Thermal decomposition characteristics of BHT and its peroxide (BHTOOH)

2,6-Di-tert-butyl-4-methylphenol (BHT) is an excellent antioxidant that is easily oxidized to 2,6-di-tert-butyl-4-hydroperoxyl-4-methyl-2,5-cyclohexadienone (BHTOOH). For the safety of BHT production and usage, it is meaningful to study the thermal stability and decomposition properties of BHT and BHTOOH. In this paper, the thermal decomposition properties of BHT and BHTOOH were compared by the mini closed pressure vessel test (MCPVT) and differential scanning calorimetry (DSC). Their kinetics of thermal decomposition were studied using thermogravimetric analysis (TGA). The thermal decomposition products of BHT and BHTOOH were analyzed by gas chromatography-mass spectrometry (GC-MS). The results show that there was no significant change in temperature pressure when BHT was warmed up under a nitrogen atmosphere, indicating that BHT was stable within 400 K. The thermal decomposition reaction of BHTOOH was rapid with an initial reaction temperature of 375.2 K. The initial exothermic temperature (Ti) and heat release (QDSC) of DSC were 384.9 K and 865.0 J g-1, respectively. The apparent activation energies (Ea) for the thermal decomposition reactions of BHT and BHTOOH calculated by the Kissinger method were 151.8 kJ mol-1 and 66.07 kJ mol-1, respectively. The main decomposition products of BHT were isobutene and 2-tert-butyl-4-methylphenol. The thermal decomposition products of BHTOOH included BHT, 2,6-di-tert-butyl-4-ethylphenol, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, 4,4'-(1,2-ethanediyl) bis [2,6-bis (1,1-dimethylethyl) phenol, etc. Based on the thermal decomposition behavior and products, the reaction pathway has been described. These results indicate that BHT is a potential thermal hazard during production, storage and application. For the safety of the chemical industry, the oxidation of BHT should be avoided.

Demonstrating the reliability of in vivo metabolomics based chemical grouping: towards best practice

While grouping/read-across is widely used to fill data gaps, chemical registration dossiers are often rejected due to weak category justifications based on structural similarity only. Metabolomics provides a route to robust chemical categories via evidence of shared molecular effects across source and target substances. To gain international acceptance, this approach must demonstrate high reliability, and best-practice guidance is required. The MetAbolomics ring Trial for CHemical groupING (MATCHING), comprising six industrial, government and academic ring-trial partners, evaluated inter-laboratory reproducibility and worked towards best-practice. An independent team selected eight substances (WY-14643, 4-chloro-3-nitroaniline, 17α-methyl-testosterone, trenbolone, aniline, dichlorprop-p, 2-chloroaniline, fenofibrate); ring-trial partners were blinded to their identities and modes-of-action. Plasma samples were derived from 28-day rat tests (two doses per substance), aliquoted, and distributed to partners. Each partner applied their preferred liquid chromatography-mass spectrometry (LC-MS) metabolomics workflows to acquire, process, quality assess, statistically analyze and report their grouping results to the European Chemicals Agency, to ensure the blinding conditions of the ring trial. Five of six partners, whose metabolomics datasets passed quality control, correctly identified the grouping of eight test substances into three categories, for both male and female rats. Strikingly, this was achieved even though a range of metabolomics approaches were used. Through assessing intrastudy quality-control samples, the sixth partner observed high technical variation and was unable to group the substances. By comparing workflows, we conclude that some heterogeneity in metabolomics methods is not detrimental to consistent grouping, and that assessing data quality prior to grouping is essential. We recommend development of international guidance for quality-control acceptance criteria. This study demonstrates the reliability of metabolomics for chemical grouping and works towards best-practice.

Comparison of Pulmonary and Extrapulmonary Models of Sepsis-Associated Acute Lung Injury

To compare different rat models of sepsis at different time points, based on pulmonary or extrapulmonary injury mechanisms, to identify a model which is more stable and reproducible to cause sepsis-associated acute lung injury (ALI). Adult male Sprague-Dawley rats were subjected to (1) cecal ligation and puncture (CLP) with single (CLP1 group) or two repeated through-and-through punctures (CLP2 group); (2) tail vein injection with lipopolysaccharide (LPS) of 10mg/kg (IV-LPS10 group) or 20 mg/kg (IV-LPS20 group); (3) intratracheal instillation with LPS of 10mg/kg (IT-LPS10 group) or 20mg/kg (IT-LPS20 group). Each of the model groups had a sham group. 7-day survival rates of each group were observed (n=15 for each group). Moreover, three time points were set for additional experimental studying in each model group: 4 hours, 24 hours and 48 hours after modeling (every time point, n=8 for each group). Rats were sacrificed to collect BALF and lung tissue samples at different time points for detection of IL-6, TNF-alpha, total protein concentration in BALF and MPO activity, HMGB1 protein expression in lung tissues, as well as the histopathological changes of lung tissues. More than 50 % of the rats died within 7 days in each model group, except for the IT-LPS10 group. In contrast, the mortality rates in the two IV-LPS groups as well as the IT-LPS20 group were significantly higher than that in IT-LPS10 group. Rats received LPS by intratracheal instillation exhibited evident histopathological changes and inflammatory exudation in the lung, but there was no evidence of lung injury in CLP and IV-LPS groups. Rat model of intratracheal instillation with LPS proved to be a more stable and reproducible animal model to cause sepsis-associated ALI than the extrapulmonary models of sepsis.

Oxidation characteristic and thermal runaway of isoprene

In this study, the oxidation characteristics of isoprene were investigated using a custom-designed mini closed pressure vessel test (MCPVT). The results show that isoprene is unstable and polymerization occurs under a nitrogen atmosphere. Under an oxygen atmosphere, the oxidation process of isoprene was divided into three stages: (1) isoprene reacts with oxygen to produce peroxide; (2) Peroxides produce free radicals through thermal decomposition; (3) Free radicals cause complex oxidation and thermal runaway reactions. The oxidation of isoprene conforms to the second-order reaction kinetics, and the activation energy was 86.88 kJ·mol-1. The thermal decomposition characteristics of the total oxidation product and purified peroxide mixture were determined by differential scanning calorimetry (DSC). The initial exothermic temperatures Ton were 371.17 K and 365.84 K, respectively. And the decomposition heat QDSC were 816.66 J·g-1 and 991.08 J·g-1, respectively. It indicates that high concentration of isoprene peroxide has a high risk of thermal runaway. The results of thermal runaway experiment showed that the temperature and pressure of isoprene oxidation were prone to rise rapidly, which indicates that the oxidation reaction was dangerous. The reaction products of isoprene were analyzed by gas chromatography-mass spectrometry (GC-MS). The main oxidation products were methyl vinyl ketone, methacrolein, 3-methylfuran, etc. The main thermal runaway products were dimethoxymethane, 2,3-pentanedione, naphthalene, etc. Based on the reaction products, the possible reaction pathway of isoprene was proposed.

