Superconducting transition temperatures in the electronic and magnetic phase diagrams of Sr2VFeAsO3-δ , a superconductor.

We elucidate the magnetic phases and superconducting (SC) transition temperatures (T c) in Sr2VFeAsO3-δ (21113V), an iron-based superconductor with a thick-blocking layer fabricated from a perovskite-related transition metal oxide. At low temperatures (T < 37.1 K), 21113V exhibited a SC phase in the range 0.031 ⩽ δ ⩽ 0.145 and an antiferromagnetic (AFM) iron sublattice in the range 0.267 ⩽ δ ⩽ 0.664. Mixed-valent vanadium exhibited a dominant AFM phase in 0.031 ⩽ δ ⩽ 0.088, and a partial ferrimagnetic (Ferri.) phase in the range 0.124 ⩽ δ ⩽ 0.664. The Ferri. phase was the most dominant at a δ value of 0.267, showing an AFM phase of Fe at T < 20 K. Increasing the spontaneous magnetic moments reduced the magnetic shielding volume fraction due to the SC phase. This result was attributed to the magnetic phase of vanadium, which dominates the superconductivity of Fe in 21113V. The T c-δ curve showed two maxima. The smaller and larger of T c maxima occurred at δ = 0.073 and δ = 0.145, respectively; the latter resides on the phase boundary between AFM and the partial Ferri. phases of vanadium. 21113V is a useful platform for verifing new mechanisms of T c enhancement in iron-based superconductors.

Detection of a novel silent deletion, a missense mutation and a nonsense mutation in TCOF1.

BACKGROUND: Treacher Collins syndrome (TCS) is a disorder of craniofacial development, that is caused by mutations in the TCOF1 gene. TCS is inherited as an autosomal dominant trait, and haploinsufficiency of the TCOF1 gene product treacle is proposed to be etiologically involved. METHODS: Mutational analysis of the TCOF1 gene was done in 10 patients diagnosed with TCS using single-strand conformation polymorphism and direct sequencing. RESULTS: Among these 10 patients, a novel 9 bp deletion was found, together with a previously reported 2 bp deletion, a novel missense mutation and a novel nonsense mutation in three different families. Familial studies allowed judgment of whether these abnormal findings were responsible for the TCS phenotype, or not. The 9 bp deletion of three amino acids Lys-Glu-Lys (1378-1380), which was located in the nuclear localization domain of treacle, seemed not essential for the treacle function. In contrast, the novel mutation of Ala26Val is considered to affect the LisH domain, an important domain of treacle. All of the mutations thus far detected in exon 5 have resulted in frameshift, but a nonsense mutation was detected (Lys159Stop). CONCLUSION: The information obtained in the present study provides additional insights into the functional domains of treacle.

The first confirmed case with C3 deficiency caused by compound heterozygous mutations in the C3 gene; a new aspect of pathogenesis for C3 deficiency.

The complement system is an ancient cascade system that has a major role in innate and adaptive immunity. Component C3 is central to the three complement pathways. Hereditary compliment 3 (C3) deficiency characterized by severe recurrent infections and immune complex disorders is extremely rare disease. Since 1972, inherited C3 deficiency has been described in many families representing a variety of national origins; however, only 8 families of these cases have been identified their genetic defects. Interestingly, all except one (incomplete analysis) were shown to harbor homozygous C3 gene mutations. Previously we proposed a hypothesis, based on the unique process of C3 synthesis; C3 deficiency is not inherited as a simple autosomal recessive trait. Here, we report the first confirmed case with C3 deficiency caused by compound heterozygous mutations. They were a novel one base insertion (3176insT) in exon 24 which is predicted to result in a frameshift and a premature downstream stop codon (K1105X) in exon 26, and a nonsense mutation of C3303G (Y1081X) in exon 26 which was previously reported as homozygous mutations. This confirmed case suggests that our proposed hypothesis has prospects of a new aspect of pathogenesis for C3 deficiency.

Sentinel node biopsy versus elective lymph node dissection in patients with cutaneous melanoma in a Japanese population.

BACKGROUND: In Japan, elective lymph node dissection (ELND) has been the standard treatment for patients with possible nodal melanoma. Sentinel node biopsy (SNB) has now replaced ELND, not only in Japan but also worldwide. The objective of this study was to compare the interim outcomes of SNB and ELND. METHODS: A retrospective study was conducted among patients with clinically node-negative disease treated at our institute with either SNB (n = 30) or ELND (n = 72). RESULTS: The background was similar in the two groups. Nodal metastases were found in 40.0% of patients in the SNB group, but in only 26.4% in the ELND group (P = 0.173). The median follow-up was 31.5 months for the SNB group and 82 months for the ELND group. The incidence of locoregional recurrence and distant metastasis in the SNB group was 10.0% and 16.7%, respectively, and for the ELND group the incidence was 5.6% and 31.9%, respectively. The 3-year disease-free survival rate was similar in the two groups (P = 0.280), and the 3-year disease-free survival rates for node-positive patients were also similar in the two groups (P = 0.90), as were the 3-year disease-free survival rates for node-negative patients (P = 0.193). CONCLUSION: This interim result in a Japanese melanoma population with clinically node-negative disease demonstrated that SNB identified more nodal micrometastases than ELND. This increase in accurate staging likely resulted from the reliable identification of the lymph node field by lymphoscintigraphy, as well as the more detailed pathologic examination of the nodes removed in SNB. It is quite reasonable to perform SNB instead of ELND in this population.

Mutational analysis of the TCOF1 gene in 11 Japanese patients with Treacher Collins Syndrome and mechanism of mutagenesis.

Treacher Collins Syndrome (TCS) (OMIM 154500) is a congenital, craniofacial disorder inherited as an autosomal dominant trait. The responsible gene for TCS, TCOF1, was mapped to 5q32-33.1 and identified in 1996. Since then, TCOF1 mutations in patients with TCS have been reported from Europe, North and South America, however, no TCS cases from an Asian country have been molecularly characterized. Here we report mutational analysis for 11 Japanese patients with TCS for the first time, and have identified TCOF1 mutations in 9 of them. The mutations detected were various, but most likely all the mutations are predicted to result in a truncated gene product, known as treacle. One mutation frequently reported was included in our cases, but no missense mutations were detected. These findings are similar to those for the previous studies for TCS in other races. We have speculated about the molecular mechanisms of the mutations in most cases. Collectively, we have defined some of the characteristic molecular features commonly observed in TCS patients, irrespective of racial difference.

Treacher Collins syndrome with craniosynostosis, choanal atresia, and esophageal regurgitation caused by a novel nonsense mutation in TCOF1.

Treacher Collins syndrome (TCS) is caused by mutations in TCOF1 of the nonsense, small deletion, and small insertion types, which most likely result in haploinsufficiency. We report a novel de novo nonsense mutation 2731C --> T, resulting in Arg911Stop, which truncates the protein. Our patient had the classic findings of TCS, but with documented craniosynostosis, choanal atresia, and esophageal regurgitation.