Clinical therapeutic effects of eradication of Helicobacter pylori in treating patients with type 2 diabetes mellitus: A protocol for systematic review and meta-analysis

BACKGROUND

Previous studies have demonstrated that Helicobacter pylori is a critical factor in the development of gastrointestinal diseases. However, only limited studies have reported results on the relationship between H pylori infection and patients with type 2 diabetes mellitus (T2DM). Moreover, the conclusions from these past studies are variable. Because there are contradictory results on this issue, the present study aims to examine the clinical therapeutic impacts of H pylori eradication to treat patients experiencing T2DM.

METHODS

The present protocol is drafted according to the provisions of the Preferred Reporting Items for Systematic Review and Meta-analyses Protocols guidelines. PubMed, Cochrane Central Register of Controlled Trials databases, EMBASE, Web of Science, China National Knowledge Infrastructure, and Chinese BioMedical Literature Database will be searched up to May 2021 to obtain randomized controlled trials evaluating the clinical therapeutic effects of H pylori eradication to treat patients experiencing T2DM. We will use 2 investigators independently to carry out study selection, data extraction, and employ the Cochrane Collaboration criteria to evaluate their risks of bias. Furthermore, we will apply Stata 16.0 software to perform data analysis.

RESULTS

We intend to evaluate the clinical therapeutic impacts of H pylori eradication to treat patients suffering from T2DM.

CONCLUSIONS

Our findings may support existing evidence on the clinical therapeutic impacts of H pylori eradication to treat patients with T2DM.

ETHICS AND DISSEMINATION

Since all data will be extracted from the published literature, the study does not require an ethical approval.

OSF REGISTRATION NUMBER

May 31, 2021.osf.io/qtexu. (https://osf.io/qtexu/).

[The Breast Cancer Cohort Study in Chinese Women: research design and preliminary results of clinical multi-center cohort]

Objective: The incidence of breast cancer in Chinese women continues to rise. The large breast cancer cohort studies in China are relatively scarce. There are many bottlenecks in the construction of large clinical cohort for breast cancer diagnosis, treatment, and prognoses, such as inconsistent standards, high rates of lost follow-up, repeated construction, and inability to share. To better solving the difficulties and problems faced by large-scale clinical cohort research in China, this project will cooperate with several tertiary A hospitals to establish a breast cancer cohort in Chinese women. It also provides a data platform and technical support for breast cancer multi-center clinical cohort research. Methods: Based on the evidence-based medicine and expert opinion and consensus, we established a breast cancer cohort standardized indicator set-recording baseline information, diagnosis and treatment-related information of the enrolled patients, and collecting biological specimens. According to the technical specification of long-term follow-up for the endpoint, data management, and data security and in the large population-based cohort study, a standardized follow-up system for the diagnosis, treatment, and prognosis of breast cancer prospective cohorts is formed. Results: Based on standardized data sets and the computer discipline's advantage from the University of Science and Technology Beijing, we integrate the new information technology methods, including dynamic information collection terminals and social networks. Thus, the quality of control programs on compliance and intelligence data was improved, and a Chinese women breast cancer cohort database was developed. By February 2020, 12 147 patients were included in the clinical cohort database. Biological specimens'resources in cohort construction were collected and cooperated with Shandong University to research the multi-center quality control system and shared evaluation system of biobanks. Building an open and shared biobank network and forming a full chain of breast cancer research platform. Conclusion: With the implementation of the "13(th) Five-Year Plan" precision medicine research, this study provides a research foundation for precision diagnosis and treatment of breast cancer and provides data support for the country to formulate relevant medical policies.

Application of dexmedetomidine for lung injury in elderly patients undergoing one-lung ventilation

Introduction

This study aimed to evaluate the effects of dexmedetomidine (DEX) on lung injury, the oxygenation index and perioperative pulmonary complications in elderly patients who underwent thoracotomy with one-lung ventilation (OLV).

Material and methods

A total of 120 elderly patients with lung cancer were included in the present study. According to the random number table method, these patients were randomly divided into two groups: group D and group C. Patients in group D were intravenously pumped with 0.5 μg/kg/h of DEX before anesthesia. The infusion was completed within 15 min, and anesthesia was induced by venous injection. Patients in group C were pumped with equal volumes of normal saline.