Mode of Action Hypothesis Testing in Chemical Safety Assessments Using Metabolomics as Supporting Evidence: Phenobarbital and Cyclobutrifluram Metabolomics Profile Comparison

In long term rodent studies administering Cyclobutrifluram (TYMIRIUM® Technology), a new agrochemical, there was a slight elevation of incidence of hepatocellular carcinomas in male CD-1 mice that was within the historical control range but appeared to be dose responsive. Cyclobutrifluram's ability to activate mouse constitutive androstane receptor (CAR) mediated gene transcription was confirmed in vitro, therefore a 28-day dietary toxicity study was conducted in vivo in male CD-1 mice to assess the CAR activation mode of action hypothesis of Cyclobutrifluram along with phenobarbital, a known CAR activator. In addition to other end points comprehensive (polar and lipidomic) hybrid metabolomics analyses were performed on terminal plasma and liver samples following 2-, 7- and 28-days dietary exposure to cyclobutrifluram and phenobarbital. The data generation and quality assessments were performed in line with the principles of the MEtabolomics standaRds Initiative in Toxicology (MERIT). First the full annotated feature set was used to compare the metabolomic changes induced by the administration of the two test substances using Shared and Unique Structures plots. This gave a comprehensive overview of the similarity of the two effect profiles showing good correlation and demonstrated that no other, alternative effect signatures were detected. Then the phenobarbital induced differentially abundant metabolites were selected, compared to the literature and their direction of change was assessed in cyclobutrifluram profiles, finding good agreement. Both approaches concluded that the metabolomics data supports the CAR activation hypothesis. Comparison of the metabolomic effect profiles can be a line of evidence in mode of action hypothesis testing in the chemical risk assessment process.

Feasibility of electroacupuncture at Baihui (GV20) and Zusanli (ST36) on survival with a favorable neurological outcome in patients with postcardiac arrest syndrome after in-hospital cardiac arrest: study protocol for a pilot randomized controlled trial

BACKGROUND

At present, even the first-line medication epinephrine still shows no evidence of a favourable neurological outcome in patients with sudden cardiac arrest (SCA). The high mortality of patients with postcardiac arrest syndrome (PCAS) can be attributed to brain injury, myocardial dysfunction, systemic ischaemia/reperfusion response, and persistent precipitating pathology. Targeted temperature management, the only clinically proven method in the treatment of PCAS, is still associated with a series of problems that have not been completely resolved. Acupuncture is a crucial therapy in traditional Chinese medicine. On the basis of the results of previous studies, we hypothesize that electroacupuncture (EA) might provide therapeutic benefits in the treatment of PCAS. This study will explore the feasibility of EA on SCA patients.

METHODS

This is a prospective pilot, randomized controlled clinical trial. Eligible patients with PCAS after in-hospital cardiac arrest (IHCA) admitted to our department will be randomly allocated to the control group or the EA group. Both groups will receive standard therapy according to American Heart Association guidelines for cardiopulmonary resuscitation. However, the EA group will also receive acupuncture at the Baihui acupoint (GV20) and Zusanli acupoint (ST36) with EA stimulation for 30 min using a dense-dispersed wave at frequencies of 20 and 100 Hz, a current intensity of less than 10 mA, and a pulse width of 0.5 ms. EA treatment will be administered for up to 14 days (until either discharge or death). The primary endpoint is survival with a favourable neurological outcome. The secondary endpoints are neurological scores, cardiac function parameters, and other clinical parameters, including Sequential Organ Failure Assessment (SOFA) scores and Acute Physiology and Chronic Health Evaluation (APACHE) II scores, on days 0 to 28.

DISCUSSION

This study will provide crucial clinical evidence on the efficacy of EA in PCAS when used as an adjunctive treatment with AHA standard therapy.

TRIAL REGISTRATION

chictr.org.cn : ChiCTR2000040040. Registered on 19 November 2020. Retrospectively registered. http://www.chictr.org.cn/ .

CuAPO-5 as a Multiphase Catalyst for Synthesis of Verbenone from α-Pinene

Copper(II)-containing aluminum phosphate material (CuAPO-5) was synthesized hydrothermally and used as a multiphase catalyst for the oxidation of α-pinene to verbenone. The catalysts were analyzed using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area techniques, X-ray photoelectron spectroscopy (XPS), and ammonia temperature programmed reduction (NH₃-TPD). Scanning electron microscopy (SEM), X-ray energy spectrometry (EDS), inductively coupled plasma emission spectroscopy (ICP-OES), Fourier infrared spectroscopy (FT-IR), and ultraviolet-visible spectroscopy (UV-vis) were performed to characterize the material. The effects of reaction temperature, reaction time, n(α-pinene)/n(TBHP), and solvent on the catalytic performance of CuAPO-5 were investigated. The results show that all the prepared catalysts have AFI topology and a large specific surface area. Copper is evenly distributed in the skeleton in a bivalent form. The introduction of copper increases the acid content of the catalyst. Under the optimized reaction conditions, 96.8% conversion of α-pinene and 46.4% selectivity to verbenone were achieved by CuAPO-5(0.06) molecular sieve within a reaction time of 12 h. CuAPO-5(0.06) can be recycled for five cycles without losing the conversion of α-pinene and the selectivity to verbenone.

Macrolactonization of methyl 15-hydroxypentadecanoate to cyclopentadecanolide using KF-La/γ-Al2O3 catalyst

It has been a challenge to synthesize macrolide musk in excellent yields with high purity. KF-La/γ-Al₂O₃ catalyst was prepared from a highly basic mesoporous framework using a mild method. The prepared KF-La/γ-Al₂O₃ catalyst was employed for the synthesis of cyclopentadecanolide from methyl 15-hydroxypentadecanoate. The morphology and structure of prepared catalysts were characterized using XRD, TG-DTG, SEM, EDX, TEM, BET and CO₂-TPD. The results revealed that the K₃AlF₆ and LaOF are produced on the surface of KF-La/γ-Al₂O₃, and LaO can promote the dispersion of KF on the surface of Al₂O₃. Catalysts pore size main distribution ranges between 10 and 30 nm, the maximum CO₂ desorption temperature is 715°C when the La loading is 25%. Because F^- ion has a higher electronegativity than O^2- ion, the KF-promoted metal oxide (Al₂O₃ or/and La₂O₃) contained more strong basic sites, compared with that of the corresponding metal oxide. The yield of cyclopentadecanolide obtained at 0.5 g KF-25La/γ-Al₂O₃ catalyst and a reaction temperature of 190°C for 7 h were 58.50%, and the content after reactive distillation is 98.8%. The KF-La/γ-Al₂O₃ catalyst has a larger pore size and basic strength, which is more conducive to the macrolactonization of long-chain hydroxy ester.

