Reconstruction of maxillary defects with free fibula flap assisted by computer techniques

OBJECTIVE

Free fibula flaps are widely used for maxillary reconstruction. The three-dimensional position of the fibula flap is very difficult to control in conventional operations based solely on the surgeon's experience. We aimed to improve this surgery by using computerized techniques.

METHODS

Twenty-seven patients with maxillary tumors underwent maxillectomy and free fibula flap reconstruction in our department between 2011 and 2013. Virtual planning and surgical navigation were used for eight patients, and conventional surgery was performed in 19 patients. The three-dimensional fibular positions were evaluated in the two groups. Differences between the postoperative position of the fibular segments and the virtual plans were evaluated in the computer-assisted surgery group.

RESULTS

The three-dimensional position of the fibula flap in the computer-assisted surgery group, including the vertical distance (p = 0.013), horizontal position (p = 0.019) and extension of the posterior end (p = 0.041), was significantly more accurate and nearer to the ideal position than that in the conventional surgery group. The average difference between the actual postoperative position of the fibular segments and the virtual plan in the computer-assisted surgery group was <5 mm.

CONCLUSION

Application of computer-assisted techniques such as virtual planning and surgical navigation significantly improve the clinical outcomes of maxillary reconstruction with free fibula flaps.

Muscarinic-mediated vasoconstriction in human, rat and sheep umbilical cords and related vasoconstriction mechanisms

OBJECTIVE

The umbilical cord provides nutrition and oxygen to the fetus. The aim of this study was to determine the effects of acetylcholine (ACh) on umbilical cords from humans and other mammals, and the mechanisms of ACh-mediated vasoconstriction in the human umbilical cord.

DESIGN

Human and animal umbilical cords used in vascular and cellular experiments.

SETTING

Institute for Fetology, First Hospital of Soochow University, Suzhou, China.

POPULATION

A total of 85 pregnant women, 16 Sprague Dawley rats and seven pregnant sheep.

METHODS

Umbilical cord veins and arteries from humans, rats and sheep, aortas and mesenteric arteries from rats, and mesenteric, carotid and femoral arteries from ovine fetuses were used to compare vascular functions in response to ACh and to determine the mechanisms of ACh-mediated umbilical vasoconstriction. Vascular tension and ion channel currents were measured on isolated vessels and smooth muscle cells from human umbilical cords.

MAIN OUTCOME MEASURES

Provision of new evidence to conclude that ACh-stimulated vasoconstriction is common to all umbilical cords, and cellular mechanisms are linked to potassium channels.

RESULTS

ACh caused reliable vasoconstriction in umbilical veins/arteries in humans, rats and sheep, but not in any other vessels, including fetal vessels. Atropine inhibited the effects of ACh. The mRNA of ACh-muscarinic receptor subtypes M1 -M5 was expressed in human umbilical vessels. The protein kinase C antagonist GF109203X and the calcium inhibitor nifedipine decreased ACh-induced vasoconstriction in human umbilical vessels. ACh also caused a reduction in whole-cell potassium channel currents and the single-channel current of large-conductance calcium-activated potassium (BKca) channels.

CONCLUSION

Umbilical vessels are significantly different from other vessels in their response to ACh. BKca channels in smooth muscle cells may play important roles in ACh-mediated vasoconstriction in human umbilical cords. This information may be important for fetal medicine and practice with regard to the effect on fetal development of umbilical vascular functions.

Types of female partners reported by black men who have sex with men and women (MSMW) and associations with intercourse frequency, unprotected sex and HIV and STI prevalence

We used baseline data from a study of Black MSM/MSMW in 6 US cities to examine the association of female partnership types with disease prevalence and sexual behaviors among the 555 MSMW participants. MSMW reported more than three times as many total and unprotected sex acts with each primary as they did with each non-primary female partner. We compared MSMW whose recent female partners were: (1) all primary ("PF only", n = 156), (2) both primary and non-primary ("PF & NPF", n = 186), and (3) all non-primary ("NPF only", n = 213). HIV/STI prevalence did not differ significantly across groups but sexual behaviors did. The PF only group had the fewest male partners and was the most likely to have only primary male partners; the PF & NPF group was the most likely to have transgender partners. PF & NPF men reported the most sex acts (total and unprotected) with females; NPF only men reported the fewest. Implications for HIV risk and prevention are discussed.

