Development of diffuse large B-cell lymphoma in a patient with Waldenström's macroglobulinemia/lymphoplasmacytic lymphoma: clonal identity between two B-cell neoplasms

Waldenström's macroglobulinemia (WM)/ lymphoplasmacytic lymphoma (LPL) is an indolent mature B-cell neoplasm. In rare cases of WM/LPL, diffuse large B-cell lymphoma (DLBCL) develops as a result of histologic transformation. In this report, we present a case of DLBCL developing in a patient with WM/LPL. Combination chemotherapy for DLBCL was effective and complete remission was eventually achieved. We attempted to determine the clonal relatedness between WM/LPL and DLBCL in the patient by analyzing complementarity-determining region 3 (CDR3) in the immunoglobulin heavy chain gene. A common CDR3 sequence was found in tumor cells of DLBCL and those of WM/LPL, indicating that tumor cells of DLBCL are clonally identical to those of WM/LPL. Therefore, in the present case, DLBCL is developed from WM/LPL cells by clonal evolution

Cryo-EM structures of human zinc transporter ZnT7 reveal the mechanism of Zn²⁺ uptake into the Golgi apparatus

クライオ電子顕微鏡により、ゴルジ体の亜鉛輸送体による亜鉛輸送機構の全容を解明 細胞の亜鉛恒常性維持機構の理解に大きな進展. 京都大学プレスリリース. 2023-08-29.Zinc ions (Zn²⁺) are vital to most cells, with the intracellular concentrations of Zn²⁺ being tightly regulated by multiple zinc transporters located at the plasma and organelle membranes. We herein present the 2.2-3.1 Å-resolution cryo-EM structures of a Golgi-localized human Zn²⁺/H+ antiporter ZnT7 (hZnT7) in Zn²⁺-bound and unbound forms. Cryo-EM analyses show that hZnT7 exists as a dimer via tight interactions in both the cytosolic and transmembrane (TM) domains of two protomers, each of which contains a single Zn²⁺-binding site in its TM domain. hZnT7 undergoes a TM-helix rearrangement to create a negatively charged cytosolic cavity for Zn²⁺ entry in the inward-facing conformation and widens the luminal cavity for Zn²⁺ release in the outward-facing conformation. An exceptionally long cytosolic histidine-rich loop characteristic of hZnT7 binds two Zn²⁺ ions, seemingly facilitating Zn²⁺ recruitment to the TM metal transport pathway. These structures permit mechanisms of hZnT7-mediated Zn²⁺ uptake into the Golgi to be proposed

The PHCCEx domain of Tiam1/2 is a novel protein- and membrane-binding module

Tiam1 and Tiam2 (Tiam1/2) are guanine nucleotide-exchange factors that possess the PH–CC–Ex (pleckstrin homology, coiled coil and extra) region that mediates binding to plasma membranes and signalling proteins in the activation of Rac GTPases. Crystal structures of the PH–CC–Ex regions revealed a single globular domain, PHCCEx domain, comprising a conventional PH subdomain associated with an antiparallel coiled coil of CC subdomain and a novel three-helical globular Ex subdomain. The PH subdomain resembles the β-spectrin PH domain, suggesting non-canonical phosphatidylinositol binding. Mutational and binding studies indicated that CC and Ex subdomains form a positively charged surface for protein binding. We identified two unique acidic sequence motifs in Tiam1/2-interacting proteins for binding to PHCCEx domain, Motif-I in CD44 and ephrinB's and the NMDA receptor, and Motif-II in Par3 and JIP2. Our results suggest the molecular basis by which the Tiam1/2 PHCCEx domain facilitates dual binding to membranes and signalling proteins

Maternal Feeding Controls Fetal Biological Clock

BACKGROUND: It is widely accepted that circadian physiological rhythms of the fetus are affected by oscillators in the maternal brain that are coupled to the environmental light-dark (LD) cycle. METHODOLOGY/PRINCIPAL FINDINGS: To study the link between fetal and maternal biological clocks, we investigated the effects of cycles of maternal food availability on the rhythms of Per1 gene expression in the fetal suprachiasmatic nucleus (SCN) and liver using a transgenic rat model whose tissues express luciferase in vitro. Although the maternal SCN remained phase-locked to the LD cycle, maternal restricted feeding phase-advanced the fetal SCN and liver by 5 and 7 hours respectively within the 22-day pregnancy. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that maternal feeding entrains the fetal SCN and liver independently of both the maternal SCN and the LD cycle. This indicates that maternal-feeding signals can be more influential for the fetal SCN and particular organ oscillators than hormonal signals controlled by the maternal SCN, suggesting the importance of a regular maternal feeding schedule for appropriate fetal molecular clockwork during pregnancy

Status of adult outpatients with congenital heart disease in Japan: The Japanese Network of Cardiovascular Departments for Adult Congenital Heart Disease Registry

BackgroundThe Japanese Network of Cardiovascular Departments for Adult Congenital Heart Disease (JNCVD-ACHD) was founded in 2011 for the lifelong care of adult patients with congenital heart disease (ACHD patients). This network maintains the first Japanese ACHD registry.Methods and resultsFrom 2011 to 2019, the JNCVD-ACHD registered 54 institutions providing specialized care for ACHD patients in 32 of the 47 prefectures in Japan. The registry collected data on the disease profile for 24,048 patients from 50 institutions and the patient characteristics for 9743 patients from 24 institutions. The most common ACHDs were atrial septal defect (20.5 %), ventricular septal defect (20.5 %), tetralogy of Fallot (12.9 %), and univentricular heart (UVH)/single ventricle (SV; 6.6 %). ACHD patients without biventricular repair accounted for 37.0 % of the population. Also examined were the serious anatomical and/or pathophysiological disorders such as pulmonary arterial hypertension (3.0 %) including Eisenmenger syndrome (1.2 %), systemic right ventricle under biventricular circulation (sRV-2VC; 2.8 %), and Fontan physiology (6.0 %). The sRV-2VC cases comprised congenitally corrected transposition of the great arteries without anatomical repair (61.9 %) and transposition of the great arteries with atrial switching surgery (38.1 %). The primary etiology (86.4 %) for Fontan physiology was UVH/SV. In addition, developmental/chromosomal/genetic disorders were heterotaxy syndromes (asplenia, 0.9 %; polysplenia, 0.7 %), trisomy 21 (4.0 %), 22q11.2 deletion (0.9 %), Turner syndrome (0.2 %), and Marfan syndrome (1.1 %).ConclusionsAlthough the specific management of ACHD has systematically progressed in Japan, this approach is still evolving. For ideal ACHD care, the prospective goals for the JNCVD-ACHD are to create local networks and provide a resource for multicenter clinical trials to support evidence-based practice

Seismic exploration at Fuji volcano with active sources : The outline of the experiment and the arrival time data

Fuji volcano (altitude 3,776m) is the largest basaltic stratovolcano in Japan. In late August and early September 2003, seismic exploration was conducted around Fuji volcano by the detonation of 500 kg charges of dynamite to investigate the seismic structure of that area. Seismographs with an eigenfrequency of 2 Hz were used for observation, positioned along a WSW-ENE line passing through the summit of the mountain. A total of 469 seismic stations were installed at intervals of 250-500 m. The data were stored in memory on-site using data loggers. The sampling interval was 4 ms. Charges were detonated at 5 points, one at each end of the observation line and 3 along its length. The first arrival times and the later-phase arrival times at each station for each detonation were recorded as data. P-wave velocities in the surface layer were estimated from the travel time curves near the explosion points, with results of 2.5 km/s obtained for the vicinity of Fuji volcano and 4.0 km5/s elsewhere