Successful Treatment with Integrated Chinese and Western Medicine for Massive Colchicine Overdose: A Case Report

A 42-year-old male was hospitalized 13.5 hours after ingestion of 50 mg (approximately 0.7 mg/kg) colchicine in a suicide attempt. The patient developed gastrointestinal dysfunction, grade IV myelosuppression, and restrictive respiratory failure without occurrences of cardiovascular collapse or fatal dysrhythmias. Emergency treatment with integrated Chinese and Western medicine was started and the patient fully recovered without long-term complications. This report describes a massive overdose of colchicine successfully treated with integrated Chinese and Western medicine. Current treatment options are reviewed.

P-551 High concordance of the embryonic cell-free DNA with the inner cell mass: impact of blastocyst quality, patient age and mode of fertilization

Study question

Does the embryonic cell-free DNA (cfDNA) in the culture medium represent the chromosomal content of the inner cell mass (ICM)? Which factors impact concordance rates?

Summary answer

There is high ploidy concordance between ICM biopsies and embryonic cfDNA. This value is independent of female age, insemination technique and embryo quality.

What is known already

The existence of embryonic cfDNA in spent blastocyst medium (SBM) has been confirmed in recent studies, opening a new era of possibilities for non-invasive preimplantation genetic testing for aneuploidy (niPGT-A). High concordance rates of cfDNA with trophectoderm (TE) biopsies and with whole blastocysts have been reported. However, the compartment(s) from where this DNA originates remain unclear. Both TE and ICM are potential sources, but, at the moment, the origin of this cfDNA is unknown as well as the mechanisms underlying its secretion into the medium.

Study design, size, duration

We carried out a prospective study to investigate the concordance of cfDNA with the corresponding TE and ICM biopsies. 141 day-6/7 blastocysts were donated for research after written informed consent signature for the project approved by the Ethics Committee. Embryos underwent TE biopsy and SBM collection in the same PGT-A cycle. ICM biopsy in thawed blastocysts was performed after TE biopsy diagnosis. cfDNA, TE and ICM biopsies were analyzed from January 2019 to November 2021.

Participants/materials, setting, methods

Embryos were cultured in routine conditions up to day 4. They were then washed and transferred to a new 10μl culture medium droplet. On day 6, SBM was collected and frozen at -20 °C; and blastocyst biopsy and vitrification were performed. Subsequently, blastocysts were thawed and ICM biopsy was conducted. All samples were analyzed by NGS (Ion ReproSeq PGS kit, ThermoFisher Scientific) and the results were analyzed with customized algorithms for TE, ICM and cfDNA.

Main results and the role of chance

In combination, the three sample types (cfDNA, ICM and TE) were informative in 81.6% of the blastocysts (115/141).

Considering the ICM as the reference, ploidy concordance (i.e. being both euploid or aneuploid) for cfDNA was 86.1% (99/115) and for TE was 89.6% (103/115), without statistical difference. False positive rates were similar for cfDNA and for TE biopsies (6.1% and 9.6%, respectively), and false negative rates were not significantly different, but higher in cfDNA (7.8%) than in TE (0.9%), due to potential contamination with maternal DNA. Ploidy concordance between embryo cfDNA and TE biopsies was 89.6% (103/115).

When the results were stratified by female age (≤37 or > 37 years), insemination technique (ICSI or IVF), blastocyst expansion degree (expanded, hatching or fully hatched), and ICM/TE quality (A or B), the informativity of the cfDNA was very similar between the different groups and ranged from 83.7% to 100%. Nevertheless, there were subtle differences for ICM-cfDNA ploidy concordance. It was slightly increased for the older female age group (88.3% vs 83.6% female age ≤37) as well as for ICSI (89.7% vs 82.5% in IVF) and for ICM quality B (88.4% vs 80.0% for ICM A). None of those differences reached statistical significance.

Limitations, reasons for caution

When stratifying according to the different criteria, the sample size analyzed was too small to draw strong conclusions. Therefore, more studies, with bigger sample size, are needed to replicate the results.

Wider implications of the findings

The embryonic cfDNA released to the culture medium provides information of the overall blastocyst chromosomal constitution, as suggested by the high ploidy concordance rates reported between ICM and cfDNA. This supports the use of niPGT-A as an alternative to other invasive aneuploidy detection methods that require a biopsy.

Trial registration number

ClinicalTrials.gov. ID NCT03520933

Application of plan-do-check-act management to improve first-attempt insertion success rates of internal jugular vein catheterization for standardized training residents in an intensive care unit

BACKGROUND

In the intensive care unit (ICU), internal jugular vein puncture and catheterization are basic rescue operations that physicians need to complete quickly and independently. It is necessary to improve the first-attempt success rate of internal jugular vein catheterization, shorten the catheterization duration and reduce the incidence of complications for standardized training residents (STRs).

OBJECTIVE

To improve first-attempt insertion success rates of internal jugular vein catheterization for STRs.

METHODS

Based on the PDCA cycle management method and current situation investigation, the PDCA management objectives were set, and the implementation content, monitoring items and continuous improvement plan were formulated. The data of residents who were trained in the ICU of Fangcun Hospital, Second Affiliated Hospital of Guangzhou University of Chinese Medicine, from January 2016 to April 2016 and managed by the PDCA cycle (PDCA group), were compared with the data of residents trained in the same department from August 2015 to November 2015 before the implementation of PDCA (historic control group), the first-attempt success rate of puncture and catheterization, the duration of puncture and catheterization, and the incidence of complications were analysed.

RESULTS

Thirty-six cases of internal jugular vein catheterization were performed by the PDCA group, 21 cases (58%) were performed by residents in the third year of standardized training, and 15 cases (42%) were performed by residents in the second year of standardized training. Compared with the historic control group, there was no significant difference in the seniority of residents (X² = 0.240, P = 0.625) or the 'majors of the residents (X² = 1.306, P = 0.835). The first-attempt success rate of puncture in the PDCA group was 94% (34/36), which was significantly higher than that of the historic control group (55% (11/20) (P = 0.001). In the PDCA group, the first-attempt success rate of puncture among third-year standardized training residents was 95% (20/21), and the first-attempt success rate in the second-year was 93% (14/15), which were significantly higher than the corresponding rates of 62% (8/13) and 43% (3/7) respectively, in the historic control group (all P = 0.021). The duration of catheterization was [4 (3,5)] min after PDCA, which was significantly shorter than that in the historic control group [9 (6.25,13.00)] min (Z = - 5.214, P < 0.001). The incidence rate of complications in the PDCA group was 0% (0 /36), which was significantly lower than the rate of 20% (4 / 20) in the historic control group (P < 0.013).

CONCLUSION

PDCA cycle management can help improve the first-attempt success rate of internal jugular vein puncture and catheterization, shorten the duration of puncture and catheterization, and reduce the incidence of complications. The idea and method of PDCA cycle management can be applied to other training and management protocols for STRs.

