Discovery of TNG908: A Selective, Brain Penetrant, MTA-Cooperative PRMT5 Inhibitor That Is Synthetically Lethal with MTAP-Deleted Cancers

It has been shown that PRMT5 inhibition by small molecules can selectively kill cancer cells with homozygous deletion of the MTAP gene if the inhibitors can leverage the consequence of MTAP deletion, namely, accumulation of the MTAP substrate MTA. Herein, we describe the discovery of TNG908, a potent inhibitor that binds the PRMT5·MTA complex, leading to 15-fold-selective killing of MTAP-deleted (MTAP-null) cells compared to MTAPintact (MTAP WT) cells. TNG908 shows selective antitumor activity when dosed orally in mouse xenograft models, and its physicochemical properties are amenable for crossing the blood-brain barrier (BBB), supporting clinical study for the treatment of both CNS and non-CNS tumors with MTAP loss.

Study of association between corneal shape parameters and axial length elongation during orthokeratology using image-pro plus software

BACKGROUND

The aim was to validate the correlation between corneal shape parameters and axial length growth (ALG) during orthokeratology using Image-Pro Plus (IPP) 6.0 software.

METHODS

This retrospective study used medical records of myopic children aged 8-13 years (n = 104) undergoing orthokeratology. Their corneal topography and axial length were measured at baseline and subsequent follow-ups after lens wear. Corneal shape parameters, including the treatment zone (TZ) area, TZ diameter, TZ fractal dimension, TZ radius ratio, eccentric distance, pupil area, and pupillary peripheral steepened zone(PSZ) area, were measured using IPP software. The impact of corneal shape parameters at 3 months post-orthokeratology visit on 1.5-year ALG was evaluated using multivariate linear regression analysis.

RESULTS

ALG exhibited significant associations with age, TZ area, TZ diameter, TZ fractal dimension, and eccentric distance on univariate linear regression analysis. Multivariate regression analysis identified age, TZ area, and eccentric distance as significantly correlated with ALG (all P < 0.01), with eccentric distance showing the strongest correlation (β = -0.370). The regressive equation was y = 1.870 - 0.235a + 0.276b - 0.370c, where y represents ALG, a represents age, b represents TZ area, and c represents eccentric distance; R2 = 0.27). No significant relationships were observed between the TZ radius ratio, pupillary PSZ area, and ALG.

CONCLUSIONS

IPP software proves effective in capturing precise corneal shape parameters after orthokeratology. Eccentric distance, rather than age or the TZ area, significantly influences ALG retardation.

[Clinical and prognostic analysis of opsoclonus-myoclonus-ataxia syndrome in children]

Objective: To summarize the clinical and prognostic features of children with opsoclonus-myoclonus-ataxia syndrome (OMAS). Methods: A total of 46 patients who met the diagnostic criteria of OMAS in the Department of Neurology, Beijing Children's Hospital from June 2015 to June 2023 were retrospectively analyzed. Centralized online consultations or telephone visits were conducted between June and August 2023. The data of the children during hospitalization and follow-up were collected, including clinical manifestations, assistant examination, treatment and prognosis. According to the presence or absence of tumor, the patients were divided into two groups. The chi-square test or Mann-Whitney U test was used to compare the differences between the two groups. Univariate Logistic regression was used to analyze the factors related to OMAS recurrence and prognosis. Results: There were 46 patients, with 25 males and the onset age of 1.5 (1.2, 2.4) years. Twenty-six (57%) patients were diagnosed with neuroblastoma during the course of the disease, and no patients were categorized into the high-risk group. A total of 36 patients (78%) were followed up for≥6 months, and all of them were treated with first-line therapy with glucocorticoids, gammaglobulin and (or) adrenocorticotrophic hormone. Among the 36 patients, 9 patients (25%) were treated with second-line therapy for ≥3 months, including rituximab or cyclophosphamide, and 17 patients (47%) received chemotherapy related to neuroblastoma. At the follow-up time of 4.2 (2.2, 5.5) years, 10 patients (28%) had relapsed of OMAS. The Mitchell and Pike OMS rating scale score at the final follow-up was 0.5 (0, 2.0). Seven patients (19%) were mildly cognitively behind their peers and 6 patients (17%) were severely behind. Only 1 patient had tumor recurrence during follow-up. The history of vaccination or infection before onset was more common in the non-tumor group than in the tumor group (55%(11/20) vs. 23%(6/26), χ²=4.95, P=0.026). Myoclonus occurred more frequently in the non-tumor group (40%(8/20) vs. 4%(1/26), χ²=7.23, P=0.007) as the onset symptom. Univariate Logistic regression analysis showed that the tumor group had less recurrence (OR=0.19 (0.04-0.93), P=0.041). The use of second-line therapy or chemotherapy within 6 months of the disease course had a better prognosis (OR=11.64 (1.27-106.72), P=0.030). Conclusions: OMAS in children mostly starts in early childhood, and about half are combined with neuroblastoma. Neuroblastoma in combination with OMAS usually has a low risk classification and good prognosis. When comparing patients with OMAS with and without tumors, the latter have a more common infection or vaccination triggers, and myoclonus, as the onset symptom, is more common. Early addition of second-line therapy is associated with better prognosis in OMAS.

GDF15 linked to maternal risk of nausea and vomiting during pregnancy

GDF15, a hormone acting on the brainstem, has been implicated in the nausea and vomiting of pregnancy, including its most severe form, hyperemesis gravidarum (HG), but a full mechanistic understanding is lacking1-4. Here we report that fetal production of GDF15 and maternal sensitivity to it both contribute substantially to the risk of HG. We confirmed that higher GDF15 levels in maternal blood are associated with vomiting in pregnancy and HG. Using mass spectrometry to detect a naturally labelled GDF15 variant, we demonstrate that the vast majority of GDF15 in the maternal plasma is derived from the feto-placental unit. By studying carriers of rare and common genetic variants, we found that low levels of GDF15 in the non-pregnant state increase the risk of developing HG. Conversely, women with β-thalassaemia, a condition in which GDF15 levels are chronically high5, report very low levels of nausea and vomiting of pregnancy. In mice, the acute food intake response to a bolus of GDF15 is influenced bi-directionally by prior levels of circulating GDF15 in a manner suggesting that this system is susceptible to desensitization. Our findings support a putative causal role for fetally derived GDF15 in the nausea and vomiting of human pregnancy, with maternal sensitivity, at least partly determined by prepregnancy exposure to the hormone, being a major influence on its severity. They also suggest mechanism-based approaches to the treatment and prevention of HG.

