颧根与侧颅底重要结构的解剖学测量

目的：通过测量颧根与侧颅底各重要结构间的距离关系,为临床侧颅底外科手术治疗提供定位参考。方法：取成人颅骨标本50例（去颅盖标本8例,整颅42例）100侧,用游标卡尺、圆规和直尺测量颧根与侧颅底重要结构的距离。结果：实验测得左右侧颧根与外耳门前缘中点、乳突尖、茎突、翼突外侧板根部、舌下神经管外口、茎乳孔、颈静脉孔外缘、颈动脉管外口后缘、棘孔、卵圆孔、破裂孔的距离分别为22.30±2.84mm和22.02±3.27mm、40.37±3.21mm和40.56±3.54mm、32.53±2.78mm和32.92±2.68mm、35.13±3.14mm和35.19±2.74mm、49.29±2.88mm和48.98±2.87mm、32.92±2.44mm和33.05±2.61mm、35.15±2.86mm和34.68±3.13mm、33.17±2.78mm和33.17±2.72mm、28.83±2.62mm和28.68±2.63mm、31.15±2.76mm和31.49±2.73mm、43.67±3.32mm和44.15±3.02mm,左右侧数据无差异（P〉0.05）。结论：颧根可以作为侧颅底外科手术的定位标志,为直视条件下经颞下等入路的侧颅底外科手术提供解剖学依据。     

Translation initiator EIF4G1 mutations in familial Parkinson disease

Genome-wide analysis of a multi-incident family with autosomal-dominant parkinsonism has implicated a locus on chromosomal region 3q26-q28. Linkage and disease segregation is explained by a missense mutation c.3614G>A (p.Arg1205His) in eukaryotic translation initiation factor 4-gamma (EIF4G1). Subsequent sequence and genotype analysis identified EIF4G1 c.1505C>T (p.Ala502Val), c.2056G>T (p.Gly686Cys), c.3490A>C (p.Ser1164Arg), c.3589C>T (p.Arg1197Trp) and c.3614G>A (p.Arg1205His) substitutions in affected subjects with familial parkinsonism and idiopathic Lewy body disease but not in control subjects. Despite different countries of origin, persons with EIF4G1 c.1505C>T (p.Ala502Val) or c.3614G>A (p.Arg1205His) mutations appear to share haplotypes consistent with ancestral founders. eIF4G1 p.Ala502Val and p.Arg1205His disrupt eIF4E or eIF3e binding, although the wild-type protein does not, and render mutant cells more vulnerable to reactive oxidative species. EIF4G1 mutations implicate mRNA translation initiation in familial parkinsonism and highlight a convergent pathway for monogenic, toxin and perhaps virally-induced Parkinson disease.     

Characterization of recombinant amyloidogenic chicken cystatin mutant I66Q expressed in yeast

Amyloidogenic chicken cystatin mutant I66Q (cC I66Q) was successfully secreted by yeasts Pichia pastoris and Saccharomyces cerevisiae. The soluble monomer and dimer forms of amyloidogenic cC I66Q were found in the culture medium, while large amounts of insoluble aggregate and polymeric form cC I66Q besides the monomer and dimer forms were secreted into the culture medium. The amyloidogenic cC I66Q showed a comparable circular dichroism spectrum to that of the wild cystatin, and the monomer form exhibited a similar level of inhibitory activity toward papain, but the dimmer form did not. During storage of amyloidogenic cC I66Q under physiological and acidic conditions, typical binding with Congo red and thioflavin T, and the formation of amyloid fibrils were observed, whereas the characteristic of similar amyloidosis was hardly detected for the wild recombinant cystatin.     