Reactivity and kinetics of 1,3-butadiene under ultraviolet irradiation at 254 nm

The reaction process of gaseous 1,3-butadiene following ultraviolet irradiation at the temperature range from 298 to 323 K under nitrogen atmosphere was monitored by UV–vis spectrophotometry. A gaseous mini-reactor was used as a reaction vessel and could be directly monitored in a UV–vis spectrophotometer. We investigated the reactivity and kinetics of 1,3-butadiene under non-UV and UV irradiation to evaluate its photochemical stability. A second-order kinetic model with 50.48 kJ·mol^–1 activation energy fitted the reaction data for non-UV irradiation, whereas a first-order kinetic model was appropriate in the case of UV irradiation with activation energies of 19.92–43.65 kJ mol^–1. This indicates that ultraviolet light could accelerate the photolysis reaction rate of 1,3-butadiene. In addition, the reaction products were determined using gas chromatography-mass spectrometry (GC–MS), and the reaction pathways were identified. The photolysis of 1,3-butadiene gave rise to various volatile products by cleavage and rearrangement of single C–C bonds. The differences between dimerization and dissociation of 1,3-butadiene under ultraviolet irradiation were elucidated by combining experimental and theoretical methods. The present findings provide fundamental insight into the photochemistry of 1,3-butadiene compounds.

Economic burden of public health care and hospitalisation associated with COVID-19 in China

OBJECTIVES

This study aimed to evaluate the socio-economic burden imposed on the Chinese healthcare system during the coronavirus disease 2019 (COVID-19) pandemic.

STUDY DESIGN

A cross-sectional study was used to investigate how COVID-19 impacted health and medical costs in China. Data were derived from a subdivision of the Centers for Disease control and Prevention of China.

METHODS

We prospectively collected information from the Centers for Disease Control and Prevention and the designated hospitals to determine the cost of public health care and hospitalisation due to COVID-19. We estimated the resource use and direct medical costs associated with public health.

RESULTS

The average costs, per case, for specimen collection and nucleic acid testing (NAT [specifically, polymerase chain reaction {PCR}]) in low-risk populations were $29.49 and $53.44, respectively; however, the average cost of NAT in high-risk populations was $297.94 per capita. The average costs per 1000 population for epidemiological surveys, disinfectant, health education and centralised isolation were $49.54, $247.01, $90.22 and $543.72, respectively. A single hospitalisation for COVID-19 in China cost a median of $2158.06 ($1961.13-$2325.65) in direct medical costs incurred only during hospitalisation, whereas the total costs associated with hospitalisation of patients with COVID-19 were estimated to have reached nearly $373.20 million in China as of 20, May, 2020. The cost of public health care associated with COVID-19 as of 20, May, 2020 ($6.83 billion) was 18.31 times that of hospitalisation.

CONCLUSIONS

This study highlights the magnitude of resources needed to treat patients with COVID-19 and control the COVID-19 pandemic. Public health measures implemented by the Chinese government have been valuable in reducing the infection rate and may be cost-effective ways to control emerging infectious diseases.

Calcium Glycerolate Catalyst Derived from Eggshell Waste for Cyclopentadecanolide Synthesis

The synthesis costs of macrolide musks are higher than those of other commercial musks. To make this process less expensive, eggshell waste was calcined at a low temperature to obtain a catalyst for the cyclopentadecanolide production via reactive distillation using a glycerol entrainer. X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy analyses of the original and recovered catalysts revealed that the main catalytic ingredient was calcium glycerolate (CaG) and not calcium diglyceroxide (CaDG). The basic strengths of CaG and CaDG obtained by Hammett indicators were 7.2 < H_≤ 15.0 and 9.8 < H_≤15.0, while the corresponding base amounts were 1.9 and 7.3 mmol/ g, respectively. Because CaG was soluble in glycerine, the catalyst was efficiently reused. The reaction product containing over 95.0% cyclopentadecanolide with a yield of 49.8% was obtained at a temperature of 190°C and catalyst amount of 12 wt% after 7 h of reaction. Thus, eggshell waste may be directly placed into the reaction mixture after calcination at 600°C to synthesise a large amount of cyclopentadecanolide within a relatively short time. The results of this work indicate that eggshell waste can serve as a potential eco-friendly and affordable catalyst source for the production of macrolide musks.

Automatic Recognition of Ocular Surface Diseases on Smartphone Images Using Densely Connected Convolutional Networks

Ocular surface disorder is one of common and prevalence eye diseases and complex to be recognized accurately. This work presents automatic classification of ocular surface disorders in accordance with densely connected convolutional networks and smartphone imaging. We use various smartphone cameras to collect clinical images that contain normal and abnormal, and modify end-to-end densely connected convolutional networks that use a hybrid unit to learn more diverse features, significantly reducing the network depth, the total number of parameters and the float calculation. The validation results demonstrate that our proposed method provides a promising and effective strategy to accurately screen ocular surface disorders. In particular, our deeply learned smartphone photographs based classification method achieved an average automatic recognition accuracy of 90.6%, while it is conveniently used by patients and integrated into smartphone applications for automatic patient-self screening ocular surface diseases without seeing a doctor in person in a hospital.

Thermal stability and pathways for the oxidation of four 3-phenyl-2-propene compounds

Cinnamaldehyde, cinnamyl alcohol, β-methylstyrene and cinnamic acid are four important biomass 3-phenyl-2-propene compounds. In the field of perfume and organic synthesis, their thermal stability and oxidation pathways deserve attention. This paper reports a new attempt to investigate the thermal stability and reactivity by a custom-designed mini closed pressure vessel test (MCPVT). The pressure and temperature behaviors were measured by MCPVT under nitrogen and oxygen atmosphere. The temperature of initial oxygen absorption (T a) and rapid oxidation (T R) were calculated. The results showed that four 3-phenyl-2-propene compounds were stable under nitrogen atmosphere. The T a of cinnamaldehyde, cinnamyl alcohol, β-methylstyrene, and cinnamic acid was 271.25 K, 292.375 K, 323.125 K, and 363.875 K, and their T R was 301.125 K, 332.75 K, 357.91 K, and 385.375 K, respectively. The oxidation reactivity order was derived to be cinnamaldehyde > cinnamyl alcohol > β-methylstyrene > cinnamic acid. The oxidation kinetics were determined using n versus time (n-t) plots, which showed a second-order reaction. Peroxide was determined by iodimetry, and the oxidation products were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the peroxide value of cinnamaldehyde, cinnamyl alcohol, β-methylstyrene, and cinnamic acid reached 18.88, 15.07, 9.62, and 4.24 mmol kg-1 at 373 K for 6 h, respectively. The common oxidation products of four 3-phenyl-2-propene compounds were benzaldehyde, benzoic acid, and epoxide, which resulted from the carbon-carbon double bond oxidation. The substituents' oxidation products were obtained from the oxidation of cinnamaldehyde, cinnamyl alcohol, and β-methylstyrene. In particular, the difference is that no oxidation products of the carboxyl group of cinnamic acid were detected. The common oxidation products of the four 3-phenyl-2-propene compounds were benzaldehyde, benzoic acid, and epoxide, which resulted from the carbon-carbon double bond oxidation. The substituents' oxidation products were caught in the oxidation of cinnamaldehyde, cinnamyl alcohol, and β-methylstyrene. In particular, the difference is that no oxidation products of the carboxyl group of cinnamic acid were detected. According to the complex oxidation products, important insights into the oxidation pathways were provided.