[The efficacy analysis of neurosurgical robot-assisted DBS in the treatment of elderly Parkinson's disease]

Objective: To investigate the surgical efficacy of neurosurgery robot deep brain stimulation(DBS) in the treatment of elderly Parkinson's disease(PD). Methods: The clinical data of elderly patients (≥75 years) with PD who underwent neurosurgical robot-assisted DBS surgery in the Department of Neurosurgery of the General Hospital of Northern Theater Command from September 2016 to September 2022 were collected retrospectively. Operation time, electrode implantation duration, postoperative pneumocephalus volume, electrode implantation accuracy, the Tao's DBS surgery scale, perioperative complications were analyzed.The unified Parkinson's disease rating scales (UPDRS), UPDRS-Ⅲ, tremor, rigidity, bradykinesia, axial, Barthel Activities of Daily Living (ADL-Barthel), Levodopa Equivalent Daily Dose (LEDD), Montreal Cognitive Assessment (MoCA), Hamilton Anxiety Scale (HAMA) and Hamilton Depression Scale (HAMD) scores and mortality were assessed respectively before operation, 6, 12 and 24 months after operation and last follow-up. Results: A total of 25 elderly patients were enrolled, including 14 males and 11 females, aged(78.3±3.2) years. Nine patients had underlying diseases. Nine patients (36%) underwent bilateral Globus Pallidus pars Interna deep brain stimulation (GPi-DBS) and 16 patients (64%) underwent bilateral subthalamic nucleus deep brain stimulation (STN-DBS).The operation time was (1.56±0.19) hours, the electrode implantation duration was (1.01±0.19) hours, the pneumocephalus volume was 9.8(4.7, 23.3) cm3, and the electrode implantation accuracy was (0.84±0.24) mm, the Tao's DBS surgery scale was (80.2±6.2).The follow-up time [M(Q1, Q3)] was 57.3(27.9, 75.7) months. No serious complications such as intracranial hemorrhage, infection or poor wound healing occurred during the perioperative period. The improvement rate of UPDRS, UPDRS-Ⅲ, rigidity, bradykinesia, and LEDD at 6 months after surgery was significantly higher than that at 24 months after surgery and at the last follow-up (all P<0.05); the improvement rate of axial symptoms, ADL-Barthel score, and MoCA score at 6 months after surgery was significantly higher than that at the last follow-up (P<0.05). HAMD and HAMA scores showed no significant improvement during follow-up after surgery (both P>0.05). At the last follow-up, 12 patients died, with death time of (35.1±20.2) months after operation, and the death age of [M(Q1, Q3)] 80(79, 83)years. Conclusions: Robot-assisted DBS surgery for elderly patients with PD is accurate and safe, and the postoperative symptoms are significantly improved, and they can benefit from neuromodulation for long term, and the risks are controllable.

Fetally-encoded GDF15 and maternal GDF15 sensitivity are major determinants of nausea and vomiting in human pregnancy

Human pregnancy is frequently accompanied by nausea and vomiting that may become severe and life-threatening, as in hyperemesis gravidarum (HG), the cause of which is unknown. Growth Differentiation Factor-15 (GDF15), a hormone known to act on the hindbrain to cause emesis, is highly expressed in the placenta and its levels in maternal blood rise rapidly in pregnancy. Variants in the maternal GDF15 gene are associated with HG. Here we report that fetal production of GDF15, and maternal sensitivity to it, both contribute substantially to the risk of HG. We found that the great majority of GDF15 in maternal circulation is derived from the feto-placental unit and that higher GDF15 levels in maternal blood are associated with vomiting and are further elevated in patients with HG. Conversely, we found that lower levels of GDF15 in the non-pregnant state predispose women to HG. A rare C211G variant in GDF15 which strongly predisposes mothers to HG, particularly when the fetus is wild-type, was found to markedly impair cellular secretion of GDF15 and associate with low circulating levels of GDF15 in the non-pregnant state. Consistent with this, two common GDF15 haplotypes which predispose to HG were associated with lower circulating levels outside pregnancy. The administration of a long-acting form of GDF15 to wild-type mice markedly reduced subsequent responses to an acute dose, establishing that desensitisation is a feature of this system. GDF15 levels are known to be highly and chronically elevated in patients with beta thalassemia. In women with this disorder, reports of symptoms of nausea or vomiting in pregnancy were strikingly diminished. Our findings support a causal role for fetal derived GDF15 in the nausea and vomiting of human pregnancy, with maternal sensitivity, at least partly determined by pre-pregnancy exposure to GDF15, being a major influence on its severity. They also suggest mechanism-based approaches to the treatment and prevention of HG.

[Efficacy of video-assisted thoracoscopic surgical decortication for stage Ⅲ tuberculous empyema]

Objective: To investigate the clinical efficacy, safety and feasibility of "double-portal" video-assisted thoracoscopic surgical(VATS) decortication among patients with stage Ⅲ tuberculous empyema, and then to evaluate the recovery of chest deformity. Method: This study was a single center retrospective study. A total of 49 patients with stage Ⅲ tuberculous empyema who underwent VATS pleural decortication at the Department of Thoracic Surgery, Public Health Clinical Center of Chengdu between June 2017 and April 2021 were enrolled, including 38 males, and 11 females, aged 13-60 (27.5±10.4) years. The safety and feasibility of VATS were further evaluated. The inner circumference of the chest on sternal and xiphoid planes on chest CT scans before and 1, 3, 6, 12months after decortication were collected through the measuring software of the CT. The samples in-pair test was used to compare the changes in the chest to reflect the recovery of the chest deformity. Results: In the 49 patients, The surgical time was (186±61) min, and the volume of blood loss was (366±267) ml. There were 8 cases (16.33%) with postoperative complications during the perioperative period. Constant air leak and pneumonia were the main postoperative complications. No relapse of empyema or dissemination of tuberculosis occured during the period of follow-up. Before surgery, the inner thoracic circumference of the thorax at the level of the carina plane was (655±54) mm, and the inner thoracic circumference of the thorax at the level of the xiphoid plane was (720±69) mm. Patients were followed for 12-36 months. The inner thoracic circumference of the thoracic cavity at the level of carina was (666±51), (667±47) and (671±47) mm at the 3rd, 6th and 12th months after operation, which were significantly larger than that at the level of carina before operation (all P<0.05). The inner thoracic circumference diameter of the thoracic cavity measured at the xiphoid level at the 3rd, 6th and 12th months after the operation was (730±65), (733±63) and (735±63) mm respectively(all P<0.05).The inner thoracic circumference of the thoracic cavity increased significantly than that before surgery (P<0.05). At 6 months after operation, there was significant difference in the improvement of the inner thoracic circumference of the carina plane in patients with age less than 20 years and FEV₁% less than 80% (P=0.015, P=0.003). The improvement in the inner thoracic circumference of the carina plane in patients with pleural thickening≥8 mm compared with those with less than 8 mm was not statistically different(P=0.070). Conclusions: For some patients with stage Ⅲ tuberculous empyema, pleural decortication under thoracoscopy is safe and feasible, and can significantly restore the inner thoracic circumference of the patient's chest, improve the collapse of the patient's chest, and have significant clinical effect. The "double-portal VATS" surgical technology has the advantage of less trauma, wide operation field, large operation space and is easy to master, which is worth further exploring for clinical application.

[Fibroblasts overpressing WNT2b cause impairment of intestinal mucosal barrier]

OBJECTIVE

To investigate the mechanism by which fibroblasts with high WNT2b expression causes intestinal mucosa barrier disruption and promote the progression of inflammatory bowel disease (IBD).

METHODS

Caco-2 cells were treated with 20% fibroblast conditioned medium or co-cultured with fibroblasts highly expressing WNT2b, with the cells without treatment with the conditioned medium and cells co-cultured with wild-type fibroblasts as the control groups. The changes in barrier permeability of Caco-2 cells were assessed by measuring transmembrane resistance and Lucifer Yellow permeability. In Caco-2 cells co-cultured with WNT2b-overexpressing or control intestinal fibroblasts, nuclear entry of β-catenin was detected with immunofluorescence assay, and the expressions of tight junction proteins ZO-1 and E-cadherin were detected with Western blotting. In a C57 mouse model of dextran sulfate sodium (DSS)-induced IBD-like enteritis, the therapeutic effect of intraperitoneal injection of salinomycin (5 mg/kg, an inhibitor of WNT/β-catenin signaling pathway) was evaluated by observing the changes in intestinal inflammation and detecting the expressions of tight junction proteins.