Results

At T2 and T3, compared with group C, group D had a significant decrease in cardiac index, mean arterial pressure and central venous pressure (p < 0.05). At T2, T3 and T4, compared with group C, group D had a significant increase in pH and PaO2 (p < 0.05). At T2, T3 and T4, compared with group C, group D had a significant decrease in Qs/Qt (p < 0.05). At T6, compared with group C, group D had a significant decrease in the supernatant of bronchoalveolar lavage fluid of tumor necrosis factor-α and interleukin 6 (p < 0.05). At T5, compared with group C, group D had a significant decrease in Visual Analogue Scale score (p < 0.05), and a significant increase in Ramsay Sedation Scale score (p < 0.05), and the number of respiratory and cardiovascular events also decreased (p < 0.05).

Conclusions

In elderly patients, dexmedetomidine can reduce Qs/Qt and increase PaO2 during OLV in surgery. It can reduce lung injury. Moreover, DEX reduced respiratory and cardiovascular complications in the perioperative period.

Fast separation of water-soluble vitamins by hydrophilic interaction liquid chromatography based on submicrometer flow-through silica microspheres

In the present study, submicrometer flow-through silica microspheres (Sub-FTSiO₂) was for the first time obtained via a suspension polymerization method coupled with sol-gel transition and phase separation. The Sub-FTSiO₂ was characteristic of rich mesopores, penetrable macropores and small particle size, which would be beneficial to fast mass transfer, low column backpressure and high column efficiency. It was directly used as the hydrophilic interaction liquid chromatographic (HILIC) stationary phase, and the fast separation of seven water-soluble vitamins in 2.2 min was realized. The proposed method was successfully applied to the determination of water-soluble vitamins in two functional beverages on the market. The prepared Sub-FTSiO₂ was well demonstrated for fast HILIC, and would be potential as the stationary phase matrix for fast liquid chromatography in diverse separation modes.

Application of alveolar recruitment strategy and positive end-expiratory pressure combined with autoflow in the one-lung ventilation during thoracic surgery in obese patients

Background

The present study aims to evaluate the influence of alveolar recruitment strategy (ARS) and positive end-expiratory pressure (PEEP) combined with autoflow on respiratory mechanics, the oxygen index (OI), pulmonary shut [Qs/Qt(%)], and the concentrations of IL-6 and TNF-α in venous blood after surgery in obese patients who experienced thoracic surgery with one-lung ventilation (OLV).

Methods

A total of 36 obese patients with ASAII-III degree, who experienced selective pulmonary lobectomy, were within 36-74 years old, and had a BMI of 30-40 kg/m², were randomly divided into two groups: control group (C group) and protective ventilation group (P group). In the P group, ARS was given once when OLV began. Then, ventilation at 7 mmHg of PEEP and autoflow were given. The P_peak before OLV (T₁), at 30 minutes after OLV (T₂), and at the 5 minutes after two-lung ventilation (TLV) (T₃), and the changes of P_plat and Cdyn were recorded. Then, arteriovenous blood was drawn at T₁, T₂, T₃ and T₄ (6 hours after the operation), blood-gas indicators, including SPO₂, PaCO₂ and PaO₂, were measured, and the value of Qs/Qt(%) was calculated. Afterwards, venous blood was collected at T₁ and T₅ (18 hours after surgery), and the concentrations of IL-6 and TNF-α were detected. The clinical pulmonary infection score (CPIS) was determined at the first day and seventh day after the operation.

Results

In both groups, Cdyn and OI decreased, while P_plat, P_peak and Qs/Qt(%) increased (P<0.05) at T₂, when compared with those at T₁. At T₂ and T₃, P_plat and P_peak decreased (P<0.05) in the P group, when compared with the C group. At T₂, T₃ and T₄, OI increased (P<0.05) in the P group, when compared with the C group. At T₂, T₃ and T₄, PaCO₂ and Qs/Qt(%) decreased in the P group, when compared with the C group. The concentrations of IL-6 and TNF-α decreased in the P group, when compared with the C group.

Conclusions

The ventilation model of ARS and PEEP combined with autoflow can better reduce airway pressure and the production of injurious inflammatory cytokines in blood in obese patients. Furthermore, it can reduce Qs/Qt during and at 6 hours after thoracotomy, improve OI and maintain the acid-base balance of the internal environment, which may be applied in clinical work. This brings new enlightenment and needs to be clarified through further studies.

