巢式PCR法在早期梅毒诊断中的应用评价

目的：评价巢式PCR（nPCR）法在早期梅毒诊断中的临床应用价值,以提高早期梅毒诊断的灵敏度和特异性。方法：选择2010年10月至2011年11月来我院就诊,经临床综合分析为一期梅毒的患者195例和同期就诊的120例非梅毒患者为研究对象,采用nPCR法对棉拭子标本和血液标本中梅毒螺旋体特异性基因tpp47进行扩增检测,所有标本同时做暗视野镜检和Tp—ELISA血清学检测。结果：nPCR法共检测出阳性标本176例,其灵敏度和特异性分别为90．3％和100％,明显高于暗视野镜检和Tp-ELISA法,差异有统计学意义。结论：nPCR法在早期梅毒诊断中具有较高灵敏度和特异性,可以作为暗视野镜检和血清学检测的补充试验。     

Anatomical Studies on Hypocotyl of Circaeaster

The stem of Circaeaster agrestis Maxim. is very short but the length of hypocotyl is comparatively long, almost occupying the whole length of the plant. This tender hypocotyl is mainly supported by the thickening of cuticle on the outer wall of the epidermal cell and the primary xylem in the center. Between primary xylem and primary phloem there are 2–3 layers of parenchymatous cells, regularly or irregularly arranged, but no cambial zone can be recognized. The transition region where root and stem meet showed no evidence of twisting, splitting or inversion of the strands in the primary vascular tissues which are common in most of the dicots. The extending cotyledon traces differentiate directly from the parenchymatous cells which locate on the outside of the poles of primary xylem. The first and the second leaf traces are organized in the middle of the primary phloem.     

The primary enamel knot determines the position of the first buccal cusp in developing mice molars

The enamel knot (EK), which is located in the center of bud and cap stage tooth germs, is a transitory cluster of non-dividing epithelial cells. The EK acts as a signaling center that provides positional information for tooth morphogenesis and regulates the growth of tooth cusps by inducing secondary EKs. The morphological, cellular, and molecular events leading to the relationship between the primary and secondary EKs have not been described clearly. This study investigated the relationship between the primary and secondary EKs in the maxillary and mandibular first molars of mice. The location of the primary EK and secondary EKs was investigated by chasing Fgf4 expression patterns in tooth germ at some intervals of in vitro culture, and the relationship between the primary EK and secondary EK was examined by tracing the primary EK cells in the E13.5 tooth germs which were frontally half sliced to expose the primary EK. After 48 hr, the primary EK cells in the sliced tooth germs were located on the buccal secondary EKs, which correspond to the future paracone in maxilla and protoconid in mandible. The Bmp4 expression in buccal part of the dental mesenchyme might be related with the lower growth in buccal epithelium than in lingual epithelium, and the Msx2 expressing area in epithelium was overlapped with the enamel cord (or septum) and cell dense area. The enamel cord might connect the primary EK with enamel navel to fix the location of the primary EK in the buccal side during the cap to bell stages. Overall, these results suggest that primary EK cells strictly contribute to form the paracone or protoconid, which are the main cusps of the tooth in the maxilla or mandible.     

HDAC2 promotes loss of primary cilia in pancreatic ductal adenocarcinoma

Loss of primary cilia is frequently observed in tumor cells, including pancreatic ductal adenocarcinoma (PDAC) cells, suggesting that the absence of this organelle may promote tumorigenesis through aberrant signal transduction and the inability to exit the cell cycle. However, the molecular mechanisms that explain how PDAC cells lose primary cilia are still ambiguous. In this study, we found that inhibition or silencing of histone deacetylase 2 (HDAC2) restores primary cilia formation in PDAC cells. Inactivation of HDAC2 results in decreased Aurora A expression, which promotes disassembly of primary cilia. We further showed that HDAC2 controls ciliogenesis independently of Kras, which facilitates Aurora A expression. These studies suggest that HDAC2 is a novel regulator of primary cilium formation in PDAC cells.     

白鲜根的发育解剖学研究

应用半薄切片、常规石蜡切片并结合离析法,对药用植物白鲜(Dictamnus dasycarpus Turcz.)根的发生发育过程进行了研究。结果表明:白鲜根的发生发育过程包括4个阶段,即原分生组织阶段、初生分生组织阶段、初生结构阶段以及次生结构阶段。原分生组织位于根冠内侧及初生分生组织之间,衍生细胞分化为初生分生组织。初生分生组织由原表皮、基本分生组织以及中柱原组成。原表皮分化为表皮,基本分生组织分化为皮层,中柱原分化为维管柱,共同组成根的初生结构;在初生结构中,部分表皮细胞外壁向外延伸形成根毛,皮层中分布有油细胞,内皮层有凯氏带,初生木质部为二原型或偶见三原型,外始式;根初生结构有髓或无。次生结构来源于原形成层起源的维管形成层的活动以及中柱鞘起源的木栓形成层的活动;白鲜次生韧皮部宽广,其中多年生根中可占根横切面积的85%,另外除基本组成分子外,还分布有油细胞;周皮发达,木栓层厚;初生皮层、次生木质部和次生韧皮部薄壁细胞中常充满丰富的淀粉粒。     