Series of new β-cyclodextrin-cored starlike carriers for gene delivery

The development of safe and effective β-cyclodextrin (β-CD)-cored cationic star gene carriers has attracted considerable attention. In this work, a series of star-shaped hemocompatible CD-PGPP, CD-PGAEPP, and CD-PGAPP vectors composed of β-CD cores and piperazine (PP)-, N-(aminoethyl)piperazine (AEPP)-, or N-(3-aminopropyl)-2-pyrrolidinone (APP)-functionalized poly(glycidyl methacrylate) arms were successfully proposed and compared for highly efficient gene delivery. Such star carriers possess plentiful secondary amine, tertiary amine, and nonionic hydroxyl groups. CD-PGPP, CD-PGAEPP, and CD-PGAPP were effective in condensing plasmid DNA into nanoparticles, whose sizes were 100-200 nm and positive ζ potentials were 25-40 mV at nitrogen/phosphate (N/P) ratios of 10 and above. CD-PGPP, CD-PGAEPP, and CD-PGAPP showed significantly lower cytotoxicity than control poly(ethylenimine) (PEI; ∼25 kDa). At most N/P ratios, CD-PGAPP exhibited better gene transfection performance than CD-PGPP and CD-PGAEPP particularly in HepG2 cells. More importantly, in comparison with PEI, all of the CD-PGPP, CD-PGAEPP, and CD-PGAPP vectors did not cause undesirable hemolysis.

Relationship between the IL-4 gene promoter -590C/T (rs2243250) polymorphism and susceptibility to autoimmune diseases: a meta-analysis

OBJECTIVE

Studies investigating the association between interleukin (IL)-4 gene promoter -590C/T (rs2243250) polymorphism and autoimmune diseases report conflicting results. To derive a more precise estimation of the relationship, a meta-analysis was performed.

METHODS

A systematic literature search was conducted to identify relevant studies. Pooled odds ratio (OR) with 95% confidence interval (CI) was used to estimate the strength of association.

RESULTS

A total of 6001 cases and 6788 controls from 24 studies were analysed. Significant association of the C allele of IL-4 rs2243250 polymorphism with rheumatoid arthritis (RA) was detected (odds ratio (OR) = 0.696, 95% confidence interval (CI) = 0.601-0.807). Stratification by ethnicity indicated an association between the IL-4 rs2243250 polymorphism and RA in Caucasians. Furthermore, the overall ORs of the associations between the C allele and multiple scleorosis (MS) were 1.340 (95% CI = 1.102-1.630). However, we failed to reveal any association between IL-4 rs2243250 polymorphism and systemic lupus erythematosus (SLE), type 1 diabetes (T1D) or Graves' disease (GD).

CONCLUSIONS

The present study suggests that the IL-4 rs2243250 polymorphism might be associated with genetic susceptibility to autoimmune diseases, including RA and MS.

IL-10 promoter SNPs and susceptibility to leprosy in ethnic groups from southwest China

The purpose of this study was to determine whether interleukin-10 (IL-10) promoter polymorphisms are associated with leprosy or their subtypes in ethnic groups from southwest China. Genotyping using TaqMan® SNP Genotyping Master Mix and ABI 7500 real-time PCR system was performed for IL-10 T3575A, G2849A, C2763A, A1082G, C819T, and C592A in 189 healthy controls (40 ± 18 years) and 193 patients (46 ± 18 years) with leprosy [multibacillary, N = 131; paucibacillary (PB), N = 62]. The allelic frequencies of -2763C (97.9 vs 94.0%, P = 0.0074) and -1082A (92.8 vs 88.6%, P = 0.0452) in leprosy patients were significantly higher than in control subjects. The genetic frequency of -2763CC and -1082AA was not only significantly higher among leprosy patients than among control subjects [odds ratio (OR) = 3.33, 95% confidence interval (95%CI) = 1.39-7.99, P = 0.0071 and OR = 1.76, 95%CI = 1.02-3.03, P = 0.0420, respectively] but also significantly higher among PB patients than among control subjects (OR = 2.46, 95%CI = 1.22-4.96, P = 0.0115 and OR = 5.58, 95%CI = 2.06-15.12, P = 0.0007, respectively). The frequency of IL-10 haplotype 3575A/2849G/2763A/1082G/819C/592C was significantly higher among leprosy patients (OR = 5.57, 95%CI = 1.13-27.52, P = 0.0351) and PB patients (OR = 10.5, 95%CI = 1.36- 81.05, P = 0.0241) than among control subjects. IL-10 promoter -2763C/CC,-1082A/AA and haplotype 3575A/2849G/2763A/1082 G/819C/592C are associated with susceptibility to leprosy and the PB subtype in southwest China.

Identification and biochemical characterization of Laodelphax striatellus neutral ceramidase

Ceramidases are a group of enzymes that catalyse hydrolysis of ceramides to generate fatty acid and sphingosine. In this study, we report the cloning and characterization of the rice small brown planthopper Laodelphax striatellus neutral ceramidase (nCDase), LsnCer. LsnCer was identified by sequencing the transcriptome of L. striatellus and is a protein of 717 amino acids with a predicted molecular weight of 79.3 kDa. Similarly to other known nCDases, the optimum pH for LsnCer is 8.0 and the optimum temperature is 37 °C for its in vitro activity. LsnCer activity is inhibited by Zn(2+) significantly and Fe(2+) slightly. LsnCer has broad substrate specificity with a preference for ceramides with a medium acyl-chain or a monounsaturated long acyl-chain. Infection with rice strip virus (RSV) or treatment with insecticides significantly increased LsnCer mRNA expression and its enzymatic activity in L. striatellus. These results suggest that LsnCer is a bona fide nCDase that may have a role in adaption of L. striatellus to environmental stresses.

