Localization of bovine corneal protein 54K (BCP 54) in the prenatal mouse eye

Electrophysiological studies have suggested that a subpopulation of interneurons near the border of layer II and III in rat piriform cortex are excited by serotonin (5-hydroxytryptamine; 5-HT) via 5-HT2A (formerly 5-HT2) rather than 5-HT2C (formerly 5-HT1C) receptors. However, the pharmacological agents used in those studies were limited in specificity. In the present study, we tested a new, highly selective 5-HT2A receptor antagonist MDL 100,907 (R-(+)-alpha-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl-ethyl)]-4- piperidine-methanol, which has a 300-fold greater affinity for 5-HT2A than 5-HT1C receptors or alpha 1-adrenoceptors) on excitatory responses of interneurons to 5-HT in rat piriform cortex slices. We observed a parallel, reversible rightward shift in the 5-HT concentration-response curve in the presence of 1-10 nM concentrations of MDL 100,907. Schild regression analysis resulted in a slope of 1.13 and a Kd value of 1.17 which is close to the published Ki value of 0.36 for MDL 100,907. These data confirm that 5-HT2A rather than 5-HT2C receptors mediate excitation by 5-HT of interneurons in the piriform cortex. Because of its rapid equilibration and reversibility, MDL 100,907 appears to be an excellent tool for studies of 5-HT2A receptor function in the brain.     

Twin boundaries in C54-TiSi2

A large-grained microstructure of C54-TiSi₂ has been produced by rapid thermal annealing of Ti/Si thin film couples. Unlike the metastable C49-TiSi₂ phase, which is heavily faulted, the C54-TiSi₂ is relatively fault-free. We have, however, observed for the first time the presence of twins in C54-TiSi₂. The presence of twinning is explained by an atomic model for polytypism in this structure. The faceting of twin boundaries and the dissociation of grain boundaries have also been observed for the first time in C54-TiSi₂. It is proposed that the latter observations are related to boundary migration. This paper is based on a presentation made in the symposium “Interface Science and Engineering” presented during the 1988 World Materials Congress and the TMS Fall Meeting, Chicago, IL, September 26–29, 1988, under the auspices of the ASM-MSD Surfaces and Interfaces Committee and the TMS Electronic Device Materials Committee.     

Structural and functional characterisation of the signal recognition particle-specific 54 kDa protein (SRP54) of tomato

The major oligosaccharide chains of bovine, frog and human rhodopsins are identical in structure. These molecules are unique in terms of their abridged size as compared to other asparagine-linked glycoproteins, a property which must be reflected in the activities and properties of the glycosyltransferases of the retina that are concerned with their biosynthesis. One of the unusual characteristics of the major oligosaccharide chain is its lack of branching. A key enzymatic step required for branching to occur would be the transfer of a residue of N-acetylglucosamine to the terminal unsubstituted mannose residue of the major rhodopsin oligosaccharide. We have investigated the kinetic properties of enzymes that would catalyse this process. The N-acetylglucosaminyl-transferases (GlcNAc-transferases) of Golgi-enriched fractions of bovine retina, human retina, rat liver Golgi and a partially purified GlcNAc-transferase II from rat liver were examined using as acceptors rhodopsin, opsin and the oligosaccharide isolated from rhodopsin. The identification of the substrates and products of the reactions was carried out by chromatographic means. From an evaluation of the Vmax/K(m) ratios it was observed that bovine and human retinas have very limited abilities compared to the rat liver enzymes to carry out the transfer of GlcNAc to these acceptors, showing from 100- to about 800-fold lower efficiency in this regard. A comparison of the activities obtained with intact rhodopsin or opsin and the rhodopsin oligosaccharide indicated that the activity of GlcNAc-transferase II was not appreciably influenced by the polypeptide portion of the molecule. It was also observed that prior galactosylation of rhodopsin blocked the addition of GlcNAc to rhodopsin. It is suggested that these properties contribute to the assembly of the abridged structures that have been observed in the oligosaccharides of rhodopsins of all species thus far examined.     

穴位注射、针灸推拿配合治疗梨状肌综合症54例

采用足三里穴位药物注射,辅助针刺推拿手法治疗梨状肌综合症54例,其中男性39例,女性15例.最短治愈时间7天,最长时间为3个疗程,在临床上有较高的应用价值.     

Bacillus subtilis Ffh, a homologue of mammalian SRP54, can intrinsically bind to the precursors of secretory proteins

We analyzed the binding activity of B. subtilis Ffh to the precursors of secretory proteins by purifying mature and precursor proteins of beta-lactamase derived from pUC18 and its derivatives, of which the signal peptide region was replaced with that of E. coli OmpA, B. subtilis AprE, PBP5* or an alkalophilic Bacillus sp. #1011 CGTase. Each of them was mixed with purified B. subtilis Ffh in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC). The tested precursor proteins, including those of E. coli, of which the signal sequences differ from those of B. subtilis in the number of charged amino acids and hydrophobicity, cross-linked with Ffh, whereas mature proteins did not. The addition of scRNA, the B. subtilis counterpart of mammalian SRP 7S RNA, into the mixture did not affect the complex formation. These findings suggest that B. subtilis Ffh intrinsically binds to several precursor proteins.     

UIC54钢轨的研制与生产

为参与国际市场竞争，武钢研制开发了UIC54钢轨。通过分析大量钢轨成分与基体硬度对应关系，合理设计化学成分，确定工艺路线与工艺参数，优化孔型设计参数，并对钢轨生产的各工序制定严格的内控目标与措施，确保了出口巴基斯坦UIC54钢轨的研制成功，性能全部达到新铁标的要求，完善了大型厂钢轨产品系列。     

Heart transplantation in patients over 54 years of age. Mortality, morbidity and quality of life

AIMS: As a consequence of recent advances in heart transplantation, upper age limits for the procedure have been liberalized in many centres. It was the purpose of this study to compare post-transplant mortality, morbidity and quality of life in a consecutive series of 72 patients > 54 years (mean age, 57.6 +/- 2.7 years) with a control group of 72 adult patients < or = 54 years (mean age, 42.4 +/- 9.5 years) transplanted at one centre between 1985 and 1991. METHODS AND RESULTS: Patients were followed for 41 +/- 27 months post-transplant. Actuarial 1-, 5- and 7-year survival rates were 78 +/- 5%, vs 81 +/- 5%, 52 +/- 7% vs 66 +/- 6% and 46 +/- 8% vs 63 +/- 6% in patients > 54 years and < or = 54 years, respectively (P = ns). Causes of death were not significantly different between the groups. Patients > 54 years experienced significantly fewer rejection episodes after the 6th month post-transplant (0.5 +/- 0.9 vs 0.9 +/- 1.0, P < 0.04), and incidence and treatment of rejection episodes as well as incidence of infection was comparable between the groups. Non-lymphoid malignancies, mainly skin cancer, occurred more often in the older age group (27% vs 13%, P < 0.05). Quality of life, as assessed by the Nottingham Health Profile, was better in 5/6 dimensions of social functioning in older patients and the difference reached statistical significance for the dimensions of emotional reactions (P = 0.005) and sleep (P = 0.0005). CONCLUSION: In conclusion, carefully selected patients > 54 years can undergo heart transplantation with mortality and morbidity comparable to younger patients. Quality of life post-transplant seems even to be slightly better in the older age group.