Follow-up survey of parents of children with major birth defects in New York State

BACKGROUND: One of the objectives of the New York State birth defect surveillance system, the New York State Congenital Malformations Registry (CMR), is to identify children in need of special programs and assist prevention/intervention programs and services with evaluation. In 1999, the CMR started a statewide mass-mailing program to inform parents of children with major birth defects about programs and support groups that might be helpful to them. A follow-up survey by mail was conducted in 2002 to evaluate the usefulness of the mailing program. METHODS: The survey was mailed between September and December of 2001 to parents of children born in 2001 and reported to the CMR with selected major birth defects. Non-respondents were followed-up by telephone. RESULTS: Of the 226 eligible families, 54% (122) responded to the survey. Approximately 66% of responding parents stated that the information provided by the mailing program was helpful, and 48% had contacted and/or used the programs and services listed in the information sheets. Parents with children younger than 6 months of age at the time of mailing were more likely to find the information helpful, compared to parents with children 6 months of age or older. The majority of responding parents had contacted and/or used the Early Intervention Program. CONCLUSION: The findings from the current survey show that the statewide information-mailing program administered by CMR is helpful and useful to the families of children with major birth defects in New York State.     

Utilization of newly developed immobilized enzyme reactors for preparation and study of immunoglobulin G fragments

The newly developed immobilized enzyme reactors (IMERs) with proteolytic enzymes chymotrypsin, trypsin or papain were used for specific fragmentation of high molecular-mass and heterogeneous glycoproteins immunoglobulin G (IgG) and crystallizable fragment of IgG (Fc). The efficiency of splitting or digestion were controlled by RP-HPLC. The specificity of digestion by trypsin reactor was controlled by MS. IMERs (trypsin immobilized on magnetic microparticles focused in a channel of magnetically active microfluidic device) was used for digestion of the whole IgG molecule. The sufficient conditions for IgG digestion in microfluidic device (flow rate, ratio S:E, pH, temperature) were optimized. It was confirmed that the combination of IMERs with microfluidic device enables efficient digestion of highly heterogeneous glycoproteins such as IgG in extremely short time and minimal reaction volume.     

Threading with chemostructural restrictions method for predicting fold and functionally significant residues: application to dipeptidylpeptidase IV (DPP-IV)

We present a new method for more accurate modeling of protein structure, called threading with chemostructural restrictions. This method addresses those cases in which a target sequence has only remote homologues of known structure for which sequence comparison methods cannot provide accurate alignments. Although remote homologues cannot provide an accurate model for the whole chain, they can be used in constructing practically useful models for the most conserved-and often the most interesting-part of the structure. For many proteins of interest, one can suggest certain chemostructural patterns for the native structure based on the available information on the structural superfamily of the protein, the type of activity, the sequence location of the functionally significant residues, and other factors. We use such patterns to restrict (1) a number of possible templates, and (2) a number of allowed chain conformations on a template. The latter restrictions are imposed in the form of additional template potentials (including terms acting as sequence anchors) that act on certain residues. This approach is tested on remote homologues of alpha/beta-hydrolases that have significant structural similarity in the positions of their catalytic triads. The study shows that, in spite of significant deviations between the model and the native structures, the surroundings of the catalytic triad (positions of C(alpha) atoms of 20-30 nearby residues) can be reproduced with accuracy of 2-3 A. We then apply the approach to predict the structure of dipeptidylpeptidase IV (DPP-IV). Using experimentally available data identifying the catalytic triad residues of DPP-IV (David et al., J Biol Chem 1993;268:17247-17252); we predict a model structure of the catalytic domain of DPP-IV based on the 3D fold of prolyl oligopeptidase (Fulop et al., Cell 1998;94:161-170) and use this structure for modeling the interaction of DPP-IV with inhibitor.     

Coordination topology and stability for the native and binding conformers of chymotrypsin inhibitor 2

We demonstrate that the stabilization of the binding region is accomplished at the expense of a loss in the stability of the rest of the protein. A novel molecular mechanics (MM) approach is introduced to distinguish residue stabilities of proteins in a given conformation. As an example, the relative stabilities of folded chymotrypsin inhibitor 2 (CI2) in unbound form, and CI2 in complex with subtilisin novo is investigated. The conformation of the molecule in the two states is almost identical, with an approximately 0.6-A root-mean-square deviation (RMSD) of the Calpha atoms. On binding, the packing density changes only at the binding loop. However, residue fluctuations in the rest of the protein are greatly altered solely due to those contacts, indicating the effective propagation of perturbation and the presence of remotely controlling residues. To quantify the interplay between packing density, packing order, residue fluctuations, and residue stability, we adopt an MM approach whereby small displacements are inserted at selected residues, followed by energy minimization; the displacement of each residue in response to such perturbations are organized in a perturbation-response matrix L. We define residue stability lambda(i) = summation operator((j)L(ij))/ summation operator((j) L(ji)) as the ratio of the amount of change to which the residue is amenable, to the ability of a given residue to induce change. We then define the free energy associated with residue stability, DeltaG(lambda) = -RT ln lambda. DeltaG(lambda) intrinsically selects the residues that are in the folding core. Upon complexation, the binding loop becomes more resistant to perturbation, in contrast to the alpha-helix that favors change. Although the two forms of CI2 are structurally similar, residue fluctuations differ vastly, and the stability of many residues is altered upon binding. The decrease in entropy introduced by binding is thus compensated by these changes.     

