Clinical and pathologic findings in hemochromatosis type 3 due to a novel mutation in transferrin receptor 2 gene

BACKGROUND & AIMS: Although most patients with hereditary hemochromatosis are homozygous for a single mutation of the HFE gene on chromosome 6p, accumulating evidence indicates that the disease is genetically heterogeneous. Type 3 hemochromatosis, recently described in 4 families, is linked to mutations of the gene encoding transferrin receptor 2 on chromosome 7q22. Here we report data from a family carrying a new mutation of the transferrin receptor 2 gene. METHODS: Detailed clinical and histopathologic documentation was available for most family members. The entire coding sequence and exon/intron boundaries of the transferrin receptor 2 gene were analyzed by direct sequencing. RESULTS: A 12-nucleotide deletion in exon 16, causing the loss of 4 amino acids (AVAQ 594-597 del), was detected at the homozygous state in the 3 patients with histologically proven iron overload. The deletion segregated with the disease within the family and was not found in 100 healthy controls. Some clinical and pathologic characteristics, such as low penetrance in the premenopausal woman, and early iron deposition in periportal hepatocytes resembled those of classic, HFE-related hemochromatosis. CONCLUSIONS: Our data support the role of the transferrin receptor 2 gene in hemochromatosis type 3 as well as its critical involvement in the maintenance of iron homeostasis in humans.     

Time-divided ingestion pattern of casein-based protein supplement stimulates an increase in fat-free body mass during resistance training in young untrained men

We hypothesized that during prolonged resistance training, time-divided ingestion pattern of casein-based protein supplement is of superior efficiency in comparison with the ingestion of the same supplement immediately before each training session. In a crossover study, 13 men aged 18 to 19 years were evaluated during 2 well-controlled, 8-week training and supplementation periods. In the time-focused supplementation regimen (TFR), the subjects consumed the supplement in the morning and in the afternoon, immediately before the training session. Time-divided supplementation regimen (TDR) included 1 morning dose, whereas the second dose was ingested in the evening, 5 hours after training. The daily dose of the supplement contained approximately 70 g of protein (82% casein) and less than 1 g of carbohydrate and fat. Body mass, body composition (dual-energy x-ray absorptiometry scanned), and one-repetition maximum (1RM) for bench press and squat were determined at the beginning and at the end of both 8-week training and supplementation periods. Training produced a significant increase in 1RM strength both in the bench press (9.4% and 7.2%) and the squat exercise (10.7% and 17.8%) in the TFR and TDR, respectively, with no differences between the supplementation regimens. Fat-free mass increased from 62.4 ± 1.2 to 63.5 ± 1.3 kg (P = .046) with TDR, whereas no change was evident with TFR. The increase in 1RM strength in the squat exercise was related to the increase in fat-free mass in TDR (r = 0.569; P = .041). These findings may have practical implications for the timing of ingestion of protein supplements to enhance the efficacy of resistance training.     

Facial emotion perception in Chinese patients with schizophrenia and non-psychotic first-degree relatives

Although there is a consensus that patients with schizophrenia have certain deficits in perceiving and expressing facial emotions, previous studies of facial emotion perception in schizophrenia do not present consistent results. The objective of this study was to explore facial emotion perception deficits in Chinese patients with schizophrenia and their non-psychotic first-degree relatives. Sixty-nine patients with schizophrenia, 56 of their first-degree relatives (33 parents and 23 siblings), and 92 healthy controls (67 younger healthy controls matched to the patients and siblings, and 25 older healthy controls matched to the parents) completed a set of facial emotion perception tasks, including facial emotion discrimination, identification, intensity, valence, and corresponding face identification tasks. The results demonstrated that patients with schizophrenia performed significantly worse than their siblings and younger healthy controls in accuracy in a variety of facial emotion perception tasks, whereas the siblings of the patients performed as well as the corresponding younger healthy controls in all of the facial emotion perception tasks. Patients with schizophrenia also showed significantly reduced speed than younger healthy controls, while siblings of patients did not demonstrate significant differences with both patients and younger healthy controls in speed. Meanwhile, we also found that parents of the schizophrenia patients performed significantly worse than the corresponding older healthy controls in accuracy in terms of facial emotion identification, valence, and the composite index of the facial discrimination, identification, intensity and valence tasks. Moreover, no significant differences were found between the parents of patients and older healthy controls in speed after controlling the years of education and IQ. Taken together, the results suggest that facial emotion perception deficits may serve as potential endophenotypes for schizophrenia.     

