La) and the lanthanides cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). Their average abundance in the Earth’s crust range from 66μg g⁻¹ in Ce to 0.5μg g⁻¹ in Tm and ?0.1μg g⁻¹ in Pm. Recent great improvements in more routine analytical technique, the use of REEs as fertilisers, at least in East Asian agriculture, and the importance of these elements as indicators in both pedological and physiological processes and reactions have contributed to an increased interest in these previously less considered elements in environmental sciences. This review of recent and current literature deals with REEs in primary and secondary soil minerals, concentrations in surface soils, factors influencing adsorption, solubility and transport in soils, including weathering and transformations of REE minerals, and vertical distribution in soil profiles. Reviewed and discussed are also concentrations, distribution and localisation of REEs in plants and plant organs, soil-plant relationships and interactions, effects on plant growth and crop production and their importance in plant physiology and biochemistry. The REEs are found, usually several elements together, as phosphates, carbonates and silicate minerals finely dispersed especially in magmatic and metamorphic rocks. REE concentrations in surface soils of humid climates, such as the A(E)-horizons of Podzols and Laterites, are usually lower than in the parent material, due to higher weathering and leaching rates than of the average soil constituents. Some fractionation may occur due to the formation of more element-specific secondary minerals. Transfer from soil to plant is usually low, but extreme accumulators are found, e.g., among several species of ferns. Roots have generally higher concentrations than shoots. Possible uptakemechanisms of REEs are discussed. Uptake is positively, though often weakly, correlated with soil acidity and easily soluble concentrations of the elements, but rarely well related to their total concentrations in the soil. Under certain conditions, low concentrations of at least some REEs seem to favour plant growth and productivity, but the physiological mechanisms are still not well understood. Some considerations concerning the boundary between essential and non-essential micro nutrients are discussed.     

Role of calcium in secretion of chorionic gonadotropin by first trimester human placenta.

The role of calcium in regulation of secretion of human chorionic gonadotropin (hCG) by first trimester human placental minces in vitro has been investigated. Depletion of calcium in the medium by addition of EGTA resulted in a drastic decrease in the levels of immunoreactive hCG in the medium with consequent of accumulation of hCG in the tissue. Addition of A 23187 which is a calcium ionophore resulted in a dose dose dependent increase in the hCG in the medium and this stimulatory response could not be observed in the absence of calcium. Use of lanthanum (a calcium antagonist) in place of calcium in the medium used resulted in a significant decrease in the levels of hCG in the medium. Addition of veratridine (a sodium channel activator) stimulated hCG secretion in a dose dependent manner. These results suggest that calcium is essential for normal secretion of hCG by human placenta.     

Protein phosphorylation in Bradyrhizobium japonicum bacteroids and cultures.

Protein phosphorylation was demonstrated in Bradyrhizobium japonicum bacteroids in vivo and in cultures in vivo and in vitro. Comparison of in vivo-labeled phosphoproteins of bacteroids and of cultured cells showed differences in both the pattern and intensity of labeling. In cultured cells, comparison of the labeling patterns and intensities of in vivo- and in vitro-labeled phosphoproteins showed a number of similarities; however, several phosphoproteins were found only after one of the two labeling conditions. The labeling intensity was time dependent in both in vivo and in vitro assays and was dependent on the presence of magnesium in in vitro assays. Differences in the rates of phosphorylation and dephosphorylation were noted for a number of proteins. The level of incorporation of 32P into protein was only 2% or less of the total phosphate accumulated during the in vivo labeling period. Several isolation and sample preparation procedures resulted in differences in labeling patterns. Phosphatase inhibitors and several potential metabolic effectors had negligible effects on the phosphorylation pattern. There were no significant changes in the phosphorylation patterns of cells cultured on mannitol, acetate, and succinate, although the intensity of the labeling did vary with the carbon source.     

Protein synthesis in skeletal muscle of the perfused rat hemicorpus compared with rates in the intact animal.

The rate of protein synthesis was measured in muscles of the perfused rat hemicorpus, and values were compared with rates obtained in whole animals. In gastrocnemius muscle of fed rats the rate of synthesis measured in the hemicorpus was the same as that in the whole animal. However, in plantaris, quadriceps and soleus muscles rates were higher in the hemicorpus than those in vivo. In the hemicorpus, starvation for 1 day decreased the rate of protein synthesis in gastrocnemius and plantaris muscles, in parallel with decreases in the RNA content, but the soleus remained unaffected. Similar effects of starvation were observed in vivo, so that the relationships between rates in vivo and in the hemicorpus were the same as those in fed rats. Proteins of quadriceps and plantaris muscles were separated into sarcoplasmic and myofibrillar fractions. The rate of synthesis in the sarcoplasmic fraction of the hemicorpus from fed rats was similar to that in vivo, but synthesis in the myofibrillar fraction was greater. In the plantaris of starved rats the rates of synthesis in both fractions were lower, but the relationships between rates measured in vivo and in the perfused hemicorpus were similar to those seen in fed rats. The addition of insulin to the perfusate of the hemicorpus prepared from 1-day-starved animals increased the rates of protein synthesis per unit of RNA in gastrocnemius and plantaris muscles to values above those seen in fed animals when measured in vivo or in the hemicorpus. Insulin had no effect on the soleus. Overall, the rates of protein synthesis in the hemicorpus differed from those in vivo. However, the effect of starvation when measured in the whole animal was very similar to that measured in the isolated rat hemicorpus when insulin was omitted from the perfusate.     

