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1.
ABSTRACTAlthough communication about sexuality is a significant pathway through which peers influence adolescent sexual development, little research has examined the role of peer networks in the use of sexualized media. We applied a social network approach to assess the role of close peers in adolescent pornography use and sexting in a sample of Croatian high school students. Sexual conversation networks’ characteristics did not correlate with pornography use. In contrast, sexting was associated with the proportion of same gender peers, the proportion of older peers and the proportion of sexually experienced peers in the network – pointing to the role of peer influence. Participants’ gender did not moderate these associations. Specific mechanisms underlying the observed associations and the role of peer selection remain important tasks for future research. 相似文献
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Effect of leptin on the regulation of placental hormone secretion in cultured human placental cells.
Raquel Coya Pedro Martul Jaime Algorta Ma Angeles Aniel-Quiroga Ma Angeles Busturia Rosa Se?arís 《Gynecological endocrinology》2006,22(11):620-626
Placenta is an important source of leptin during pregnancy that contributes to the high plasma leptin levels in pregnant women. Leptin and its functional receptors are synthesized in trophoblast cells that, in turn, secrete gestational hormones supporting a paracrine or autocrine role for leptin in the endocrine activity of the placenta. In the present study we examined the effect of leptin on in vitro release of gestational hormones (human chorionic gonadotropin (hCG), human placental lactogen (hPL), progesterone, estrogens and testosterone) by human term placental cells in culture. Placentas at term were obtained immediately after delivery from mothers with uncomplicated pregnancies. Progesterone, hCG, hPL, estradiol, estrone, estriol and testosterone levels were measured by different assays in culture media of cells maintained in monolayer culture after incubation for 12, 24, 48 or 72 h with leptin or placebo. Incubation with leptin did not modify hCG, hPL, progesterone, estriol and estrone secretion for any of the doses and times assayed. However, leptin led to a dose-dependent decrease in estradiol release. This effect was observed when treatment with recombinant human leptin spanned from 12 to 72 h. At this time an increase in testosterone levels was observed in leptin-treated cells versus placebo. These results indicate that leptin can be considered a gestational hormone implied in the endocrine function of the placenta, with an important role in control of the production of steroid reproductive hormones in placental cells in vitro. 相似文献
4.
U. Logonder Z. Jenko-Pranikar T. Scott-Davey J. Punger
ar I. Kriaj J.B. Harris 《Experimental neurology》2009,219(2):591-594
A mutant form of ammodytoxin A, a neurotoxic phospholipase A2 from the venom of the long nosed viper Vipera ammodytes ammodytes, was prepared by site-directed mutagenesis, conjugated to a nanogold particle and inoculated into the antero-lateral aspect of one hind limb of female mice. Eight hours later the mice were killed, the soleus muscles of both ipsi- and contra-lateral hind limbs were removed, exposed to a silver enhancing medium and then prepared for transmission electron microscopy. Silver-enhanced particles were subsequently found concentrated in the peri-synaptic area, particularly within the synaptic gutter and the deep synaptic folds, and in many cases had been taken up into the cytoplasm of the terminal boutons of the motor axon. The results suggest that the presynaptic neurotoxicity of snake venom phospholipases A2 involves several components of the neuromuscular apparatus, including intracellular organelles of the motor nerve terminal. 相似文献
5.
Background
Reports on childhood cancer survivors estimated cumulative probability of developing secondary neoplasms vary from 3,3% to 25% at 25 years from diagnosis, and the risk of developing another cancer to several times greater than in the general population. 相似文献6.
7.
Birsen Uçar Ayten Yakut Nurdan Kural Ferit Büyükaşık Erkan Vardareli 《Pediatric nephrology (Berlin, Germany)》1997,11(1):31-35
.We report five patients with Laurence-Moon-Bardet-Biedl syndrome (LMBBS) who had renal involvement. Intravenous pyelography
showed bilateral or unilateral calyceal clubbing and blunting in all patients. In addition, one patient had a parapelvic cyst
in the left kidney and another had bilateral lobulated renal outlines of the fetal type. One patient had a urinary concentrating
defect and two patients showed increased fractional sodium excretion. Estimated tubular phosphate reabsorption values were
in normal limits in all of five patients. No patient had a urine acidification defect, proteinuria, glycosuria, or hyperaminoaciduria.
One patient died from end-stage renal failure. The remaining four patients had normal serum creatinine values and estimated
creatinine clearances. 99mTechnetium-diethylenetriamine pentaacetate renal scanning showed prolonged and delayed concentration and delayed excretion
in three of the four patients who survived. A focal scar was determined on the left kidney of one of four patients by 99mtechnetium-dimercaptosuccinic acid renal scanning. All LMBBS cases with or without renal symptoms should be routinely evaluated
for renal abnormalities. Renal scanning is a valuable method, especially for determining the renal involvement in the early
stage of disease.
Received November 14, 1995; received in revised form and accepted May 23, 1996 相似文献
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9.
The temporal bones from fetuses with known autosomal trisomy syndromes were examined histopathologically after spontaneous or induced abortions. Fetal ages dated from the 17th to the 24th week of pregnancy. In all, 17 temporal bones from nine fetuses were studied and included seven cases of Down's syndrome and two of Edwards' syndrome. Temporal bones from fetuses with Down's syndrome had more abnormalities of the external and middle ears than of the inner ear. The bones from the fetuses with Edwards' syndrome showed abnormalities of the external or middle ear and retarded development of the inner ear (failed ossification of the otic capsule and unformed organ of Corti). 相似文献
10.
D Portmann F Gharbi V Darrouzet J P Bébéar M Portmann 《Revue de laryngologie - otologie - rhinologie》1991,112(5):441-443
Post-traumatic facial palsies are generally observed after a transverse, longitudinal or comminuted fracture of the pars petrosa. Occasionally, the fracture does not involve the Fallopian aqueduct and another mechanism must be sought. The authors present a case of facial palsy that occurred after a Le Fort's fracture of the base of the skull, not involving the Fallopian aqueduct on the CT scan. This was confirmed by surgical exploration. The authors recall the possibility of a facial palsy through the stretching of the nerve by the petrosal nerve. 相似文献