Assessment of biocompatibility of 3D printed photopolymers using zebrafish embryo toxicity assays

3D printing has emerged as a rapid and cost-efficient manufacturing technique to enable the fabrication of bespoke, complex prototypes. If the technology is to have a significant impact in biomedical applications, such as drug discovery and molecular diagnostics, the devices produced must be biologically compatible to enable their use with established reference assays and protocols. In this work we demonstrate that we can adapt the Fish Embryo Test (FET) as a new method to quantify the toxicity of 3D printed microfluidic devices. We assessed the biocompatibility of four commercially available 3D printing polymers (VisiJetCrystal EX200, Watershed 11122XC, Fototec SLA 7150 Clear and ABSplus P-430), through the observation of key developmental markers in the developing zebrafish embryos. Results show all of the photopolymers to be highly toxic to the embryos, resulting in fatality, although we do demonstrate that post-printing treatment of Fototec 7150 makes it suitable for zebrafish culture within the FET.

Pdcd4 deficiency enhances macrophage lipoautophagy and attenuates foam cell formation and atherosclerosis in mice

Macrophage foam cells, a major component of the atherosclerotic lesion, have vital roles in the development of atherosclerosis. Lipoautophagy, a type of autophagy characterized by selective delivery of lipid droplet for lysosomal degradation, may impact atherosclerosis by regulating macrophage foam cell formation. Previously, we reported that programmed cell death 4 (PDCD4), a tumor suppressor, negatively regulated autophagy in tumor cells. However, its roles in macrophage lipoautophagy, foam cell formation and atherosclerosis remain to be established. Here we found that Pdcd4 deficiency clearly improved oxidized low-density lipoproteins-impaired autophagy efflux, promoted autophagy-mediated lipid breakdown in murine macrophages and thus prevented macrophage conversion into foam cells. Importantly, Pdcd4 deficiency in mice significantly upregulated macrophage autophagy in local plaques along with attenuated lipid accumulation and atherosclerotic lesions in high-fat-fed Apolipoprotein E knockout mice. Bone marrow transplantation experiment demonstrated that PDCD4-mediated autophagy in hematopoietic cells contributed to the development of atherosclerosis. These results indicate that endogenous PDCD4 promotes for macrophage foam cell formation and atherosclerosis development via inhibiting autophagy and provides new insights into atherogenesis, suggesting that promoting macrophage autophagy through downregulating PDCD4 expression may be beneficial for treating atherosclerosis.

A mix of S and ΔS variants of STAT3 enable survival of activated B-cell-like diffuse large B-cell lymphoma cells in culture

Activated B-cell-like diffuse large B-cell lymphoma (ABC DLBCL) is characterized by increased expression and activator of signal transducer and activator of transcription 3 (STAT3). ABC DLBCL cells require STAT3 for growth in culture. In ABC DLBCL cells, eosinophils and perhaps all cells, four variant STAT3 mRNAs (Sα, ΔSα, Sβ and ΔSβ) are present as a result of two alternative splicing events, one that results in the inclusion of a 55-residue C-terminal transactivation domain (α) or a truncated C-terminal domain with 7 unique residues (β) and a second that includes (S) or excludes (ΔS) the codon for Ser-701 in the linker between the SH2 and C-terminal domains. A substantial literature indicates that both α and β variants are required for optimal STAT3 function, but nothing is known about functions of ΔS variants. We used a knockdown/re-expression strategy to explore whether survival of ABC DLBCL cells requires that the four variants be in an appropriate ratio. No single variant rescued survival as well as STAT3Sα-C, Sα with activating mutations (A661C and N663C) in the SH2 domain. Better rescue was achieved when all four variants were re-expressed or Sα and ΔSα or Sβ and ΔSβ were re-expressed in pairs. Rescue correlated with expression of STAT3-sensitive genes NFKBIA and NFKBIZ. We consider a variety of explanations why a mix of S and ΔS variants of STAT3 should enable survival of ABC DLBCL cells.

Non-directed, carbonate-mediated C–H activation and aerobic C–H oxygenation with Cp*Ir catalysts

Carbonate additives enhance the activity of [Cp*Ir(H₂O)₃](OTf)₂ for non-directed C–H activations and the aerobic C–H oxygenation of alkyl arenes.