含有母性影响遗传基因的连锁定位系的构建

母性影响遗传基因由于其杂交后代的表型受母本基因型的影响, 而不能直接反映当代个体的基因型, 这给连锁定位测交亲本(三隐性或双隐性系统)的培育带来困难, 从而影响这类基因的定位研究。设计了一套杂交培育方案, 其核心是使母性影响遗传基因先纯合, 再使非母性影响遗传基因纯合。采用所设计的方案, 成功培育了家蚕第13连锁群的赤蚁(ch)、无鳞毛翅(nlw, 新突变)和褐色卵t (b-t, 母性影响遗传)的三隐性系统, 并培育了第19连锁群的狭胸(nb)和第二肾形卵(ki-2, 母性影响遗传, 待定位突变基因)的双隐性系统。     

医学实验中常见设计类型的辨析及统计方法的合理选用

目的帮助医学研究工作者提高对常见统计应用识别能力,提高对统计学的正确利用率。方法：明确阐述秒种常见医学实验设计类型的异同点和应用场合,揭示常见统计应用错误的实质和危害性。结果：给出不适合用ｔ检验取代方差分析的充足理由和正确运用统计学的基本要领。结论：要提高实际工作者的统计学应用水平。需要经常对其进行统计培养,积极引导与统计学工作者开展科研协作。     

鼠源抗HFRSV衣壳蛋白McAbF3株单链抗体基因克隆构建及表达

为了获得原抗ＨＦＲＳＶ衣壳蛋白ＭｃＡｂＦ３＾１株轻链可变区基因,由连接肽体外连接获得单链抗体基因,在大肠杆菌中表达,从鼠源抗ＨＦＲＳＶ衣壳蛋白ＭｃＡｂＦ３株细胞中分离总ＲＮＡ,以ｏｌｉｇｏ（ｄＴ）１８为引物逆转录成ｃＤＮＡ,通过ＰＣＲ扩增出抗体的轻链（ＶＬ）和重链可变区（Ｖ１１）基因,由连接本外连接获得单链抗体（ＳｅＦｖ）基因。将此单链抗体（ＳｅＦｖ）基因插入原核表达载体ＰＥＴ２８ａ,经大肠杆菌（     

沿海沙岸风蚀地黄泥客土和深埋造林效果分析

论述了广泛省汕头潮阳市田心镇华林管理区沙质海岸风蚀地试验示范林的造林存在蒸发量大于降水量,降水量过于集中,常年风大和冬连春旱等４个极为不利因素。试验采用黄泥客土和深埋造林可缓解这些不利因素,从而提高了造林成活率和保存率,是沙质海岸风蚀地造林的好方法。     

The Influence of Sequence Microvariation Among HLA-DR3 Alleles on their Structure and Complexes Formation with Presentation Peptides

The three-dimensional structure of human leukocyte antigens HLA-DR*0301 and HLA-DR*0302 have been calculated using the homology modeling approach. General structural features of our models are similar to those of related HLA molecules. The typical layout of segments of the secondary structure is well preserved. However polypeptide chains are less tightly bound, which causes slightly broader opening of the binding groove. It also results in the modified layout of pockets in the binding groove. Amino acids defining the restricted sequence diversity of studied proteins are easily available for interactions with ligands.A set of docking simulations was performed using modeled structures of both HLA molecules and various specific peptide ligands. The control docking of influenza hemagglutinin peptide into HLA-DR*0101 molecule gives the complex structure which is in good agreement with that from crystallographic studies. The extensive analysis of the structure of modeled complexes of HLA-DR*0301 and HLA-DR*0302 with various ligands indicates that sequence microvariation of both alleles is not directly controlling the binding specificity. Preferences for binding of specific ligands, as evaluated from interactions in modeled complexes, agree qualitatively with experimental observations. Thus the computer aided docking simulations can be successfully used to calculate the three-dimensional structure of HLA-ligand complexes. However detailed explanation of binding specificity can not be achieved using presently available modeling procedures.Electronic Supplementary Material available.     

Chemical Structure and NMR of a New Saponin from Dipsacus japonicus (Dipsacaceae)

A new triterpenoid saponin containing five sugars was isolated from the ethanolic root extract of Dipsacus japonicus Miq., and its structure was established as 3-O-［β-D-glucopyranosyl(1→4)］［α-L-rhamnopyranosyl(1→3)］-β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl-oleanoic acid. The sites of glycosylation and the sequence of sugars in the glycoside can be determined unambiguously and total assignment of severely overlapping proton resonance of sugar residues were achieved by a combined use of the 1D-SEMDY and NOE difference spectroscopy in rotating frame techniques, without having recourse to chemical degration or modification. The results showed that these new NMR techniques are very effective and convenient for the structure determination and spectral assignment of this class of compounds.