RESULTS

In the coculture system, WNT2b overexpression in the fibroblasts significantly promoted nuclear entry of β-catenin (P < 0.01) and decreased the expressions of tight junction proteins in Caco-2 cells; knockdown of FZD4 expression in Caco-2 cells obviously reversed this effect. In DSS-treated mice, salinomycin treatment significantly reduced intestinal inflammation and increased the expressions of tight junction proteins in the intestinal mucosa.

CONCLUSION

Intestinal fibroblasts overexpressing WNT2b causes impairment of intestinal mucosal barrier function and can be a potential target for treatment of IBD.

Ubiquitinated PCNA Drives USP1 Synthetic Lethality in Cancer

CRISPR Cas9-based screening is a powerful approach for identifying and characterizing novel drug targets. Here, we elucidate the synthetic lethal mechanism of deubiquitinating enzyme USP1 in cancers with underlying DNA damage vulnerabilities, specifically BRCA1/2 mutant tumors and a subset of BRCA1/2 wild-type (WT) tumors. In sensitive cells, pharmacologic inhibition of USP1 leads to decreased DNA synthesis concomitant with S-phase-specific DNA damage. Genome-wide CRISPR-Cas9 screens identify RAD18 and UBE2K, which promote PCNA mono- and polyubiquitination respectively, as mediators of USP1 dependency. The accumulation of mono- and polyubiquitinated PCNA following USP1 inhibition is associated with reduced PCNA protein levels. Ectopic expression of WT or ubiquitin-dead K164R PCNA reverses USP1 inhibitor sensitivity. Our results show, for the first time, that USP1 dependency hinges on the aberrant processing of mono- and polyubiquitinated PCNA. Moreover, this mechanism of USP1 dependency extends beyond BRCA1/2 mutant tumors to selected BRCA1/2 WT cancer cell lines enriched in ovarian and lung lineages. We further show PARP and USP1 inhibition are strongly synergistic in BRCA1/2 mutant tumors. We postulate USP1 dependency unveils a previously uncharacterized vulnerability linked to posttranslational modifications of PCNA. Taken together, USP1 inhibition may represent a novel therapeutic strategy for BRCA1/2 mutant tumors and a subset of BRCA1/2 WT tumors.

[Analysis of clinical and imaging features of 6 cases of linear scleroderma en coup de sabre with central nervous system involvement in children]

Objective: To summarize the clinical and imaging features of linear scleroderma en coup de saber (LSCS) with central nervous system involvement in children. Methods: The clinical data(clinical manifestations and imaging features) of 6 children diagnosed with LSCS with central nervous system involvement who were admitted to Beijing Children's Hospital Affiliated to Capital Medical University from May 2019 to November 2021 were retrospectively analyzed. Results: The 6 patients were all female, aged 6.8 (3.3, 11.0) years at the time of diagnosis, and aged 3.0 (1.7, 4.1) years at the time of discovery of facial skin lesions. Facial skin lesions appeared before neurological symptoms in 5 cases, and neurological symptoms appeared 2 months before skin lesions in 1 case. All the patients had "sword wound" skin lesions on the forehead with alopecia. Neurological manifestations included epileptic seizures in 6 cases, focal neurological defects in 5 cases, and headaches in 2 cases. The intracranial lesions were all ipsilateral to the skin lesions. The magnetic resonance imaging (MRI) of 6 cases showed abnormal signals mainly involving white matter in 1 hemisphere, and 3 cases showed local encephalomalacia. The scattered low signal was observed in 5 cases on susceptibility weighted imaging. Localized brain parenchyma or leptomeninges enhancement was seen on Gadolinium-enhanced sequences in 5 cases. Scattered foci of calcification on the affected side were seen on cranial CT in 4 cases. Skin biopsy was performed in 2 cases. Part of the lesion of the brain was removed in 1 case, and the pathological findings suggested small vasculitis, which was consistent with skin pathological changes. All patients received symptomatic treatment with antiepileptic drugs. Oral prednisone combined with methotrexate was given in 4 cases, and 1 case was given oral prednisone only. One case was presumed to be in the resting stage of the disease due to significant cerebral atrophy in half of the brain, and only antiepileptic drugs were added. The patients were followed up for 6-36 months. The skin lesions of scleroderma and alopecia did not progress in 5 cases, and hemifacial atrophy was developed in 1 case, which was considered to be combined with Parry-Romberg syndrome. The seizures were controlled in 4 cases. One case had reduced seizure frequency but left hemiplegia. One patient still had intractable epilepsy and paroxysmal headache. Conclusions: LSCS with central nervous system involvement is more common in girls, with seizures and neurological defects as the main manifestations. Intracranial lesions are mostly ipsilateral to the skin lesions. Cerebral microbleeds, calcification, and encephalomalacia foci are common, and the pathological changes in skin and intracranial lesions are consistent with small-vessel vasculitis. Prednisone combined with methotrexate treatment has shown some efficacy, but some children remain with refractory epilepsy and neurological deficit symptoms.

Abstract 2603: USP1 inhibitor synthetic lethality in BRCA1-mutant cancer is driven by PCNA ubiquitination

CRISPR-based functional genomic screening is a powerful approach for identifying novel classes of synthetic lethal drug targets. Here, we define the deubiquitinase USP1 as a synthetic lethal target in cancers with underlying DNA repair vulnerabilities. A highly potent and selective small molecule USP1 inhibitor conferred a viability defect in BRCA1-mutant, but not WT cell lines by activating replication stress. Genome-wide CRISPR screening uncovered RAD18 and UBE2K, which promote PCNA mono- and poly-ubiquitination respectively, as key mediators of USP1-BRCA1 dependency. Increased cellular mono- and poly-ubiquitination reduced PCNA protein levels, and restoration of PCNA protein expression rescued USP1 inhibitor sensitivity. USP1 dependency is associated with upregulated RAD18 and UBE2K expression, suggesting that elevated PCNA ubiquitination in the context of BRCA1 deficiency mediates USP1 synthetic lethality. Interestingly, USP1, but not PARP1 inhibition, elicited a viability defect in a subset of BRCA1/2 WT lung cancer cell lines, indicative of novel synthetic lethal interactions unique to USP1. Moreover, dual inhibition of PARP1 and USP1 are strongly synergistic in PARP1 inhibitor-responsive cell line models. Strong in vivo anti-tumor activity across multiple tumor models was demonstrated with USP1 inhibition alone and in combination with the PARP1 inhibitor olaparib. Our studies suggest that USP1 and PARP1 inhibitors target BRCA1-mutant cancer though distinct yet synergistic mechanisms. As such, USP1 inhibitors may provide novel treatment strategies for PARP1 inhibitor-resistant and -naïve BRCA1-mutant cancer.

