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排序方式: 共有1260条查询结果,搜索用时 19 毫秒
1.
Marieke Peeters Ludo Verhoeven Jan de Moor Hans van Balkom 《Research in developmental disabilities》2009,30(4):712-726
The goal of this longitudinal study was to investigate the precursors of early reading development in 52 children with cerebral palsy at kindergarten level in comparison to 65 children without disabilities. Word Decoding was measured to investigate early reading skills, while Phonological Awareness, Phonological Short-term Memory (STM), Speech Perception, Speech Production and Nonverbal Reasoning were considered reading precursors. Children with cerebral palsy lag behind on all reading precursors at the beginning of the second year of kindergarten. For the children without disabilities, early reading skills in Grade 1 were best predicted by Phonological Awareness and Phonological STM while Speech Production was the most important predictor of early reading success for the children with cerebral palsy, followed by Phonological Awareness and Speech Perception. Furthermore, for children with cerebral palsy, Speech Production appears to dominate reading development, as Speech Production measured at the beginning of the second year of kindergarten was strongly predictive of all other reading precursors measured at the end of the second year of kindergarten. The results of this study reveal that children with cerebral palsy with additional speech impairments are at risk for limited literacy development. Clinical implications are discussed. 相似文献
2.
It is demonstrated that tubular fragments derived from human testes and cultured in vitro produce a factor that stimulates the production of testosterone by human interstitial cells and by Percoll-purified Leydig cells from rat and mouse origin. The active principle in the conditioned media is a thermo-labile and trypsin-sensitive protein with an MW greater than 10,000. The factor is active in the presence as well as in the absence of maximally effective concentrations of LH and its activity is not accompanied by measurable changes in cAMP production. There are several points of analogy between this factor and a Leydig cell stimulatory protein produced by rat Sertoli cells. Molecular weight fractionation of spent media from human testicular tubules using an Amicon ultrafiltration system results in a 38- to 102-fold increase in Leydig cell stimulatory activity in a fraction corresponding to a molecular weight of 10,000 up to 30,000. These figures are comparable to those observed after molecular weight fractionation of spent media from rat Sertoli cells. Dose-response curves with partially purified preparations from human and rat origin yield parallel dose-response curves. In rat Sertoli cells as well as in human testicular tubules, the production of the active principle is stimulated by FSH and dibutyryl cAMP. Finally, maximally effective concentrations of the active principles of human and rat origin display no additive effects whereas additive effects are clearly evident with other Leydig cell stimulatory factors such as LHRHa and EGF. The hypothesis is advanced that the Leydig cell stimulatory factors from tubular origin may act as paracrine regulatory molecules responsible for the effects of FSH on Leydig cell function. 相似文献
3.
Male subfertility induced by acute scrotal heating affects embryo quality in normal female mice 总被引:5,自引:0,他引:5
Jannes P; Spiessens C; Van der Auwera I; D'Hooghe T; Verhoeven G; Vanderschueren D 《Human reproduction (Oxford, England)》1998,13(2):372-375
The aim of this experiment was to design a suitable mouse model for male
subfertility in which to study the effect of decreased sperm quality on
embryo quality in vivo and in vitro. To achieve male subfertility, testes
of adult male mice were immersed in water at either 42 degrees C (heated)
or 33 degrees C (controls) during 20 min. Twenty-eight days after
treatment, all heat stressed males showed a significant decrease in
relative testis weight [384.7 mg in controls (286.7-460.6) versus 323 mg in
stress heated groups (117.9-405.6); P < 0.001], sperm concentration
[3.75 x 10(6)/ml (2.75-7.25) versus 1.00 x 10(6)/ml (0-4.00); P < 0.001]
and progressive sperm motility [57.5% (48.0-79.0) versus 42.5% (14.0-66.0);
P < 0.001]. Moreover, after mating to heat exposed males, not only the
number of pregnant females (20/22 versus 18/30) but also the weight of
their embryos [275.4 mg (78.7-339.4) versus 261.8 mg (68.1-339.0); P <
0.001] was significantly lower at 14.5 days post coitum when compared to
controls. Neither the number of resorption sites nor the number of viable
embryos per pregnant female was significantly different between groups.
Also, the in-vitro fertilization rate of oocytes, fertilized by spermatozoa
collected from heat stressed males, was significantly lower (44.9%; P <
0.0001) when compared to controls (65.1%; P < 0.0001). In conclusion,
the results of this study suggest that male subfertility induced by acute
scrotal heating may result in impaired sperm quality, reduced embryo weight
in vivo and decreased fertilization rate in vitro.
相似文献
4.
Lieve Peremans Veronique Verhoeven Hilde Philips Joke Denekens Paul Van Royen 《The European journal of contraception & reproductive health care》2007,12(4):317-325
OBJECTIVE: To evaluate how Belgian health care providers deal with a request for emergency contraception. METHOD: In 2002-2003 we conducted 12 focus groups with pharmacists, general practitioners and school physicians. A skilled moderator accompanied by an observer conducted the focus groups using a semi-structured screenplay. RESULTS: All these health care providers agree with the free access to emergency contraception (EC), but experience considerable frustration with regard to the practical aspects and the legal framework. General practitioners (GPs) claim to spend a lot of time on requests for EC and they are concerned about the quality of the counselling provided in pharmacies. Pharmacists are creative when giving counselling in the pharmacy, but there is, nevertheless, a problem with a lack of privacy. School physicians are frustrated that there is no legal possibility to respond to a request for EC when they feel they are ideally placed to advise adolescents. CONCLUSION: The over-the-counter sale of EC offers women better access, but many barriers still interfere with optimal care. Pharmacists experience a lack of skills to communicate with adolescents and a lack of privacy to give counselling. GPs have good intentions, but are confronted with a lack of willingness on the part of the patients and also financial barriers. School physicians want more possibilities to help adolescents. 相似文献
5.
