Phylogeny of Wolbachia in filarial nematodes

Intracellular bacteria have been observed in various species of filarial nematodes (family Onchocercidae). The intracellular bacterium of the canine filaria Dirofilaria immitis has been shown to be closely related to Wolbachia, a rickettsia-like micro-organism that is widespread among arthropods. However, the relationships between endosymbionts of different filariae, and between these and the arthropod wolbachiae, appear not to have been studied. To address these issues we have examined ten species of filarial nematodes for the presence of Wolbachia. For nine species, all samples examined were PCR positive using primers specific for the ftsZ gene of Wolbachia. For one species, the examined samples were PCR negative. Sequences of the amplified ftsZ gene fragments of filarial wolbachiae fall into two clusters (C and D), which are distinct from the A and B clusters recognized for arthropod wolbachiae. These four lineages (A-D) are related in a star-like phylogeny, with higher nucleotide divergence observed between C and D wolbachiae than that observed between A and B wolbachiae. In addition, within each of the two lineages of filarial wolbachiae, the phylogeny of the symbionts is consistent with the host phylogeny. Thus, there is no evidence for recent Wolbachia transmission between arthropods and nematodes. Endosymbiont 16S ribosomal DNA sequences from a subset of filarial species support these findings.     

Phylogeny of Epidermophyton floccosum and other dermatophytes

Eleven strains of Epidermophyton floccosum were compared with 5 Microsporum and 5 Trichophyton species with respect to the restriction fragment length polymorphism (RFLP) of the mitochondrial DNA to reveal their phylogenetic relationships. The phylogeny of 11 species showed that the three dermatophyte genera could not be separated from each other and could be considered to be congeneric. This result is not inconsistent with the results from ribosomal RNA sequences.     

Clinical applications of primed in situ labelling (PRINS) rapid identification of a marker chromosome in a fetus

This article describes the adaptation of a pattern search algorithm, for the computational optimization of model molecular structures, to run on a parallel computer. The parallel efficiency (speedup) of the algorithm is discussed, and the rate of convergence of the parallel procedure is compared to that of the sequential implementation. More generally, the article also illustrates how inherently nonparallelizable stochastic procedures may be successfully parallelized by rearrangement of the algorithm.     

Primed in situ labeling (PRINS): a method for rapid identification and quantification of human chromosomes in both lymphocytes and sperm nuclei

In this work, a specific primer for X alphoid satellite DNA was used to detect chromosome X through primed in situ labeling (PRINS). The method allows the rapid identification of chromosome X in metaphase and its quantification in interphase. PRINS is equally applicable to both lymphocytes and sperm nuclei.     

Phylogeny of the cholecystokinin/gastrin family

The neuroendocrine peptides cholecystokinin (CCK) and gastrin, originally identified in mammals, are characterized by a common amidated C-terminal tetrapeptide sequence, Trp-Met-Asp-Phe.NH2, which also constitutes the minimal structure necessary for biological activity of both. Hence, it has been proposed that CCK and gastrin have evolved from a common ancestor. Although the occurrence of CCK/gastrin-related peptides has been suggested in representatives of several invertebrate phyla, the evidence, mostly based on immunoreactivity, has not been substantiated by peptide identification. Instead, CCK/gastrin-specific antibodies might be cross-reacting with Asp-Phe-amides, like the lymnaDFamides, isolated from the freshwater snail Lymnaea stagnalis. Cionin, isolated from Ciona intestinalis, a representative of the protochordates that occupy a key position at the transition to vertebrates, so far represents the oldest genuine member of the CCK/gastrin family, dating the emergence of these peptides back to at least 500 million years ago. The CCK/gastrin family appears to be represented in the whole chordate phylum, and in addition to mammals, CCK and gastrin have recently been identified in a number of nonmammalian species representing the major vertebrate classes, including fishes, amphibians, reptiles, and birds. This now makes it possible to consider the CCK/gastrin phylogeny based on structural information. A duplication of the ancestral gene appears to have already occurred before or during the appearance of cartilaginous fish, giving rise to two peptides most likely homologous to mammalian CCK and gastrin. Indicative of a function of gastrin, the acid secretory system appears to have developed concomitantly in sharks. The segregation of CCK and gastrin early in vertebrate evolution resembles the situation in other peptide families, in accordance with a suggested widespread pattern of multiplication within vertebrate peptide and protein families around 400 million years ago. At the amphibian level, two separate peptide systems, resembling mammalian CCK and gastrin, have been characterized by identification of the mature bioactive peptides, cDNAs, gene structures, primary and secondary sites of gene expression, and their physiological actions. The overall gene structure, including exon/intron organization, is similar in all mammalian and nonmammalian CCK/gastrin genes. CCK is well conserved in all vertebrate species investigated, while the mammalian gastrins at first sight appear as a distinct group with little similarity to the nonmammalian gastrins outside the invariant C-terminal tetrapeptide and the C-terminal flanking peptide of the prohormone. However, evidence indicates that the transition from nonmammalian to mammalian gastrin may not be as dramatic as first anticipated. In conclusion, the CCK/gastrin family appears to be represented in most, if not all, chordates, to which group it may also be limited. The two major classes, CCK and gastrin, probably arose as distinct peptide systems early in vertebrate history. While CCK is well conserved in all vertebrates, a major structural change of gastrin accompanied the transition to mammals.     