Citation Format: Justin Engel, Madhavi Bandi, Antione Simoneau, Katherine Lazarides, Deepali Gotur, Truc Pham, Shangtao Liu, Samuel Meier, Ashley Choi, Hongxiang Zhang, Binzhang Shen, Fang Li, Douglas Whittington, Shanzhong Gong, Xuewen Pan, Yi Yu, Lina Gu, Scott Throner, John Maxwell, Yingnan Chen, Alan Huang, Jannik Andersen, Tianshu Feng. USP1 inhibitor synthetic lethality in BRCA1-mutant cancer is driven by PCNA ubiquitination [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2603.

D-Galactose-Induced Accelerated Aging Model on Auditory Cortical Neurons by Regulating Oxidative Stress and Apoptosis in Vitro

OBJECTIVES

Age-related hearing loss (ARHL) is much more prevalent with age, affecting not only peripheral but central auditory system. We have previously established an aging model of peripheral auditory system in vitro using cultured cochlear basilar membrane. However, there is no ideal accelerated aging model on central auditory system in vitro. To establish the aging model, auditory cortical neurons (ACNs) were primary cultured and treated with either vehicle or different doses of D-galactose (D-gal). We studied the effect of D-gal on ACNs by evaluating the hallmarks of aging, including cell proliferation, oxidative stress, mitochondrial function, and neuronal apoptosis. Compared with the control group, cell viability was significantly inhibited in the D-gal-treated group in a dose-dependent manner. The production of reactive oxygen species was strongly increased in the D-gal-treated group. Meanwhile, the level of 8-hydroxy-2'-deoxyguanosine, which is a biomarker of DNA oxidative damage, was even higher in the D-gal-treated group than that in the control group. Conversely, the levels of ATP and mitochondrial membrane potential were notably decreased in the D-gal-treated group contrast to that in the control group. Furthermore, the number of neuronal apoptosis in the D-gal-treated group, compared with that in the control group, was dramatically increased in a dose-dependent approach. Together, our results demonstrate that ACNs treated with D-gal in vitro display senescence characteristics by regulating oxidative stress and apoptosis, indicating accelerated aging model on ACNs are successfully established. And the model provides a promising approach for exploring underlying mechanisms of the ARHL.

Effects of oral sialic acid on gut development, liver function and gut microbiota in mice

Sialic acid (N-acetylneuraminic acid), a 9-carbon monosaccharide, has been widely studied in immunology, oncology and neurology. However, the effects of sialic acid on organ and intestinal development, liver function and gut microbiota were rarely studied. In this study, we found that oral sialic acid tended to increase the relative weight of liver and decreased the serum aspartate aminotransferase (GPT) activity. In addition, sialic acid treatment markedly reduced gut villus length, depth, the ratio of villus length/depth (L/D), areas, width and the number of goblet cells. Furthermore, gut microbes were changed in response to oral sialic acid, such as Staphylococcus lentus, Corynebacterium stationis, Corynebacterium urealyticum, Jeotgalibaca sp_PTS2502, Ignatzschineria indica, Sporosarcina pasteurii, Sporosarcina sp_HW10C2, Facklamia tabacinasalis, Oblitimonas alkaliphila, Erysipelatoclostridium ramosum, Blautia sp_YL58, Bacteroids thetaiotaomicron, Morganella morganii, Clostridioides difficile, Helicobacter tryphlonius, Clostridium sp_Clone47, Alistipes finegoldii, [pseudomonas]_geniculata and Pseudomonas parafulva at the species level. In conclusion, oral sialic acid altered the intestinal pathological state and microbial compositions, and the effect of sialic acid on host health should be further studied.

[Clinical and genetic analysis of 5 pediatric patients with hemiplegic migraine presenting as acute encephalopathy]

Objective: To analyze the clinical and genetic characteristics, diagnosis and treatment of hemiplegic migraine (HM) manifested as acute encephalopathy in children, so as to improve the understanding of this disease. Methods: The clinical data of 5 children diagnosed with HM characterized by acute encephalopathy who were admitted to Beijing Children's Hospital affiliated to Capital Medical University from August 2018 to June 2020 were retrospectively analyzed. Results: Among the 5 cases, 3 were males and 2 females with an age of 9.7 (3.9-12.7) years. The age of disease onset was 7.0(2.1-12.7) years. The peak symptoms of 5 children showed encephalopathy such as drowsiness and coma, as well as other clinical manifestations including headache, visual abnormality, hemiplegia, aphasia, convulsions, and fever, etc. The time to reach the peak was on the 2nd-6th day of the course of the disease. Before the onset of the disease 2 cases were found to have mild brain trauma and 2 cases had similar attacks in the past. Brain magnetic resonance imaging (MRI) showed hemispheric or partial cerebral cortex swelling and restricted diffusion of subcortical white matter in all cases, and cerebellar atrophy in 3 cases. All children received symptomatic treatment, and 2 of them were also treated with low-dose corticosteroids in the meantime. Finally all cases recovered clinically from the attack, but one had atrophic changes left in the affected area on brain MRI. Whole exon sequencing revealed variations of CACNA1A gene in all cases, among which 4 were de novo mutations and 1 case inherited from the mother who had migraine without aura. After the diagnosis, the 5 children were treated with long-term flunarizine and followed up for 22(7-29) months by telephone or in the outpatient clinic. Before the last follow-up, none of them showed weakness or encephalopathy, but one still had intermittent headaches and occasional transient right limb numbness. Conclusions: Hemipleg is often accompanied by impaired consciousness in addition to headache, hemiplegia, aphasia, visual abnormality, etc. Most patients recover completely after a short period, while a few recover slowly and may suffer sequelae such as brain atrophy and cognitive impairment and even death. CACNA1A gene variation is the most common genetic variation. Flunarizine could prevent recurrence of severe attack.

Kinetic and thermodynamic analysis defines roles for two metal ions in DNA polymerase specificity and catalysis

Magnesium ions play a critical role in catalysis by many enzymes and contribute to the fidelity of DNA polymerases through a two-metal ion mechanism. However, specificity is a kinetic phenomenon and the roles of Mg²⁺ ions in each step in the catalysis have not been resolved. We first examined the roles of Mg²⁺ by kinetic analysis of single nucleotide incorporation catalyzed by HIV reverse transcriptase. We show that Mg.dNTP binding induces an enzyme conformational change at a rate that is independent of free Mg²⁺ concentration. Subsequently, the second Mg²⁺ binds to the closed state of the enzyme-DNA-Mg.dNTP complex (K_d = 3.7 mM) to facilitate catalysis. Weak binding of the catalytic Mg²⁺ contributes to fidelity by sampling the correctly aligned substrate without perturbing the equilibrium for nucleotide binding at physiological Mg²⁺ concentrations. An increase of the Mg²⁺ concentration from 0.25 to 10 mM increases nucleotide specificity (k_cat/K_m) 12-fold largely by increasing the rate of the chemistry relative to the rate of nucleotide release. Mg²⁺ binds very weakly (K_d ≤ 37 mM) to the open state of the enzyme. Analysis of published crystal structures showed that HIV reverse transcriptase binds only two metal ions prior to incorporation of a correct base pair. Molecular dynamics simulations support the two-metal ion mechanism and the kinetic data indicating weak binding of the catalytic Mg²⁺. Molecular dynamics simulations also revealed the importance of the divalent cation cloud surrounding exposed phosphates on the DNA. These results enlighten the roles of the two metal ions in the specificity of DNA polymerases.