铁跨膜转运蛋白与脑神经疾病的相关性研究进展

铁是人体内必不可少的微量元素,细胞的氧化代谢及免疫应答、红细胞的生成等都有铁元素的参与[1]。人体可以利用两种形式的铁,非血红素铁和血红素铁。通过文献归纳、整理,我们率先总结出铁在体内细胞转运的工作模式:两个中心,三个体系,网络调控。两个中心:铁的细胞转运调节是以铁调素及胞     

何首乌复方结合90min运动对饮食所致高胆固醇血症SD大鼠体脂及血清指标的影响研究

目的探讨何首乌复方结合90min游泳运动对高脂饮食SD大鼠体脂及血清指标的影响。方法将56只雄性SD大鼠,随机分为5组:基础组、高脂组、运动组、药物组、运动药物组,饲喂基础和高脂饲料,进行游泳运动和何首乌复方灌胃。喂养8周后,测体质量、体长,取血检测血清指标,解剖取内脏及脂肪垫称重。结果高脂组Lee′s指数与基础组比较极显著(P<0.01),说明高脂饮食对SD大鼠的肥胖模型建造成功。与高脂组相比,药物组大鼠体质量下降(P<0.01),运动药物组左侧附睾脂肪垫下降(P<0.01)且左侧肾周脂肪垫下降(P<0.05),运动组、药物组、运动药物组皮褶厚度下降(P<0.01),药物组总胆固醇(TC)下降(P<0.01)且三酰甘油(TG)下降(P<0.05)。结论何首乌复方能降低大鼠体质量;与90min游泳运动协同有减脂肪作用;对保护心血管有益。     

TFR和VEGF基因双顺反子慢病毒感染骨髓内皮祖细胞的研究

目的:研究转铁蛋白受体 (transferrin receptor,TFR)和血管内皮生长因子(vascular endothelial growth factor,VEGF)的双基因共表达慢病毒载体是否能介导目的基因在中华小型猪骨髓内皮祖细胞（endothelial progenitor cells,EPCs）中的有效表达。方法:通过分子克隆技术构建双顺反子慢病毒表达载体pLenti-GFP-TIR;分离培养中华小型猪骨髓EPCs,用流式细胞仪(FCM)检测细胞表面抗原CD31和Flk-1的表达;并利用Lipofectin 2000将含目的基因的转移质粒与pRsv-REV、pMDlg-pRRE及pMD2G共转染293T细胞并进行慢病毒包装。72 h后,收集病毒上清,感染中华小型猪骨髓EPCs,并通过RT-PCR法检测TFR和VEGF基因的表达。结果:①成功地构建了双顺反子慢病毒表达载体pLenti-GFP-TIR;②FCM检测证实,分离的细胞为骨髓EPCs;包装好的慢病毒颗粒可成功地感染中华小型猪骨髓EPCs;③RT-PCR法检测表明,TFR和VEGF呈高水平的表达。结论:TFR和VEGF基因双顺反子慢病毒载体Lenti-GFP-TIR可有效地转移目的基因至中华小型猪骨髓EPCs中,并成功地表达目的基因,为进一步探讨移植细胞分子成像奠定了基础。     

Type 3 hemochromatosis and beta-thalassemia trait

Type 3 hemochromatosis is a rare autosomal recessive disorder due to mutations of the TFR2 gene. We describe clinical, biochemical and histopathologic findings of a patient with type 3 hemochromatosis at presentation and during a follow-up of more than 20 yr and we evaluate the effect of an associated beta-thalassemia trait on phenotypic expression. At the age of 33 yr the patient showed a marked iron overload and severe iron-related complications. After removal of 26 g of iron by subcutaneous deferoxamine infusion a marked clinical improvement was observed. Liver biopsies, performed at the age of 34 and 49 yr, indicate that in type 3 hemochromatosis there is a progressive hepatocellular iron accumulation from Rappaport's zone 1-3 and that iron loading in sinusoidal and portal macrophages occurs only in the more advanced stage. As observed in HFE hemochromatosis, the beta-thalassemia trait seems to aggravate the clinical picture of patients lacking TFR2, favoring higher rates of iron accumulation probably by activation of the erythroid iron regulator.