Decreased survival of experimental critical flaps in rats after sensory denervation with capsaicin

The role of capsaicin-sensitive primary sensory neurons on the survival of experimental critical flaps was studied in the rat. Pretreatment with capsaicin, which depletes neuropeptide transmitter content from primary sensory neurons, caused a dramatic decrease in flap survival area compared to normal animals. In contrast, pretreatment with reserpine, which depletes catecholamines from adrenergic neurons, including the sympathetic post-ganglionic fibers, resulted in a significant increase in the survival area. It was concluded that both capsaicin-sensitive primary sensory neurons and sympathetic postganglionic adrenergic neurons play a role in systemic vascular regulation and that intact primary sensory neurons are of importance for the survival of ischemic tissue.     

Regulation of Photosynthetic Activity in the Primary Leaves of Bean (Phaseolus vulgaris L.) by Materials Moving in the Water-conducting System

Endogenous factors which determine the photosynthetic capacity of the leaf were studied in the fully expanded, primary leaves of young seedings of bean (cv. Bulgarian). Following removal of the shoot above the primary leaf node and excision of all axillary buds, the primary leaves increased in area and thickness, in chlorophyll content, in levels of soluble protein, and in the specific activity of ribulose-1,5-bisphosphate carboxylase. Plants in which phloem continuity was disrupted by heat-girdling of the stem, between the shoot above the primary leaf node and the organs below, did not exhibit similar increases, whereas the shoot above the girdle continued to grow for several days. Plants in which all developing trifoliate leaves were excised as soon as they became macroscopic exhibited an increase in their photosynthetic activity, area, and thickness, while their main stem and (leafless) branches made considerable growth. Transpiration from the primary leaves was the same in decapitated plants as in the heat-girdled ones, although in the latter it accounted for only about 30% of total transpiration.     

原发性肠系膜肿瘤的诊断与治疗

目的:探讨原发性肠系膜肿瘤的诊断及治疗方法。方法:对各种类型的原发性肠系膜肿瘤的临床表现、术前检查及诊断、治疗等进行对比分析。结果:原发性肠系膜肿瘤临床表现多样、复杂,缺乏特异性诊断依据,但在B超引导下细针穿刺等有助于其诊断。实性肿瘤多为恶性,手术切除率低。囊性肿瘤多为良性,手术切除率高。结论:手术是治疗本病的唯一有效手段。     

Large-scale phylogenomic analyses indicate a deep origin of primary plastids within cyanobacteria

The emergence of photosynthetic eukaryotes has played a crucial role in evolution and has strongly modified earth's ecology. Several phylogenetic analyses have established that primary plastids arose from a cyanobacterium through endosymbiosis. However, the question of which present-day cyanobacterial lineage is most closely related to primary plastids has been unclear. Here, we have performed an extensive phylogenomic investigation on the origin of primary plastids based on the analysis of up to 191 protein markers and over 30,000 aligned amino acid sites from 22 primary photosynthetic eukaryotes and 61 cyanobacteria representing a wide taxonomic sampling of this phylum. By using a number of solutions to circumvent a large range of systematic errors, we have reconstructed a robust global phylogeny of cyanobacteria and studied the placement of primary plastids within it. Our results strongly support an early emergence of primary plastids within cyanobacteria, prior to the diversification of most present-day cyanobacterial lineages for which genomic data are available.     

Sonic Hedgehog Promotes Neurite Outgrowth of Primary Cortical Neurons Through Up-Regulating BDNF Expression

Sonic hedgehog (Shh), a secreted glycoprotein factor, can activate the Shh pathway, which has been implicated in neuronal polarization involving neurite outgrowth. However, little evidence is available about the effect of Shh on neurite outgrowth in primary cortical neurons and its potential mechanism. Here, we revealed that Shh increased neurite outgrowth in primary cortical neurons, while the Shh pathway inhibitor (cyclopamine, CPM) partially suppressed Shh-induced neurite outgrowth. Similar results were found for the expressions of Shh and Patched genes in Shh-induced primary cortical neurons. Moreover, Shh increased the levels of brain-derived neurotrophic factor (BDNF) not only in lysates and in culture medium but also in the longest neurites of primary cortical neurons, which was partially blocked by CPM. In addition, blocking of BDNF action suppressed Shh-mediated neurite elongation in primary cortical neurons. In conclusion, these findings suggest that Shh promotes neurite outgrowth in primary cortical neurons at least partially through modulating BDNF expression.     