[Clinical features of anti-myelin oligodendrocyte glycoprotein antibody-associated diseases in children with cortical encephalitis]

Objective: To describe the clinical features of anti-myelin oligodendrocyte glycoprotein (MOG) antibody-positive cortical encephalitis in children. Methods: Patients who were hospitalized in Beijing Children's Hospital from June 2018 to October 2019, with positive MOG antibodies and phenotype of cortical encephalitis were retrospectively analyzed. Cell-based assays (CBAs) were used to test MOG antibodies. Results: Five patients had the phenotype of cortical encephalitis during follow-up, with 3 females and 2 males. The age of onset ranged from 8 years to 12 years and 1 month. At the last follow-up, 3 cases exhibited a monophasic course and 2 cases were with relapse and remission courses. Six out of 8 episodes which had the phenotype of cortical encephalitis presented with seizures, among which 3 episodes had status epilepticus. None had recurrent seizures during remission. Other symptoms included fever (7/8), headache and vomiting (4/8), somnolence (3/8) and hemiplegia (1/8). Unilateral cortical swelling was observed in cerebral magnetic resonance imaging (MRI) of all patients, without any hemorrhage and necrosis. White blood cell (WBC) counts of cerebrospinal fluid increased, ranging from8×10(6)/L to 186×10(6)/L. All patients recovered well after treatment with intravenous immunogloblin and glucocorticoid. Two patients had relapses during follow-up and were additionally treated with mycophenolate mofetil. Conclusions: Anti-MOG antibodies can induce cortical encephalitis. In clinical setting, fever, headache and seizures are common, however, severe consciousness disturbance and local neurological deficits are rare in these patients. Cerebral MRI shows unilateral cortical swelling without any hemorrhage and necrosis. Usually, immunotherapy works well. No patients exist repeated seizures in remission, but some patients may have relapses.

[Clinical observation on the overlapping syndrome of myelin oligodendrocyte glycoprotein antibody and anti-N-methyl-D aspartate receptor in children]

Objective: To investigate the clinical features, imaging findings and prognosis of children with overlapping syndrome of myelin oligodendrocyte glycoprotein (MOG) antibody disease and anti-N-methyl-D aspartate receptor (NMDAR) encephalitis (MNOS). Methods: The clinical manifestations, immunological antibodies in blood and cerebrospinal fluid, cranial image, treatment and follow-up of 11 patients diagnosed as MNOS in the Department of Neurology, Beijing Children's Hospital from January 2011 to April 2019 were analyzed retrospectively. Results: A total of 11 patients, including 4 males and 7 females were analyzed, the age of onset was (10.4±2.3) years. A total of 29 episodes occurred in 11 children. At the last follow-up, 8 cases showed relapsed remission course, the interval of recurrence was 3 to 60 months. The onset symptoms of 11 patients included convulsions (10 cases), lethargy (6 cases), psychosis (6 cases). Among 29 episodes, the common symptoms were convulsions (16 episodes), psychosis (13 episodes),and lethargy (10 episodes). According to the diagnostic criteria of anti-NMDAR encephalitis and MOG-antibody disease, 29 episodes were divided into three phenotypes, including anti-NMDAR encephalitis(4 episodes), MOG-antibody diseases (10 episodes) and overlapping types (15 episodes).Twenty-seven times of acute stage cranial magnetic resonance imaging (MRI) were available, common lesions included cortical focus (22 times), subcortical white matter (7 times), brainstem (9 times). All patients were sensitive to first-line immunotherapy. Eight patients had recurrence during glucocorticoid reduction, 6 of them were treated with additional second-line immunosuppressive therapy, including cyclophosphamide (1 case) and mycophenolate mofetil (5 cases). The follow-up time of patients were 5-99 months. At the last follow-up, all patients were in remission, the pediatric cerebral performance category (PCPC) score was 1 (10 cases) and 2 (1 cases). Conclusions: MNOS mainly affects older children. In the period of acute episodes, convulsions and psychosis are common. The cranial MRI showed extensive brain involvement and mainly in the cortex. The recurrence rates of MNOS are relatively high, patients are sensitive to first-line immunotherapy. No significant neurological dysfunction was left in the remission stage.

Molecular cloning and variant analysis of the TSHR gene in goose (Anser cygnoides)

1. The thyroid-stimulating hormone receptor (TSHR) is a glycoprotein hormone receptor which has a pivotal role in metabolic regulation and photoperiod control during reproduction in birds and mammals. However, the molecular characterisation of TSHR in goose is unknown. 2. The goose TSHR cDNA (TSHR-1) is 2334 bp in length and encodes a protein of 763 amino acids. This trial identified another three novel splice variants of goose TSHR, TSHR-2 (lacking the exon 3 in TSHR-1 transcript), TSHR-3 (lacking the exon 6 in the TSHR-1 transcript) and TSHR-4 (lacking 12 bp of exon 8 and the entire exon 9 in the TSHR-1 transcript). 3. Bioinformatics analysis indicated that all the deduced TSHR amino acid sequences contained seven putative transmembrane domains, and the TSHR-3 protein lacked one potential N-linked glycosylation site (N-E-S) compared to the other three deduced proteins. 4. A phylogenetic tree based on amino acid sequences showed that the goose TSHR protein was closely related to those of other avian species, especially duck and chickens. 5. One microsatellite and three single nucleotide polymorphisms (SNPs) were identified. For the c1109A/G locus, AA and GA genotypes were found in the Zhedong-White goose population, GG and GA genotypes were detected in the Landes goose population, but the AA genotype was only detected in the other four goose populations. 6. All the information derived from this study can facilitate further studies on the functions of the goose TSHR gene.

Factors associated with resistance to complications in long-standing type 1 diabetes in China

OBJECTIVE

Type 1 diabetes (T1DM) is associated with a higher risk of premature death, but there are factors in certain patients with T1DM that protect them from complications and premature death. These factors had not been identified in non-Caucasian populations, so we aimed to identify factors that protect against the development of diabetic nephropathy (DN) and diabetic retinopathy (DR) in long-standing T1DM in China

METHODS

Ninety-five T1DM patients with >30 years’ duration of diabetes were enrolled in this nationwide study. Differences between groups of patients with and without complications were compared, and multivariable regression analysis was used to evaluate the relationships between candidate protective factors and the development of DN or DR.

RESULTS

Thirty of the participants did not have DN and the same amount did not have DR. 6/52 of participants without DN were from a rural area, whereas 11/28 of participants with DN had been born in a rural area (P = 0.005). Systolic blood pressure (SBP) was higher in participants with DN (135 ± 26 mmHg vs 121 ± 13 mmHg; P = 0.002). In participants without DR, 27/30 were married or cohabitating, and only 3/30 were single, never married, or widowed, but for those with proliferative DR (PDR), 13/26 had been married (P = 0.003). A rural or urban origin and SBP were associated with DN in the multivariable analysis.

CONCLUSION

we have shown that higher socioeconomic status, indicated by birth in an urban area, and being married or cohabitating, are accompanied by better blood pressure control and a lower risk of microvascular complications in Chinese patients with long-standing T1DM. These findings illustrate the importance of improving care for patients with T1DM in China.