Waxberry-like hierarchically porous ethyl-bridged hybrid silica microsphere: A substrate for enzyme catalysis and high-performance liquid chromatography

In this study, the ethyl-bridged hybrid silica microsphere with hierarchically meso-macroporous structure was initially synthesized through a method combining dispersion polymerization with sol-gel transition and phase separation. The flow-through macropores rendered the microsphere a rough surface like a waxberry, and thus the material was named as waxberry-like ethyl-bridged hybrid silica sphere (WEHS). WEHS was characteristic of appropriate alkali-stability, which was highly difficult for the pure silica. Additionally, WEHS possessed hierarchical meso- and macropores, which added additional value for faster mass transfer than the conventional fully porous silica materials. Taking the advantages of WEHS, it was successfully applied as the substrate to immobilize lipase; the prepared immobilized lipase exhibited high catalytic activity and favorable reusability under alkaline conditions, which was significant in pitch control of neutral-alkaline papermaking industry. Moreover, as the high-performance liquid chromatographic stationary phase matrix, WEHS made the separation under alkaline mobile phase into a reality for the silica-based materials. Besides, an ultra-fast and efficient separation in minutes was achieved with lower consumption of solvents and saving analytical time, which is highly desired in modern analysis. In general, WEHS was a novel and promising candidate in the myriads of silica-based materials.

Penehyclidine ameliorates acute lung injury by inhibiting Toll-like receptor 2/4 expression and nuclear factor-κB activation

The aim of the present study was to investigate the effect of penehyclidine (PHC) on endotoxin-induced acute lung injury (ALI), as well as to examine the mechanism underlying this effect. A total of 60 rats were randomly divided into five groups, including the control (saline), LPS and three LPS + PHC groups. ALI was induced in the rats by injection of 8 mg lipopolysaccharide (LPS)/kg body weight. The rats were then treated with or without PHC at 0.3, 1 or 3 mg/kg body weight 1 min following LPS injection. After 6 h, serum levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 were determined by ELISA. In addition, the mRNA expression levels of toll-like receptor (TLR)2 and TLR4 were examined by reverse transcription-quantitative polymerase chain reaction in the lung tissue samples, and nuclear factor (NF)-κB p65 protein expression levels were examined by western blot analysis. The results demonstrated that lung injury was ameliorated by treatment with PHC (1 and 3 mg/kg body weight) as compared with treatment with LPS alone. Injection of LPS significantly increased the mRNA expression levels of TLR2 and TLR4, as well as the protein expression levels of NF-κB p65 in the lung tissue samples. Serum levels of TNF-α and IL-6 were also upregulated by LPS injection. Treatment of the rats with PHC following LPS injection suppressed the LPS-induced increase in TLR2/4 mRNA and NF-κB p65 protein expression levels. PHC also inhibited the increase in TNF-α and IL-6 serum levels. In addition, PHC reduced LPS-induced ALI and decreased the serum levels of TNF-α and IL-6, possibly by downregulating TLR2/4 mRNA expression and inhibiting NF-κB activity, and consequently alleviating the inflammatory response.

Nickel Oxide Nanoparticle-Deposited Silica Composite Solid-Phase Extraction for Benzimidazole Residue Analysis in Milk and Eggs by Liquid Chromatography-Mass Spectrometry

A novel nickel oxide nanoparticle-deposited silica (SiO2@NiO) composite was prepared via liquid-phase deposition (LPD) and then employed as a solid-phase extraction (SPE) sorbent. When the SPE was coupled with liquid chromatography-electrospray ionization mass spectrometry (LC-ESI/MS) analysis, an analytical platform for the sensitive determination of benzimidazole residues in egg and milk was established. The limits of detection of nine benzimidazoles were in the range of 0.8-2.2 ng/mL in milk and 0.3-2.1 ng/g in eggs, respectively, which was 5-10 times superior to the methods with other adsorbents for SPE. The recoveries of nine benzimidazoles spiked in milk and egg ranged from 70.8 to 118.7%, with relative standard deviations (RSDs) being less than 18.9%. This work presented the excellent extraction performance of NiO on benzimidazoles for the first time, and the applicability of the LPD technique used as sorbents for trace analysis in complex matrices was also demonstrated.

