[Dynamic characteristics of brain networks in patients with irritable bowel syndrome based on functional magnetic resonance imaging].

The disorder of brain-gut interaction is an important cause of irritable bowel syndrome (IBS), but the dynamic characteristics of the brain remain unclear. Since there are many shortcomings for evaluating brain dynamic nature in the previous studies, we proposed a new method based on slope calculation by point-by-point analysis of the data from functional magnetic resonance imaging, and detected the abnormalities of brain dynamic changes in IBS patients. The results showed that compared with healthy subjects, there were dynamic changes in the brain for the IBS patients. After correction by false discovery rate (FDR), significant abnormalities were only found in two functional connections of the right posterior cingulate gyrus linked to left middle frontal gyrus, and the right posterior cingulate gyrus linked to left pallidus. The above results of the brain dynamic analysis were totally different from those of the brain static analysis of IBS patients. Our findings provide novel complementary information for illustrating the central nervous mechanism of IBS and may offer a new direction to explore central target for patients with IBS.

[Clinical value of cleaved lymphocytes in assisting the diagnosis of pertussis in children].

OBJECTIVE: To study the value of cleaved lymphocytes in peripheral blood smear in assisting the early diagnosis of pertussis. METHODS: Nasopharyngeal swabs and peripheral blood samples were collected from 107 children with pertussis-like disease. PCR-flow fluorescent hybridization was used to detect the nucleic acids of Bordetella pertussis. Based on the detection results, the children were divided into two groups: pertussis (n=52) and non-pertussis (n=55). According to age, the pertussis group was divided into two subgroups: <1 year old (n=42) and ≥1 year old (n=10). According to disease severity, the pertussis group was divided into another two subgroups: mild (n=45) and severe (n=7). An automatic blood cell analyzer was used to determine peripheral blood cell counts. Wright's staining and peroxidase staining were used to observe and count cleaved lymphocytes under a microscope. RESULTS: Cleaved lymphocytes in peripheral blood were round with small cytoplast, less cytoplasm and cleaved or lobulated nuclei. According to the negative peroxidase staining results, these cells were confirmed as lymphocytes. Compared with the non-pertussis group, the pertussis group had significantly higher leukocyte count, lymphocyte percentage, platelet count, and percentage of cleaved lymphocytes (P<0.001). For the children with pertussis, the <1 year old subgroup had significantly higher lymphocyte percentage, platelet count, and percentage of cleaved lymphocytes than the ≥1 year old subgroup (P<0.05). The severe subgroup had slightly higher leukocyte count, lymphocyte percentage, platelet count, and percentage of cleaved lymphocytes than the mild subgroup (P>0.05). CONCLUSIONS: The detection of cleaved lymphocytes combined with peripheral blood cell counts provides a new option for the early diagnosis of pertussis in children.

[Phenotype and Genotype Analysis in Two Pedigrees with Hereditary Coagulation Factor â ª Deficiency].

OBJECTIVE: To analyze the phenotype and genotype in two pedigrees with hereditary coagulation factor Ⅺ (FⅪ) deficiency, and investigate the molecular mechanisms of FⅪ deficiency. METHODS: Two patients with hereditary coagulation FⅪ deficiency were admitted to Chaozhou Central Hospital in Nov 2014 and Jan 2018. The prothrombin time (PT), activated partial thromboplastin time (APTT), FⅪ activity (FⅪ∶C) and FⅪ antigen (FⅪ∶Ag) were tested for phenotypic diagnosis. All the exons and exon-intron boundaries of FⅪ gene of proband were analyzed by PCR and sequencing. The family members were tested for the mutant site of proband. Then the mRNA of FⅪ in the proband was analyzed with RT-PCR. RESULTS: The proband-1 was a 7-year-old boy, PT was 10.7 s and APTT was 97.4 s (reference range: 9-12.8 s; 24-40 s), FⅪ∶C (0.6%) and FⅪ∶Ag<1% (reference range: 65%-150%; 72.1%-122.3%). The proband-2 was a 30-year-old female, and showed the PT (11.7 s), APTT (71.3 s), FⅪ∶C (0.7%) and FⅪ∶Ag<1%. FⅧ∶C, FⅨ∶C and FⅫ∶C of two proband were within the normal range. DNA sequencing showed that the proband-1 had a combined mutation of c.326-1G>A and c.1107C>A (p.Tyr351X) in exon 10. His grandmother, mother and brother had a heterozygous splicing mutation of c.326-1G>A, his grandmother and father had a homozygous mutation of c.1107C>A. FXI mRNA was undetected in the proband-1. The proband-2 had a homozygous mutation of c.841C>T (p.Gln263X) in exon 8, and this mutation was also found in her father, mother, daughter and son. CONCLUSION: The c.326-1G>A, c.1107C>A(p.Tyr351X) and c.841C>T (p.Gln263X) might be the molecular pathogenesis for two probands with hereditary coagulation factor Ⅺ deficiency.

Single particle cryo-EM reconstruction of 52 kDa streptavidin at 3.2 Angstrom resolution.

The fast development of single-particle cryogenic electron microscopy (cryo-EM) has made it more feasible to obtain the 3D structure of well-behaved macromolecules with a molecular weight higher than 300 kDa at ~3 Å resolution. However, it remains a challenge to obtain the high-resolution structures of molecules smaller than 200 kDa using single-particle cryo-EM. In this work, we apply the Cs-corrector-VPP-coupled cryo-EM to study the 52 kDa streptavidin (SA) protein supported on a thin layer of graphene and embedded in vitreous ice. We are able to solve both the apo-SA and biotin-bound SA structures at near-atomic resolution using single-particle cryo-EM. We demonstrate that the method has the potential to determine the structures of molecules as small as 39 kDa.

Near-Atomic Resolution Structure Determination in Over-Focus with Volta Phase Plate by Cs-Corrected Cryo-EM.

Volta phase plate (VPP) is a recently developed transmission electron microscope (TEM) apparatus that can significantly enhance the image contrast of biological samples in cryoelectron microscopy, and therefore provide the possibility to solve structures of relatively small macromolecules at high-resolution. In this work, we performed theoretical analysis and found that using phase plate on objective lens spherical aberration (Cs)-corrected TEM may gain some interesting optical properties, including the over-focus imaging of macromolecules. We subsequently evaluated the imaging strategy of frozen-hydrated apo-ferritin with VPP on a Cs-corrected TEM and obtained the structure of apo-ferritin at near-atomic resolution from both under- and over-focused dataset, illustrating the feasibility and new potential of combining VPP with Cs-corrected TEM for high-resolution cryo-EM.