Disproportionate growth between the spine and pelvis in patients with thoracic adolescent scoliosis

A self-control ratio, the spine-pelvis index (SPI), was proposed for the assessment of patients with adolescent idiopathic scoliosis (AIS) in this study. The aim was to evaluate the disproportionate growth between the spine and pelvis in these patients using SPI. A total of 64 female patients with thoracic AIS were randomly enrolled between December 2010 and October 2012 (mean age 13 years, standard deviation (sd) 2.17; 9 to 18) and a further 73 healthy female patients with a mean age of 12.4 years (mean age 12.4 years, sd 2.24; 9 to 18), were randomly selected from a normal control database at our centre. The radiographic parameters measured included length of spine (LOS), height of spine (HOS), length of thoracic vertebrae (LOT), height of thoracic vertebrae (HOT), width of pelvis (WOP), height of pelvis (HOP) and width of thorax (WOT). SPI was defined as the ratio LOS/HOP. The SPI and LOT/HOP in patients with AIS showed a significant increase when compared with normal girls (p < 0.001 and p < 0.001 respectively), implying an abnormal pattern of growth of the spine relative to the pelvis in patients with AIS.

No significant difference in SPI was found in different age groups in the control group, making the SPI an age-independent parameter with a mean value of 2.219 (2.164 to 2.239). We also found that the SPI was not related to maturity in the control group.

This study, for the first time, used a self-control ratio to confirm the disproportionate patterns of growth of the spine and pelvis in patients with thoracic AIS, highlighting that the SPI is not affected by age or maturity.

Cite this article: Bone Joint J 2015;97-B:1668–74.

Avian sarcoma and leukosis virus gag gene in the Anser anser domesticus genome

Endogenous retroviruses are regarded as ideal genetic markers for evolutionary analyses. Birds were some of the initial vertebrates found to contain endogenous retroviruses. However, few studies have investigated the presence and distribution of endogenous retroviruses in goose. In this study, we detected the avian sarcoma and leukosis virus gag gene in the genomic DNA of 8 Chinese native breeds using polymerase chain reaction method. The results indicated that a 1.2-kb avian sarcoma and leukosis virus gag sequence was integrated into all 8 goose breeds. The mean genetic pairwise distance was 0.918% among the investigated geese. To the best of our knowledge, this is the first report demonstrating the presence of the endogenous retroviruses in the domestic goose genome. The genetic structure should be further examined in the domestic goose.

Clinical significance of serum procalcitonin level monitoring on early diagnosis of severe pneumonia on children

OBJECTIVE

To discuss the method for early diagnosis of severe pneumonia on children.

PATIENTS AND METHODS

Fifty-six children with severe pneumonia were enrolled from Department of Pediatrics and Intensive Care Unit (ICU) of our hospital and divided into two groups according to parasitological detection: bacterial pneumonia group consisting of 34 children patients and non-bacterial pneumonia group of 32 children patients. In the meanwhile, 37 healthy children, who were confirmed without infection through physical examination, were also enrolled and grouped in into normal control group. Peripheral venous blood of all children was collected to detect their procalcitonin (PCT).

RESULTS

PCT level of patients in bacterial pneumonia group was significantly higher than that in the non-bacterial pneumonia group and control group, and difference had statistical significance (p < 0.01); serum PCT level on patients in bacterial pneumonia group before and after treatment had statistical significance (p < 0.01); serum PCT level on patients in non-bacterial pneumonia group before and after treatment had no statistical significance (p > 0.05).

CONCLUSIONS

PCT was a very important biomarker for the diagnosis of bacterial infection and also a sensitive indicator for the distinction of child bacterial pneumonia and non-bacterial pneumonia. It had significant clinical diagnosis and differential diagnosis value.

Multiple tooth loss is associated with vascular cognitive impairment in subjects with acute ischemic stroke

BACKGROUND AND OBJECTIVE

Emerging evidence shows that tooth loss is associated with cognitive impairment and dementia. Vascular cognitive impairment (VCI) is a common consequence of ischemic stroke. This study investigated the association of tooth loss with VCI in patients with acute stroke.

MATERIAL AND METHODS

A total of 161 subjects with acute ischemic stroke were recruited. Within 1 wk after admission, fasting blood tests were undertaken and the number of teeth present was recorded. VCI was evaluated with the Montreal Cognitive Assessment (MoCA).

RESULTS

The patients with loss of ≥ 8 teeth exhibited significantly lower MoCA values as compared to those with loss of ≤ 7 teeth (13.2 ± 6.6 vs. 17.3 ± 6.0, p < 0.001). Multivariate logistic regression analysis showed that loss of ≥ 8 teeth (OR = 3.1, 95% CI: 1.2-7.9, p = 0.02) and stroke history (OR = 3.8, 95% CI: 1.1-14.1, p = 0.04) were significantly associated with VCI (MoCA score ≤ 20.0).

CONCLUSION

Within the limitations of this study, the current findings provide the first evidence that multiple tooth loss is independently associated with VCI in patients with acute ischemic stroke.