Comparative genomic hybridisation of ductal carcinoma in situ of the breast: identification of regions of DNA amplification and deletion in common with invasive breast carcinoma

Comparative genomic hybridisation has been used to map copy number changes in nine cases of ductal carcinoma in situ of the breast obtained from wax-embedded archive material. A wide variety of abnormalities were detected including gain of regions of 1q, 17q, 19q, 20p and 20q and loss on 13q, 14q, 17p, 16q and 22q. Amplification of areas on 10p, 8q and 20q were also observed. Chromosomal alterations were more frequent in higher grade DCIS and closely resemble those previously detected in invasive breast cancer using the same technique. These data provide strong molecular support for the view that DCIS is a precursor lesion of invasive breast carcinoma.     

Endometrial hyperplasia and carcinoma in situ

Endometrial hyperplasias--both simple and adenomatous are presented, as well as the differences between them and the endometrial carcinoma. The concept of endometrial carcinoma in situ (ESIS) and the criteria for invasiveness by the malignancies of the uterine corpus are discussed. Illustrations for various cases with ESIS are provided and the clinical behaviour by ESIS is discussed.     

Phylogeny and PCR-based classification of Wolbachia strains using wsp gene sequences

Wolbachia are a group of intracellular inherited bacteria that infect a wide range of arthropods. They are associated with a number of different reproductive phenotypes in their hosts, such as cytoplasmic incompatibility, parthenogenesis and feminization. While it is known that the bacterial strains responsible for these different host phenotypes form a single clade within the alpha-Proteobacteria, until now it has not been possible to resolve the evolutionary relationships between different Wolbachia strains. To address this issue we have cloned and sequenced a gene encoding a surface protein of Wolbachia (wsp) from a representative sample of 28 Wolbachia strains. The sequences from this gene were highly variable and could be used to resolve the phylogenetic relationships of different Wolbachia strains. Based on the sequence of the wsp gene from different Wolbachia isolates we propose that the Wolbachia pipientis clade be initially divided into 12 groups. As more sequence information becomes available we expect the number of such groups to increase. In addition, we present a method of Wolbachia classification based on the use of group-specific wsp polymerase chain reaction (PGR) primers which will allow Wolbachia isolates to be typed without the need to clone and sequence individual Wolbachia genes. This system should facilitate future studies investigating the distribution and biology of Wolbachia strains from large samples of different host species.     

皖北黄牛MHC基因遗传多样性及分子系统关系

[目的]研究皖北黄牛品种的遗传多样性、亲缘关系及起源进化.[方法]采集50个皖北黄牛和14个地方黄牛品种的血样,根据黄牛MHC基因序列设计1对引物,进行PCR扩增.对50个皖北黄牛个体和14个地方黄牛品种个体的MHC基因进行序列比对分析,检测MHC单倍型及核苷酸多态性指标,并构建分子系统发育树.[结果]共检测到7种MHC基因单倍型,核苷酸多态位点24个,占分析位点的7.86%,包括18个转换,1个颠换,5个转换/颠换.皖北黄牛品种单倍型间的序列差异在0.26%～4.53%之间,单倍型多样度(H)为0.602～0.617,核苷酸多样度(π)为0.012～0.019.[结论]皖北黄牛的遗传多样性不丰富,与鲁西黄牛具有较近的亲缘关系,二者聚为姐妹群.     

