乳腺癌组织中P33^INC1蛋白的表达及临床意义

目的探讨抑癌基因P33^INC1蛋白表达与乳腺癌发生、发展的关系。方法用S-P免疫组织化学法检测90例乳腺癌标本中P33^INC1蛋白的表达。结果P33^INC1蛋白在乳腺癌组织中表达的阳性率为38．89％（35/90），在癌旁组织为75．56％（68/90），两者比较差异有高度显著性（P〈0．01）。P33^INC1蛋白的低表达与肿瘤大小、腋窝淋巴结转移数目有明显关系（P〈0．05或0．01），与年龄、病理类型和病理分级无明显关系。结论P33^INC1基因是一个抑癌基因，它的低表达与乳腺癌的发生、发展有密切关系。     

Cochlin Isoforms and Their Interaction with CTL2 (SLC44A2) in the Inner Ear

Choline transporter-like protein 2 (CTL2) is a multi-transmembrane protein expressed on inner ear supporting cells that was discovered as a target of antibody-induced hearing loss. Its function is unknown. A 64 kDa band that consistently co-precipitates with CTL2 from inner ear extracts was identified by mass spectroscopy as cochlin. Cochlin is an abundant inner ear protein expressed as multiple isoforms. Its function is also unknown, but it is suspected to be an extracellular matrix component. Cochlin is mutated in individuals with DFNA9 hearing loss. To investigate the CTL2–cochlin interaction, antibodies were raised to a cochlin-specific peptide. The antibodies identify several cochlin polypeptides on western blots and are specific for cochlin. We show that the heterogeneity of the cochlin isoforms is caused, in part, by in vivo post-translational modification by N-glycosylation and, in part, caused by alternative splicing. We verified that antibody to CTL2 co-immunoprecipitates cochlin from the inner ear and antibody to cochlin co-immunoprecipitates CTL2. Using cochlear cross-sections, we show that CTL2 is more widely distributed than previously described, and its prominent expression on cells facing the scala media suggests a possible role in homeostasis. A prominent but previously unreported ribbon-like pattern of cochlin in the basilar membrane was demonstrated, suggesting an important role for cochlin in the structure of the basilar membrane. CTL2 and cochlin are expressed in close proximity in the inner sulcus, the spiral prominence, vessels, limbus, and spiral ligament. The possible functional significance of CTL2–cochlin interactions remains unknown.     

神经微丝蛋白在先天性巨结肠和巨结肠同源病的表达变化

目的 了解神经微丝蛋白（neurofilament protein，NFP）在先天性巨结肠（Hirschsprung’s disease，HD）和巨结肠同源病（allied Hirsehsprung’s disorder，HAD）肠组织的表达，观察NFP与先天性巨结肠及其同源病的相互关系，进一步探讨两种疾病的发病机制。方法 采用鼠抗人NFP单克隆抗体通过免疫组化法对15例先天性巨结肠，11例巨结肠同源病肠组织NFP的表达进行研究，10例正常结肠组织作对照。结果对照组正常肠段肌间神经丛中有大量NFP阳性纤维和NFP阳性神经细胞，阳性细胞突起少而粗短；HD狭窄段肠管肌间神经丛中未见NFP阳性细胞，但可见大量着色深的NFP阳性纤维；HAD狭窄段肌间神经丛中可见形态各异的NFP阳性细胞，细胞大，且着色深，突起多，丛中只见少量NFP阳性纤维。HD的扩张段和HAD的扩张段分别与正常结肠比较，NFP的表达无统计学意义（P〉0．05）；HD狭窄段分别与HAD狭窄段和正常结肠比较，NFP的表达均有差异（P〈0．01）；HAD狭窄段和正常结肠比较，差异也有显著性意义（P〈0．01）。结论 NFP可能与HD和HAD的发生均有关系，但NFP在HD和HAD的表达有差异。     

