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941.
Angiopoietin-like proteins (Angptls) are known to possess biological activities not only in the vascular system, but in the other mammalian tissues; however, their expression patterns and function in embryogenesis have not been extensively characterized. Here, we identify three zebrafish genes (Zangptl1, Zangptl2 and Zangptl6) highly homologous to mammalian Angptl1/ARP1, Angptl2/ARP2 and Angptl6/AGF, and describe their adult and embryonic temporal and spatial expression patterns. Zangptl1 is expressed faintly in the somites, while Zangptl2 is first detected in the yolk sac extension, spinal cord and branchial arches and is later expressed in the liver primordium and pectoral fin buds. Zangptl6 is expressed in the notochord. In addition to its embryonic expression, Zangptl2 is induced in adult fish during fin regeneration.  相似文献   
942.

Background

Epignathus is a rare congenital orofacial teratoma infrequently associated with intracranial extension. Intracranial extension of an epignathus indicates a poor prognosis; however, only a small number of such cases have been reported. While there have been some studies reporting cases of epignathus expanding directly into the cranium, others have reported no communication between an epignathus and an intracranial tumor.

Case presentation

A fetus at gestational week 27 was suspected of having an epignathus with intracranial tumor as shown by ultrasonographic and magnetic resonance imaging. The fetus was stillborn and an autopsy was performed. An epignathus measuring 12?×?6?×?6?cm and weighing 270?g protruded from the mouth, with its base on the soft palate. An intracranial tumor weighing 14?g was located at the middle intracranial fossa and connected to the epignathus through the right side of the sella turcica. The intracranial tumor was encapsulated, and there was no invasion into the brain. Histologically, both the epignathus and intracranial tumor were immature teratomas, with neural and pulmonary components that were especially immature as compared to those of the internal organs and brain tissues of the fetus.