Cascade Raman sideband generation and orbital angular momentum relations for paraxial beam modes

In this work, the nonlinear parametric interaction of optical radiation in various transverse modes in a Raman-active medium is investigated both experimentally and theoretically. Verification of the orbital angular momentum algebra (OAM-algebra) [Strohaber et al.,Opt. Lett.37,3411 (2012)] was performed for high-order Laguerre Gaussian modes ℓ>1. It was found that this same algebra also describes the coherent transfer of OAM when Ince-Gaussian modes were used. New theoretical considerations extend the OAM-algebra to even and odd Laguerre Gaussian, and Hermite Gaussian beam modes through a change of basis. The results of this work provide details in the spatiotemporal synthesis of custom broadband pulses of radiation from Raman sideband generation.

Beta-interferon exposure and onset of secondary progressive multiple sclerosis

BACKGROUND AND PURPOSE

Beta-interferons (IFNβ) are the most widely prescribed drugs for patients with multiple sclerosis (MS). However, whether or not treatment with IFNβ can delay secondary progressive MS (SPMS) onset remains unknown. Our aim was to examine the association between IFNβ exposure and SPMS onset in patients with relapsing-remitting MS (RRMS).

METHODS

A retrospective cohort study using British Columbia (Canada) population-based clinical and health administrative data (1985-2008) was conducted. RRMS patients treated with IFNβ (n = 794) were compared with untreated contemporary (n = 933) and historical (n = 837) controls. Cohort entry was the first clinic visit during which patients became eligible for IFNβ treatment (baseline). The outcome was time from baseline to SPMS onset. Cox regression models with IFNβ as a time-dependent exposure were adjusted for sex, and baseline age, disease duration, disability, *socioeconomic status and *comorbidities (*available for the contemporary cohorts only). Additional analyses included propensity score adjustment.

RESULTS

The median follow-up for the IFNβ-treated, untreated contemporary and historical controls were 5.7, 3.7 and 7.3 years, and the proportions of patients reaching SPMS were 9.2%, 11.8% and 32.9%, respectively. After adjustment for confounders, IFNβ exposure was not associated with the risk of reaching SPMS when either the contemporary or the historical untreated cohorts were considered (hazard ratio 1.07; 95% confidence interval 0.93-1.48, and hazard ratio 1.04; 95% confidence interval 0.74-1.46, respectively). Further adjustments and the propensity score yielded results consistent with the main analysis.

CONCLUSIONS

Amongst patients with RRMS, use of IFNβ was not associated with a delayed onset of SPMS.

Glycosyltransferase-mediated Sweet Modification in Oral Streptococci

Bacterial glycosyltransferases play important roles in bacterial fitness and virulence. Oral streptococci have evolved diverse strategies to survive and thrive in the carbohydrate-rich oral cavity. In this review, we discuss 2 important biological processes mediated by 2 distinct groups of glycosyltransferases in oral streptococci that are important for bacterial colonization and virulence. The first process is the glycosylation of highly conserved serine-rich repeat adhesins by a series of glycosyltransferases. Using Streptococcus parasanguinis as a model, we highlight new features of several glycosyltransferases that sequentially modify the serine-rich glycoprotein Fap1. Distinct features of a novel glycosyltransferase fold from a domain of unknown function 1792 are contrasted with common properties of canonical glycosyltransferases. The second biological process we cover is involved in building sticky glucan matrix to establish cariogenic biofilms by an important opportunistic pathogen Streptococcus mutans through the action of a family of 3 glucosyltransferases. We focus on discussing the structural feature of this family as a glycoside hydrolase family of enzymes. While the 2 processes are distinct, they all produce carbohydrate-coated biomolecules, which enable bacteria to stick better in the complex oral microbiome. Understanding the making of the sweet modification presents a unique opportunity to develop novel antiadhesion and antibiofilm strategies to fight infections by oral streptococci and beyond.

Distribution of pilus islands and alpha-like protein genes of group B Streptococcus colonized in pregnant women in Beijing, China

Group B Streptococcus (GBS) is one of the major pathogens of severe newborn sepsis and meningitis. Understanding its regional molecular epidemiology is helpful for regulating efficient prevention practice. A total of 160 GBS strains were collected from colonized pregnant women in six hospital settings in Beijing, China. Polymerase chain reaction (PCR) assays were used to identify the pilus island (PI), alp genes profiling of the alpha-like protein family, and capsular polysaccharide (cps) serotyping. The clonal relationships between strains were investigated using multilocus sequence typing (MLST). All isolates carried at least one pilus island. The most frequently detected pilus island was PI-2a alone (70 isolates, 43.8 %). The most prevalent alp gene was rib (60 isolates, 37.5 %). Moreover, a strong association was noted between alp genes, serotyping, and pilus island profiles. The GBS isolates under study hinted similar molecular epidemical characteristics in Beijing to those reported worldwide, but having their regional distributional features.