P–225 The effect of rapid and delayed insemination on reproductive outcome in conventional insemination and intracytoplasmic sperm injection invitro-fertilization cycles

Study question

Does rapid or delayed insemination after egg retrieval affect fertilization, blastocyst development and live birth rates in CI and ICSI cycles?

Summary answer

When performing CI or ICSI &lt;1.5h and &gt;6.5h after retrieval, detrimental effects are moderate on fertilization but do not impact blastocyst usage and birth rates.

What is known already

Several studies have shown that CIor ICSI performed between 3 to 5 h after oocyte retrieval has improved laboratory outcomes. However, some studies indicate that insemination of oocytes, by either CI or ICSI, within 2 hours or more than 8 hours after oocyte retrieval has a detrimental effect on the reproductive outcome. With some ART centres experiencing an increase in workload, respecting these exact time intervals is frequently challenging.

Study design, size, duration

A single-center retrospective cohort analysis was performed on 6559 patients (9575 retrievals and insemination cycles) between January 1st2017 to July 31st2019. The main outcome measures were live-birth rates. Secondary outcomes included analysis of fertilization per all oocytes retrieved, blastocyst utilization, clinical pregnancy, and miscarriage rates. All analyses used time of insemination categorized in both CI and ICSI cycles. Fertilization rates across categories was analyzed by ANOVA and pregnancy outcomes compared using Chi-square tests.

Participants/materials, setting, methods

As part of laboratory protocol, oocyte retrieval was performed 36 h post-trigger. Cycles involving injection with testicular/epidydimal sperm, donor or frozen oocytes were excluded. The time interval between oocyte retrieval and insemination was analyzed in eight categories: 0 (0- &lt;0.5h), 1 (0.5-&lt;1.5h), 2 (1.5-&lt;2.5h), 3 (2.5-&lt;3.5h), 4 (3.5-&lt;4.5), 5 (4.5-&lt;5.5), 6 (5.5-&lt;6.5) and 7 (6.5-&lt;8h). The number of retrievals in each group (0–7) was 586, 1594, 1644, 1796, 1836, 1351, 641 and 127 respectively.

Main results and the role of chance

This study had a mean patient age of 36.0 years and mean of 12.2 oocytes per retrieval in each category. There were 4,955 CI and 4,620 ICSI retrievals. The smallest groups were time category 7 and 0 for CI and ICSI respectively. The results showed that the mean fertilization rate per egg retrieved for CI ranged from 54.1 to 64.9% with a significant difference between time category 0 and 5 (p &lt; 0.001) and category 1 and 5 (p &lt; 0.0.001). Mean fertilization rate for ICSI per egg retrieved ranged from 52.8 to 67.3% with no significant difference between time categories compared to category 5. Blastocyst utilization rate for CI and ICSI were not significantly different for all time categories. In the CI and ICSI groups there were 6,540 and 6,178 total fresh and frozen transfers. The miscarriage and clinical pregnancy rate in CI and ICSI were not significantly different across time categories. The overall mean live birth rate for CI was 32.4% (range: 23.1 to 35.5%). Live-birth rates differed significantly (p = 0.04) in CI with time categories 0 and 7 the lowest. In the ICSI group, the overall mean live birth rate was 30.8% (range: 29.1 to 35.7%),with no significant differences between time categories.

Limitations, reasons for caution

As this is a retrospective study, the influence of uncontrolled variables cannot be excluded. The group spread was uneven with the early and late time categories having the lowest number of representative retrievals and this could have affected the results obtained.

Wider implications of the findings: Our results indicate that both CI and ICSI are optimal when performed between 1.5–6.5 hours after oocyte retrieval. Further prospective studies on reproductive outcomes related to time of insemination are warranted. This data indicates a minimal detrimental effect when it is untenable to follow strict insemination time intervals.

Trial registration number

2015P000122

Characteristics and hazards of the cinnamaldehyde oxidation process

Pressure and temperature behavior of the cinnamaldehyde oxidation process was determined using a custom-designed mini closed pressure vessel test (MCPVT), which is a new method to investigate the stability and hazard assesment of the cinnamaldehyde oxidation reaction. The oxidation products were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that cinnamaldehyde was stable under nitrogen atmosphere but very unstable under oxygen atmosphere. The initial oxidation products were analyzed by iodimetry and the cinnamaldehyde peroxide value could reach 139.44 mmol kg⁻¹ when the oxidation temperature was 308 K. The oxidation kinetics of cinnamaldehyde were studied by using the pressure versus time (P–t) curves obtained from the MCPVT process. The reaction is a second-order reaction, the kinetic equation is ln k = −2233.66 × (1/T) + 11.19, and the activation energy E_a is 18.57 kJ mol⁻¹ at 308–338 K. The explosion of the cinnamaldehyde oxidation reaction was observed by MCPVT, in which the onset temperature was 373 K. The main products of cinnamaldehyde oxidation are acetaldehyde, benzaldehyde, phenylacetaldehyde, acetophenone, 2-hydroxyphenyl acetone, cinnamaldehyde epoxide, benzoic acid, and cinnamic acid. Oxidation is a three-step process: (1) cinnamaldehyde reacts with oxygen to form peroxides; (2) complex oxidation reactions are caused by the thermal decomposition of peroxides; (3) rapid oxidation and thermal decomposition lead to explosion hazard.

An explosion of the cinnamaldehyde oxidation process was observed and evaluated by MCPVT (mini closed pressure vessel test).

Characteristics and kinetics of the glycerol ester of rosinviaan oxidation process under ultraviolet irradiation

A self-designed mini gas–solid reaction device was applied as promising equipment to investigate the oxidation characteristics and kinetics of the glycerol ester of rosin (GER) under 254 nm UV irradiation in air.

Resveratrol proniosomes as a convenient nanoingredient for functional food

Proniosomes are free-flowing powders composed of water-soluble carriers blended with surfactants, which form niosomes upon hydration. In this work, proniosomal formulations containing the natural antioxidant resveratrol (RSV) were prepared and fully characterized. A pre-formulation study on RSV-loaded niosomes was carried out to determine the most promising ratio between the two surfactants, Tween 20 and Span 60, in terms of entrapment efficiency and antioxidant activity. The optimized formulae were subsequently adapted to be prepared as proniosomes by the slurry method, including lactose or maltodextrin as carriers. The impact of surfactants and carriers properties on size, entrapment efficiency and release kinetics of proniosomes were evaluated. In vitro release of RSV in simulated gastric and intestinal media was determined, as well as the vesicular stability. Moreover, the biocompatibility of the formulations was determined on intestinal cells in vitro. Overall, the developed proniosomes provide promising nanoingredient for functional food, improving resveratrol stability and bioavailability.

