Intraosseous schwannoma of the mandible: new case series, literature update, and proposal of a classification

Intraosseous schwannoma of the mandible is rare, with diagnostic and therapeutic challenges. The aims of this study were to report new cases of intraosseous schwannoma of the mandible and to propose a clinical classification, providing suggestions for treatment methods. The cases of 13 patients treated at the authors' hospital and 86 cases reported previously in the literature were reviewed. The most common clinical feature was facial swelling (60/93). The rate of cortical thinning or expansion was 44.8% (43/96); widening of the inferior alveolar nerve canal on radiographs was observed in 15 patients.

Clinical outcomes of keratinized mucosa augmentation in jaws reconstructed with fibula or iliac bone flaps

This prospective study was undertaken to evaluate the treatment outcomes of keratinized mucosa augmentation (KMA) on the buccal and palatal/lingual sides of implants in jaws reconstructed after oncological surgery. Forty-two implants in 12 patients whose jaws had been reconstructed with a fibula or iliac bone flap were included. KMA was performed at 3 months after implant placement; this included an apically displaced partial-thickness flap and a free gingival graft (FGG) around the implants to increase the keratinized mucosa width (KMW). Patients were followed up for at least 6 months post-surgery. KMW, shrinkage, and patient pain and discomfort measured on a visual analogue scale were analysed. A histological analysis was performed of tissue epithelium from two patients. The results showed that KMW was >2 mm on both the buccal and palatal/lingual sides during follow-up. Before surgery, histological analysis showed epithelium with no epithelial spikes; normal keratinized epithelial spikes were observed at 8 weeks after KMA. Greater KMW was observed around implants in reconstructed maxillae than around those in reconstructed mandibles (P < 0.001). Patients felt more pain at the donor site than at the recipient site during the first 3 days post-surgery. KMA with FGG was predictable in reconstructed jaws and may help maintain the long-term stability of implants.

P–257 An unknown cause lead to polyspermy in IVF cycles and 0PN zygotes in ICSI cycles in male patient

Study question

The patient sperm has normal morphology and motility, which paternal factors cause the abnormal fertilization in IVF/ICSI and what is the underlying mechanism?

Summary answer

A genetic mutation of BEX1 and decreased PLC-zeta has been found in patient, which may provide novel insights of polyspermy and pronucleus formation during fertilization.

What is known already

In mammals, pronucleus formation, a landmark event for fertilization, is critical for embryonic development. Abnormal fertilization refers to the abnormal number of pronucleus and polar bodies in zygotes during in vitro fertilization, with an incidence of 5–15%, among which the incidence of polyspermy and 0PN is about 2–10% and 30%. However, the mechanisms underlying pronucleus formation still unclear. More research has focused on oocyte activation, while paternal relevant abnormal fertilizations have been rarely established. The mechanism of how sperm and/or substances carried by sperm influence the physiological process of fertilization is also unclear.

Study design, size, duration

In our study, we first work on the preliminary observation and analysis of sperm morphology, structure and sperm chromosome number, and then made further analysis at the genetic level to find out the cause of this particular phenotype in this patient. We use of zone-free golden hamster ova test the fertilizing capacity and rescue the pronucleus formation with SrCl2.

Participants/materials, setting, methods

The patient, golden hamster, Papanicolaou stain, scanning electron microscope (SEM), Transmission Electron Microscope (TEM), Fluorescence in situ hybridization (FISH), Whole Exome Sequencing (WES), IVF, ICSI, Assisted Oocyte Activation (AOA).

