New hosts for equine herpesvirus 9

Equine herpesvirus 9 was detected in a polar bear with progressive encephalitis; the source was traced to 2 members of a potential equid reservoir species, Grevy's zebras. The virus was also found in an aborted Persian onager. Thus, the natural host range is extended to 6 species in 3 mammalian orders.     

后极性白内障超声乳化手术临床观察

目的探讨后极性白内障超声乳化手术的特点,探讨如何避免和减少手术中后囊膜破裂等并发症。方法回顾性病例研究。分析13例（23眼）后极性白内障超声乳化手术的手术操作、超声乳化仪的参数设置、后囊膜破裂的发生情况、并发症的处理及手术效果。结果23眼中,后囊膜破裂7眼,其中,后极部混浊斑和后囊膜分离时后囊膜破裂4例,前房波动时后囊膜破裂2眼,后囊膜抛光时后囊膜破裂1眼。行前部玻璃体切割3眼,皮质沉入玻璃体腔的1眼行后段玻璃体切割。结论后囊膜破裂可以发生在后极性白内障超声乳化手术的任何阶段,吸除后极部混浊斑时最易发生后囊膜破裂,手术中保持前房稳定和减少对后囊膜的牵拉,最后处理后极部混浊斑,可以避免和减少后囊膜破裂的发生。     

Immunostimulatory and antigen delivery properties of liposomes made up of total polar lipids from non-pathogenic bacteria leads to efficient induction of both innate and adaptive immune responses

Novel liposomes prepared from total polar lipids of non-pathogenic bacteria, viz. Leptospira biflexa serovar Potac (designated leptosomes) and Mycobacterium smegmatis (designated smegmosomes) were evaluated for their adjuvant effects with various antigen presenting cells (APCs), viz. murine macrophage cell line, J774A.1 and bone marrow derived dendritic cells (BMDCs). These liposomes induced strong membrane fusion as evident from resonance energy transfer (RET) assays and effectively transferred the fluorescent probe to the membrane of these APCs. Moreover, both vesicles caused significant activation of APCs as revealed by release of proinflammatory cytokines (IL-6, IL-12, TNF-α) and enhanced expression of co-stimulatory signals and maturation markers (CD80, CD86, MHCII), which was significantly higher for smegmosomes as compared to leptosomes. Additionally, activation of APCs by liposomes correlated with their ability to stimulate allospecific T cell proliferation and IFN-γ release. In contrast, conventional PC/chol liposomes failed to fuse and induced only a very low level of APC activation. Interestingly, the stimulatory activity of these lipid vesicles was restricted to APCs as they did not cause any significant activation or mitogenic effect on lymphocytes (B and T cells) in vitro. Overall, the activation of APCs by both leptosomes and smegmosomes correlated with activation of strong humoral and cell mediated immune responses in C57/BL6 mice to entrapped ovalbumin (OVA) and was significantly higher than those induced by conventional liposomes and alum, which failed to activate cytotoxic T lymphocytes (CTLs). Taken together these results demonstrate the adjuvant potential of these novel lipid vesicles that may simultaneously induce both innate and adaptive immune responses due to their immune stimulatory and antigen delivery properties.     

电场定位中极板参数对电场影响的Maxwell 2D仿真

背景：在心内三维电场的定位技术中,均匀性和方向性是定位电场的两个重要性能。影响到电场的均匀性和方向性的因素较多,有电极因素、介质因素。分析各种因素对电场性能的影响对提高定位精度有重要意义。 目的：分析电极的大小和距离对电场性能的影响。 方法：在单一介质中,逐渐改变电极的大小和距离参数,测量不同电极参数下电场的均匀性偏差和方向偏差,通过比较,得出了电场的均匀性和方向性随电极参数的变化规律。 结果与结论：结果表明,随着电极变大,距离变大,电场的均匀性和方向性都变好。当电极增大到可以覆盖测量区域时,电场的均匀性为0.017,可以满足定位精度要求。     

Comparative genomic hybridization analysis of human oocytes and polar bodies

BACKGROUND: Classical cytogenetic methods and fluorescent in situ hybridization (FISH) have been employed for the analysis of chromosomal abnormalities in human oocytes. However, these methods are limited by the need to spread the sample on a microscope slide, a process that risks artefactual chromosome loss. Comparative genomic hybridization (CGH) is a DNA-based method that enables the investigation of the entire chromosome complement. We optimized and evaluated a CGH protocol for the chromosomal analysis of first polar bodies (PBs) and oocytes. The protocol was then employed to obtain a detailed picture of meiosis I errors in human oogenesis. METHODS: 107 MII oocyte-PB complexes were examined using whole genome amplification (WGA) and CGH. RESULTS: Data was obtained for 100 complexes, donated from 46 patients of average age 32.5 (range 18-42). 22 complexes from 15 patients were abnormal, giving an aneuploidy rate of 22%. CONCLUSIONS: The results presented in this study more than double the quantity of CGH data from female gametes currently available. Abnormalities caused by whole chromosome non-disjunction, unbalanced chromatid predivision and chromosome breakage were reliably identified using the CGH protocol. Analysis of the data revealed a preferential participation of chromosome X and the smaller autosomes in aneuploidy and provided further evidence for the existence of age-independent factors in female aneuploidy.     