Phylogeny of Devonian Lycopsids Inferred from Bayesian Phylogenetic Analyses

To investigate the phylogeny of early lycopsids, cladistic analyses using both parsimony and Bayesian approaches are presented, with a data matrix of 33 morphological characters across 25 taxa.The resulting parsimony and Bayesian trees showed overall similarities in tree topologies. In the Bayesian tree, the Protolepidodendrales and the heterosporous lycopsids are recognized as two monophyletic groups, and within the latter group, the Isoetales sensu lato forms a subclade. This topology implies that the acquisition of a ligulate character evolved twice in the lycopsids, once in the protolepidodendralean Leclercqia Banks et al., and once in the heterosporous lycopsid clade.Phylogenetic positions of several lycopsid plants previously reported from the Mid-Upper Devonian of South China, which have uncertain ordinal affinities, were estimated by the cladistic analyses; cf.Longostachys Xue et Hao, Longostachys Zhu et al., Monilistrobus Wang et Berry, and Yuguangia Hao et al. fall well within the Isoetales clade, as earliest members of this order, while Minostrobus Wang and Wuxia Berry et al. are nested within the basal part of the heterosporous lycopsids. Bayesian analyses are a very useful approach in systematic studies and can be applied in analyzing paleobotanical data sets as well.     

Ductal carcinoma in situ

The incidence of ductal carcinoma in situ (DCIS) has increased significantly in the last 2 decades, due to the diagnosis of asymptomatic cancers by screening mammography. These cancers are usually diagnosed by the presence of calcification on mammography. Histologic classification of these tumors is controversial, and established and proposed classification systems are reviewed. The role of breast conservation in the treatment of many of these lesions is generally accepted, although areas of debate regarding its application in these patients persists.     

Modified phacoemulsification in situ

We describe a phacoemulsification technique for cataracts in eyes with anticipated weak zonular apparatus. After central sculpting, a crater 90% deep is made. A horizontal fracture is created with the phaco probe and chopper. The nucleus is chopped, dividing the inferior hemisection into 2 pie-shaped pieces, which are then emulsified. Without rotating the nucleus, a groove is made at the superior hemisection and a vertical fracture created with the chopper. The bevel of the phaco probe is then turned down to emulsify each quadrant separately. This technique is especially useful in eyes with weakened zonular apparatus such as those with hypermature cataract, uveitis, long-standing glaucoma, trauma, retinitis pigmentosa, and operated retinal detachments.     

采矿方法研究与现场实验

本文从采矿方法研究及与此相关的现场实验内容、实验目的、初步步骤作简略介绍，并附有实例，其目的是促使比较复要开采技术条件的岩金矿山采矿方法研究达到更高的技术水平。     

Astrocytic neurotransmitter receptors in situ and in vivo

In the brain, astrocytes are associated intimately with neurons and surround synapses. Due to their close proximity to synaptic clefts, astrocytes are in a prime location for receiving synaptic information from released neurotransmitters. Cultured astrocytes express a wide range of neurotransmitter receptors, but do astrocytes in vivo also express neurotransmitter receptors and, if so, are the receptors activated by synaptically released neurotransmitters? In recent years, considerable efforts has gone into addressing these issues. The experimental results of this effort have been compiled and are presented in this review. Although there are many different receptors which have not been identified on astrocytes in situ, it is clear that astrocytes in situ express a number of different receptors. There is evidence of glutamatergic, GABAergic, adrenergic, purinergic, serotonergic, muscarinic, and peptidergic receptors on protoplasmic, fibrous, or specialized (Bergmann glia, pituicytes, Müller glia) astrocytes in situ and in vivo. These receptors are functionally coupled to changes in membrane potential or to intracellular signaling pathways such as activation of phospholipase C or adenylate cyclase. The expression of neurotransmitter receptors by astrocytes in situ exhibits regional and intraregional heterogeneity and changes during development and in response to injury. There is also evidence that receptors on astrocytes in situ can be activated by neurotransmitter(s) released from synaptic terminals. Given the evidence of extra-synaptic signaling and the expression of neurotransmitter receptors by astrocytes in situ, direct communication between neurons and astrocytes via neurotransmitters could be a widespread form of communication in the brain which may affect many different aspects of brain function, such as glutamate uptake and the modulation of extracellular space.     

Carcinoma in situ and seminoma in equine testis

The presence of atypical germ cells resembling carcinoma in situ of human testis is reported for the first time in an unilaterally cryptorchid stallion. These cells were found in association with developing intratubular seminoma indicating they represented carcinoma in situ.