Coupling carbon nanotube film microextraction with desorption corona beam ionization for rapid analysis of Sudan dyes (I-IV) and Rhodamine B in chilli oil

A rapid analysis method by coupling carbon nanotube film (CNTF) microextraction with desorption corona beam ionization (DCBI) was developed for the determination of Sudan dyes (I-IV) and Rhodamine B in chilli oil samples. Typically, CNTF was immersed into the diluted solution of chilli oil for extraction, which was then placed directly under the visible plasma beam tip of the DCBI source for desorption and ionization. Under optimized conditions, five dyes were simultaneously determined using this method. Results showed that the analytes were enriched by the CNTF through the π-π interactions, and the proposed method could significantly improve the sensitivities of these compounds, compared to the direct analysis by DCBI-MS/MS. The method with a linear range of 0.08-12.8 μg g(-1) and good linear relationships (R(2) > 0.93) in a multiple reaction monitoring (MRM) mode was developed. Satisfactory reproducibility was achieved. Relative standard deviations (RSDs) were less than 20.0%. The recoveries ranged from 80.0 to 110.0%, and the limits of detection (LODs) were in the range of 1.4-21 ng g(-1). Finally, the feasibility of the method was further exhibited by the determination of five illegal dyes in chilli powder. These results demonstrate that the proposed method consumes less time and solvent than conventional HPLC-based methods and avoids the contamination of chromatographic column and ion source from non-volatile oil. With the help of a 72-well shaker, multiple samples could be treated simultaneously, which ensures high throughput for the entire pretreatment process. In conclusion, it provides a rapid and high-throughput approach for the determination of such illicit additions in chilli products.

Preparation, chromatographic evaluation and application of adenosine 5'-monophosphate modified ZrO2/SiO2 stationary phase in hydrophilic interaction chromatography

The zirconia-coated silica (ZrO2/SiO2) material was obtained by coupling layer-by-layer (LbL) self-assembly method and sol-gel technology, to take dual advantages of the suitable porous structure of SiO2 and basic resistance of ZrO2. Adenosine 5'-monophosphate (5'-AMP) was then self-assembled onto ZrO2/SiO2 via Lewis acid-base interaction, generating 5'-AMP-ZrO2/SiO2. The chromatographic properties of 5'-AMP-ZrO2/SiO2 were systemically studied by evaluating the effect of acetonitrile content, pH and buffer concentration in the mobile phase. The results demonstrated that the 5'-AMP-ZrO2/SiO2 possessed hydrophilic interaction chromatographic (HILIC) property comprising hydrophilic, hydrogen-bonding, electrostatic and ion-exchange interactions. For basic analytes, the column efficiency of ZrO2/SiO2 and 5'-AMP-ZrO2/SiO2 was superior to the bare ZrO2, and different selectivity was obtained after the introduction of 5'-AMP. For acidic analytes, good resolution was obtained on 5'-AMP-ZrO2/SiO2 while the analysis failed on the bare ZrO2 column owing to strong adsorption. Hence, the proposed 5'-AMP-ZrO2/SiO2 had great potential in analyzing acidic compounds in HILIC mode. It was an extended application of ZrO2 based SP.

Effects of isobutyrate supplementation on ruminal microflora, rumen enzyme activities and methane emissions in Simmental steers

The objective of this study was to evaluate the effects of isobutyrate supplementation on rumen microflora, enzyme activities and methane emissions in Simmental steers consuming a corn stover-based diet. Eight ruminally cannulated Simmental steers were used in a replicated 4 × 4 Latin square experiment. The treatments were control (without isobutyrate), low isobutyrate (LIB), moderate isobutyrate (MIB) and high isobutyrate (HIB) with 8.4, 16.8 and 25.2 g isobutyrate per steer per day respectively. Isobutyrate was hand-mixed into the concentrate portion. Diet consisted of 60% corn stover and 40% concentrate [dry matter (DM) basis]. Dry matter intake (averaged 9 kg/day) was restricted to a maximum of 90% of ad libitum intake. Population of total bacteria, cellulolytic bacteria and anaerobic fungi were linearly increased, whereas that of protozoa and total methanogens was linearly reduced with increasing isobutyrate supplementation. Real-time PCR quantification of population of Ruminococcus albus, Ruminococcus flavefaciens, Butyrivibrio fibrisolvens and Fibrobacter succinogenes was linearly increased with increasing isobutyrate supplementation. Activities of carboxymethyl cellulase, xylanase and β-glucosidase were linearly increased, whereas that of protease was linearly reduced. Methane production was linearly decreased with increasing isobutyrate supplementation. Effective degradabilities of cellulose and hemicellulose of corn stover were linearly increased, whereas that of crude protein in diet was linearly decreased with increasing isobutyrate supplementation. The present results indicate that isobutyrate supplemented improved microflora, rumen enzyme activities and methane emissions in steers. It was suggested that the isobutyrate stimulated the digestive micro-organisms or enzymes in a dose-dependent manner. In the experimental conditions of this trial, the optimum isobutyrate dose was approximately 16.8 g isobutyrate per steer per day.