Si-ni-tang (a Chinese herbal formula) for improving immunofunction in sepsis: study protocol for a pilot randomized controlled trial

Background

Immunologic derangement may be the critical pathophysiologic mechanism in sepsis, and immunotherapy might be a potential new treatment. Si-ni-tang (SNT), an ancient Chinese herbal formula documented in Shanghan Lun, has been used for treating severe sepsis for thousands of years. Research shows that it may have a therapeutic benefit for sepsis. This study will evaluate the feasibility of testing the effects of SNT on immune function in sepsis patients.

Methods/design

This is a pilot randomized controlled study. Eligible sepsis patients admitted to our medical intensive care unit will be randomly allocated to the control group or the SNT group. Both groups will receive standard therapy according to the recommendations of the Surviving Sepsis Campaign. In addition, the SNT group will receive SNT (150 mL per day for 3 days) orally or by gastric tube, while the control group will receive 150 mL of normal saline. The primary outcome is to assess the feasibility of this treatment. The secondary outcomes include: (1) immune function measured by monocyte human leukocyte antigen-DR (mHLA-DR) expression, procalcitonin, and the ratio of CD4+ to CD8+ T lymphocytes and (2) other clinical data, such as the 28-day all-cause mortality, Sequential Organ Failure Assessment (SOFA) scores, Acute Physiology and Chronic Health Evaluation (APACHE) II scores, both of the latter on days 0 and 3.

Discussion

This study aims to evaluate the feasibility of testing the efficacy of SNT for treating sepsis when used as an adjunctive treatment with the standard therapy recommended by the Surviving Sepsis Campaign.

Trial registration

ClinicalTrials.gov, NCT02777606. Registered on 22 June 2016. Retrospectively registered. https://clinicaltrials.gov/

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3646-3) contains supplementary material, which is available to authorized users.

Characteristics and Kinetics of Rosin Pentaerythritol Ester via Oxidation Process under Ultraviolet Irradiation

A self-designed reaction device was used as a promising equipment to investigate the oxidation characteristics and kinetics of rosin pentaerythritol ester (RPE) under UV irradiation. Photo-oxidation kinetics and the initial quantum yield (Φ) of RPE were calculated. The initial oxidation product of the photo-oxidation reaction-peroxide was analyzed by iodimetry. The peroxide concentration is related to the light intensity (I) and the temperature (T), and the increasing T and I would destabilize the RPE by accelerating peroxide forming. Photo-oxidation of RPE follows the pseudo first-order reaction kinetics. The relationship between activation energy and logarithm of light intensity (ln I) is linear, and it is expressed as Ea = -4.937ln I + 45.565. Φ was calculated by the photo-oxidation kinetics, and the average value of Φ was 7.19% in the light intensity range of 200⁻800 μW cm^-2. This research can provide fundamental information for application of RPE, and help obtain a better understanding of the stability of rosin esters.

Meta-analysis of the influence of lifestyle changes for preoperative weight loss on surgical outcomes

Background

The aim was to investigate whether preoperative weight loss results in improved clinical outcomes in surgical patients with clinically significant obesity.

Methods

This was a systematic review and aggregate data meta-analysis of RCTs and cohort studies. PubMed, MEDLINE, Embase and CINAHL Plus databases were searched from inception to February 2018. Eligibility criteria were: studies assessing the effect of weight loss interventions (low-energy diets with or without an exercise component) on clinical outcomes in patients undergoing any surgical procedure. Data on 30-day or all-cause in-hospital mortality were extracted and synthesized in meta-analyses. Postoperative thromboembolic complications, duration of surgery, infection and duration of hospital stay were also assessed.

Results

A total of 6060 patients in four RCTs and 12 cohort studies, all from European and North American centres, were identified. Most were in the field of bariatric surgery and all had some methodological limitations. The pooled effect estimate suggested that preoperative weight loss programmes were effective, leading to significant weight reduction compared with controls: mean difference –7·42 (95 per cent c.i. –10·09 to –4·74) kg (P &lt; 0·001). Preoperative weight loss interventions were not associated with a reduction in perioperative mortality (odds ratio 1·41, 95 per cent c.i. 0·24 to 8·40; I2 = 0 per cent, P = 0·66) but the event rate was low. The weight loss groups had shorter hospital stay (by 27 per cent). No differences were found for morbidity.

Conclusion

This limited preoperative weight loss has advantages but may not alter the postoperative morbidity or mortality risk.

Successful low-dosage thrombolysis of massive pulmonary embolism in primigravida: A case report

RATIONAL

Thrombolysis in primigravida with hemodynamic instability is controversial, especially treatment with low-dosage recombinant tissue plasminogen activator (rtPA), and related studies are extremely rare. Here, we report the case of a 26-year-old primigravida diagnosed with an acute massive pulmonary embolism (PE) that prompted initiation of thrombolysis with low-dose alteplase.

PATIENT CONCERNS

The patient was admitted to the Emergency Department with chief complaints of a sudden onset of extremely dyspnea, chest tightness, and confusion over a 6-hour period. She was found to have significant dilation of her right ventricle, moderate pulmonary arterial hypotension, as shown by transthoracic echocardiography, and a typical S1-Q3-T3 pattern, as shown by electrocardiogram (ECG).

DIAGNOSIS

Acute massive PE in primigravida.

INTERVENTION

The patient underwent intravenous thrombolysis with a half dose of alteplase.

OUTCOMES

The fetus lived through this severe event during the mother's stay in the Intensive Care Unit; however, surgical abortion was unexpectedly proposed due to long-term hypoxia and high-risk of relapse and exacerbation and was performed successfully after the agreement of her kin. The patient recovered gradually, and results of her laboratory tests and postsurgical, repeated contrast-enhanced computed tomography had normalized by her 3-month follow-up.

LESSONS

Administration of low-dosage alteplase in primigravida with hemodynamic instability is extremely rare and controversial; however, our case suggests that this treatment strategy is relatively safe and feasible. In addition, nonradiometric examination played a major role in the diagnosis of PE in this patient. Because radiation use is contraindicated during pregnancy, these examinations could be the first choice for pregnant patients with suspected PE.

A novel splice site mutation of the PRKAR1A gene, C.440+5 G>C, in a Chinese family with Carney complex

BACKGROUND

Carney complex (CNC) is an extremely rare, multiple endocrine neoplasia syndrome that occurs in an autosomal dominant manner. Mutations in PRKAR1A have been reported to be a common genetic cause of CNC.

METHODS

In this study, we reported a Chinese pedigree of CNC that manifests mainly as spotty skin pigmentation and primary pigmented nodular adrenocortical disease. Whole blood samples of this pedigree were collected for DNA/RNA analysis. Polymerase chain reaction (PCR) and reverse-transcription polymerase chain reaction analyses were performed to amplify the 11 exons and adjacent introns of PRKAR1A. Direct sequencing was used to detect the mutation, and DNA from 70 Han Chinese people was extracted and sequenced as a control to estimate the frequency of the identified mutation.