Main results and the role of chance

During 2016–2018, they did 4 cycle assistant reproduction technology. Cycle1, conventional IVF(C-IVF), 9 MII oocytes, 9 3PN zygotes; Cycle2, ICSI, 10 MII oocytes, 10 0PN zygotes; Cycle3, donor-oocytes C-IVF, 6 MII oocytes, 6 3PN zygotes, and the donor did C-IVF get normal zygotes and embryos; Cycle4, donor-sperm C-IVF, 7 MII oocytes, 4 2PN zygotes, 3 useable embryos. Remarkably, clinical examination about male shows normal sperm semen parameters. Papanicolaou stain and SEM shows that the sperm of the patient has normal morphology. The TEM data shows that the spermatozoa with normal head morphology and intact 9 + 2 sperm flagella structure. In the sperm FISH analysis, Chromosome ploidy is haploid. We performed WES on the male, after exclusion of frequent variants and application of technical and biological filters, two homozygous missense mutations were identified in BEX1 (c.191G&gt;A [p. W64X]), which has been few reports of male infertility. The western blot result show that the PLC-zeta was decreased in patient. After 10mM SrCl2 assisted oocyte activation, the zygote has the pronucleus formation in ICSI.

Limitations, reasons for caution

At present, we only observe sperm related factors (morphology, structure, chromosome number, genetic mutation). Next step is to detect the substances sperm carried (e.g. RNA-seq, proteomics). In this case, what is of great concern to us is the inconsistencies of the abnormal fertilization during the conventional IVF and ICSI cycles.

Wider implications of the findings: Many studies of fertilization mechanism, the main focus is on the maternal cytoplasmic factors, such as the Ca 2+ release initiate the fast block of oocytes. There are few reports about abnormal fertilization due to sperm factors. Our case may offer new insights for the study of fertilization.

Trial registration number

Not applicable

Redox-responsive biocompatible nanocarriers based on novel heparosan polysaccharides for intracellular anticancer drug delivery

Heparosan is a natural precursor of heparin biosynthesis in mammals. It is stable in blood circulation but can be degraded in lysosomes, showing good biocompatibility and long circulation features. So heparosan can be designed as anticancer drug carriers to increase tumor selectivity and improve the therapeutic effect. A novel redox-sensitive heparosan-cystamine-vitamin E succinate (KSV) micelle system was constructed for intracellular delivery of doxorubicin (DOX). Simultaneously, the redox-insensitive heparosan-adipic acid dihydrazide-vitamin E succinate copolymer (KV) was synthesized as control. DOX-loaded micelles (DOX/KSV) with an average particle size of 90–120 nm had good serum stability and redox-triggered depolymerization. In vitro drug release test showed that DOX/KSV micelles presented obvious redox-triggered release behavior compared with DOX/KV. Cytotoxicity and cell uptake were investigated using MGC80-3 tumor cells and COS7 fibroblast-like cells. The cell survival rate of blank micelles was more than 90%, and the cytotoxicity of DOX/KSV in MGC80-3 cells was higher than in COS7 cells, indicating that the carrier has better biocompatibility and less toxicity side effect. The cytotoxicity of DOX/KSV against MGC80-3 cells was significantly greater than that of free DOX and DOX/KV. Furthermore, compared with DOX/KV in MGC80-3 cells, DOX/KSV micelles uptook more anticancer drugs and then released DOX faster into the cell nucleus. The micelles were endocytosed by multiple pathways, but clathrin-mediated endocytosis was the main pathway. Therefore, heparosan polysaccharide could be a potential option as anticancer carrier for enhancing efficacy and mitigating toxicity.

Targeting Lyn regulates Snail family shuttling and inhibits metastasis

The acquisition of an invasive phenotype by epithelial cells occurs through a loss of cellular adhesion and polarity, heralding a multistep process that leads to metastatic dissemination. Since its characterization in 1995, epithelial-mesenchymal transition (EMT) has been closely linked to the metastatic process. As a defining aspect of EMT, loss of cell adhesion through downregulation of E-cadherin is carried out by several transcriptional repressors; key among them the SNAI family of transcription factors. Here we identify for the first time that Lyn kinase functions as a key modulator of SNAI family protein localization and stability through control of the Vav-Rac1-PAK1 (Vav-Rac1-p21-activated kinase) pathway. Accordingly, targeting Lyn in vitro reduces EMT and in vivo reduces metastasis of primary tumors. We also demonstrate the clinical relevance of targeting Lyn as a key player controlling EMT; patient samples across many cancers revealed a strong negative correlation between Lyn and E-cadherin, and high Lyn expression in metastatic tumors as well as metastasis-prone primary tumors. This work reveals a novel pancancer mechanism of Lyn-dependent control of EMT and further underscores the role of this kinase in tumor progression.