A simple sample preparation approach based on hydrophilic solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry for determination of endogenous cytokinins

Cytokinins (CKs), a vital family of phytohormones, play important roles in the regulation of shoot and root development. However, the quantification of CKs in plant samples is frequently affected by the complex plant matrix. In the current study, we developed a simple, rapid and efficient hydrophilic interaction chromatography-solid phase extraction (HILIC-SPE) method for CKs purification. CKs were extracted by acetonitrile (ACN) followed by HILIC-SPE (silica as sorbents) purification. The extraction solution of plant samples could be directly applied to HILIC-SPE without solvent evaporation step, which simplified the analysis process. Moreover, with HILIC chromatographic retention mechanism, the hydrophobic co-extracted impurities were efficiently removed. Subsequently, CKs were separated by RPLC, orthogonal to the HILIC pretreatment process, and detected by tandem mass spectrometry. The method exhibits high specificity and recovery yield (>77.0%). Good linearities were obtained for all eight CKs ranging from 0.002 to 100ngmL(-1) with correlation coefficients (r) higher than 0.9927. The limits of detection (LODs, signal/noise=5) for the CKs were between 1.0 and 12.4pgmL(-1). Reproducibility of the method was evaluated by intra-day and inter-day measurements and the results showed that relative standard deviations (RSDs) were less than 10.5%. Employing this method, we successfully quantified six CKs in 20mg Oryza sativa leaves and the method was also successfully applied to Brassica napus (flower and leaves).

Determination of 5-hydroxymethylfurfural using derivatization combined with polymer monolith microextraction by high-performance liquid chromatography

A simple and sensitive method for the determination of 5-hydroxymethylfurfural (HMF) in coffee, honey, beer, Coke, and urine by high-performance liquid chromatography (HPLC) is presented. This method is based on the formation of the 2,4-dinitrophenylhydrazone of HMF and subsequent polymer monolith microextraction (PMME) of this derivative. A poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-co-EGDMA) monolithic capillary column was selected as the extraction medium. Several parameters affecting the derivatization of HMF with 2,4-dinitrophenylhydrazine (DNPH) followed by extraction of the derivative were optimized. The procedure is simple and offers high sensitivity and specificity since the derivative of HMF is well preconcentrated by PMME with poly(MAA-co-EGDMA) monolith and well separated from the other components of the samples under examination. The recoveries in coffee, honey, beer, Coke, and urine samples were in the range of 83.9-110.8% spiked at different levels with HMF. The inter- and intraday precisions were less than 10%. The LOD (S/N = 3) and LOQ (S/N = 10) for HMF were 1.0 ng/mL and 3.4 ng/mL, respectively.

Preparation of pH-responsive stationary phase for reversed-phase liquid chromatography and hydrophilic interaction chromatography

Novel pH-responsive polymer-grafted silica was successfully synthesized through the radical "grafting from" polymerization on azo initiator-immobilized silica. The immobilization of azo initiator onto the silica surface was achieved by the reaction of surface amino groups with 4,4'-azobis(4-cyanovaleric acid chloride). The polymer-grafted silica was prepared by stirring suspension of the azo initiator-immobilized silica in anhydrous dioxane containing acrylic acid (AAc) and butyl acrylate (BA). The resulting polymer-grafted silica was demonstrated to be pH responsive to hydrophobic/hydrophilic property by reversed-phase liquid chromatography (RPLC) and hydrophilic interaction chromatography (HILIC). In RPLC mode, the retention of aromatic compounds decreased with the increase in the pH of mobile phase. However, the opposite result was obtained in HILIC mode; the retention of soybean isoflavones was stronger with the mobile phase at higher pH. Finally, the separations of sulfonamides and soybean isoflavones were carried out in RPLC mode and the separation of some nucleotides was achieved in HILIC mode.

HPLC separation of fullerenes on two charge-transfer stationary phases

Two charge-transfer stationary phases were prepared by immobilizing p-nitrobenzoic acid and naphthyl acetic acid onto silica. The nitrophenyl moiety and the naphthyl moiety were grafted to silica gel through the spacer of aminoalkyl silanes. The HPLC separation of C60, C70, and higher fullerenes on the new stationary phases was also studied. The influence of mobile phase and column temperature on the separation of C60 and C70 was examined, respectively. The retentions of C60 and C70 on the two stationary phases increased with decreasing toluene content in the mobile phase or with increasing column temperature. Higher fullerenes can be separated well using toluene as the mobile phase on the stationary phase of p-nitrobenzoic acid-bonded silica.