[Clinical characteristics and related factors of somatization symptoms in outpatients with psychiatric disorders of the department of cardiology in general hospitals]

Objective: To explore the clinical characteristics and related factors of somatization symptoms in outpatients with psychiatric disorders of the cardiology department in general hospital. Methods: Cross-sectional survey method was used in this study. From August 2017 to September 2018, 508 outpatients of our department with suspected mental disorders, who complained of physical discomfort and screened by the "Three Questions" method recommended by the Chinese Expert Consensus on Psychological Prescriptions of Cardiovascular Patients in 2014, were consecutively included. General Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire (PHQ-9), Patient Health Questionnaire-15 (PHQ-15) and self-made general demographic questionnaire (including age, sex, marital status, educational level, occupation, duration of disease, clinical diagnosis and the process of medical treatment for the main somatic symptoms in recent one year) were used to investigate these patients, under the assistance of unified training psychological consultants. The detection rate of anxiety and depression, the degree and distribution of somatization symptoms in outpatients with mental disorders were analyzed, and the related factors affecting the occurrence of somatization symptoms were screened by multivariate logistic regression. Results: The selected patients were (51.3±10.1) years old, of which 37.8% (192/508) were males and 62.2% (316/508) were females. The total detection rate of anxiety/depression was 86.8% (441/508), and the detection rate of somatization symptoms was 93.1% (473/508). The number of positive symptom items in PHQ-15 was 8.0±2.7, and the detection rate of anxiety/depression was 78.6% (372/473) in patients with somatization symptoms. There were significant differences in the proportion of women, the average number of outpatient visits and hospitalizations in the past one year, GAD-7 score and PHQ-9 score among the patients with mild, moderate and severe somatization symptoms (all P<0.05). PHQ-15 score was positively correlated with GAD-7 score (r=0.524 5, P<0.001) and PHQ-9 score (r=0.574 9, P<0.001) in patients with somatization symptoms. Stepwise logistic regression analysis showed that total scores of PHQ-9 (OR=8.020, 95%CI 3.470-18.930, P<0.001) and GAD-7 (OR=6.526, 95%CI 2.903-13.045, P<0.001) and female (OR=4.440, 95%CI 1.059-9.073, P=0.011) were related factors of somatizations. Conclusions: The incidence of somatization symptoms is high in patients with psychological disorders in outpatients of cardiology department in general hospital. Anxiety, depression and gender are the main related risk factors of somatization symptoms in this patient cohort. Degree of anxiety and depression increased in proportion to the severity of somatization symptoms. Anxiety, depression and female is related to somatization symptoms.

Kinetic characterization of Cas9 enzymes

Bacterial adaptive immune systems employ clustered regularly interspaced short palindromic repeats (CRISPR) along with their CRISPR-associated genes (Cas) to form CRISPR RNA (crRNA)-guided surveillance complexes, which target foreign nucleic acids for destruction. Cas9 is unique in that it is composed of a single polypeptide that utilizes both a crRNA and a trans-activating crRNA (tracrRNA) or a single guide RNA to create double-stranded breaks in sequences complementary to the RNA via the HNH and RuvC nuclease domains. Cas9 has become a revolutionary tool for gene-editing applications. Here, we describe methods for studying the cleavage activities of Cas9. We describe protocols for rapid quench-flow and stopped-flow kinetics and interpretation of the results. The protocols detailed here will be paramount for understanding the mechanistic basis for specificity of this enzyme, especially in efforts to improve accuracy for clinical use.

A new probe for detecting zinc-bound carbonic anhydrase in cell lysates and cells

We report the synthesis and application of a small molecule probe for carbonic anhydrase (CA) to track holo-CA in cell lysates and live-cell models of zinc dyshomeostasis. The probe displays a 12-fold increase in fluorescence upon binding to bovine CA and also responds to human CA isoforms.

Electron tunnelling and hopping effects on the temperature coefficient of resistance of carbon nanotube/polymer nanocomposites

Effectively tailoring the temperature coefficient of resistance (TCR) is critical for multifunctional carbon nanotube (CNT) polymer composites with sensing capability. By developing a new multiscale percolation network model, this work reveals theoretically that the zero-TCR could be achieved by adjusting competing contributions from thermally assisted tunnelling transport at CNT junctions and thermal expansion of matrices. On the other hand, the negative temperature coefficient of nanocomposites above glass transition temperature could be greatly enhanced because the transport mechanism at the CNT junctions experienced a transition from tunnelling to hopping. Both tube-tube and/or tube-matrix interactions at conjunction and the structural distortion of nanotubes are considered in the newly proposed model. To validate the model, CNT/polymer nanocomposites with nearly constant resistance values (zero-TCR) below the glass transition temperature and a high TCR (98% resistance change ratio) resulting from the glass transition of the polymer matrix are successfully developed. The study also suggests that the desired parameters to achieve the zero-TCR property and the potential resistance change ratio could be improved by the glass transition in nanocomposites. This could be beneficial for the development of high quality sensing materials.

DNA Unwinding Is the Primary Determinant of CRISPR-Cas9 Activity

Bacterial adaptive immunity utilizes RNA-guided surveillance complexes comprising Cas proteins together with CRISPR RNAs (crRNAs) to target foreign nucleic acids for destruction. Cas9, a type II CRISPR-Cas effector complex, can be programed with a single-guide RNA that base pairs with the target strand of dsDNA, displacing the non-target strand to create an R-loop, where the HNH and the RuvC nuclease domains cleave opposing strands. While many structural and biochemical studies have shed light on the mechanism of Cas9 cleavage, a clear unifying model has yet to emerge. Our detailed kinetic characterization of the enzyme reveals that DNA binding is reversible, and R-loop formation is rate-limiting, occurring in two steps, one for each of the nuclease domains. The specificity constant for cleavage is determined through an induced-fit mechanism as the product of the equilibrium binding affinity for DNA and the rate of R-loop formation.

Detection and clinical significance of glomerular M-type phospholipase A2 receptor in patients with idiopathic membranous nephropathy

BACKGROUND

Glomerular M-type phospholipase A₂ receptor (PLA₂ R) is important for diagnosing idiopathic membranous nephropathy (IMN). The relation between glomerular PLA₂ R expression and response to treatment remains to be explored.

AIMS

We conducted the study to explore the positive rate and clinical significance of glomerular M-type PLA₂ R in IMN patients.

METHODS

A total of 122 IMN patients receiving neither glucocorticoid nor immunosuppressant therapy prior to renal biopsies was included and followed for more than 1 year. The control group comprised 30 patients with secondary membranous nephropathy and 100 patients with non-membranous forms of nephropathy. PLA₂ R level and IgG subclasses in glomeruli were detected. The primary end-point was the reduction of proteinuria to less than 50% of baseline value.

RESULTS

A total of 82.0% of patients with IMN had positive glomerular PLA₂ R deposits, compared with 16.7% in the secondary membranous nephropathy group (P < 0.001). Additionally, PLA₂ R-positive expression combined with IgG4 ≥ 2+ was found in 94.3% IMN patients, compared with 40.0% in secondary membranous nephropathy patients (P < 0.01). Among IMN patients, the remission rate of proteinuria after either glucocorticoid or glucocorticoid combined immunosuppressant therapy for at least 6 months was 83.9% in the PLA₂ R-positive group compared with 54.5% in the negative group (P < 0.05).