Jagged-1-HES-1 signaling inhibits the differentiation of TH17 cells via ROR gammat

Notch signaling plays an important role in differentiation of T cells. However, little is known as to action of it in differentiation of Th17 cell subset. In this study, a soluble Jagged-1/Fc chimera protein (Jagged-1) was directly used to activate Jagged-1-Notch signaling, while Hes-1-targeting siRNA was used to knock down Hes-1 gene to investigate effect of Jagged-1-Hes-1 signaling on the differentiation of CD4+ T cells into Th17 cells. The results showed that Jagged-1 could promote the expression of Hes-1 and Deltex-1 mRNAs and the expression of NICD, Hes-1 and Deltex-1 proteins, which might be significantly blocked by DAPT, a specific inhibitor of Notch signaling. Jagged-1-Hes-1 signaling resulted in the markedly decreased in situ expression of RORgammat in the CD4+ T cells induced by IL-6 plus TGF-ß. Flow cytometric analysis showed the reduction of IL-17 production in CD4+ T cells by Jagged-1, but the enhancement of it by Hes-1-targeting siRNA. The level of IL-10 produced by the treated cells was also enhanced, whereas the expression of IL-17 was prominently attenuated, which could be offset by anti-Jagged-1 antibody or DAPT. The results indicate that Jagged-1-Hes-1 signaling can suppress the skewing of CD4+ T cells toward Th17 cells via RORgammat, for which Hes-1 may be crucial.

The critical aggregation concentration of peptide surfactants is predictable from dynamic hydrophobic property

Peptide surfactants are a kind of newly emerged functional materials, which have a variety of applications such as building nanoarchitecture, stabilizing membrane proteins and controlling drug release. In the present study, we report the modelling and prediction of critical aggregation concentration (CAC), an important parameter that characterizes the self-assembling behaviour of peptide surfactants through the use of statistical modelling and quantitative structure-property relationship (QSPR) approaches. In order to accurately describe the structural and physicochemical properties of the highly flexible peptide molecules, a new method called molecular dynamics-based hydrophobic cross-field (MD-HCF) is proposed to capture both the hydrophobic profile and dynamic feature of 32 surface-activity, structure-known peptides. A number of statistical models are then developed using partial least squares (PLS) regression with or without improvement by genetic algorithm (GA). We demonstrate that MD-HCF performs much better than the widely used CODESSA method in both its predictability and interpretability. We also highlight the importance of dynamic hydrophobic property in accurate prediction and reasonable explanation of peptide self-assembling behaviour in solution, albeit which is exhaustive to compute compared with those derived directly from peptide static structure. To the best of our knowledge, this study is the first to computationally model and predict the self-assembling behaviour of peptide surfactants.

Immunohistochemical study on cathepsin-B and cathepsin-d in pancreatic-cancer

Lysosomal enzymes, cathepsin B and D, have been studied in their possible relationship to the ability of malignant cells to invade and metastasize. In the current investigation, these cathepsins were detected immunohistochemically using avidin-biotin-peroxidase complex method in the pancreatic cancer cells of 21 patients. The positive rate of identification of cathepsin B and D was 43% and 81%, respectively. Cathepsin D stained more strongly than cathepsin B and the plasma membrane stained quite strongly in two instances. A correlation between the presence of cathepsin B or D in cancer cells and the degree of metastasis to lymph nodes, liver, or lung was not recognized.

PIK3CA exon 20 mutations as a potential biomarker for resistance to anti-EGFR monoclonal antibodies in KRAS wild-type metastatic colorectal cancer: a systematic review and meta-analysis

BACKGROUND

We conducted a systematic review and meta-analysis to dissect the association between PIK3CA mutations and resistance to anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (MoAbs) according to PIK3CA exon of mutations in metastatic colorectal cancer (mCRC).

METHODS

We systematically identified studies exploring the association between PIK3CA mutations and clinical outcomes of mCRC patients treated with anti-EGFR MoAbs. The primary clinical outcomes included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The pooled relative risk (RR) or hazard ratio (HR) was estimated by using fixed effect model or random effect model according to heterogeneity between studies.