Perphenylcarbamoylated β-cyclodextrin bonded-silica particles as chiral stationary phase for enantioseparation by pressure-assisted capillary electrochromatography

Perphenylcarbamoylated beta-cyclodextrin bonded-silica particles (5 microm) were packed into 75-mum fused-silica capillaries, and used for the enantiomer separation of neutral and basic solutes by pressure-assisted capillary electrochromatography. Triethylammonium acetate and phosphate buffer were employed as the BGEs. A cathodic EOF was observed with these two BGEs. Seven chiral analytes were successfully resolved into their enantiomers under optimized conditions, and five of them could be baseline-separated within 12 min due to their high electrophoretic mobility. Better results were achieved with phosphate buffer as the BGE. The effects of organic content and pH on the enantioseparation were also investigated.

Preparation of pyrenebutyric acid bonded silica stationary phases for the application to the separation of fullerenes

A novel immobilization method was proposed for the preparation of pyrenebutyric acid-bonded silica (PYB-silica) stationary phases. The pyrene moiety was grafted to silica gel through spacers of aminoalkyl silanes. The HPLC separation of C60, C70 and higher fullerenes on the new pyrenebutyric acid-bonded silica stationary phases was also studied. Based on the temperature effect, the intermolecular interaction between stationary phases and solutes and the retention mechanism were discussed. The results of column loading capacity test demonstrated the potential for the separation of fullerenes in large amounts on the PYB-silica stationary phases.

Preparation of a sulfonated fused-silica capillary and its application in capillary electrophoresis and electrochromatography

In the present paper, two new methods, sol-gel and chemical bonding methods, were proposed for preparation of sulfonated fused-silica capillaries. In the sol-gel method, a fused-silica capillary was coated with the sol solution obtained by hydrolysis of 3-mercaptopropyltrimethoxysilane (MPTS) and tetramethoxysilane, and followed by age; while in the chemical bonding method, a capillary was chemically bonded directly with MPTS. Then, both the resulting capillaries were oxidized with an aqueous solution of hydrogen peroxide solution (H2O2) (30%, m/m) to obtain the sulfonated capillaries. The electroosmotic flow (EOF) for the sulfonated capillaries was found to remain almost constant within the studied pH range, and greater than that of the uncoated capillary. However, the coating efficiency of the capillary prepared by chemical bonding method was higher than that by sol-gel method, by comparing their magnitude of the EOF, the degree of disguise of the silanol and reproducibility of preparation procedure. The effects of the electrolyte's concentration and the content of methanol (MeOH) on the EOF were also studied. Especially, the study of the apparent pH (pH*) on the EOF in a water-MeOH system was reported. Finally, capillary electrophoretic separation of seven organic acids was achieved within 6.5 min under optimal condition using the chemically bonded sulfonated capillary. Moreover, separation of four alkaloids on the sulfonated capillary was compared with that on uncoated capillary in different conditions. Ion-exchange mechanism was found to play a key role for separation of these four basic analytes on the sulfonated capillary.

Nonaqueous capillary electrophoresis using a titania-coated capillary

In this work, an ordered mesoporous titania film was introduced to coat a capillary by means of the sol-gel technique. Its electroosmotic flow (EOF) property was investigated in a variety of nonaqueous media (methanol, formamide and N,N'-dimethylformamide and mixtures of methanol and acetonitrile). The titania-coated capillary exhibited a distinctive EOF behavior, the direction and magnitude of which were strongly dependent on various parameters such as the solvent composition, apparent pH (pH*) and the electrolytes. The nonaqueous capillary electrophoresis separation of several alkaloids was investigated in the positively charged titania-coated capillary. Comparison of separation between coated and uncoated capillaries under optimal nonaqueous conditions was also carried out.

