[Surgical reconstruction of maxillary defects using a computer-assisted techniques]

The maxilla is the most important bony support of the mid-face skeleton and is critical for both esthetics and function. Maxillary defects, resulting from tumor resection, can cause severe functional and cosmetic deformities. Furthermore, maxillary reconstruction presents a great challenge for oral and maxillofacial surgeons. Nowadays, vascularized composite bone flap transfer has been widely used for functional maxillary reconstruction. In the last decade, we have performed a comprehensive research on functional maxillary reconstruction with free fibula flap and reported excellent functional and acceptable esthetic results. However, this experience based clinical procedure still remainssome problems in accuracy and efficiency. In recent years, computer assisted techniques are now widely used in oral and maxillofacial surgery. We have performed a series of study on maxillary reconstruction with computer assisted techniques. The computer assisted techniques used for maxillary reconstruction mainly include: (1) Three dimensional (3D) reconstruction and tumor mapping: providing a 3D view of maxillary tumor and adjacent structures and helping to make the diagnosis of maxillary tumor accurate and objective; (2) Virtual planning: simulating tumor resection and maxillectomy as well as fibula reconstruction on the computer, so that to make an ideal surgical plan; (3) 3D printing: producing a 3D stereo model for prebending individualized titanium mesh and also providing template or cutting guide for the surgery; (4) Surgical navigation: the bridge between virtual plan and real surgery, confirming the virtual plan during the surgery and guarantee the accuracy; (5) Computer assisted analyzing and evaluating: making a quantitative and objective of the final result and evaluating the outcome. We also performed a series of studies to evaluate the application of computer assisted techniques used for maxillary reconstruction, including: (1) 3D tumor mapping technique for accurate diagnosis and treatment of maxillary tumor; (2) Maxillary reconstruction with free fibula flap used computer assisted techniques; (3) Computer assisted orbital floor reconstruction after maxillectomy. The results suggested that computer assisted techniques could significantly improve the clinical outcome of maxillary reconstruction.

Experiments of a monolithic radial transmission line

This paper presents the experimental results of a monolithic radial transmission line (MRTL) that may be used in pulsed power generators and microwave devices. The MRTL with a hyperbolic impedance profile is 508 mm in radius, corresponding to a one-way transit time of 15 ns for the electromagnetic wave. In the experiments, up to twenty identical voltage pulses, 10 ns in FWHM and 2 ns in rise-time, were fed into the MRTL through 20 input BNC connectors that are uniformly distributed along the outer circumference of the MRTL. It was found that the amplitude of the voltage from the output BNC connector located in the center of the MRTL is nearly proportional to the total number of the input branches. The effect of the failure modes on the output voltage was investigated. For the MRTL driven by 20 input branches, while the open-circuit or short-circuit even in one input branch considerably decreases the amplitude of the output voltage, the jitter shorter than 2 ns in 3 input branches makes no obvious effect on the output voltage.

Systematic review with meta-analysis: the gastrointestinal benefits of COX-2 selective inhibitors with concomitant use of low-dose aspirin

BACKGROUND

It is uncertain whether concurrent use of low-dose aspirin removes the gastrointestinal benefit displayed by COX-2 selective inhibitors (coxibs) when compared to traditional nonsteroidal anti-inflammatory drugs (NSAIDs).

AIM

To evaluate the gastrointestinal risks associated with coxibs and traditional NSAIDs and the interaction with concurrent use of low-dose aspirin.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Library through April 2016 to identify randomised trials comparing the gastrointestinal risk between coxibs and traditional NSAIDs in patients taking or not taking low-dose aspirin. Results were combined using random effects meta-analysis. Subgroup analyses by concurrent use of aspirin were undertaken.

RESULTS

Eleven trials (84 150 participants) were included. The overall relative risk (RR) of coxibs vs. traditional NSAIDs for complicated gastrointestinal events was 0.54 (95% CI, confidence interval 0.32-0.92), with a significant subgroup difference (P = 0.04) according to concurrent use of aspirin (used: RR = 0.96, 95% CI 0.66-1.24; not used: RR = 0.33, 95% CI 0.14-0.83). The overall RR for clinical gastrointestinal events was 0.59 (95% CI 0.47-0.75), with a significant subgroup difference according to aspirin usage (P = 0.008; used: RR = 0.77, 95% CI 0.62-0.95; not used: RR = 0.50, 95% CI 0.39-0.64). Overall coxibs were associated with significantly lower risk of symptomatic ulcers (RR = 0.60, 95% CI 0.50-0.72) and endoscopic ulcers (RR = 0.29, 95% CI 0.16-0.53) than traditional NSAIDs; a significant subgroup difference was shown for endoscopic ulcers (P = 0.05) but not for symptomatic ulcers (P = 0.27).

