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101.
102.
Marieke E. Altink Alejandro Arias‐Vásquez Barbara Franke Dorine I.E. Slaats –Willemse Cathelijne J.M. Buschgens Nanda N.J. Rommelse Ellen A. Fliers Richard Anney Keeley‐Joanne Brookes Wai Chen Michael Gill Aisling Mulligan Edmund Sonuga‐Barke Margaret Thompson Joseph A. Sergeant Stephen V. Faraone Philip Asherson Jan K. Buitelaar 《Journal of child psychology and psychiatry, and allied disciplines》2008,49(10):1053-1060
Background: The dopamine receptor D4 (DRD4) 7‐repeat allele and maternal smoking during pregnancy are both considered as risk factors in the aetiology of attention deficit hyperactivity disorder (ADHD), but few studies have been conducted on their interactive effects in causing ADHD. The purpose of this study is to examine the gene by environment (G×E) interaction of the DRD4 7‐repeat allele and smoking during pregnancy on ADHD and oppositional behavior in families from the International Multicenter ADHD Genetics project; and further, to test the hypothesis that the direction of effect of the DRD4 7‐repeat allele differs between ADHD affected and unaffected children. Methods: Linear mixed models were used to assess main and interactive effects of the DRD4 7‐repeat allele and smoking during pregnancy in 539 ADHD‐affected children and their 407 unaffected siblings, aged 6–17 years. Results: There was some evidence pointing to differential effects of the DRD4 7‐repeat allele on ADHD and oppositional symptoms in the affected (fewer symptoms) and unaffected children (increasing ADHD symptoms of teacher ratings). Affected children were more often exposed to prenatal smoking than unaffected children. There were limited main effects of prenatal smoking on severity of symptoms. Given the number of tests performed, no indication was found for G×E interactions. Conclusion: Despite the large sample size, no G×E interactions were found. The impact of the DRD4 7‐repeat allele might differ, depending on affected status and rater. This finding is discussed in terms of differences in the activity of the dopaminergic system and of different genes involved in rater‐specific behaviors. 相似文献
103.
Perkins SN; Hursting SD; Haines DC; James SJ; Miller BJ; Phang JM 《Carcinogenesis》1997,18(5):989-994
Transgenic mice with both alleles of the p53 tumor suppressor gene product
'knocked out' by gene targeting are susceptible to early development of
tumors, chiefly lymphomas and sarcomas. Compared with the control group,
administration of dehydroepiandrosterone (DHEA) at 0.3% of the diet to male
p53-deficient mice extended their lifespan by delaying death due to
neoplasms (from 105 to 166 days on study, P = 0.002), primarily by
suppressing lymphoblastic lymphoma (from 45 to 6% of neoplastic deaths, P =
0.010). Treatment with a synthetic DHEA analog,
16alpha-fluoro-5-androsten-17-one (compound 8354), at 0.15% of the diet
also increased lifespan, to 140 days for mice that developed tumors (P =
0.037). The effects of these steroids on lifespan and tumor development did
not appear to be strongly related to inhibition of food consumption and
weight gain, in that a group pair-fed with control diet to the reduced food
consumption of the DHEA-treated group developed and died of the same types
of neoplasms at the same rate as the controls fed ad libitum. The
chemopreventive effect of these steroids has been proposed to be due to
suppression of DNA synthesis by inhibition of glucose 6-phosphate
dehydrogenase, the rate-limiting enzyme of the pentose phosphate pathway.
Although DHEA and its analog are strong non- competitive inhibitors of this
enzyme in vitro, treatment with DHEA did not deplete cellular nucleotide
pools in the liver, as would have been predicted. The chemopreventive
effect of DHEA in this model may be due to steroid-induced thymic atrophy
and suppression of T cell lymphoma, permitting these mice to survive long
enough to develop tumors with longer latency.
相似文献
104.
105.
Bone blood pH and gas tensions after femoral vein ligation 总被引:1,自引:0,他引:1
106.
The diagnosis of CSF rhinorrhoea on clinical grounds alone can be difficult. We describe how the use of non-invasive electrophoretic analysis of nasal secretions for tau protein (asialotransferrin) helped in the management of cases where the existence of a CSF leak was in doubt. Patients were thus saved unnecessary invasive investigations or surgery. A modification of the method of analysis, which improves diagnostic accuracy, is described. 相似文献
107.
In a patient with primary hyperparathyroidism an attempt was made to ablate a middle mediastinal parathyroid gland by forceful staining with radiographic contrast material. The gland was stained on two separate occasions, two weeks apart. Both times the serum calcium level temporarily fell to the normal range but reverted to abnormal levels. The patient ultimately required surgery for correction of hypercalcemia. The mechanism of staining and possible reasons for failure as well as potential complications are discussed. 相似文献
108.
109.
110.
Gallium-67 lung uptake: conjugate-view technique 总被引:1,自引:0,他引:1
A conjugate-view technique is derived for calculation of absolute gallium-67 (Ga-67) uptake from scintillation-camera images. The technique combines counts of posterior and anterior images of the lung with an attenuation correction obtained from cobalt-57 (Co-57) transmission imaging. The formulation is such that the effects of Compton scatter build-up are accounted for. Studies utilizing a canine model indicated that, normally, more activity is located in the chest wall than in the lungs. The quantitative technique must therefore accurately account for a variety of Ga-67 distributions, including that in the chest wall. Calculations were performed using a three-component model comparing results obtained with the conjugate-view approach to the actual uptake. These calculations suggest that an assumption of uniform activity distribution allows an accuracy of approximately +/- 10% over a broad range of body-part thicknesses and uptake by the lungs. It was concluded that the conjugate-view technique is necessarily approximate but can provide clinically useful results. 相似文献