CONCLUSION

The positive rate of glomerular PLA₂ R was more prevalent in IMN patients. Both PLA₂ R and IgG4 glomerular deposits may help in discriminating between idiopathic and secondary membranous nephropathy. IMN patients with positive PLA₂ R expression probably have a more beneficial response to glucocorticoid and/or immunosuppressant therapy.

Evolving safety practices in the setting of modern complex operating room: role of nurses

Operating room (OR) nursing previously referred to patient care provided during the intra-operative phase and the service provided within the OR itself. With the expansion of responsibilities of nurses, OR nursing now includes pre-operative and post-operative periods, therefore peri-operative nursing is accepted as a nursing process in OR in the contemporary medical literature. Peri-operative nurses provide care to the surgical patients during the entire process of surgery. They have several roles including those of manager or a director, clinical practitioner (scrub nurse, circulating nurse and nurse anesthetist), educator as well as researcher. Although, utmost priority is placed on insuring patient safety and well-being, they are also expected to participate in professional organization, continuing medical education programs and participating in research activities. A Surgical Patient Safety Checklist formulated by the World Health Organization serves as a major guideline to all activities in OR, and peri-operative nurses are key personnel in its implementation. Communication among the various players of a procedure in OR is key to successful patient outcome, and peri-operative nurses have a central role in making it happen. Setting up of OR in military conflict zones or places that suffering a widespread natural disaster poses a unique challenge to nursing. This review discusses all aspects of peri-operative nursing and suggests points of improvement in patient care.

Low-Frequency Self-Powered Footstep Sensor Based on ZnO Nanowires on Paper Substrate

In this work, we design and fabricate a wireless system with the main operating device based on zinc oxide (ZnO) nanowires. The main operating device is based on piezoelectric nanogenerator (NG) achieved using ZnO nanowires grown hydrothermally on paper substrate. The fabricated NG is capable of harvesting ambient mechanical energy from various kinds of human motion, e.g., footsteps. The harvested electric output has been used to serve as a self-powered pressure sensor. Without any storage device, the signal from a single footstep has successfully triggered a wireless sensor node circuit. This study demonstrates the feasibility of using ZnO nanowire piezoelectric NG as a low-frequency self-powered sensor, with potential applications in wireless sensor networks.

Enhanced responsivity resonant RF photodetectors

The responsivity of room-temperature, semiconductor-based photodetectors consisting of resonant RF circuits coupled to microstrip buslines is investigated. The dependence of the photodetector response on the semiconductor material and RF circuit geometry is presented, as is the detector response as a function of the spatial position of the incident light. We demonstrate significant improvement in detector response by choice of photoconductive material, and for a given material, by positioning our optical signal to overlap with positions of RF field enhancement. Design of RF circuits with strong field enhancement are demonstrated to further improve detector response. The improved detector response demonstrated offers opportunities for applications in RF photonics, materials metrology, or single read-out multiplexed detector arrays.

Rate-limiting Pyrophosphate Release by HIV Reverse Transcriptase Improves Fidelity

Previous measurements of the rates of polymerization and pyrophosphate release with DNA templates showed that pyrophosphate (PP_i) dissociation was fast after nucleotide incorporation so that it did not contribute to enzyme specificity (k_cat/K_m). Here, kinetic parameters governing nucleotide incorporation and PP_i release were determined using an RNA template. Compared with a DNA template of the same sequence, the rate of chemistry increased by up to 10-fold (250 versus 24 s^-1), whereas the rate of PP_i release decreased to approximately 58 s^-1 so that PP_i release became the rate-limiting step. During processive nucleotide incorporation, the first nucleotide (TTP) was incorporated at a fast rate (152 s^-1), whereas the rates of incorporation of remaining nucleotides (CGTCG) were much slower with an average rate of 24 s^-1, suggesting that sequential incorporation events were limited by the relatively slow PP_i release step. The accompanying paper shows that slow PP_i release allows polymerization and RNase H to occur at comparable rates. Although PP_i release is the rate-determining step, it is not the specificity-determining step for correct incorporation based on our current estimates of the rate of reversal of the chemistry step (3 s^-1). In contrast, during misincorporation, PP_i release became extremely slow, which we estimated to be ∼0.002 s^-1 These studies establish the mechanistic basis for DNA polymerase fidelity during reverse transcription and provide a free energy profile. We correct previous underestimates of discrimination by including the slow PP_i release step. Our current estimate of 2.4 × 10⁶ is >20-fold greater than estimated previously.

[Clinical and electroencephalographic analysis of anti-N-methyl-D-aspartate receptor encephalitis in children]

OBJECTIVE

To study the clinical and electroencephalographic (EEG) characteristics of anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDAR encephalitis) in children.

METHOD

Retrospective analysis was performed on the clinical and EEG data of 105 patients with anti-NMDAR encephalitis treated in Beijing Children's Hospital (August 2011-March 2015). Of the 105 patients, 38 were male and 67 were female.The age of onset was from 6 months and 26 days to 15 years and 8 months (average (8±4)years). The time for confirmed diagnosis was from 4 days to 850 days (median 24.5 days). According to the modified Rankin scales, the patient's clinical conditions were assessed and underwent continuous EEG (cEEG) monitoring.The data were reviewed and analyzed.

RESULT

Based on the severity of the disease, the 105 patients were divided into three groups: mild group (12 cases), moderate group (65 cases), and severe group (28 cases). There were 91 cases(86.7%)with abnormal EEG patterns, including 28 cases (26.7%) with slow background activity in EEG, 25 cases (23.8%) with generalized or diffuse slow waves, 33 cases (31.4%) had focal slow waves, 41 cases (39.0%) had epileptic waves; 10 cases (9.5%) showed unilateral or diffuse alpha-theta band rhythms in nonrapid eye movement (NREM) sleep, 7 cases (6.7%) showed extreme delta brush waves (EDB). Accordingly, the number of patients with abnormal EEG in mild, moderate and severe groups was 5, 58 (89.2%) and 28(100.0%). Seven patients with EDB phenomenon were all in the severe group, and 10 patients with abnormal alpha-theta band rhythms were in the moderate group.

CONCLUSION

In children with anti-NMDAR encephalitis, the EEG patterns are in line with the changes of EEG in general encephalitis.The extent of EEG abnormalities correlates with the clinical severity of the disease. Extreme delta brush and alpha-theta band rhythms may be suggestive of diagnosis and clinical assessment of the disease.

Relationship between CYP17 gene polymorphisms and risk of prostate cancer

Cytochrome P450 17a-hydroxylase (CYP17) plays a critical role in androgen biosynthesis. Polymorphisms of the CYP17 promoter have been proposed as risk factors for prostate cancer; however, some studies have produced inconclusive or controversial results. We investigated the relationship between polymorphisms of the CYP17 gene and the risk of prostate cancer. A total of 176 patients with prostate cancer were enrolled in the study, and 168 healthy individuals acted as the control group. The participants were divided into those <71 years old and those ≥71 years old. Restriction fragment length polymorphism-polymerase chain reaction was used to confirm the genotype of CYP17 in the samples. The prostate-specific antigen (PSA) concentrations were also measured in all subjects. When T/C and C/C were compared with T/T, the ORs were 0.478 (P = 0.489) and 0.814 (P = 0.367), respectively. There was no significant difference in PSA concentration among the three genotypes in the <71 group, whereas there were statistically significant differences in the ≥71 group (P = 0.003 and 0.012, respectively). There was no significant difference in free PSA and total PSA levels between the three groups and the control group. The T/C and C/C genotypes were not associated with the risk of prostate cancer, and there were no significant differences between them. In the ≥71 group, the T/C and C/C genotypes were closely associated with prostate cancer, which suggests that the CYP17 gene might be a risk factor for prostate cancer in males of advanced age.