The potential role of Staphylococcal enterotoxin B in rats with postburn Staphylococcus aureus sepsis

Staphylococcal enterotoxin B (SEB) is an important member of the superantigen family, which exerts a number of pathological effects in the human, as well as susceptible animals. The present study was conducted to observe the time course and tissue distribution of SEB in postburn Staphylococcus aureus infection; meanwhile, the relationship between SEB and multiple organ dysfunction was also studied. Eighty-six male Wistar rats were randomly divided into four groups as follows: normal control group (n = 10); scald control group (n = 10); postburn sepsis group (n = 50) in which rats inflicted with 20% total body surface area (TBSA) III degrees scald followed by SEB-producing S. aureus challenge were further divided into 0.5-, 2-, 6-, 12-, and 24-h subgroups, with 10 rats in each subgroup; and SEB monoclonal antibody (MAb) treatment group (n = 16) in which a dose of 4 mg/kg SEB MAb was given intravenously just before S. aureus challenge, and the rats were further divided into 2- and 6-h subgroups. It was found that after thermal injury combined with S. aureus infection, SEB was widely distributed to the liver, kidneys, lungs, and heart, exacerbating the pathophysiology of multiple organ dysfunction induced by postburn sepsis. At the same time, the gene and protein expressions of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) were also markedly upregulated in various tissues. Early treatment with SEB-specific MAb-MAb2D(1)-could markedly decrease SEB levels in plasma as well as in various tissues, and could significantly reduce the 6-h mortality rate (17.64% [3/17] vs. 55.6% [20/36], P = 0.02). These data suggested that neutralization of SEB is effective in ameliorating S. aureus sepsis and subsequent multiple organ damage, which might be attributed to its inhibitory effect on inflammatory mediator formation.

Significance of biopterin induction in rats with postburn Staphylococcus aureus sepsis

It has been demonstrated that biopterin, an essential cofactor of nitric oxide synthase (NOS), plays an important role in the pathogenesis of endotoxin-induced shock, yet its biological significance in gram-positive sepsis remains unclear. In this study, we adopted a rat model of postburn Staphylococcus aureus sepsis to investigate the potential role of biopterin in the pathogenesis of gram-positive sepsis. Wistar rats were inflicted with a 20% total body surface area (TBSA) full-thickness scald injury followed by S. aureus challenge, and then guanosine triphosphate-cyclohydrolase I (GTP-CHI) mRNA expression and biopterin levels in liver, kidneys, lungs, and heart were determined. We found that after S. aureus challenge, GTP-CHI gene expressions and biopterin levels were markedly upregulated in various tissues. Meanwhile, multiple organ dysfunction was induced by S. aureus challenge. It was shown that cardiac GTP-CHI mRNA expression and renal BH(4) levels were positively correlated with MB isoenzyme of creatine kinase (CK-MB) and creatinine (r = 0.892, P = 0.0012 and r = 0.9423, P = 0.0015, respectively). These results suggested that thermal injury combined with S. aureus challenge could induce de novo biosynthesis of biopterin, which might play a role in the development of multiple organ dysfunction syndrome secondary to postburn sepsis.

The mRNA expression patterns of tumor necrosis factor-α and TNFR-I in some vital organs after thermal injury

AIM: To investigate changes of tumor necrosis factor-α (TNF-α) and TNFR-I expression in vital organs and their significance in the pathogenesis of multiple organ damage associated with endogenous endotoxin following major burns.

METHODS: Wistar rats subjected to a 35% full-thickness scald injury were sacrificed at 12 h, 24 h, 48 h, and 72 h postburn, respectively. Meanwhile, eight rats were taken as normal controls. Tissue samples from liver, spleen, kidney, lung and intestine were collected to assay tissue endotoxin levels and measure TNF-α and TNFR-I expression. In addition, blood samples were obtained for the determination of organ function parameters.

RESULTS: Endotoxin levels in liver, spleen and lung increased markedly after thermal injury, with the highest level in liver. The gene expression of TNF-α in liver, lung and kidney was up-regulated after thermal injury, while the TNFR-I mRNA expression in liver, lung, kidney and intestine was shown decreased throughout the observation period. Thus, the mRNA expression ratio of TNF-α to TNFR-I was significantly increased postburn, particularly in pulmonary tissue (67-fold). In addition, the significant correlations between the expression of TNFR-I or the expression ratio of TNF-α/TNFR mRNA in liver tissue and serum aspartate aminotransferase levels were noted (P < 0.05-0.01). Similar results were also obtained between pulmonary TNF-α mRNA expression and myeloperoxidase activities (P < 0.01), whereas there was a highly negative correlation between levels of renal TNFR-I mRNA expression and serum creatinine.