RESULTS

Thirteen studies were considered eligible, with 576 mCRC patients included. In KRAS wild-type mCRC patients, we observed a lower ORR in patients with PIK3CA exon 20 mutations [3 studies, 377 patients; ORR = 0% versus 37%; RR = 0.25; 95% confidence interval (CI) 0.05-1.19; P = 0.082], although the result was not statistically significant because of the small sample size. Only one study provided survival data according to the PIK3CA exon of the mutations, in which PIK3CA exon 20 mutations were statistically significantly associated with shorter PFS (HR = 2.52; 95% CI 1.33-4.78; P = 0.013) and OS (HR = 3.29; 95% CI 1.60-6.74; P = 0.006) in KRAS wild-type mCRC patients treated with anti-EGFR MoAbs. The predictive power of exon 20 mutation is greater than exon 9 mutations and all exons mutations in terms of ORR, PFS, and OS.

CONCLUSION

These analyses suggest that PIK3CA exon 20 mutations may be a potential biomarker for resistance to anti-EGFR MoAbs in KRAS wild-type mCRC.

Improvement of hemocompatibility of polycaprolactone film surfaces with zwitterionic polymer brushes

Polycaprolactone (PCL) has been widely adopted as a scaffold biomaterial, but further improvement of the hemocompatibility of a PCL film surface is still needed for wide biomedical applications. In this work, the PCL film surface was functionalized with zwitterionic poly(3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate) (P(DMAPS)) brushes via surface-initiated atom transfer radical polymerization (ATRP) for enhancing hemocompatibility. Kinetics study revealed an approximately linear increase in graft yield of the functional P(DMAPS) brushes with polymerization time. The blood compatibilities of the modified PCL film surfaces were studied by platelet adhesion tests of platelet-rich plasma and human whole blood, hemolysis assay, and plasma recalcification time (PRT) assay. The improvement of hemocompatibility is dependent on the coverage of the grafted P(DMAPS) brushes on the PCL film. Lower or no platelet and blood cell adhesion was observed on the P(DMAPS)-grafted film surfaces. The P(DMAPS) grafting can further decrease hemolysis and enhance the PRT of the PCL surface. With the versatility of surface-initiated ATRP and the excellent hemocompatibility of zwitterionic polymer brushes, PCL films with desirable blood properties can be readily tailored to cater to various biomedical applications.

Molecular and enzymatic profiles of mammalian DNA methyltransferases: structures and targets for drugs

DNA methylation is an epigenetic event involved in a variety array of processes that may be the foundation of genetic phenomena and diseases. DNA methyltransferase is a key enzyme for cytosine methylation in DNA, and can be divided into two functional families (Dnmt1 and Dnmt3) in mammals. All mammalian DNA methyltransferases are encoded by their own single gene, and consisted of catalytic and regulatory regions (except Dnmt2). Via interactions between functional domains in the regulatory or catalytic regions and other adaptors or cofactors, DNA methyltransferases can be localized at selective areas (specific DNA/nucleotide sequence) and linked to specific chromosome status (euchromatin/heterochromatin, various histone modification status). With assistance from UHRF1 and Dnmt3L or other factors in Dnmt1 and Dnmt3a/Dnmt3b, mammalian DNA methyltransferases can be recruited, and then specifically bind to hemimethylated and unmethylated double-stranded DNA sequence to maintain and de novo setup patterns for DNA methylation. Complicated enzymatic steps catalyzed by DNA methyltransferases include methyl group transferred from cofactor Ado-Met to C5 position of the flipped-out cytosine in targeted DNA duplex. In the light of the fact that different DNA methyltransferases are divergent in both structures and functions, and use unique reprogrammed or distorted routines in development of diseases, design of new drugs targeting specific mammalian DNA methyltransferases or their adaptors in the control of key steps in either maintenance or de novo DNA methylation processes will contribute to individually treating diseases related to DNA methyltransferases.

Essential role of the unfolded protein response regulator GRP78/BiP in protection from neuronal apoptosis

Neurodegenerative diseases are often associated with dysfunction in protein quality control. The endoplasmic reticulum (ER), a key site for protein synthesis, senses stressful conditions by activating the unfolded protein response (UPR). Here we report the creation of a novel mouse model where GRP78/BiP, a major ER chaperone and master regulator of UPR, is specifically eliminated in the Purkinje cells (PCs). GRP78 depleted PCs activate UPR including induction of GRP94, PDI, CHOP and GADD34, feedback suppression of eIF2α phosphorylation and apoptotic cell death. In contrast to current models of protein misfolding where abnormal accumulation of ubiquitinated protein is prominent, cytosolic ubiquitin staining is dramatically reduced in GRP78 null PCs. Ultrastructural evaluation reveals that the ER shows prominent dilatation with focal accumulation of electron-dense material within the ER. The mice show retarded growth and severe motor coordination defect by week 5 and cerebellar atrophy by week 13. Our studies uncover a novel link between GRP78 depletion and reduction in cytosolic ubiquitination and establish a novel mouse model of accelerated cerebellar degeneration with basic and clinical applications.