Mechanisms responsible for long-term survival of adult rat hepatocytes in the presence of phenobarbital in primary culture

The mechanisms, by which phenobarbital (PB) supports the survival of adult rat hepatocytes in primary culture, were investigated. PB altered the shape of rat erythrocytes to produce cup-formed cells and protected them from hypotonic hemolysis. Anesthetics (ketamine, lidocaine, mepivacaine, and bupivacaine) and an anti-inflammatory agent (indomethacin), which are also known to protect erythrocytes from hypotonic hemolysis by stabilizing their membranes, efficiently supported the survival of hepatocytes in primary culture. Furthermore, the well-known biological membrane stabilizers, such as cholesterol and vitamin E, also showed the maintenance effect on primary cultured hepatocytes. PB effectively reduced the leakage of lactate dehydrogenase from hepatocytes caused by chenodeoxycholic acid in primary culture. Rotenone and amobarbital, which act repressively on the PB-sensitive site in the respiratory chain and are known to inhibit the mitochondrial formation of active oxygen species with NAD-linked substances, effectively prolonged the hepatocyte survival in primary culture. Elevation of oxygen tension in primary culture remarkably decreased the hepatocyte survival rate, which was preserved by addition of antioxidant substances, such as vitamin C, vitamin E, bifemelane, selenite, and superoxide dismutase. On the other hand, in the presence of PB, the hepatocyte survival rate hardly changed with the elevation of oxygen tension. From these findings, it seems that PB stabilizes the hepatocyte membranes and reduces the mitochondrial formation of active oxygen species and that the stabilized functions of membrane and the reduction of oxidative stress result in the prolonged survival of hepatocytes in primary culture.     

Correlation between Possession of a Respiration-Dependent Na Pump and Na Requirement for Growth of Marine Bacteria

The possession of a respiration-dependent primary sodium pump and the requirement of Na for growth were investigated in bacterial isolates from marine environments. The bacteria in which NADH oxidase specifically required Na for maximum activity were believed to possess a primary sodium pump. All bacteria that failed to grow without the addition of NaCl possessed a primary Na pump. All bacteria that had no primary Na pump grew without additional NaCl. The primary Na pump seems to be involved in the Na requirement of marine bacteria, and this can be regarded as a criterion for the definition of marine bacteria.     

Secondary infections of Hymenolepis diminuta in mice: effects of varying worm burdens in primary and secondary infections.

In one (1 c) and six (6 c) cysticercoid primary infections of Hymenolepis diminuta in NIH (inbred) and CFLP (outbred) male mice 6 +/- 1 weeks old greater than 85% of the worms established but were rejected (destrobilated or expelled) subsequently. Rejection occurs more quickly in 6 c infections than in 1 c infections. Considerable worm growth occurs in 1 c and 6 c primary infections but worms from 6 c infections weighed less than worms from 1 c infections on all days studied. Expulsion of H. diminuta does not occur more rapidly in secondary infections than in primary infections; loss of 6 c secondary worms occurs at the same rate as 6 c primary worms but 1 c secondary worms survive longer than 1 c primary worms. Although worms are not lost more quickly in secondary than in primary infections, they are affected at an early age by the immune response which stunts their growth. Increasing the intensity of primary and secondary infections increases the severity of stunting of secondary worms. The results are discussed and it is suggested that immune responses to Hymenolepis spp. in rodents are common but that thresholds of worm numbers exist below which appreciable worm loss does not occur. Stunting due to crowding, which generally is attributed to inter-worm competition, may be in part immunologically mediated. For future immunological studies attempting to induce secondary responses to H. diminuta in mice, worm growth, not survival, is the criterion to evaluate.     

The effects of decapitation on the distribution of cytokinins and growth of Phaseolus vulgaris plants

The growth of the primary leaves of Phaseolus vulgaris L. was enhanced greatly by decapitation of the rest of the shoot. This increased growth was manifested by an increase in leaf area, leaf weight, and in a higher synthesis of chlorophyll and soluble proteins. Within the roots and stems decapitation resulted in a detectable increase in the endogenous cytokinins within 2 days after the surgical treatment. In the primary leaves increased cytokinin levels were only detected after 16 days. At this time most of the recorded activity co-chromatographed with the cytokinin glucosides. When plants which were decapitated were left under normal growing conditions for 16 days and then transferred to continuous darkness for 8 days the senescence of the primary leaves of the decapitated plants, in which the cytokinins had increased, was delayed significantly when compared with that of the primary leaves of the intact plants. the significance of these findings is discussed.     