Chemoattractant-elicited increases in Dictyostelium myosin phosphorylation are due to changes in myosin localization and increases in kinase activity

We previously reported (Berlot, C. H., Spudich, J. A., and Devreotes, P. N. (1985) Cell 43, 307-314) that cAMP stimulation of chemotactically competent Dictyostelium amoebae causes transient increases in phosphorylation of the myosin heavy chain and 18,000-dalton light chain in vivo and in vitro. In this report we investigate the mechanisms involved in these changes in phosphorylation. In the case of heavy chain phosphorylation, the amount of substrate available for phosphorylation appears to be the major factor regulating the in vitro phosphorylation rate. Almost all heavy chain kinase activity is insoluble in Triton X-100, and the increase in the heavy chain phosphorylation rate in vitro parallels an increase in Triton insolubility of myosin. Changes in heavy chain phosphatase activity are not involved in the changes in the in vitro phosphorylation rate. In the case of light chain phosphorylation, increases in the vitro phosphorylation rate occur under conditions where the amount of substrate available for phosphorylation is constant and phosphatase activity is undetectable, implicating light chain kinase activation as the means of regulation. The specificity of the myosin kinases operating in vivo and in vitro was explored using phosphoamino acid and chymotryptic phosphopeptide analysis. The light chain is phosphorylated on serine both in vivo and in vitro, and phosphopeptide maps of the light chain phosphorylated in vivo and in vitro are indistinguishable. In the case of the heavy chain, both serine and threonine are phosphorylated in vivo and in vitro, although the cAMP-stimulated increases in phosphorylation occur primarily on threonine. Phosphopeptide maps of the heavy chain show that the peptides phosphorylated in vitro represent a major subset of those phosphorylated in vivo. The kinetics of the transient increases in myosin phosphorylation rates observed in vitro can be predicted quantitatively from the in vivo myosin phosphorylation data assuming that there is a constant phosphatase activity.     

Colony-forming units of the bone marrow and spleen of immunodeficient mice after stimulation of the cells with thymalin

It has been previously demonstrated by the authors that histological characteristics of colony-forming units (CFUs) in normal mice prove a certain shift in their differentiation in erythroid direction comparing to the bone marrow CFUs. Thymectomy of mature animals is accompanied with weakening growth of granular colonies at cloning of the bone marrow CFUs and with loss of stability in direction of splenic CFUs differentiation. Polypeptide preparation of the thymus--thymalin stimulates growth of the granulocytic colonies from the splenic CFUs in thymectomized mice both in in vivo and in vitro experiments. Differentiation of the bone marrow CFUs is normalized under the effect of thymalin in in vivo experiment only. The data obtained confirm the suggestion made by R. V. Petrov on existence of T-cell clone, enhancing CFUs differentiation in granulocytic direction. Activation of this clone in the spleen is revealed at thymectomy and stimulation of the cells with thymalin both in in vivo and in vitro experiments. Thus, affirmations are obtained on differences of clonic T-cell regulation of the CFUs differentiation in the bone marrow and in the spleen.     

Neuroactive steroids in the brain and age and sex specificity of behavior and anxiety: An experimental study

Changes in the brain’s neuroactive steroid levels, behavior in the open field, and the anxious-phobic status of male and female rats in the course of development have been studied. An increase in the motor and exploratory activity and emotionality in rats of both sexes in the pubertal period and a decrease in their values in mature and old animals have been detected. Anxiety has no sexual dimorphism in adult animals; it is significantly higher in males than in females in the prepubertal and pubertal periods of development and is higher in old females than in males of the same age. An increase in the level of corticosterone in some brain structures in maturing and old rats has been found; the testosterone concentration increases in one-month-old and adult animals but decreases in old individuals, while the estradiol concentration in all studied brain structures of male and female rats was low in all periods of postnatal life. Correlation analysis has shown modulation by steroid hormones of the changes in behavioral responses during development.     