血管内皮生长因子对肺表面活性物质磷脂合成的影响

目的 研究血管内皮生长因子（VEGF）对肺表面活性物质合成、分泌的影响,探讨防治早产儿呼吸窘迫综合征（RDS）的新途径.方法 孕19 d Wistar大鼠剖腹取胎鼠,原代培养肺泡Ⅱ型细胞,分成VEGF-165组、地塞米松组、VEGF加地塞米松组和对照组进行试验,测定肺表面活性物质总磷脂、磷脂酰胆碱（PC）、磷脂酰甘油（PG）、鞘磷脂（SM）含量.结果 VEGF-165组、地塞米松组与VEGF加地塞米松组总磷脂及各成分含量增加,VEGF组和地塞米松组PC、SM、PG含量差异有统计学意义.结论 VEGF-165能促进肺表面活性物质的合成和分泌,VEGF、地塞米松对肺泡磷脂各成分的影响各不相同,两者可能通过不同的机制,增加了肺泡表面活性物质的合成和分泌,改善了肺泡上皮细胞的功能.     

Dietary resistant starch and chronic inflammatory bowel diseases

These studies were performed to test the benefit of resistant starch on ulcerative colitis via prebiotic and butyrate effects. Butyrate, propionate, and acetate are produced in the colon of mammals as a result of microbial fermentation of resistant starch and other dietary fibers. Butyrate plays an important role in the colonic mucosal growth and epithelial proliferation. A reduction in the colonic butyrate level induces chronic mucosal atrophy. Short-chain fatty acid enemas increase mucosal generation, crypt length, and DNA content of the colonocytes. They also ameliorate symptoms of ulcerative colitis in human patients and rats injected with trinitrobenzene sulfonic acid (TNBS). Butyrate, and also to a lesser degree propionate, are substrates for the aerobic energy metabolism, and trophic factors of the colonocytes. Adverse butyrate effects occur in normal and neoplastic colonic cells. In normal cells, butyrate induces proliferation at the crypt base, while inhibiting proliferation at the crypt surface. In neoplastic cells, butyrate inhibits DNA synthesis and arrests cell growth in the G1 phase of the cell cycle. The improvement of the TNBS-induced colonic inflammation occurred earlier in the resistant starch (RS)-fed rats than in the RS-free group. This benefit coincided with activation of colonic epithelial cell proliferation and the subsequent restoration of apoptosis. The noncollagenous basement membrane protein laminin was regenerated initially in the RS-fed group, demonstrating what could be a considered lower damage to the intestinal barrier function. The calculation of intestinal short-chain fatty acid absorption confirmed this conclusion. The uptake of short-chain fatty acids in the colon is strongly inhibited in the RS-free group, but only slightly reduced in the animals fed with RS. Additionally, RS enhanced the growth of intestinal bacteria assumed to promote health. Further studies involving patients suffering from ulcerative colitis are necessary to determine the importance of RS in the therapy of a number of intestinal diseases and the maintenance of health. Accepted: 11 August 1999     

Intraspecific nucleotide variation at the pheromone binding protein locus in the turnip moth, Agrotis segetum

Inter- and intraspecific amino acid variability in the pheromone binding proteins (PBPs) of the Lepidoptera is believed to contribute to a molecular mechanism of pheromone blend discrimination. Messenger RNA coding for PBP sequence in Agrotis segetum (Noctuidae) was cloned, and nucleotide and inferred amino acid variation across a 769-bp region of a PBP locus was studied in two populations. A single gene copy was fully sequenced, revealing an intron/exon structure conserved with distant saturniids. While several nucleotide substitutions are predicted to result in amino acid replacement, tests for the presence of natural selection suggest that the observed variation is neutral. A phylogenetic analysis provides evidence that the two populations are in the process of genetic isolation.     