CONCLUSION

Concomitant use of low-dose aspirin reduces but does not completely eliminate the gastrointestinal benefit of coxibs over traditional NSAIDs.

Systematic review with network meta-analysis: comparative effectiveness and safety of strategies for preventing NSAID-associated gastrointestinal toxicity

BACKGROUND

Many strategies are used to prevent nonsteroidal anti-inflammatory drug (NSAID)-associated gastrointestinal toxicity, but the comparative effectiveness remains unclear.

AIM

To evaluate the comparative effectiveness of clinical strategies for preventing gastrointestinal toxicity induced by NSAIDs.

METHODS

MEDLINE, EMBASE and the Cochrane Library (from their inception to May 2015) were searched for randomised controlled trials comparing the risk of gastrointestinal adverse events in patients taking nonselective NSAIDs, selective cyclooxygenase(COX)-2 inhibitors or nonselective NSAIDs/COX-2 inhibitors plus gastroprotective agents [proton pump inhibitors (PPIs), histamine-2 receptor antagonists, misoprostol]. Both pairwise meta-analysis and Bayesian network meta-analysis were performed.

RESULTS

Analyses were based on 82 trials including 125 053 participants. Network meta-analysis demonstrated that selective COX-2 inhibitors + PPIs [Risk ratio (RR), 95% Credible Interval (CrI): ulcer complications 0.07, 0.02-0.18], selective COX-2 inhibitors (RR, 95% CrI: ulcer complications 0.25, 0.15- 0.38; symptomatic ulcer 0.12, 0.04-0.30), nonselective NSAIDs + PPIs (RR, 95% CrI: ulcer complications 0.28, 0.18-0.41; symptomatic ulcer 0.11, 0.04-0.23), nonselective NSAIDs + misoprostol (RR, 95% CrI: ulcer complications 0.47, 0.24-0.81; symptomatic ulcer 0.41, 0.13-1.00) were associated with significantly lower risk of clinical gastrointestinal events compared with nonselective NSAIDs. For all effectiveness endpoints, selective COX-2 inhibitors + PPIs was associated with the lowest absolute event probability and the highest rank, followed by selective COX-2 inhibitors and thirdly by nonselective NSAIDs + PPIs.

CONCLUSION

The combination of selective COX-2 inhibitors plus PPIs provides the best gastrointestinal protection, followed by selective COX-2 inhibitors, and thirdly by nonselective NSAIDs plus PPIs.

Note: A novel method for generating multichannel quasi-square-wave pulses

A 21-channel quasi-square-wave nanosecond pulse generator was constructed. The generator consists of a high-voltage square-wave pulser and a channel divider. Using an electromagnetic relay as a switch and a 50-Ω polyethylene cable as a pulse forming line, the high-voltage pulser produces a 10-ns square-wave pulse of 1070 V. With a specially designed resistor-cable network, the channel divider divides the high-voltage square-wave pulse into 21 identical 10-ns quasi-square-wave pulses of 51 V, exactly equal to 1070 V/21. The generator can operate not only in a simultaneous mode but also in a delay mode if the cables in the channel divider are different in length.

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.

Effects of acupuncture at ST36 on pharmacokinetics of Schisandra lignans in rats

OBJECTIVE

To investigate the influence of acupuncture at ST36 on the pharmacokinetics of Schisandra lignans including schisandrin, deoxyschisandrin and schisandrin B after intragastric administration of Schisandra chinensis (SC) in rats.

METHODS

Twelve male Sprague-Dawley rats were randomly divided into two study groups: SC and SC+acupuncture. Rats in both groups received intragastric SC extract at 5.0 g/kg. Rats in the SC+acupuncture group additionally received acupuncture stimulation at ST36 for 30 min after SC administration. Acupuncture needles were rotated bilaterally for 1 min, left in situ for 20 min, then electrically stimulated for 10 min at 50 Hz frequency and 1-3 mA intensity. A sensitive and specific high performance liquid chromatography electrospray tandem mass spectrometry procedure was developed and validated for simultaneous analysis of three bioactive lignans (schisandrin, deoxyschisandrin and schisandrin B) in rat plasma.

RESULTS

There were significant differences (p<0.05) between the two study groups in various pharmacokinetic parameters. Area under the plasma concentration-time curve (AUC0-t), area under the plasma concentration-time curve to time infinity (AUC0-∞) and peak plasma concentration (Cmax) for schisandrin, absorption half-life (T1/2α) and AUC0-t for deoxyschisandrin, and Cmax for schisandrin B were increased in the SC+acupuncture group compared with the SC group. T1/2α for schisandrin B only and time to peak concentration (Tmax) for all three lignans were reduced following acupuncture.