RESULTS

Within the pedigree, ten patients with CNC were identified, and a novel heterozygous mutation (c.440+5 G>C in intron 4a) was identified in the PRKAR1A gene. PCR amplification of cDNA from the control subjects and patients was performed. Agarose gel electrophoresis showed only one wild-type band in the cDNA corresponding to the former group, whereas an extra band was present in samples from the latter group corresponding to the skipping of exon 4a; this confirms that the variant affects PRKAR1A splicing.

CONCLUSION

In conclusion, the c.440+5 G>C mutation is a new splice site mutation that has not been reported and has the potential to broaden the mutational spectrum of PRKAR1A that is associated with CNC, which would facilitate genetic diagnosis and counseling for CNC.

Two-stage classifiers that minimize PCA3 and the PSA proteolytic activity testing in the prediction of prostate cancer recurrence after radical prostatectomy

INTRODUCTION

Early biochemical recurrence after prostate cancer surgery is associated with higher risk of aggressive disease and cancer specific death. Many new tests are being developed that will predict the presence of indicators of aggressive disease like early biochemical recurrence. Since recurrence occurs in less than 10% of patients treated for prostate cancer, validation of such tests will require expensive testing on large patient groups. Moreover, clinical application of the validated test requires that each new patient be tested. In this report we introduce a two-stage classifier system that minimizes the number of patients that must be tested in both the validation and clinical application of any new test for recurrence.

MATERIALS AND METHODS

Expressed prostatic secretion specimens were prospectively collected from 450 patients prior to robot-assisted radical prostatectomy for prostate cancer. Patients were followed for 2.5 years for evidence of biochemical recurrence. Standard clinical parameters, the levels proteolytic activity of prostate specific antigen (PSA) and the levels of PCA3 RNA, PSA RNA and TMPRSS2:ERG fusion RNA were determined in each prospective patient specimen for subsequent correlation with biochemical recurrence.

RESULTS

While levels of PCA3 and PSA proteolytic activity (PPA) in prostatic secretions provided an effective pre-surgical predictor of early biochemical recurrence in prostate cancer, application of the two-stage classifier shows that only 60% of the patients need these tests.

CONCLUSION

Two-stage classifiers can provide a parsimonious approach to both the validation and clinical application of biomarker-based tests. Adoption of the two-stage neutral zone classifier can reduce unnecessary testing in prostate cancer treatment.

Loss of p300 accelerates MDS-associated leukemogenesis

The role that changes in DNA methylation and histone modifications have in human malignancies is poorly understood. p300 and CREB-binding protein (CBP), two distinct but highly homologous lysine acetyltransferases, are mutated in several cancers, suggesting their role as tumor suppressors. In the current study, we found that deletion of p300, but not CBP, markedly accelerated the leukemogenesis ofNup98-HoxD13 (NHD13) transgenic mice, an animal model that phenotypically copies human myelodysplastic syndrome (MDS). p300 deletion restored the ability of NHD13 expressing hematopoietic stem and progenitor cells (HSPCs) to self-renew in vitro, and to expand in vivo, with an increase in stem cell symmetric self-renewal divisions and a decrease in apoptosis. Furthermore, loss of p300, but not CBP, promoted cytokine signaling, including enhanced activation of the MAPK and JAK/STAT pathways in the HSPC compartment. Altogether, our data indicate that p300 has a pivotal role in blocking the transformation of MDS to acute myeloid leukemia, a role distinct from that of CBP.

A Reporter System for Reverse Transfection Cell Arrays

The incredible speed of gene cloning and sequencing brought about by the genomic revolution has begun to outpace conven tional gene discovery approaches in the pharmaceutical industry. High-throughput approaches for studying gene function in vivo are greatly needed. One potential answer to this challenge is reverse transfection, a high-throughput gene expression method for examining the function of hundreds to thousands of genes in parallel. One limitation of reverse transfection tech nology is the need for posttransfection processing of the arrays to analyze the activity of the expressed proteins. The authors have investigated the use of a reporter construct cotransfected with other genes of interest to monitor and screen gene function on reverse transfection microarrays. They developed a serum response element (SRE) reporter linked to the green fluorescent protein (GFP) that is cotransfected with target genes on reverse transfection arrays for monitoring mitogen-activated protein (MAP) kinase signaling by multiple targets in parallel. The authors show that this reporter system is able to detect inhibition of upstream MAP kinase signaling proteins by the MEK inhibitor U0126. The ability to monitor the activity of multiple signaling proteins in a multiwell format suggests the utility of reverse transfection reporter arrays for high-throughput screening applications.

Immunohistochemical markers of CYP3A4 and CYP3A7: a new tool towards personalized pharmacotherapy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents a major global health problem, since more than 90% of primary liver cancers worldwide are HCC. Most cases of HCC are secondary to viral hepatitis infection (hepatitis B or C), alcoholism and cirrhosis. Sorafenib, an oral tyrosine kinase inhibitor that suppresses tumor proliferation and angiogenesis, emerged as the first effective systemic treatment for HCC after 30 years of research, and is currently the standard-of-care for patients with advanced HCC. Sorafenib is metabolized by cytochrome P450 (CYP450), particularly from the 3A4 isoform, producing two main metabolites: the N-oxide and the N-hydroxymethyl metabolite. We studied 11 HCC sample showing the presence of CYP3A4 and CYP3A7 in most of the samples analysed. Specifically, the immunoreactivity of CYP3A4 was stronger and more widespread than that of CYP3A7. The CYP3A4 immunoreactivity was observed in surrounding hepatocytes in 8 out of 11 cases; while the CYP3A7 immunostaining was found in normal liver cells, in 7 out of 11 cases. These results suggest the existence of a marked inter-individual variability regarding the presence of the isoforms of CYP3A. In addition, since sorafenib is metabolized by CYP3A4, but not by CYP3A7, an overexpression of CYP3A4 may lead to an increase in the degradation of the drug and then to clinical ineffectiveness. These results might implicate the necessity of an individualized approach in the treatment of HCC as positivity to CYP3A4 in HCC liver samples might predict a scarce response to sorafenib.

INPP4B is an oncogenic regulator in human colon cancer

Inositol polyphosphate 4-phosphatase type II (INPP4B) negatively regulates phosphatidylinositol 3-kinase signaling and is a tumor suppressor in some types of cancers. However, we have found that it is frequently upregulated in human colon cancer cells. Here we show that silencing of INPP4B blocks activation of Akt and serum- and glucocorticoid-regulated kinase 3 (SGK3), inhibits colon cancer cell proliferation and retards colon cancer xenograft growth. Conversely, overexpression of INPP4B increases proliferation and triggers anchorage-independent growth of normal colon epithelial cells. Moreover, we demonstrate that the effect of INPP4B on Akt and SGK3 is associated with inactivation of phosphate and tensin homolog through its protein phosphatase activity and that the increase in INPP4B is due to Ets-1-mediated transcriptional upregulation in colon cancer cells. Collectively, these results suggest that INPP4B may function as an oncogenic driver in colon cancer, with potential implications for targeting INPP4B as a novel approach to treat this disease.

