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101.
A new neutral glycoside of myo-inositol was isolated from the pregnancy urine of a single donor. Its structure was investigated by 1H-NMR spectroscopy and mass spectroscopy. It was identified as 1-O-alpha-2-acetamido-2-deoxy-D-galactopyranosyl-myo-inositol. No such structure or sequence has previously been reported in either myo-inositol or glucose glycosides.  相似文献   
102.
The relative immunogenicities of the poly[d(G-C)] and poly[d(A-C) · d(G-T)] families of helices have been determined. The specificities of the resultant immunoglobulins have been characterized for recognition of different synthetic and natural left-handed sequences and conformations. Certain modifications of poly[d(G-C)] in the sugar-phosphate bacbone and cytosine C-5 potentiate the right(R)-to-left(L) (BZ) transition under physiological conditions. The resulting polynucleotides, poly[d(GS-C)], poly[d(G-io5C)], poly[d(G-br5C)] and poly[d(G-m5C)], are also highly immunogenic. In contrast, DNAs incapable of assuming the left-handed conformation under physiological salt concentrations are weakly or non-immunogenic. These include unmodified poly[d(G-C)] as well as members of the poly[d(A-C) · d(G-T)] family of sequences bearing pyrimidine C-5 substitutions (methyl, bromo, iodo). These polynucleotides undergo the R → L isomerization under more stringent ionic and thermal conditions.The specificities of purified polyclonal and monoclonal anti-Z DNA immunoglobulins (IgG) were measured by binding to radiolabeled polynucleotides, by electrophoretic analysis of IgG bound to covalent closed circular DNAs, and by immunofluorescent staining of polytene chromosomes. The salt-induced left-handed forms of poly[d(G-C)] and its derivatives (including the cytidine C-5 methyl, bromo, iodo, and N-5 aza substituted polynucleotides) and of the modified poly[d(A-C) · d(G-T)] polymers are bound to varying degrees by different antibodies. The patterns of substrate recognition demonstrate the existence of several antigenic domains in left-handed DNAs, including the helix convex surface and the sugar-phosphate backbone. Substitutions in these regions can produce enhancing (required substitutions), neutral, or inhibitory effects on subsequent IgG binding. Additionally, certain modifications of either the convex surface of Z DNA at the C-5 position of cytidine (i.e. a methyl group) or of the backbone (i.e. phosphorothioate substitution) can lead to polymorphic lefthanded conformations that are compatible with antibody binding when present individually but not in combination. The recognition patterns exhibited with DNA substrates from the two DNA families indicate that some, but not all, IgGs show specificity for different nucleotide sequences.The anti-Z DNA IgGs were used to probe for specific left-handed Z DNA determinants on plasmid (e.g. pBR322) or viral (e.g. simian virus 40 (SV40)) DNAs and on the acid-fixed polytene chromosomes of dipteran larvae. At their extracted superhelical density, the negatively supercoiled form I, but not the relaxed, nicked, or linear forms of all tested plasmid and viral DNAs specifically bind sequence-independent anti-Z IgGs. Dimers, trimers and higher oligomers of form I DNA cross-linked by bivalent anti-Z IgGs are formed with numerous (e.g. φX174, SV40, pBR322) genomes. Their occurrence depends upon IgG concentration and specificity, the conditions of ionic strength and temperatures and the DNA genome. The IgG cross-linked DNA multimers are converted to monomers by dithiothreitol reduction. Sequence-independent monovalent anti-Z Fab fragments bind form I DNA but do not generate oligomeric species. Multimers of order >2 indicate the existence of at least two anti-Z Ig binding sites per molecule, as in the case of SV40. IgGs differ in their ability to form stable complexes with some sites on natural DNAs, presumably due to their sequence and conformation binding specificities. A differential binding of these antibodies is also observed in certain bands of polytene chromosomes, such as the telomeric regions that are involved in chromosome associations.  相似文献   
103.