Investigation of killer cell immunoglobulin-like receptors KIR2DL2 and KIR2DL3 diversity and identification of ten novel KIR2DL3 alleles in the Chinese Han population

KIR2DL2 and KIR2DL3 are important inhibitory receptors that recognize a subset of HLA-C allelic products carrying Ser77 and Asn80. In this study, we have determined KIR2DL2 and KIR2DL3 diversity in the Chinese Han population by a PCR sequence-based typing. Based on sequencing, the coding regions of 166 Chinese Han individuals, seven new polymorphic sites (238G>A, 405G>A, 476A>G, 550G>A, 608G>A, 789T>C, 947T>C) were found. KIR2DL2*00301, *00101, KIR2DL3*00101,*00201,*013, *015 and ten new KIR2DL3 variants (KIR2DL3*00105, 00106, 00107, 00108, 019, 020, 021, 022, 023 and 024) were identified, of which KIR2DL3*00101 was the most frequent allele. Compared with the sequences of KIR2DL3*00101, all sequences of 2DL3*00105, 2DL3*00106, 2DL3*00107 and 2DL3*00108 had one nucleotide substitution(789T>C, 261C>T, 489G>A and 405G>A),but none resulted in amino acid change. An A>G substitution was observed in nucleotide position 476 in 2DL3*019, 608 G>A in 2DL3*020, 824T>C in 2DL3*021 and 238 G>A in 2DL3*023. In addition, 2DL3*022 probably arose from 2DL3*00201 with a nucleotide substitution G>A at 550. There were more HLA-C1 positive individuals than HLA-C2. In conclusion, the data of allelic polymorphism for KIR2DL2 and KIR2DL3 were obtained in the Chinese Han population and ten novel KIR2DL3 alleles were identified.

Vaginal bilateral cervical lips suture in combination with intrauterine Foley catheter to arrest postpartum hemorrhage

Vaginal bilateral cervical lips suture allows retention of intrauterine Foley catheter in women with a dilated cervix. This novel indication for vaginal bilateral cervix suture may be a useful adjunct to intrauterine balloon tamponade in the management of postpartum hemorrhage.

OBJECTIVE

To describe an effective, minimally invasive surgical technique for avoiding intrauterine balloon tamponade prolapse.

MATERIALS AND METHODS

This procedure was performed in the delivery room with or without bladder retraction. The cervix was grasped with two ring forceps and firmly pulled outward, two cm horizontal suture of the cervical lips was made at both the three and nine o'clock positions, which were placed two cm as close to the cervix external os, without transversing the cervicovesical reflection anteriorly and the pouch of Douglas posteriorly, then one or more Foley catheters were inserted through the cervix and inflated with saline 60-80 ml each.

RESULTS

The balloons remained in place and hemorrhage abated in all nine cases.

CONCLUSION

vaginal bilateral cervical lips suture can prevent intrauterine balloon prolapse, which may be a useful adjunct to intrauterine balloon tamponade in management of postpartum hemorrhage.

Heteroatom substituted naphthodithiophene–benzothiadiazole copolymers and their effects on photovoltaic and charge mobility properties

Incorporation of heteroatoms into D–A copolymers enhances the functional properties for applications of OSCs and OFETs.

Systematic review and meta-analysis comparing three techniques for pancreatic remnant closure following distal pancreatectomy

BACKGROUND

Established closure techniques for the pancreatic remnant after distal pancreatectomy include stapler, suture and anastomotic closure. However, controversy remains regarding the ideal technique; therefore, the aim of this study was to compare closure techniques and risk of postoperative pancreatic fistula (POPF).

METHODS

A systematic review was carried out according to PRISMA guidelines for studies published before January 2014 that compared at least two closure techniques for the pancreatic remnant in distal pancreatectomy. A random-effects model was constructed using weighted odds ratios (ORs).

RESULTS

Thirty-seven eligible studies matched the inclusion criteria and 5252 patients who underwent distal pancreatectomy were included. The primary outcome measure, the POPF rate, ranged 0 from to 70 per cent. Meta-analysis of the 31 studies comparing stapler versus suture closure showed that the stapler technique had a significantly lower rate of POPF, with a combined OR of 0.77 (95 per cent c.i. 0.61 to 0.98; P = 0.031). Anastomotic closure was associated with a significantly lower POPF rate than suture closure (OR 0.55, 0.31 to 0.98; P = 0.042). Combined stapler and suture closure had significantly lower POPF rates than suture closure alone, but no significant difference compared with stapler closure alone.

CONCLUSION

The use of stapler closure or anastomotic closure for the pancreatic remnant after distal pancreatectomy significantly reduces POPF rates compared with suture closure. The combination of stapler and suture closure shows superiority over suture closure alone.