Conclusion

There have been several reports of epignathus and intracranial tumors that did not communicate; therefore, careful evaluation is needed when a fetus is suspected of having an epignathus extending into an intracranial lesion. Our case supports the findings that an epignathus can directly expand into the cranium. Moreover, this is a rare case of an epignathus in which the intracranial lesion was encapsulated and did not invade the brain. These rare but important findings will provide additional, potential therapeutic strategies for gynecologists, neurosurgeons, and pathologists.
  相似文献   
943.
Total syntheses of prenylated pyrrolidinoindoline alkaloids, (?)-mollenines A [(?)-1′] and B (2′), were accomplished via three- and four-step sequences including a bioinspired indole prenylation reaction followed by dioxomorpholine ring formation. Then, the stereochemistry of mollenines A and B was reassigned to 3S,6S,14S,16S by analysis of spectroscopic data and chemical syntheses with different approaches along with the comparison of calculated and experimental ECD spectra. In addition, a thermodynamically controlled epimerization reaction on the dioxomorpholine ring was observed in our synthesis.  相似文献   
944.
The effect of adrenalectomy (ADX) or saline ingestion, which is a hypertensive factor, on the expression of calcium-binding protein regucalcin mRNA in the kidney cortex of rats was investigated. The change of regucalcin mRNA levels was analyzed by Northern blotting using rat liver regucalcin complementary DNA (0.9 kb of open-reading frame). Regucalcin mRNA was expressed in the kidney cortex but not the medulla. Rats were adrenalectomized, and 48 h later they were sacrificed. ADX caused a reduction of regucalcin mRNA levels in the kidney cortex, suggesting that adrenal glands participate in the regulation of the mRNA expression. This reduction was not restored by the subcutaneous administration of dexamethasone with an effective dose (1 mg/kg body weight), which can stimulate kidney regucalcin mRNA expression. Regucalcin mRNA levels in the kidney cortex of rats were markedly suppressed by the ingestion of saline for 7 days. The ADX-induced decrease of renal cortex regucalcin mRNA levels was not appreciably restored by saline ingestion. Moreover, regucalcin mRNA levels in the kidney cortex of spontaneous hypertensive rats (SHR) were clearly decreased as compared with that of control (Wistar-Kyoto) rats. Meanwhile, calcium content in the kidney cortex was not significantly decreased by ADX or saline ingestion. The present study suggests that the expression of regucalcin mRNA in the kidney cortex of rats is suppressed by saline administration.  相似文献   
945.
We have found that a hexadeoxyribonucleotide (5′TGGGAG3′, R-95288), Koizumi, M. et al. Bioorganic & Medicinal Chemistry, 1997, 5, 2235, bearing a 3,4-dibenzyloxybenzyl (3,4-DBB) group at the 5′-end and a 2-hydroxyethylphosphate at the 3′-end, has high anti-HIV-1 activity and the least cytotoxicity in vitro and in vivo. In order to synthesize more potent hexadeoxyribonucleotides, we substituted phosphodiester (P---O) bonds in the 6-mer with the least phosphorothioate (P---S), phosphoramidate (P---N), or methylphosphonate (P---Me) bonds. When more than two P---N or P---Me bonds were introduced into a 6-mer, the phosphate-modified 6-mers had weak or no anti-HIV-1 activity, in spite of quadruplex structure formation. However, when P---S bonds were substituted for P---O bonds, anti-HIV-1 activity of their 6-mers did not dramatically decrease, compared with compounds substituted with P---N or P---Me bonds. The results suggest that the formation of a quadruplex structure is not always sufficient for anti-HIV-1 activity of the 6-mer, and that net negative charges derived from P---O or P---S bonds in the quadruplex are important for anti-HIV-1 activity. Moreover, among various phosphate-modified ODNs, we found that the anti-HIV-1 activity of ODN PS7 with only one P---S bond was the same as that of R-95288, both having a high stability in human plasma.  相似文献   
946.
为克服水稻半矮生基因sd-1减小粒重的副作用,培育了半矮生粳稻型大粒品种。本研究用具有大粒基因lk-f的高秆品种房吉和具有半矮生基因sd-1系统SC-TN1的杂种进行了鉴定分析。结果表明,选育的半矮生系统的千位重均较SC-TN1有所提高,并出现了千粒重30克以上的系统。亲子代的相关分析表明,粒长间有高度的正相关。充分说明,sd-1的半矮生性和大粒性的结合是可能的。因此指出,通过选择适当的大粒种质资源与sd-1基因组合,使半矮生性的抗倒伏和大粒的丰产性一体化,可以培育成丰产性更高的粳稻品种。  相似文献   
947.
Apx toxins produced by Actinobacillus pleuropneumoniae are essential components of new generation vaccines. In this study, apxIIA and apxIIIA genes of serovars 2, 3, 4, 6, 8 and 15 were cloned and sequenced. Amino acid sequences of ApxIIA proteins of serovars 2, 3, 4, 6, 8 and 15 were almost identical to those of serovars 1, 5, 7, 9 and 11–13. Immunoblot analysis showed that rApxIIA from serovars 2 and 15 reacts strongly with sera from animals infected with various serovars. Sequence analysis revealed that ApxIIIA proteins has two variants, one in strains of serovar 2 and the other in strains of serovars 3, 4, 6, 8 and 15. A mouse cross‐protection study showed that mice actively immunized with rApxIIIA/2 or rApxIIIA/15 are protected against challenge with A. pleuropneumoniae strains of serovars 3, 4, 6, 8, 15, and 2 expressing ApxIII/15 and ApxIII/2, respectively. Similarly, mice passively immunized with rabbit anti‐rApxIIIA/2 or anti‐rApxIIIA/15 sera were found to be protected against challenge with strains of serovars 2 and 15. Our study revealed antigenic and sequence similarities within ApxIIA and ApxIIIA proteins, which may help in the development of effective vaccines against disease caused by A. pleuropneumoniae.  相似文献   
948.
Feline leukemia virus (FeLV) subgroups have emerged in infected cats via the mutation or recombination of the env gene of subgroup A FeLV (FeLV-A), the primary virus. We report the isolation and characterization of a novel env gene, TG35-2, and report that the TG35-2 pseudotype can be categorized as a novel FeLV subgroup. The TG35-2 envelope protein displays strong sequence identity to FeLV-A Env, suggesting that selection pressure in cats causes novel FeLV subgroups to emerge.  相似文献   
949.
Plants defend against attack from herbivores by direct and indirect defence mechanisms mediated by the accumulation of phytoalexins and release of volatile signals, respectively. While the defensive arsenals of some plants, such as tobacco and Arabidopsis are well known, most of rice's (Oryza sativa) defence metabolites and their effectiveness against herbivores remain uncharacterized. Here, we used a non‐biassed metabolomics approach to identify many novel herbivory‐regulated metabolic signatures in rice. Most were up‐regulated by herbivore attack while only a few were suppressed. Two of the most prominent up‐regulated signatures were characterized as phenolamides (PAs), p‐coumaroylputrescine and feruloylputrescine. PAs accumulated in response to attack by both chewing insects, i.e. feeding of the lawn armyworm (Spodoptera mauritia) and the rice skipper (Parnara guttata) larvae, and the attack of the sucking insect, the brown planthopper (Nilaparvata lugens, BPH). In bioassays, BPH insects feeding on 15% sugar solution containing p‐coumaroylputrescine or feruloylputrescine, at concentrations similar to those elicited by heavy BPH attack in rice, had a higher mortality compared to those feeding on sugar diet alone. Our results highlight PAs as a rapidly expanding new group of plant defence metabolites that are elicited by herbivore attack, and deter herbivores in rice and other plants.  相似文献   
950.
Under CO2-limited conditions such as during stomatal closure, photorespiration is suggested to act as a sink for excess light energy and protect photosystem I (PSI) by oxidizing its reaction center chlorophyll P700. In this study, this issue was directly examined with rice (Oryza sativa L.) plants via genetic manipulation of the amount of Rubisco, which can be a limiting factor for photorespiration. At low [CO2] of 5 Pa that mimicked stomatal closure condition, the activity of photorespiration in transgenic plants with decreased Rubisco content (RBCS-antisense plants) markedly decreased, whereas the activity in transgenic plants with overproduction of Rubisco (RBCS-sense plants) was similar to that in wild-type plants. Oxidation of P700 was enhanced at [CO2] of 5 Pa in wild-type and RBCS-sense plants. PSI was not damaged by excess light stress induced by repetitive saturated pulse-light (rSP) in the presence of strong steady-state light. On the other hand, P700 was strongly reduced in RBCS-antisense plants at [CO2] of 5 Pa. PSI was also damaged by rSP illumination. These results indicate that oxidation of P700 and the robustness of PSI against excess light stress are hampered by the decreased activity of photorespiration as a result of genetic manipulation of Rubisco content. It is also suggested that overproduction of Rubisco does not enhance photorespiration as well as CO2 assimilation probably due to partial deactivation of Rubisco.  相似文献   
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