Time-resolved detection of conformational changes in oat phytochrome A: time-dependent diffusion

Conformational changes in oat phytochrome A (phy) in solution after photoexcitation of the red-absorbing form (Pr) were studied in time-domain by the pulsed laser-induced transient grating technique. It was found that the diffusion coefficient (D) of far-red-absorbing form (Pfr) of large phy (1.3 x 10(-11) m(2) s(-1)) is markedly reduced compared with that of Pr (5.8 x 10(-11) m(2) s(-1)). This large reduction indicates that the conformation of Pfr is significantly changed from that of Pr, so that the intermolecular interaction with water molecules increases. This change completes within 1 ms after the photoexcitation. On the other hand, D of Pr of intact phy (4.1 x 10(-11) m(2) s(-1)) first decreases upon photoexcitation to 0.89 x 10(-11) m(2) s(-1) within 1 ms and then gradually increases with a time constant of 100 ms to the value of Pfr, 1.7 x 10(-11) m(2) s(-1). This slower phase suggests that the conformation of the N-terminal region changes with 100 ms to decrease the intermolecular interaction with water after a global change in the large phy region. The increase of D was interpreted in terms of alpha-helix formation in the Pfr form from the random coil structure in the Pr form.     

The hepatitis C virus RNA 3'-untranslated region strongly enhances translation directed by the internal ribosome entry site

The positive-strand RNA genome of the hepatitis C virus (HCV) is flanked by 5'- and 3'-untranslated regions (UTRs). Translation of the viral RNA is directed by the internal ribosome entry site (IRES) in the 5'-UTR, and subsequent viral RNA replication requires sequences in the 3'-UTR and in the 5'-UTR. Addressing previous conflicting reports on a possible function of the 3'-UTR for RNA translation in this study, we found that reporter construct design is an important parameter in experiments testing 3'-UTR function. A translation enhancer function of the HCV 3'-UTR was detected only after transfection of monocistronic reporter RNAs or complete RNA genomes having a 3'-UTR with a precise 3' terminus. The 3'-UTR strongly stimulates HCV IRES-dependent translation in human hepatoma cell lines but only weakly in nonliver cell lines. The variable region, the poly(U . C) tract, and the most 3' terminal stem-loop 1 of the highly conserved 3' X region contribute significantly to translation enhancement, whereas stem-loops 2 and 3 of the 3' X region are involved only to a minor extent. Thus, the signals for translation enhancement and for the initiation of RNA minus-strand synthesis in the HCV 3'-UTR partially overlap, supporting the idea that these sequences along with viral and possibly also cellular factors may be involved in an RNA 3'-5' end interaction and a switch between translation and RNA replication.     

A generalized likelihood ratio test to identify differentially expressed genes from microarray data

MOTIVATION: Microarray technology emerges as a powerful tool in life science. One major application of microarray technology is to identify differentially expressed genes under various conditions. Currently, the statistical methods to analyze microarray data are generally unsatisfactory, mainly due to the lack of understanding of the distribution and error structure of microarray data. RESULTS: We develop a generalized likelihood ratio (GLR) test based on the two-component model proposed by Rocke and Durbin to identify differentially expressed genes from microarray data. Simulation studies show that the GLR test is more powerful than commonly used methods, like the fold-change method and the two-sample t-test. When applied to microarray data, the GLR test identifies more differentially expressed genes than the t-test, has a lower false discovery rate and shows more consistency over independently repeated experiments. AVAILABILITY: The approach is implemented in software called GLR, which is freely available for downloading at http://www.cc.utah.edu/~jw27c60     

Uterine Msx-1 and Wnt4 signaling becomes aberrant in mice with the loss of leukemia inhibitory factor or Hoxa-10: evidence for a novel cytokine-homeobox-Wnt signaling in implantation