GRK2 desensitizes flow-induced responses in osteoblasts

Bone desensitization after mechanical loading is essential for bone to adapt to its mechanical environment. However, the desensitization mechanism is unknown. Previous studies suggest that G protein-coupled receptors (GPCRs), including P2Y and parathyroid hormone receptors, play important roles in osteoblast mechanobiology. Thus, for the present research, we examined the role of G protein-coupled receptor kinase 2 (GRK2) in osteoblast desensitization after exposure to mechanical stimulation. We first showed the existence of osteoblast desensitization after mechanical stimulation based on cytosol Ca²⁺ and phosphorylated ERK1/2 activities, detected using a fluorescent Ca²⁺-sensitive dye and western blotting, respectively. We then demonstrated that GRK2 overexpression in MC3T3-E1 cells inhibits flow-induced ERK1/2 phosphorylation, while siRNA knockdown of GRK2 enhances ERK1/2 phosphorylation. Additionally, we found that GRK2 overexpression in MC3T3-E1 cells inhibits cyclooxygenase-2 mRNA expression in the short term and alkaline phosphatase activity in the long term. More importantly, we discovered that GRK2 translocated to the cell membrane shortly after flow stimulation - a step necessary for GPCR desensitization. Previously, we have demonstrated that P2Y2 purinergic receptors, one type of GPCRs, are involved in various flow-induced osteoblastic responses. In this research, we also showed that GRK2 overexpression does not affect ATP release. Accordingly, GRK2 is able to inhibit flow-induced osteoblast responses possibly through desensitizing P2Y2 receptors.

A point-prevalence survey of healthcare-associated infection in fifty-two Chinese hospitals

BACKGROUND

Healthcare-associated infection (HCAI) represents a major problem for patient safety worldwide.

AIM

To demonstrate the prevalence, causative agents, and risk factors for HCAI in Chinese hospitals.

METHODS

A one-day point-prevalence survey was conducted in 52 Chinese hospitals between October 2014 and March 2015. A web-based software system was developed for data entry and management.

FINDINGS

Among 53,939 patients surveyed, the prevalence of patients with at least one HCAI was 3.7%. Of 2182 HCAI episodes, the most frequently occurring types were lower respiratory tract infections (47.2%), followed by urinary tract infection (12.3%), upper respiratory tract infection (11.0%), and surgical site infection (6.2%). The prevalence of patients with at least one HCAI in critical care units was highest (17.1%). Device-associated infections, including ventilator-associated pneumonia, catheter-associated urinary tract infection, and central catheter-associated bloodstream infection, accounted for only 7.9% of all HCAIs. The most frequently isolated micro-organisms were Pseudomonas aeruginosa [206 infections (9.4%)], Acinetobacter baumannii [172 infections (7.9%)], Klebsiella pneumoniae [160 infections (7.3%)], and Escherichia coli [145 infections (6.6%)]. Of the survey patients (18,206/53,939), 33.8% were receiving at least one antimicrobial agent at the time of the survey. Risk factors for HCAI included older age (≥80 years), male gender, days of hospital admission, admission into a critical care unit, and device utilization.

CONCLUSION

Our study suggests that the overall prevalence of HCAI in surveyed Chinese hospitals was lower than that reported from most European countries and the USA. More attention should be given to the surveillance and prevention of non-device-associated HCAI in China.