The Retention of Cadmium and Selenium Influence in Fowl and Chickens of F1 Generation

The retention of cadmium and selenium influence on Cd retention in the muscle, liver and kidneys of hens, chickens and in eggs was studied. Cadmium (Cd) as cadmium chloride (CdCl(2)) and selenium (Se) as sodium selenite (Na(2)SeO(3)) were added to feed at dosages: group 0-control, group 1-20 mg/kg Cd, group 2-30 mg/kg Cd + 4 mg/kg Se. The birds were exposed to Cd for 8 weeks. Cadmium level in hens and cocks was found highest in the kidneys, followed by the liver and muscle. Se supplementation resulted in Cd increase in the muscle tissue and in the reduction of Cd content in the liver and in significant decrease in the kidneys (p < 0.05). A higher Cd level in the yolk and lower in the white was noted in both experimental groups. Nonsignificant increase of Cd in eggs was noted in experimental groups with Se supplementation. Level of cadmium in organs of 7-day-old chicks hatched from Cd-treated hens in both experimental groups was low but the tendency to accumulate preferentially the Cd in the liver and kidneys was recorded. Supplementation of selenium in hens and cocks was not reflected in the decrease of Cd in these two organs of F(1) chickens but was reflected in increase in the muscle. In spite of relatively high Cd levels in the organs of layers no layer-egg-chickens transfer was observed. It was confirm that kidneys and liver are organs more attacked by dietary cadmium than muscle. Supplementation of low dose of Se resulted in decrease of cadmium deposition in analyzed organs.     

Hereditary and environmental dental findings in identification of human remains

The paper presents the results on hereditary and environmental dental findings in identification of human remains exhumed from mass graves in the Republic of Croatia. The total of 17,880 teeth from all the categories (incisors, canines, premolars and molars) was examined. Hereditary findings of the teeth such as shape, size, position, as well as age were used in all of the cases confirming and completing the identification. In only 15% of the cases they were the starting points for the identification that would be later confirmed with another 3-5 traditional identification procedures. Disturbances in tooth eruption were recorded in 22% of the cases, impaction of teeth in 10%, and retarded eruption of teeth in 12%. Disturbances of tooth position were recorded in 65% of the cases. Tooth rotation in 26% and diastema mediana in maxilla or mandible in 39%. Disorders of tooth number in the form of unilateral and bilateral missing of lateral maxillary incisors were recorded only in 2% of the monitored cases. Abnormalities of the tooth shape were found in 11% of the cases. The majority of them were found on the tooth crowns 6%, and less on the tooth roots 5%. Environmental dental findings that were the most significant for the identifications were prosthetic appliances in 30% of cases. Prostheses were helpful in the identification of 3% of the cases, while crowns and bridges were helpful in 27% of the cases. Ante mortem teeth extractions were helpful in 25% of the cases. Teeth restorations were recorded in 20% of the identified cases, amalgams in 19% and aesthetic filings in 1%. Dental caries was helpful in only 10% of the cases, superficial caries in 3% and caries of dentin in 7% of cases.     

Natural incidence of interruptions in the internal elastic lamina of caudal and renal arteries of the rat

Interruptions in the internal elastic lamina (IEL) have been quantified by light microscopy in the caudal arteries of different strains of rats and in caudal and renal arteries of (i) male and female virgin rats up until 2 years of age, (ii) repeatedly bred rats and (ii) hypertensive rats. Results showed that gaps in the IEL exist in caudal arteries of adult males in all strains studied, but to a lesser extent in the hairless mutant. In the virgin Wistar rat these interruptions in the IEL form with age in both caudal and renal arteries, and are more numerous (i) in the male than in the female in both arteries, and (ii) in the caudal than in the renal artery in both sexes. Repeated breeding in the Wistar rat abolishes the sex difference in incidence of IEL gaps in both renal and caudal arteries. The Sprague-Dawley breeder rat is more susceptible than the Wistar breeder to their formation in the renal artery. Hypertension in the male consistently increases the formation of IEL gaps in the renal but not in the caudal artery. The importance of local factors, e.g. hemodynamics, in the formation of these defects in the IEL, and their possible relationship with the development of arteriosclerosis is discussed.     

Apoptosis and related proteins in placenta of intrauterine fetal death in prostaglandin f receptor-deficient mice

The present study investigated whether the increase of apoptosis in the placenta is associated with intrauterine fetal death in prostaglandin F receptor-deficient mice. Apoptosis was demonstrated within placental and decidual tissue by the TUNEL method. The majority of apoptosis was found in syncytiotrophoblast tissues. Enhanced TUNEL-positive staining in the syncytiotrophoblast layer was scattered in the placental tissues in clusters of apoptotic cells in the death group. Marked TUNEL-positive cells were identified in decidua of both groups. The rate of apoptosis in the placenta and decidua in the death group was higher than that in the survival group (P < 0.05). Immunohistochemical analysis showed that the level of active caspase-3 protein expression in the placenta in the death group was much higher than that in the survival group. The level of Bcl-2 protein expression in the placenta in the death group was much lower than that in the survival group. Western blot analysis demonstrated that increased expression of the active form of caspase-3 was detected in the placenta and decidua in the death group compared with that in the survival group. In contrast, a decrease in the expression of Bcl-2 was detected in the placenta and decidua in the death group compared with that in the survival group. Enhanced expression of Bax:Bcl-2 ratio was detected in placenta and decidua in the death group compared with that in the survival group. Thus, significantly increased apoptosis in the mouse placenta and decidua might be involved in the pathophysiologic mechanism of intrauterine fetal death.