首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21篇
  免费   6篇
儿科学   2篇
基础医学   7篇
内科学   14篇
神经病学   1篇
外科学   3篇
  2019年   1篇
  2018年   3篇
  2015年   3篇
  2012年   1篇
  2011年   3篇
  2010年   1篇
  2009年   1篇
  2007年   2篇
  2006年   1篇
  2004年   2篇
  2003年   1篇
  2002年   3篇
  2001年   2篇
  1999年   2篇
  1995年   1篇
排序方式: 共有27条查询结果,搜索用时 15 毫秒
1.
Male‐to‐female transsexual persons use oestrogens + antiandrogens to adapt their physical bodies to the female sex. Doses are usually somewhat higher than those used by hypogonadal women receiving oestrogen replacement. Particularly in cases of self‐adminstration of cross‐sex hormones, doses may be very high. Oestrogens are powerful stimulators of synthesis and release of prolactin and serum prolactin levels are usually somewhat increased following oestrogen treatment. Prolactinomas have been reported in male‐to‐female transsexual persons, both after use of high and conventional doses of oestrogens but remain rare events. We report two new cases of prolactinomas in male‐to‐female transsexual persons, one in a 41‐year‐old subject who had used nonsupervised high‐dose oestrogen treatment since the age of 23 years and another one in a 42 year old who had initiated oestrogen treatment at the age of 17 years. Their serum prolactin levels were strongly increased, and the diagnosis of a pituitary tumour was confirmed by imaging techniques. Both cases responded well to treatment with cabergoline treatment whereupon serum prolactin normalised. Our two cases are added to the three cases of prolactinomas in the literature in persons who had used supraphysiological doses of oestrogens.  相似文献   
2.
The gonadotropin releasing hormone (GnRH) secreting hypothalamic hamartoma (HH) is a congenital malformation consisting of a heterotopic mass of nervous tissue that contains GnRH neurosecretory neurons attached to the tuber cinereum or the floor of the third ventricle. HH is a well recognised cause of gonadotropin dependent precocious puberty (GDPP). Long term data are presented on eight children (five boys and three girls) with GDPP due to HH. Physical signs of puberty were observed before 2 years of age in all patients. At presentation with sexual precocity, the mean height standard deviation (SD) for chronological age was +1.60 (1.27) and the mean height SD for bone age was -0.92 (1.77). Neurological symptoms were absent at presentation and follow up. The hamartoma diameter ranged from 5 to 18 mm and did not change in six patients who had magnetic resonance imaging follow up. All patients were treated clinically with GnRH agonists (GnRH-a). The duration of treatment varied from 2.66 to 8.41 years. Seven of the eight children had satisfactory responses to treatment, shown by regression of pubertal signs, suppression of hormonal levels, and improvement of height SD for bone age and predicted height. One patient had a severe local reaction to GnRH-a with failure of hormonal suppression and progression of pubertal signs. It seems that HH is benign and that GnRH-a treatment provides satisfactory and safe control for most children with GDPP due to HH.  相似文献   
3.
Mutations of the p53 tumor suppressor gene are the single most common genetic alterations in human cancers. Recently, a distinct nucleotide substitution was identified in exon 10 of the p53 gene, leading to an Arg337His mutation in 97% of children with adrenocortical tumors from Southern Brazil. In the present study, we investigated the presence of this mutation in a larger series of 55 patients (37 adults and 18 children) with benign and malignant sporadic adrenocortical tumors. None of the patients had family cancer histories that conformed to the criteria for Li-Fraumeni syndrome. Twenty-one asymptomatic close relatives of patients with p53 mutations and 60 normal unrelated individuals were also studied. The missense Arg337His mutation was identified in 19 patients (14 children and 5 adults), and 8 of 11 cases studied had LOH. Among the 19 patients with the Arg337His mutation, only one boy and three adults showed fatal evolution or recurrent metastases. This mutation was also identified in heterozygous state in asymptomatic first-degree relatives of the patients, indicating that Arg337His mutation was inherited in most cases. In contrast, this mutation was not found in 120 alleles of normal unrelated controls. In conclusion, the germ line Arg337His mutation of p53 protein is present at a high frequency (77.7%) in children with benign or malignant sporadic adrenocortical tumors, but it is not restricted to the pediatric group, since 13.5% of adults with adrenocortical tumors also had this mutation. The presence of this mutation was related to unfavorable prognosis in most of the adults, but not in the children with adrenocortical tumors.  相似文献   
4.
The aim of this article is to present and discuss several aspects of the pathogenesis, the clinical, hormonal, and imaging diagnosis, and the treatment of Nelson's syndrome, based on a typical patient's report, in whom several therapeutic approaches were shown to be ineffective.  相似文献   
5.