6.
可逆性胆硷酯酶抑制剂二甲氨基甲酸-5-二氢吲哚酯的合成 总被引:1,自引:0,他引:1
为了深入研究催醒宁类化合物的结构与抑酶活性的关系,设计合成了-系列1-,3-或5-位不同取代的二氢吲哚类衍生物(中间体和终产物共24个新化合物)。中间体1,3-二甲基-5-烷氧基-2-二氢吲哚酮(A)的C3烷化。采用相转移催化方法进行;反应中还分离到三个副产物(Ⅶ~Ⅸ)。初筛结果表明:这些化合物大多有较强的抑酶活性;1,3-或5-位取代基的改变均明显影响其活性。 相似文献
7.
Braffman BH; Coleman BG; Ramchandani P; Arger PH; Nodine CF; Dinsmore BJ; Louie A; Betsch SE 《Radiology》1994,190(3):797
8.
Veronique Verhoeven Lieve Peremans Dirk Avonts Paul Van Royen 《The European journal of contraception & reproductive health care》2006,11(3):175-180
INTRODUCTION: We describe the use of emergency contraception (EC) and its association with sociodemographic, contraceptive and behavioural characteristics in a sample of family practice attendants in Belgium. METHODS: The study was part of a large Chlamydia trachomatis (CT) prevalence study in general practice. Sexually active women under 40 who consulted their general practitioner for routine gynaecological care were enrolled in the study. Participants completed a questionnaire on sociodemographic variables, urogenital symptoms, sexual history and sexual behaviour, and delivered a sample for CT testing. Logistic regression analysis was performed to identify determinants of a history of EC use in women in this sample. RESULTS: Of 815 questioned women, 23.5% had ever used EC. EC users were a heterogeneous group with respect to educational level, age and ethnicity. The use of emergency contraception was associated with the level of urbanisation, condom use, not having children yet, young age of first sexual intercourse, having had multiple partners in the past year, a history of unintended pregnancy, and current or previous STI. DISCUSSION: Information on availability and correct use of EC, and on the need for additional testing for STI, are necessary to help primary care attendees to preserve their future reproductive health. 相似文献
9.
Arjan C. Lankester Gijs M. W. Van Schijndel Pauline M. L. Rood Arthur J. Verhoeven Ren A. W. Van Lier 《European journal of immunology》1994,24(11):2818-2825
The SH2 domain-containing transforming Shc protein has been implicated in mitogenic signaling via several surface receptors through p21ras. Following tyrosine phosphorylation by either receptor or non-receptor tyrosine kinases, Shc may interact with the adaptor protein Grb2, which is linked to Sos1, a guanine nucleotide exchange factor for human ras. Ligation of the antigen receptor complex on B cells (BCR) is known to activate various intracellular signaling pathways, which may accumulate in mitogenic responses. With respect to the initial steps, the activation of BCR-associated non-receptor tyrosine kinases appears to be indispensible. In this report we show that Shc proteins become tyrosine phosphorylated after BCR ligation on both transformed and normal human B cells. This is accompanied by the association of Shc with Grb2 proteins and a yet unidentified 145-kDa tyrosine phosphorylated protein. Subcellular fractionation revealed that this activation-induced multimeric Shc complex rapidly translocates towards the plasma membrane. Co-ligation of the BCR with the CD19 molecule results in a marked increase of these events, whereas CD19 cross-linking alone does not induce Shc tyrosine phosphorylation or translocation. Thus, in B cells the Shc complex may represent a molecular junction between the BCR and the mitogenic p21ras cascade. 相似文献
10.
D. Y. Mason W. M. Comans-Bitter J. L. Cordell M. A. Verhoeven J. J. van Dongen 《The American journal of pathology》1990,136(6):1215-1222
Monoclonal antibody L26 is a highly selective marker of B cells and B-cell neoplasms in paraffin-embedded tissues, but it suffers from the drawback that the target molecule has not been identified. In this paper we provide evidence by two independent techniques that antibody L26 recognizes an intracellular epitope on the CD20 antigen (a pan B-cell marker). When this antigen was redistributed on the surface of unfixed viable B cells by incubation with monoclonal anti-CD20 followed by anti-mouse Ig, the diffuse cytoplasmic staining of L26 was abolished and replaced by coincident dotlike labeling for antibody L26 and the CD20 antigen. None of the other antibodies tested (covering 10 different B-cell-associated antigens) had this effect on the L26 staining pattern. Furthermore, COS-1 cells transfected with cDNA encoding the CD20 molecule gave positive staining with antibody L26 and with two other CD20 reagents, but not with antibodies to other pan B-cell markers (eg, CD19 and CD22). 相似文献