Identification and characterization of novel uroporphyrinogen decarboxylase gene mutations in a large series of porphyria cutanea tarda patients and relatives

Porphyria cutanea tarda (PCT) arises from decreased hepatic activity of uroporphyrinogen decarboxylase (UROD). Both genetic and environmental factors interplay in the precipitation of clinically overt PCT, but these factors may vary between different geographic areas. Decreased activity of UROD in erythrocytes was used to identify patients with UROD mutations among a group of 130 Spanish PCT patients. Nineteen patients (14.6%) were found to harbor a mutation in the UROD gene. Eight mutations were novel: M1I, 5del10, A22V, D79N, F84I, Q116X, T141I and Y182C. Five others were previously described: F46L, V134Q, R142Q, P150L and E218G. The new missense mutations and P150L were expressed in Escherichia coli. D79N and P150L resulted in proteins that were localized to inclusion bodies. The other mutations produced recombinant proteins that were purified and showed reduced activity (range: 2.3–73.2% of wild type). These single amino acid changes were predicted to produce complex structural alterations and/or reduced stability of the enzyme. Screening of relatives of the probands showed that 37.5% of mutation carriers demonstrated increased urinary porphyrins. This study emphasizes the role of UROD mutations as a strong risk factor for PCT even in areas where environmental factors (hepatitis C virus) have been shown to be highly associated with the disease.     

变应性鼻炎脱敏治疗的效果观察

目的观察变应性鼻炎（AR）脱敏治疗的效果，探讨影响变应性鼻炎脱敏治疗效果的相关因素。方法对185例AR患者通过皮肤试验，选择敏感变应原浸液，按递增剂量进行常规皮下脱敏治疗。根据患者治疗前后的症状和体征得分情况，分为显效、有效和无效。选择性别、年龄、病程、病情、伴慢性鼻窦炎、伴哮喘、脱敏治疗时间、皮试反应等8个影响变应性鼻炎脱敏治疗效果的可能因素进行多元回归分析，筛查影响脱敏治疗效果的因素。结果总有效率74．6％，其中显效22．9％，有效51．7％。影响脱敏治疗效果的主要因素是治疗时间，即时间越长，效果越好（P〈0．01）；其次是年龄因素，年龄越小，效果越好（P〈0．05）；伴慢性鼻窦炎和伴哮喘也可能影响脱敏治疗效果（P值分别为0．072和0．069）。结论变应性鼻炎脱敏治疗是有效的，脱敏治疗时间越长、年龄越小，效果越好。     

Intracranial venous sinus thrombosis in nephrotic syndrome]

A 3-year old child was admitted for a third relapse of nephrotic syndrome associated with intracranial hypertension related to dural sinus thrombosis (tomodensitometry). The treatment consisted in the association of low dose heparin and fresh frozen plasma. After a 3 year-follow-up, there was no neurologic sequelae, and the nephrotic syndrome was on complete remission. The radiologic features and the management of sinus thrombosis are discussed.     

下肢骨肉瘤的MRI与X线对照研究

目的 对比分析下肢骨肉瘤的X线与MRI表现，探讨MRI对骨肉瘤的诊断价值。方法 收集经手术或病理穿刺活检证实的下肢骨肉瘤15例，男11例，女4例，均行MRI平扫及增强扫描（4例行CT扫描），并摄有X线平片，对其MRI征象与X线征象作逐一对比。结果 MRI及X线平片对下肢骨肉瘤的诊断准确率均为100％，MRI在显示病变范围、放射状骨针、Codman三角两层结构以及跳跃病灶等方面明显优于X线平片检查。结论 X线平片是诊断骨肉瘤最简便而实用的方法，但MRI可以更好的显示病变的范围，发现早期病变。     

头皮原发性皮肤神经节细胞瘤

神经节细胞瘤是一种神经内分泌肿瘤，其发生与自主神经系统的交感或副交感神经节有关。罕见发生于膀胱、前列腺和子宫。本文作者报道1例发生于儿童头皮的原发性皮肤神经节细胞瘤。对此肿瘤进行了组织学、免疫组化和超微结构研究。该病例可能代表神经嵴细胞向鳃弓发育过程中的一种异常迁移。此外，研究结果还强调在胚胎发育过程中神经嵴和鳃弓／裂之间有复杂的相互作用。     

Do all girls with apparent idiopathic precocious puberty require gonadotropin-releasing hormone agonist treatment?

OBJECTIVE: To evaluate prospectively pubertal and predicted adult height progression until final height (FH) or near FH in girls with apparent idiopathic precocious puberty who were not treated. STUDY DESIGN: The decision not to treat at the time of initial evaluation was based on evidence of slowly progressive puberty as shown by bone age (BA) advancement <2 years above the chronologic age, whatever the hypothalamic pituitary ovarian axis activation, or no evidence of hypothalamic pituitary ovarian axis activation, whatever the BA advancement. During follow-up, patients who showed a significant decrease in predicted FH were treated with gonadotropin-releasing hormone agonist. RESULTS: Twenty-six girls with idiopathic precocious puberty were studied at a mean chronologic age of 7.4 +/- 0.9 years during a follow-up period of 6.6 +/- 2.2 years until FH or near FH. During the first 2 years of follow-up, most of the patients (group 1, n = 17; 65% of the cases) showed no substantial changes in predicted FH. They never required treatment, and menarche occurred at a mean chronologic age of 11.9 +/- 0.6 years. Their mean FH (or near FH) at 160.7 +/- 5.7 cm was close to their target height (161.3 +/- 4.7 cm). On the other hand, after a mean follow-up period of 1.4 +/- 0.8 years, 9 patients (group 2) had acceleration of bone maturation and deterioration of their predicted FH (from 162.1 +/- 6. 2 cm to 155.3 +/- 5.6 cm; P <.01), which was at that time significantly lower than their target height (P <.05) (mean target height = 159.8 +/- 4.6 cm). They received a gonadotropin-releasing hormone agonist for 2.1 +/- 0.7 years, resulting in a restoration of growth prognosis (mean FH or near FH = 160.2 +/- 6.7 cm). CONCLUSIONS: This study demonstrates that not all patients with apparent idiopathic precocious puberty require medical treatment, notably when there is no evidence of hypothalamo-pituitary ovarian activation or no significantly advanced BA to impair height potential. Most show a slowly progressing puberty. However, careful follow-up of these patients is necessary up to at least 9 years of age, because until then height prediction may deteriorate, necessitating gonadotropin-releasing hormone agonist treatment in one third of the cases.