The changing phenotype in diploid/triploid mosaicism may mimic genetic syndromes with aberrant genomic imprinting: follow up in a 14-year-old girl

Diploid/triploid mosaicism is a rare chromosome aberration characterized by growth and mental retardation, muscular hypotonia, clinodactyly, syndactyly of fingers and toes, asymmetry of the body and the face, truncal obesity, and pigmentary anomalies of the skin. Many patients initially present with severe growth retardation and develop truncal obesity later in life. Variable phenotype expression during development and restriction of triploid cells to certain tissues explain why the diagnosis of diploid/triploid mosaicism is often delayed. Here, we report on a moderately retarded 14-year-old girl with diploid/triploid mosaicism due to inclusion of the second polar body, whose changing phenotype overlaps considerably with different genetic disorders associated with aberrant genomic imprinting. The observation that triploid cells, which in our patient show remarkably variable distribution in different tissues, may also be present in easily accessible tissues such as urinary sediment or buccal smear may contribute to an earlier diagnosis of this rare syndrome.     

Visualization of second polar body chromosomes in fertilized and artificially activated mouse oocytes treated with okadaic acid

Objective Our objective was to develop a new reliable method for cytogenetic analysis of the chromosome set in second polar bodies (PBs) from one-cell-stage mouse embryos.Setting The study took place at the Reproductive Biology and Experimental Cytogenetics Laboratories.Methods Oocytes from F₁ hybrid and T6/T6 mice were fertilized in vitro and artificially activated with ethanol. Zygotes, parthenogenetic embryos, and isolated second PBs were treated with 10 µM okadaic acid (OA) for 1–2 hr, further cultured in plain medium, and fixed. Chromosomal preparations were made and C-banded, and the number of chromosomes in second PBs and embryos was counted.Results OA-induced nuclear envelope breakdown in pronuclei as well as in second PB nuclei. Countable chromosome plates were obtained in 92–93% of second PBs treated 4–4.5 hr after activation. The T6 marker chromosome could easily be recognized in second PBs from T6/T6 mice. A haploid set of chromosomes was obtained in 18 of 19 isolated second PBs treated with OA 4–5 hr after activation.Conclusion Treatment of second PBs with OA allows visualization of the PB chromosomes. Cytogenetic analysis of the second PB and the corresponding oocyte constitutes a new approach for the study of meiotic nondisjunction in experimental cytogenetics. The chromosomal study of isolated second PBs seems to be promising for clinical preimplantation cytogenetics.     

BIDIRECTIONAL SYNTHESIS OF [5-ASPARTIC ACID] ARGININE VASOPRESSIN ON POLY-N-ACRYLYLPYRROLIDINE RESIN

In the proposed biologically active conformation of vasopressin at its antidiuretic receptor, the side-chain carboxamide moiety of the 5-position asparaginyl residue has been suggested to be an active element for the initiation of the antidiuretic response. [5-Aspartic acid] arginine vasopressin, the analog in which the -NH₂ portion of the primary amide has been replaced by an -OH group, has been synthesized and tested for some of the pharmacological activities of vasopressin. The partially protected nonapeptide intermediate was assembled bidirectionally on a poly-N-acrylylpyrrolidine resin. The 6-position cysteinyl residue was attached to the resin via its side-chain through an S-carbamoyl linkage. First the COOH-terminus was extended by coupling with Pro-Arg(Tos)-Gly-NH₂, then the NH₂-terminus was extended in a stepwise manner. [5-Aspartic acid] arginine vasopressin was found to possess 86.5 ± 4.8 units/mg of antidiuretic potency, 17% of the parent hormone. In addition, the analog possesses rat pressor and rat uterotonic potencies of 6.93 ± 0.15 and 0.38 ± 0.03 units/mg, respectively. This result suggests that a carboxylic acid moiety on the 5-position aspartyl residue retains sufficient steric features and hydrophilicity in common with the carboxamide moiety present in the hormone to substitute for it as an active element at the antidiuretic receptor.