Rip3 knockdown rescues photoreceptor cell death in blind pde6c zebrafish

Achromatopsia is a progressive autosomal recessive retinal disease characterized by early loss of cone photoreceptors and later rod photoreceptor loss. In most cases, mutations have been identified in CNGA3, CNGB3, GNAT2, PDE6C or PDE6H genes. Owing to this genetic heterogeneity, mutation-independent therapeutic schemes aimed at preventing cone cell death are very attractive treatment strategies. In pde6c(w59) mutant zebrafish, cone photoreceptors expressed high levels of receptor-interacting protein kinase 1 (RIP1) and receptor-interacting protein kinase 3 (RIP3) kinases, key regulators of necroptotic cell death. In contrast, rod photoreceptor cells were alternatively immunopositive for caspase-3 indicating activation of caspase-dependent apoptosis in these cells. Morpholino gene knockdown of rip3 in pde6c(w59) embryos rescued the dying cone photoreceptors by inhibiting the formation of reactive oxygen species and by inhibiting second-order neuron remodelling in the inner retina. In rip3 morphant larvae, visual function was restored in the cones by upregulation of the rod phosphodiesterase genes (pde6a and pde6b), compensating for the lack of cone pde6c suggesting that cones are able to adapt to their local environment. Furthermore, we demonstrated through pharmacological inhibition of RIP1 and RIP3 activity that cone cell death was also delayed. Collectively, these results demonstrate that the underlying mechanism of cone cell death in the pde6c(w59) mutant retina is through necroptosis, whereas rod photoreceptor bystander death occurs through a caspase-dependent mechanism. This suggests that targeting the RIP kinase signalling pathway could be an effective therapeutic intervention in retinal degeneration patients. As bystander cell death is an important feature of many retinal diseases, combinatorial approaches targeting different cell death pathways may evolve as an important general principle in treatment.

A novel allele, HLA-A*03:01:09, identified by sequence-based typing in a Chinese individual

We describe the identification of a novel allele HLA-A*03:01:09 in a Chinese individual.

Identification of the novel HLA-B allele, HLA-B*39:42, in a Chinese individual

The HLA-B*39:42 allele differs from the closest matching allele B*39:01:01:01 by two nucleotide substitutions in exon 3.

HLA-B*27:44, a novel allele identified by sequence-based typing, is a well-documented allele in China

The sequence of HLA-B*27:44 differs in exon 2 from the sequence of B*27:08 by one amino acid change at codon 74.

A novel HLA-B allele, B*40:01:06, identified by sequence-based typing in a Chinese individual

The sequence of HLA-B*40:01:06 differs in exon 3 from the sequence of B*40:01:01 by one nucleotide 435 (codon121) G to A.

A novel HLA-B allele, B*07:55, identified by sequence-based typing

The novel allele differs from HLA-B*07:02:01 by a single nucleotide substitution at position 538 in exon 3.

Identification of a novel HLA-A allele, A*24:128 in a Chinese individual

The novel HLA-A*24:128 shows one nucleotide change from HLA-A*24:02:01:01 in exon 2 at position 155 from A to G.

A novel HLA-A allele, A*24:02:17, identified by sequence-based typing

The A*24:02:17 allele differs from the most close matching allele A*24:02:01:01 by one nucleotide substitution in exon 2, at position 264.

A novel HLA-B allele, B*13:18, identified by sequence-based typing

The B*13:18 allele differs from the most closely matching allele B*13:02:01 by one nucleotide substitution in exon 3, at position 539.

Consistent pseudopotential interactions in lattice Boltzmann models

We outline a systematic procedure on how to construct and derive interactions for nonideal lattice fluids. Using a mesoscopic approach based on exact lattice theories, we prove the consistency of the resulting diffuse interface theory with continuum thermodynamics. Translated in the framework of the so called "Shan-Chen" model for nonideal lattice fluids, this paper shows how to adjust the associated pseudopotentials to reproduce a free energy model based on a square gradient theory of equilibrium interfaces.