Successful implantation absolutely depends on the reciprocal interaction between the implantation-competent blastocyst and the receptive uterus. Expression and gene targeting studies have shown that leukemia inhibitory factor (LIF), a cytokine of the IL-6 family, and Hoxa-10, an abdominalB-like homeobox gene, are crucial to implantation and decidualization in mice. Using these mutant mice, we sought to determine the importance of Msx-1 (another homeobox gene formerly known as Hox-7.1) and of Wnt4 (a ligand of the Wnt family) signaling in implantation because of their reported functions during development. We observed that Msx-1, Wnt4, and a Wnt antagonist sFRP4 are differentially expressed in the mouse uterus during the periimplantation period, suggesting their role in implantation. In addition, we observed an aberrant uterine expression of Msx-1 and sFRP4 in Lif mutant mice, and of Wnt4 and sFRP4 in Hoxa-10 mutant mice, further reinforcing the importance of these signaling pathways in implantation. Collectively, the present results provide evidence for a novel cytokine-homeotic-Wnt signaling network in implantation.     

Investigation of extended-spectrum beta-lactamases produced by clinical isolates of Klebsiella pneumoniae and Escherichia coli in Korea

AIMS: Isolates obtained from various regions in Korea in 2002 were identified and their susceptibility to extended-spectrum cephalosporins, monobactams and/or cephamycins was studied along with any production of extended-spectrum beta-lactamases (ESBLs). METHODS AND RESULTS: Bacteria identified by the conventional techniques and Vitek GNI card were Klebsiella pneumoniae and Escherichia coli. Using disk diffusion and double-disk synergy tests, we found that 39.2% of strains produced ESBLs. About 52% of isolates transferred resistance to ceftazidime by conjugation. Banding patterns of PCR amplification with the designed primers showed that 837- and 259-bp fragments specific to bla(TEM) genes were amplified in 63.3% of strains. 929- and 231-bp fragments (bla(SHV)), 847- and 520-bp fragments (bla(CMY)), 597- and 858-bp fragments (bla(CTX-M)) were amplified in 61.5, 17.3 and 7.7% of strains respectively. About 51.9% of strains contained more than two types of beta-lactamase genes. Especially, one strain contained bla(TEM), bla(CMY) and bla(CTX-M) genes. SIGNIFICANCE: Resistance mechanisms to beta-lactams, comprising mostly ESBL production, lead to the resistance against even recently developed beta-lactams in enterobacteria, which is now a serious threat to antibiotic therapy. The high prevalence of bla(CMY) genes and multidrug-resistant genes may also make therapeutic failure and lack of eradiation of these strains by extended-spectrum cephalosporins or cephamycins.     

绿洲农业生态经济系统的结构与功能分析以张掖绿洲为例

通过分析张掖绿洲农业生态经济系统的结构与功能,发现其种群结构单一、产业结构不甚合理、空间结构脆弱,决定了绿洲功能较差,产投比低下的特点,并据此从可持续发展的角度提出了改善绿洲农业生态经济系统结构、提高其功能的对策与建议     

Developmental regulation of hepatic ceruloplasmin mRNA and serum activity by exogenous thyroxine and dexamethasone.

Ceruloplasmin (Cp) is a copper-dependent oxidase with roles that include the regulation of iron metabolism, participation in the acute-phase response to inflammation, and antioxidant systems. Although developmental increases in hepatic Cp gene expression and serum activity have been described, the molecular mechanisms that are responsible for this regulation are not fully understood. The studies described here explored the possible role of glucocorticoids and thyroxine (T4) in the early neonatal development of Cp by the administration of these hormones on postnatal Day 1 (24 hr after birth), and the measurement of both hepatic Cp mRNA and serum activity through postnatal Day 10. Administration of the synthetic glucocorticoid hormone, dexamethasone (2 micrograms/g body wt), resulted in an increase in Cp mRNA on Days 3-7 that was accompanied by an increase in serum Cp activity that reached statistical significance at Day 10. Exogenous T4 (2 micrograms/g body wt) significantly increased Cp mRNA 24 hr after administration. Serum Cp activity was also significantly elevated by the early neonatal administration of T4. Furthermore, gestational hypothyroidism resulted in a significant decrease in Cp activity after postnatal Day 3. These data suggest a role for thyroid hormone and possibly glucocorticoids in the normal developmental regulation of Cp.