CONCLUSIONS

Acupuncture stimulation at ST36 affects the pharmacokinetics of SC in rats. Acupuncture may have a beneficial role in promoting the absorption of lignans from extracts of SC.

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.

Quality control and producing areas differentiation of Gardeniae Fructus for eight bioactive constituents by HPLC-DAD-ESI/MS

Gardeniae Fructus (G.Fructus), the fruit of Gardenia jasminoides Ellis (Rubiaceae), is a commonly used traditional Chinese medicine (TCM) that has been used for the treatment of hepatitis, jaundice, hypersonic, diabetes and hematuria. Numerous researches have demonstrated that the major active constituents in G.Fructus were responsible for the majority of medical effects of this fruit and their quantification were important for the quality control of G.Fructus. However, in the current quality control standard, only geniposide was used as characteristic marker of G.Fructus, which could not reflect the overall quality of this fruit. In order to identify more chemical makers for improving the quality control standard and evaluate producing areas differentiation of G.Fructus, in the present study, a novel and sensitive high-performance liquid chromatography-diode array detector coupled to an electrospray tandem mass spectrometer (HPLC-DAD-ESI/MS) was developed for the simultaneous determination of 8 major constituents, including geniposidic acid (1), chlorogenic acid (2), genipin-1-β-gentiobioside (3), geniposide (4), genipin (5), rutin (6), crocin-1 (7), crocin-2 (8) in G.Fructus. Moreover, chemometric analysis techniques with principal component constituent analysis (PCA) and cluster analysis (CA) involved were introduced in statistical analysis of 8 investigated constituents in the 34 batches samples to discriminate the samples from different producing areas. The results indicated that the contents of the 8 major bioactive constituents in G.Fructus varied significantly among different producing areas. From results of the loading plot from PCA analysis, genipin-1-β-gentiobioside may have more influence in discriminating the sample from different producing areas, and which was found to be the most abundant bioactive component besides geniposide in all the 34 batches samples, suggesting that it should be added as chemical marker for further investigation on the pharmacological actions and the quality control of G.Fructus.

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.

Differential pharmacokinetics and the brain distribution of morphine and ephedrine constitutional isomers in rats after oral administration with Keke capsule using rapid-resolution LC-MS/MS

Opioid and ephedra alkaloids known as the active ingredients for Keke capsule, which is used to treat coughs and bronchial asthma, could have potential adverse effects on the central nervous system. Therefore, an efficient, sensitive rapid-resolution LC-MS/MS method for the simultaneous determination of morphine, ephedrine, and pseudoephedrine in rat plasma and brain tissue homogenate has been developed. The method was validated in the plasma and brain tissue samples, showed good linearity over a wide concentration range (r(2) > 0.99). The intra- and interday assay variability was less than 15% for all analytes, and the accuracy was between -8.8 and 5.7%. The study provided the pharmacokinetics profiles and the brain regional distribution of the three active alkaloids after oral administration of Keke capsule. The results also indicated that significant difference in pharmacokinetics parameters of the epimers was observed between ephedrine and pseudoephedrine.

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.

Simultaneous determination of eleven characteristic lignans in Schisandra chinensis by high-performance liquid chromatography

Background:

Schisandra chinensis, one of the well-known traditional Chinese herbal medicines, is derived from the dry ripe fruits of Schisandra chinensis (Turcz.) Baill. according to the 9th China Pharmacopeia. Lignans are the main components isolated from extracts of S. chinensis and their content varies depending on where S. chinensis was collected. We have established a qualitative and quantitative method based on the bioactive lignans for control of the quality of S. chinensis from different sources.

Materials and Methods:

To develop a high-performance liquid chromatography method, an Elite ODS C18 column (250 mm Χ 4.6 mm, 5μm) at a column temperature of 30°C and flow rate of 1.0ml/min using acetonitrile (A) and water (B) as the mobile phase with a linear gradient and the peaks were monitored at 217 nm.

Results:

All calibration curves showed good linearity (r ≥ 0.9995) within test ranges. This method showed good repeatability for the quantification of these eleven components in S. chinensis with intra- and inter-day relative standard deviations less than 0.43% and 1.21%, respectively. In the recovery test, results of accuracy ranged from 99.51% to 101.31% with RSD values less than 2.

Conclusion:

The validated method can be successfully applied to quantify the eleven investigated components in 22 samples of S. chinensis from different sources.