The role of ppGalNAc-T family in breast cancer development and progression

Glycosylation of proteins is an essential process in all eukaryotes. Mucin-type O-linked glycosylation is an evolutionarily conserved protein modification as a kind of glycosylation of proteins. The role of O-glycosylation was well documented in multiple cancers. While in breast cancer, the enzymes that catalyzed the initiation of O-glycosylation remained elusive. In this review, we briefly introduced the process of the initiation of O-glycosylation and summarized the roles of enzymes that catalyzed the initiation step of O-glycosylation in the breast cancer carcinogenesis, development, and progression. Finally, we summarized some attempts exploring the therapy against aberrant O-glycosylation.

A survey of outcomes and management of patients post fragility fractures in China

We found that the fragility hip and vertebral fractures caused excess mortality rates in this Chinese female population, which was unexpectedly lower than those in western countries and other Asian countries. This was the first nationwide survey relating to post-fracture outcomes conducted among Chinese population in Mainland China.

INTRODUCTION

This study aimed to investigate the mortality, self-care ability, diagnosis, and medication treatment of osteoporosis following fragility hip and vertebral fractures through a nationwide survey among female patients aged over 50 in Mainland China.

METHODS

This was a multicenter, retrospective cohort study based on medical chart review and patient questionnaire. Female patients aged 50 or older admitted for low-trauma hip or vertebral fractures and discharged from Jan 1, 2008 to Dec 31, 2012 were followed.

RESULTS

Total of 1151 subjects of hip fracture and 842 subjects of vertebral fracture were included. The mean age was 73.4 ± 10.0, and the median of duration from index fracture to interview was 2.6 years. The overall 1-year, 2-year, 3-year, 4-year, and 5-year cumulative mortality rates were 3.5, 7.0, 11.2, 13.1, and 16.9 %, respectively. The first year mortality rates in hip (3.8 %, 95% CI 3.3-4.4 %) and vertebral fracture (3.1 %, 95% CI 2.5-3.7 %) were significantly higher than that in the general population (1.6 %). Impaired self-care ability was observed in 33.2, 40.6, and 23.8 % of overall, hip fracture, and vertebral fracture group, respectively. The overall diagnosis rate of osteoporosis was 56.8 %, and bone mineral density (BMD) measurement had never been conducted in 42.0 % among these women. After the index fracture, 69.6 % of them received supplements and/or anti-osteoporotic medications, among which 39.6 % only received calcium with/without vitamin D supplementation.

CONCLUSIONS

The osteoporotic hip and vertebral fractures caused excess mortality rates in this population of Mainland China. The current diagnosis and medical treatment following the fragility fractures is still insufficient in Mainland China.

Prevalence and risk factors of Helicobacter pylori infection in asymptomatic Chinese children: a prospective, cross-sectional, population-based study

BACKGROUND

Limited research has been published on current Helicobacter pylori infection rate in asymptomatic children in China.

AIM

To assess current Helicobacter pylori infection rate, distribution characteristics and risk factors in Chinese asymptomatic children.

METHODS

A prospective, cross-sectional, population-based study was performed from 2009 to 2011 in three cities of China. Helicobacter pylori infection was diagnosed by a stool antigen test. Multi-stage cluster random sampling was used to select asymptomatic children including neonates. Socioeconomic details were obtained through a standardised questionnaire.

RESULTS

Among total of 3491 children (0-18 years), the global infection rate was 6.8% and there were no significant differences between genders. Age specific infection rate between regions was significantly different (P < 0.05). The infection rate significantly increased with age (P for trend <0.01). It was low during the newborn (0.6%) to preschool period and was significantly increased in high school students (13.5%) (P < 0.01). Multivariable regression indicated that hand sanitisation, individually served meals, higher education level of mother, above average living space and residence in urban areas were significantly protective against infection (OR 0.749, 0.698, 0.720, 0.838 and 0.770 respectively). Conversely, consuming meals in unsanitised conditions, sharing towels, receiving pre-chewed food from the mother, artificial feeding and family history of gastrointestinal disease were significantly associated with the risk of infection (OR 1.200, 1.965, 2.002, 1.071 and 2.093 respectively).

CONCLUSIONS

Helicobacter pylori infection rate increases with age in Chinese asymptomatic children and is common after 10 years of age. The rate of infection is related to socioeconomic status.

Giant piezoresistivity in aligned carbon nanotube nanocomposite: account for nanotube structural distortion at crossed tunnel junctions

High piezoresistivity is critical for multifunctional carbon nanotube polymer composites with sensing capability. By developing a new percolation network model, this work reveals theoretically that a giant piezoresistivity in the composites can be potentially achieved by controlled nanotube alignment resulting from field based alignment techniques. The tube-tube and/or tube-matrix interaction in conjunction with the aligned carbon nanotube networks are fully considered in the newly proposed model. The structural distortion of nanotubes is determined self-consistently by minimizing the pseudo-potential energy at crossed-tube junctions based on the Lennard-Jones potential and simulation of coarse grain molecular dynamics. The tunneling transport through crossed-tube junctions is calculated by the Landauer-Büttiker formula with empirical fitting by first-principle calculation. The simulation results also reveal that the piezoresistivity can be further improved by using low carbon nanotube loadings near the percolation threshold, carbon nanotubes with a small aspect ratio, high intrinsic conductivity and polymers with a small Poisson's ratio. This giant piezoresistive effect offers a tremendously promising future, which needs further thorough exploration.

Reverse-dipper pattern of blood pressure may predict lacunar infarction in patients with essential hypertension

BACKGROUND AND PURPOSE

The fluctuation of circadian blood pressure (BP) is of great diversity in patients with essential hypertension and may provide significant prognostic value for stroke. However, it remains uncertain whether reverse-dipper pattern of BP influences the incidence of lacunar infarction in hypertensive patients.

METHODS

In the current study, 362 hypertensive patients (195 males, 167 females) were enrolled. BP patterns were evaluated with 24-h ambulatory BP monitoring (ABPM). Multinomial logistic regression was applied to analyse the possible relationships between lacunar infarction and various clinical risk factors such as ABPM.

RESULTS

A total of 93 patients (25.7%) had reverse-dipper BP pattern. Non-dipper pattern of BP was observed in 179 hypertensive patients (49.4%) and dipper pattern in 90 patients (24.9%). The percentage of lacunar infarction was the highest in the patients with reverse-dipper pattern compared with pure hypertension or atherothrombotic cerebral infarction (P < 0.05). After multinomial logistic regression analysis, reverse-dipper pattern of BP (odds ratio 2.492; 95% confidence interval 1.133-5.479; P < 0.05) and age (odds ratio 1.084; 95% confidence interval 1.047-1.123; P < 0.01) were found to be directly associated with lacunar infarction.

CONCLUSIONS

Reverse-dipper BP pattern may serve as an independent risk factor for lacunar infarction and more personalized BP management should be offered to the patients who have elevated nocturnal BP.