Alkaline pretreatment and the synergic effect of water and tetralin enhances the liquefaction efficiency of bagasse

Bagasse liquefaction (BL) in water, tetralin, and water/tetralin mixed solvents (WTMS) was investigated, and effects of tetralin content in WTMS, temperature, and alkaline pretreatment of bagasse on liquefaction efficiency were studied. At 300°C, bagasse conversion in WTMS with tetralin content higher than 50 wt% was 86-87 wt%, whereas bagasse conversion in water or tetralin was 67 wt% or 84 wt%, respectively. Because the solid conversion from liquefaction in WTMS with tetralin content higher than 50 wt% was always higher than that in water or tetralin at temperatures between 250 and 300°C, a synergic effect between water and tetralin is suggested. Alkaline pretreatment of bagasse resulted in significantly higher conversion and heavy oil yield from BL in water or WTMS. The effect of deoxygenation by the present liquefaction method is demonstrated by lower oxygen contents (16.01-19.59 wt%) and higher heating values (31.9-34.8 MJ/kg) in the produced oils.

Adipocytes contribute to resistance of human melanoma cells to chemotherapy and targeted therapy

Epidemiological evidence has linked the development and progression of several cancers including melanoma with obesity. However, whether obesity impinges on responses of cancer cells to treatment remains less understood. Here we report that human adipocytes contribute to resistance of melanoma cells to various therapeutic agents. Exposure to media from adipocyte cultures (adipocyte media) increased cell proliferation and reduced sensitivity of melanoma cells to apoptosis induced by diverse chemotherapeutic drugs, including the DNA-damaging drug cisplatin, the microtubuletargeting agent docetaxel, and the histone deacetylase inhibitor SAHA. This was associated with increased activation of PI3K/Akt and MEK/ERK signaling, and was attenuated by a PI3K or MEK inhibitor. The effect of adipocyte media on melanoma cells was, at least in part, due to the interaction between the adipokine leptin and its long form receptor OB-Rb, in that immunodepletion of leptin in adipocyte media or siRNA knockdown of OB-Rb in melanoma cells reversed the increase in Akt and ERK activation, enhancement in cell proliferation, and importantly, protection of melanoma cells against the drugs. In support, recombinant leptin partially recapitulated the effect of adipocyte media on melanoma cells. Of note, OB-Rb was increased on the surface of melanoma cells compared to melanocytes, whereas leptin short form receptors appeared to be suppressed post-transcriptionally, suggesting that OB-Rb was selectively upregulated in melanoma cells. Collectively, these results indicate that adipocytes contribute to the resistance of melanoma cells to chemotherapeutic drugs and agents targeting the PI3K/Akt and MEK/ERK pathways, and suggest that inhibition of the leptin/ OB-Rb system may be useful to improve the efficacy of multiple therapeutic approaches in the treatment of melanoma.

A continuous perfusion microplate for cell culture

We describe a 96-well microplate with fluidically connected wells that enables the continuous fluid perfusion between wells without the need for external pumping. A single unit in such a perfusion microplate consists of three wells: a source well, a sample (cell culture) well in the middle and a waste well. Fluid perfusion is achieved using a combination of the hydrostatic pressure generated by different liquid levels in the wells and the fluid wicking through narrow strips of a cellulose membrane connecting the wells. There is an excellent correspondence between the observed perfusion flow dynamics and the flow simulations based on Darcy's Law. Hepatocytes (C3A cells) cultured for 4 days in the perfusion microplate with no media exchange in the cell culture well had the same viability as hepatocytes exposed to a daily exchange of media. EOC 20 cells that require media conditioned by LADMAC cells were shown to be equally viable in the adjacent cell culture well of the perfusion microplate with LADMAC cells cultured in the source well. Tegafur, a prodrug, when added to primary human hepatocytes in the source well, was metabolized into a cytotoxic metabolite that kills colon cancer cells (HCT 116) cultured in the adjacent cell culture well; no toxicity was observed when only medium was in the source well. These results suggest that the perfusion microplate is a useful tool for a variety of cell culture applications with benefits ranging from labor savings to enabling in vivo-like toxicity studies.

Modulating cell-cell communication with a high-throughput label-free cell assay

A high-throughput label-free cell assay for modulating cell-cell communication is demonstrated with the Epic® system, a resonant waveguide grating sensor platform. Natural killer (NK) cells are known to be able to recognize abnormal cells (e.g., cancer cells and cells presenting intercellular adhesion molecule 1 [ICAM1] through cell surface receptors) and kill them. In this study, the effect of effecter cells NK92MI on two kinds of target cells, cervical cancer cells (HeLa) and Chinese hamster ovarian cells overexpressing ICAM1 (CHO-ICAM1), was examined. Living target cells' response to NK92MI cells was monitored in real time and measured as wavelength shift in picometers. The authors showed that the detectability of target cell response is affected by multiple factors: the ratio of effecter cells to target cells (E/T), the interaction time of the two types of cells, and the target cell type. For example, with the effecter cells NK92MI and the same incubation time of 16 h, a minimal E/T ratio of 1 is required to detect HeLa cell response, whereas an E/T of 0.5 is sufficient to detect CHO-ICAM1 cell response. The authors confirmed that NK92MI cell-mediated target cell cytotoxicity results in negative optical signals and is associated with apoptosis mainly through caspase pathways. Distinct optical signals could be generated with the pretreatment of the target cells with various known pharmaceutical reagents, making the assay useful for discovering new chemicals that may affect cell-cell communications.

Nanocrystals as tool to improve piroxicam dissolution rate in novel orally disintegrating tablets

In this paper, orally disintegrating tablets (ODT) were prepared using nanocrystal formulations in order to optimise dissolution properties of lipophilic, poorly soluble drug piroxicam (PRX). Different nanocrystal formulations were prepared using a high pressure homogenisation technique and poloxamer 188 as stabiliser. Characterisation of PRX nanocrystal ODT was carried out by infrared spectroscopy (FTIR), X-ray powder diffractometry (XRPD), differential scanning calorimetry and photon correlation spectroscopy. Dissolution study of PRX ODT was performed in distilled water (pH 5.5) and was compared to that of PRX coarse suspension ODT, PRX/poloxamer 188 physical mixture and bulk PRX samples. The XRPD and FTIR studies demonstrated that the homogenisation process led to a polymorphic transition from form I (bulk commercial PRX) to form III and monohydrate form of the nanocrystals. All ODT formulations prepared using PRX nanosuspensions showed a higher PRX dissolution rate compared with the ODT prepared with the coarse PRX. Since the solubility of the different PRX polymorphic forms increased only slightly from bulk PRX (form I) to monohydrate, form II and form III, we can conclude that the improvement in PRX dissolution rate is mainly caused by the increased surface-to-volume ratio due to the submicron dimension of the drug particles.