Urine washing (UW) and urinating onto hand (UH) are reported for the first time for a wild callitrichid monkey, the moustached tamarin,Saguinus mystax. Both patterns are very rare and no sex difference in frequency is apparent. The temporal distribution shows a maximum of UH/UW around midday when ambient temperature is at maximum and humidity at minimum. No seasonal effects were observed, but any seasonal effect might be masked by the low frequency of UH/UW. UH/UW are not linked to a single behavioural context and may have multiple functions in thermoregulation/water conservation, cleaning, improving grip, and as a social signal.  相似文献   
104.
ObjectivesThyroid dysfunction can be a result of excessive iodine intake, which may have adverse health consequences, particularly for women in fertile age. In 2010, we conducted a cross-sectional study among lactating women with excessive iodine intake in the Saharawi refugee camps in Algeria and found a high prevalence of thyroid dysfunction. Three years later, we conducted a follow-up study to monitor the iodine situation and explore whether thyroid dysfunction still was highly prevalent when the women no longer were post-partum. None of the women were treated for hyper- or hypothyroidism between baseline and follow-up.MethodsIn 2013, we were able to recapture 78 of the 111 women from the baseline. Thyroid hormones and antibodies were measured in serum and thyroid size was assessed by palpation. Urinary iodine concentration (UIC) and drinking water iodine concentration were measured.ResultsThe overall prevalence of thyroid dysfunction and/or positive antibodies was 34.3% and was not significantly changed from baseline. Of the non-pregnant women we reexamined, 17 had hypo- or hyperthyroidism in 2010; among these, 12 women still had abnormal thyroid function at follow-up. In addition, we found 9 new cases with marginally abnormal thyroid function. Women with thyroid dysfunction and/or positive antibodies had significantly higher BMI and thyroglobulin than women with normal thyroid function. We also found that women with high breast milk iodine concentration (BMIC) at baseline had more thyroid dysfunction at follow-up than the women with lower BMIC at baseline.ConclusionsAt follow-up, the prevalence of thyroid dysfunction was still high and had not changed during the 3 years between studies and from a postpartum period. The women still had a high iodine intake indicated by high UIC. Breast milk iodine concentration from baseline predicted thyroid dysfunction at follow-up.  相似文献   
105.
Several α/β-D-ribonucleosides were synthesized in good yields under mild conditions by N-glycosylations of acetyl 2,3,5-tri-O-benzoyl- β-D-ribofuranose with silylated nucleobases in acetonitrile using NP doped with iodine as catalyst.  相似文献   
106.
An appropriate and controlled supply of thyroid hormones is vital for proper body function. In turn, an appropriate synthesis of T3 and T4 in the thyroid gland is dependent on a sufficient and balanced iodide concentration in blood serum. Due to widespread iodine deficiency or some cases of iodine over exposure, iodide biomonitoring in serum is important and it is that biomonitoring approach being closest to the bioavailable I supply for the thyroid gland. Therefore, this paper describes a biomonitoring method for iodide determination in serum based on ion chromatography–inductively coupled plasma mass spectrometry (IC–ICP-MS). Since in literature only very few data are available on iodide in serum but many in urine the method is also extended to I monitoring in urine. The method was additionally designed to have short analysis time (8 min) for increased sample throughput, good precision in serial measurement (serum: 4.86%; urine: 1.4%), and day-to-day determination (serum: 5.7%; urine: 2.28%), high accuracy (serum: 105%; urine: 101%) and good recovery (serum: 102%; urine: 99%) even in matrix-rich samples at low I concentration. Also, investigations were performed to elucidate whether internal standardization during chromatography, sample preparation for protein-matrix removal or matrix-matched calibration are advantageous for analytical performance. Finally, limits of detection (3σ) of 0.12 μg/L or 0.05 μg/L (serum or urine) and limit of quantification (10σ) of 0.39 μg/L or 0.17 μg/L (serum or urine) were achieved.  相似文献   
107.
Styrene is rapidly metabolised to mandelic acid (MA) and phenylglyoxylic acid (PGA), which are excreted in urine. In this work, we have developed a simple, sensitive and specific high-performance liquid chromatographic method with minor sample preparation procedures for the simultaneous determination of MA and PGA in urine of workers exposed to styrene. Moreover, urine samples from workers of two plastic factories were analysed, styrene exposure levels of the workers were estimated and data obtained from the two factories were compared.  相似文献   
108.