A theory of gene-culture coevolution of parental preference and sex ratio in humans

A theory on the evolution of human primary sex ratio is proposed. Effects of parental preference for sons, reflected in birth control based on offspring sex ratio and female biased infanticide, on the evolution of primary sex ratio are analyzed. Both are shown to select for female bias in primary sex ratio. The gene-culture coevolution of female infanticide and primary sex ratio is also studied and it is shown that female infanticide develops more in societies in which the father plays a more important role in the transmission of culture than the mother does.     

The fine structure of the kidney of Achatina achatina (L.)

Summary The kidney sac of Achatina achatina, the site of primary urine formation, seems to contain no direct structural analogue of the vertebrate glomerular podocytes. The nephrocytes which line the kidney sac and separate the blood from the primary urine are supported by a basal lamina which is permeable to ferritin but impermeable to colloidal gold particles (ca. 100 Å, and 80–240 Å respectively). The blood capillaries within the kidney sac are of two types, fenestrated and unfenestrated. The basal lamina which surrounds them is impermeable to haemocyanin. The nephrocytes are then, bathed apically by primary urine and basally by an ultrafiltrate of the blood. It is proposed that fluid enters the urinary space from the connective tissue by passing between the nephrocytes, perhaps through pores in the septate junctions. Other possible mechanisms of primary urine formation are discussed. The nephrocytes contain peroxisomes which may be involved in urate metabolism.The cells of the ureteral epithelium bear a lumenal microvillous border. Their lateral and basal plasma membranes are elaborately folded. These cytoplasmic folds enclose extracellular channels through which fluid is transported from the urine back into the blood.     

Effects of insects on primary production in temperate herbaceous communities: a meta-analysis

Abstract.  1. The effects of insects on primary production in temperate herbaceous communities were investigated in a meta-analysis. The following hypotheses were tested: (1) the effect of insects on primary production depends on community type, (2) the effect of insects on primary production varies as a function of productivity, (3) insects have a greater effect on primary production in communities with low species diversity, and (4) insects have a larger effect on primary production during outbreaks.
2. Data were collected from 24 studies in which insecticides were used to suppress insects in self-sown or pastoral communities. Effect sizes were calculated from sprayed and control plot standing crop or yield, expressed as the log response ratio, ln (sprayed plot phytomass/control plot phytomass).
3. There was a significant increase in primary production as a result of insect suppression. Forb-dominated communities showed a more variable response than graminoid communities. During outbreaks, insects had a greater negative impact on primary production. Effect size was unaffected by productivity or plant species richness.
4. Although insects lower primary production in a diversity of temperate herbaceous communities, the basic measures by which such communities are often described have little effect on the proportional impact that insects have on primary production. While outbreaks are significant predictors of higher negative impact on primary production, causes of outbreaks are not always related to traits of the plant community.     

Vascularization of the pituitary of the Australian lungfish and Neoceratodus forsteri

The vascularization of the brain and the pituitary region of the Australian lungfish, Neoceratodus forsteri is described from serial section reconstruction. The distal lobe has no direct arterial blood supply and receives blood solely from a pituitary portal system basically similar to that of other sarcopterygians. The primary capillary plexus of the median eminence receives its arterial blood from the infundibular arteries, which on their way distribute some small branches to the prechiasmatic region. The primary plexus also receives capillaries from the adjacent pial hypothalamic plexus. The primary capillary plexus of the median eminence comprises a rostral 'uncovered' and caudal 'covered' part which are not sharply delineated. Distinct portal vessels connect the 'uncovered' rostral part of the primary plexus with the secondary capillary plexus supplying the rostral subdivision of the pars distalis. The 'covered' caudal part of the primary plexus merges into the proximal subdivision of the pars distalis, apparently without formation of distinct portal vessels. The primary plexus has some connections with the plexus intermedius via a hypophysial stem capillary plexus. The plexus intermedius has a substantial arterial supply and gives off capillaries to the parenchyma of the pars intermedia. The adenohypophysis is drained into an unpaired hypophysial vein. The significance of the vascular pathways is discussed from comparative, functional, and evolutionary viewpoints.     

On the evolutionary stability of Mendelian segregation

We present a model of a primary locus subject to viability selection and an unlinked locus that causes sex-specific modification of the segregation ratio at the primary locus. If there is a balanced polymorphism at the primary locus, a population undergoing Mendelian segregation can be invaded by modifier alleles that cause sex-specific biases in the segregation ratio. Even though this effect is particularly strong if reciprocal heterozygotes at the primary locus have distinct viabilities, as might occur with genomic imprinting, it also applies if reciprocal heterozygotes have equal viabilities. The expected outcome of the evolution of sex-specific segregation distorters is all-and-none segregation schemes in which one allele at the primary locus undergoes complete drive in spermatogenesis and the other allele undergoes complete drive in oogenesis. All-and-none segregation results in a population in which all individuals are maximally fit heterozygotes. Unlinked modifiers that alter the segregation ratio are unable to invade such a population. These results raise questions about the reasons for the ubiquity of Mendelian segregation.