The occurrence of metachronous adrenocortical carcinoma has rarely been described. We report a case of a child with virilizing adrenocortical metachronous tumors that, despite several metastases, presented long-term survival (15 years). We analyzed in this tumor IGF2, IGF1R and FGFR4 gene expression, and evaluated the presence of p.R337H germline p53 mutation and somatic CTNNB1 mutation. IGF2 gene was over-expressed in both left (Weiss score 5) and right (Weiss 7) adrenocortical tumors. IGF1R expression levels were higher in the right adrenocortical tumor. FGFR4 over-expression was also detected in the right adrenocortical tumor. In addition, this patient harbors the germline p.R337H p53 mutation and loss of heterozygosity (LOH) was detected in the tumors. No somatic CTNNB1 mutations were found in both tumors. In conclusion, we demonstrated in this unusual case the over-expression of growth signaling pathways, which are molecular mechanisms previously related to adrenocortical tumorigenesis. Furthermore, the absence of somatic CTNNB1 mutations, which is a molecular marker of poor prognosis in adults, might be related to the long-term survival of this patient.  相似文献   
6.
7.
8.
WT1 mutations have been described in a variety of syndromes, including Denys-Drash syndrome (DDS), which is characterized by predisposition to Wilms’ tumor, genital abnormalities and development of early nephropathy. The most frequent WT1 defects in DDS are missense mutations located in exons 8-9. Our aim is to report a novel WT1 mutation in a 46,XY patient with a DDS variant, who presented a mild nephropathy with a late onset diagnosed during adolescence. He had ambiguous genitalia at birth. At 4 months of age he underwent nephrectomy (Wilms’ tumor) followed by chemotherapy. Ambiguous genitalia were corrected and bilateral gonadectomy was performed. Sequencing of WT1 identified a novel heterozygous mutation (c.742A>T) in exon 4 that generates a premature stop codon (p.K248X). Interestingly, this patient has an unusual DDS nephropathy progression, which reinforces that patients carrying WT1 mutations should have the renal function carefully monitored due to the possibility of late-onset nephropathy.  相似文献   
9.
Despite advances in our understanding of the mechanisms involved in sex determination and differentiation, the specific roles of many genes in these processes are not completely understood in humans. Both DMRT1 and FGF9 are among this group of genes. Dmrt1 controls germ cell differentiation, proliferation, migration and pluripotency and Sertoli cell proliferation and differentiation. Fgf9 has been considered a critical factor in early testicular development and germ cell survival in mice. We screened for the presence of DMRT1 and FGF9 mutations in 33 patients with 46,XY gonadal dysgenesis. No deletions in either DMRT1 or FGF9 were identified using the MLPA technique. Eight allelic variants of DMRT1 were identified, and in silico analysis suggested that the novel c.968-15insTTCTCTCT variant and the c.774G>C (rs146975077) variant could have potentially deleterious effects on the DMRT1 protein. Nine previously described FGF9 allelic variants and six different alleles of the 3’ UTR microsatellite were identified. However, none of these DMRT1 or FGF9 variants was associated with increased 46,XY gonadal dysgenesis. In conclusion, our study suggests that neither DMRT1 nor FGF9 abnormalities are frequently involved in dysgenetic male gonad development in patients with non-syndromic 46,XY disorder of sex development.  相似文献   
10.
Primary adrenal insufficiency is a rare condition in pediatric age, and its association with precocious sexual development is very uncommon. We report a 2-yr-old Brazilian boy with DAX1 gene mutation whose first clinical manifestation was isosexual gonadotropin-independent precocious puberty. He presented with pubic hair, enlarged penis and testes, and advanced bone age. T levels were elevated, whereas basal and GnRH-stimulated LH levels were compatible with a prepubertal pattern. Chronic GnRH agonist therapy did not reduce T levels, supporting the diagnosis of gonadotropin-independent precocious puberty. Testotoxicosis was ruled out after normal sequencing of exon 11 of the LH receptor gene. At age 3 yr he developed clinical and hormonal features of severe primary adrenal insufficiency. The entire coding region of the DAX1 gene was analyzed through direct sequencing. A nucleotide G insertion between nucleotides 430 and 431 in exon 1, resulting in a novel frameshift mutation and a premature stop codon at position 71 of DAX-1, was identified. Surprisingly, steroid replacement therapy induced a clear decrease in testicular size and T levels to the prepubertal range. These findings suggest that chronic excessive ACTH levels resulting from adrenal insufficiency may stimulate Leydig cells and lead to gonadotropin-independent precocious puberty in some boys with DAX1 gene mutations.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号