Extending the concept of template-assembled synthetic proteins

Abstract: The creation of native-like macromolecules in copying nature’s way represents a fascinating challenge in protein chemistry today. In the absence of a detailed knowledge of the complex folding pathway the ultimate goal in protein de novo design, the construction of artificial proteins with predetermined three-dimensional structure and tailor-made functions based on a defined, generally valid set of rules, appears to be still out of reach. With progress in synthesis strategies and biostructural characterization methods, topological templates have become a versatile tool for inducing and stabilizing secondary and tertiary structures, such as protein loops, β-turns, α-helices, β-sheets and a variety of folding motifs. In this article, we extend the concept of template-assembled synthetic proteins for the construction of protein-like topologies with multiply bridged, oligocyclic chain architectures termed locked-in tertiary folds that exhibit unique physicochemical and folding properties because of the highly confined conformational space. Furthermore, we show that some fundamental questions in protein assembly can be approached applying the template concept. Using covalent template trapping of self-associated peptide assemblies in aqueous solution the structural and physical forces guiding protein folding, supramolecular assembly and molecular recognition processes can be studied on a molecular level.     

Pharmacokinetics and biotransformations of oxaliplatin in comparison with ormaplatin following a single bolus intravenous injection in rats

Purpose: Traditionally ultrafilterable Pt has been used to estimate the body exposure to platinum drugs. However, previous studies have shown that ultrafilterable Pt consists of both cytotoxic and inert biotransformation products of platinum drugs. Therefore, it has been proposed that pharmacokinetic parameters of the parent drug and its cytotoxic biotransformation products are more likely to be correlated with the drug toxicity and efficacy than those of ultrafilterable Pt. Oxaliplatin and ormaplatin are likely to form very similar biotransformation products in vivo based on previous studies. However, ormaplatin causes severe and irreversible neurotoxicity while oxaliplatin causes moderate and reversible neurotoxicity. To evaluate the hypothesis that the neurotoxicity is associated with the pharmacokinetics of active biotransformation products, we investigated the biotransformations and pharmacokinetics of oxaliplatin and ormaplatin in rats at equimolar doses. Methods: ³H-oxaliplatin and ³H-ormaplatin were administered to Wistar male rats through single bolus i.v. injections (20 μmol/kg). Blood was sampled from 3.5 min to 360 min and centrifuged at 2000 g to separate the plasma from red blood cells (RBCs). The RBCs were sonicated and centrifuged at 13 000 g to separate the cytosol from the membrane fraction. Both plasma and RBC cytosol were filtered through YMT30 membranes (M_r = 30 000 kDa), and the ultrafiltrates were analyzed using a single column HPLC technique to identify and quantitate the biotransformation products. The pharmacokinetics of oxaliplatin, ormaplatin, and their biotransformation products were characterized utilizing the curve stripping and nonlinear least-squares fitting program RSTRIP. Results: The decays of total, plasma, plasma ultrafilterable (PUF), RBC-bound, and plasma protein-bound Pt-dach (only Pt species with an intact dach carrier ligand were quantitated in this study) were described by biphasic curves. No significant kinetic differences between oxaliplatin and ormaplatin were observed for total, plasma, and PUF Pt-dach in the initial α decay phase. However, Pt-dach bound to plasma proteins fourfold more quickly for ormaplatin than for oxaliplatin, and the AUC for Pt-dach bound to plasma proteins was twofold higher for ormaplatin than for oxaliplatin. The concentration of RBC-bound Pt-dach was highest at the initial time-point of 3.5 min for both drugs, which suggested a very rapid RBC uptake. The binding of Pt-dach to RBCs was slightly greater initially for ormaplatin than for oxaliplatin. However, the RBC-bound Pt-dach decayed more rapidly for ormaplatin (t_1/2αRBC = 5.1 min) than for oxaliplatin (t_1/2αRBC = 15.3 min). Thus the AUC_RBC was slightly greater for oxaliplatin than for ormaplatin. The AUC was also slightly greater for oxaliplatin than for ormaplatin for the Pt-dach associated with the RBC membrane and RBC cytosolic proteins. However, there was no significant difference between oxaliplatin and ormaplatin for Pt-dach in the RBC cytosolic ultrafiltrate. There was also no significant difference in the AUC_puf between oxaliplatin and ormaplatin. Both oxaliplatin and ormaplatin produced the same types of major plasma biotransformation products including Pt(dach)Cl₂, Pt(dach)(Cys)₂, Pt(dach)(GSH)₂, Pt(dach)(GSH), Pt(dach)(Met), and free dach. The decays of oxaliplatin, ormaplatin, and their biotransformation products were described by biphasic curves. The C_max and AUC were 19- and 15-fold higher, respectively, for oxaliplatin than for ormaplatin. However, the C_max and AUC were 29- and 16-fold less for Pt(dach)Cl₂ derived from oxaliplatin than for that derived from ormaplatin. No significant differences were observed among the C_max values and AUC values for the other plasma biotransformation products. Pt-dach species formed in RBCs were also identified and quantitated. Oxaliplatin was observed in the RBC cytosol, while no ormaplatin was found. The same types of major RBC biotransformation products were observed including Pt(dach)Cl₂, Pt(dach)(Cys)₂, Pt(dach)(GSH), Pt(dach) (GSH)₂, and free dach. Among these Pt-dach species, Pt(dach)Cl₂ was present at a twofold lower concentration initially but persisted longer for oxaliplatin than for ormaplatin, while the other RBC biotransformation products behaved kinetically similarly and no significant AUC differences were observed. Conclusion: Our study suggests that the different toxicity and efficacy profiles between oxaliplatin and ormaplatin may be related to the different pharmacokinetic features of these two drugs, especially the different plasma concentrations of their common biotransformation product Pt(dach)Cl₂. This in turn suggests that Pt(dach)Cl₂ and its hydrolysis products may be uniquely neurotoxic. Received: 12 June 1998 / Accepted: 22 October 1998     