The experimental conditions in the potentiometric method for the determination of the iodine-binding capacity (Ib) of starch and amylose [R. L. Bates, D. French, and R. E. Rundle (1943) J. Amer. Chem. Soc. 65, 142-148] were not suitable for glycogen because of the much lower affinity for iodine of the latter. This difficulty was overcome by titration of small volume with both the iodine and glycogen at high concentration. Using the concentration cell circuit Pt electrode-blank-bridge-glycogen-Pt electrode, small increments of standard iodine solution were added to the blank solution and each was titrated to null by adding iodine to the glucogen solution [G. A. Gilbert and J. V. R. Marriott (1948) Trans. Faraday Soc. 44, 84-93]. Glycogen was determined by an anthrone-sulfuric acid method [F. W. Fales (1951) J. Biol. Chem. 193, 113-124]. Glycogens with Ib's ranging from 1.8 to 5.3% were observed.  相似文献   
109.
目的探讨尿干化学分析法与尿沉渣分析法在诊断患者尿路感染中的临床价值。方法收集2017年9月至2018年7月于重庆市黔江中心医院就诊的疑似尿路感染患者尿液标本400份,分别利用尿干化学分析及尿沉渣分析法检测标本,比较不同检测分析法的灵敏度、特异度、阳性预测值及阴性预测值。结果尿干化学分析法检测阳性率为42.25%(169/400),尿沉渣分析法检测阳性率为32.75%(131/400),尿沉渣分析法检测阳性率明显低于尿干化学分析法(X~2=7.7010,P=0.0070),差异有统计学意义。尿干化学分析法检测白细胞计数阳性率为25.25%(101/400)、亚硝酸盐阳性率为17.00%(68/400);尿沉渣分析法检测白细胞计数阳性率为24.25%(97/400),细菌计数阳性率为8.50%。尿沉渣分析法检测白细胞计数阳性率与尿干化学分析法比较,差异无统计学意义(X~2=0.1070,P=0.8060)。尿干化学分析法灵敏度为72.95%,特异度为90.67%,阳性预测值为89.35%,阴性预测值为75.76%;尿沉渣分析法灵敏度为57.97%,特异度为94.30%,阳性预测值为91.60%,阴性预测值为67.66%。尿干化学分析法检测的灵敏度及阴性预测值明显高于尿沉渣分析法(X~2=10.2660,P=0.0020;X~2=3.9930,P=0.0480),差异具有统计学意义。结论尿干化学分析法及尿沉渣分析法均有一定的临床诊断价值。可针对两种检测方法的联合应用进一步研究,以期提高尿路感染诊断的灵敏度及特异度。  相似文献   
110.
Selective breeding of dogs over hundreds of years has inadvertently resulted in breed-specific propensities to particular diseases. Furthermore, it has likely induced more subtle affects on the physiology of certain breeds and moved them from their evolutionary optima. In the absence of obvious disease phenotypes such subtle changes could have yet unrecognised breed-specific implications for health and well-being. Here we have applied NMR metabolomics as a discovery-driven approach to identify the impact of breed on the urinary profile of dog and to determine if non-disease-related breed differences can be identified. Multiple urines were collected non-invasively over a two-week period from seven neutered male Labrador retrievers and miniature Schnauzers. Following NMR analyses by 1-dimensional 1H and 2-dimensional 1H J-resolved (JRES) spectroscopy, principal component analysis revealed that the metabolic variability within each individual is relatively small compared to inter-individual variability, and that some separation between breeds was evident. A supervised model, using partial least squares discriminant analysis (PLS-DA) with class based upon breed, was trained using the JRES data. The model predicted correctly the breed of seven additional urines, yielding a model sensitivity and specificity of 100%. Several significant metabolic differences between the breeds were identified. A second model was developed using PLS-DA with class based upon individual dogs, which again achieved high classification accuracy for the test set. Overall, this confirms that canine urine is information-rich and that breed is a major determinant of urinary metabolic fingerprints. In the future this may enable a more accurate development of specific nutritional care for an individual or breed.  相似文献   
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