Correlations between age-dependent protein and lipid concentrations in plasma and platelet functions in children

The correlations between the levels of various plasma proteins and lipids and platelet function on glass and platelet factor 3 (PF 3)-availability in children of different age-groups were investigated. Several statistically significant positive and some significant negative correlations were found. Although conclusions based solely on such correlations should be considered with reservation, in our opinion the following factors should stimulate platelet function: prealbumin (adhesion and PF 3-availability in all age-groups, aggregation—specifically for children in puberty); ₁-antitrypsin (PF 3-availability); ₂-macroglobulin (platelet spreading capacity, PF 3-availability); plasminogen (platelet adhesion and aggregation—specifically for boys in puberty); caeruloplasmin (number of free adhering platelets spreading capacity); lysolecithin and lecithin (time-dependent increase of spontaneous platelet adhesion and aggregation, PF 3-availability); and free fatty acids (FFA) (PF 3-availability).Plasminogen and complement component C3 show a negative relationship to the time-dependent increase of spontaneous platelet adhesiveness and aggregability in platelet-rich plasma.     

实验性头颅侧向旋转脑弥漫轴索损伤神经丝蛋白亚单位含量变化

目的： 探讨实验性头颅侧向旋转脑弥漫轴索损伤（ＤＡＩ）中神经丝（ＮＦ）蛋白亚单位含量变化． 方法： ＳＤ大鼠２４只,等分为三个损伤组（伤后２, １２, ２４ ｈ）及一个对照组,对损伤组制作头颅侧向旋转脑ＤＡＩ模型． 用Ｗｅｓｔｅｒｎ 印迹技术进行免疫活性定量测定,以检测全部损伤及对照组大鼠脑干组织ＮＦ蛋白亚单位ＮＦ６８的含量． 结果： 脑干ＮＦ６８含量在伤后２ ｈ 倾向下降,１２ ｈ 显著减少,继续降低至２４ ｈ;其降解产物ＮＦ５６, ＮＦ５２在伤后２ ｈ～１２ ｈ 趋于增加,２４ ｈ 提高至显著水平． 结论： 头颅侧向旋转ＤＡＩ后脑干神经丝产生磷酸化反应,引起ＮＦ６８水解,造成ＮＦ６８含量减少． 提示神经丝蛋白亚单位水解是ＤＡＩ中神经丝结构破坏的重要原因．