CONCLUSION: Burn injury could result in the translocation of gut-derived endotoxin that was mainly distributed in the liver, spleen and lung. The translocated endotoxin then made the expression of TNF-α and TNFR-I mRNA up-regulated and down-regulated respectively in various organs, which might be involved in the pathogenesis of multiple organ damage following burns.

Effect of 2,4-diamino-6-hydroxy-pyrimidine on postburn Staphylococcus aureus sepsis in rats

OBJECTIVE

Guanosine triphosphate-cyclohydrolase I (GTP-CHI) is the first and rate-limiting enzyme for the de novo biosynthesis of biopterin. The objective of present study was to observe the effect of 2,4-diamino-6-hydroxy-pyrimidine (DAHP), an inhibitor of GTP-CHI, on the development of postburn Staphylococcus aureus sepsis.

DESIGN

A prospective, controlled animal study.

SETTING

A research laboratory in a hospital.

SUBJECTS

Male Wistar rats.

INTERVENTIONS

Fifty-six male Wistar rats were randomly divided into four groups as follows: normal control group (n = 10), scald control group (n = 10), postburn sepsis group (n = 20), and DAHP treatment group (n = 16). In the scald control group, rats were subjected to a 20% total body surface area third-degree scald injury and then were killed at 24 hrs. In the postburn sepsis group (n = 20), rats were inflicted with 20% total body surface area third-degree scald followed by Staphylococcus aureus challenge, and they were further divided into 2- and 6-hr groups. In the DAHP treatment group (n = 16), animals were intraperitoneally injected with a dose of 1 g/kg DAHP before Staphylococcus aureus challenge and then were further divided into 2- and 6-hr groups. Tissue samples from liver, kidneys, lungs, and heart were collected to determine GTP-CHI, inducible nitric oxide synthase, and tumor necrosis factor-alpha messenger RNA expression. Meanwhile, biopterin and nitric oxide concentrations in these tissues were also measured.

MEASUREMENTS AND MAIN RESULTS

After the scald injury followed by Staphylococcus aureus challenge, GTP-CHI messenger RNA expression and biopterin concentrations were significantly elevated in various tissues such as liver, heart, kidneys, and lungs, as were the values of inducible nitric oxide synthase messenger RNA expression and nitric oxide formation (p <.01). Pretreatment with DAHP significantly reduced GTP-CHI/biopterin induction (p <.05-.01), and the up-regulation of inducible nitric oxide synthase/nitric oxide was also suppressed. Furthermore, DAHP administration inhibited the gene expression of tumor necrosis factor-alpha. Two hours after septic challenge, tumor necrosis factor-alpha messenger RNA expression in liver, kidneys, and lungs in the DAHP-treated group was 35.7%, 37.3%, and 33.0% of that in the postburn septic group, respectively. Additionally, in animals without DAHP treatment, the 6-hr mortality rate was 55.6% (20 of 36), whereas it was only 25.0% in DAHP-treated animals (4 of 16, p =.08).

CONCLUSIONS

Early treatment with DAHP might be a potential strategy to prevent the development of postburn Staphylococcal sepsis, which appears to be associated with down-regulation of biopterin and nitric oxide formation by DAHP.

Lipopolysaccharide-binding protein and lipopolysaccharide receptor CD14 gene expression after thermal injury and its potential mechanism(s)

BACKGROUND

We hypothesized that lipopolysaccharide-binding protein (LBP) and lipopolysaccharide receptor CD14 would present a pair of key molecules in pathophysiologic alterations induced by low concentrations of endotoxin after trauma. The aim of this study was to investigate the relationship between endotoxin translocation and tissue LBP/CD14 messenger ribonucleic acid (mRNA) expression after burn injury, and to define the potential role of LBP/CD14 in mediating inflammatory mediator induction, as well as the pathogenesis of organ damage.

METHODS

Wistar rats were subjected to a 35% full-thickness scald injury, and tissue samples from liver, kidneys, lungs, and intestine were collected to measure LBP/CD14 and tumor necrosis factor-alpha (TNF-alpha) mRNA expression. Peritoneal macrophages were harvested by peritoneal lavage to determine CD14 mRNA expression.

RESULTS

It was found that endotoxin levels in liver, spleen, and lung increased markedly after thermal injury, with the highest level in liver. Both tissue LBP and CD14 mRNA expression increased markedly after burns, peaking at 12 hours, and then decreasing gradually. At 48 hours, LBP gene expression had a tendency to the baseline level, whereas CD14 mRNA expression increased again. Likewise, CD14 mRNA levels were up-regulated markedly in peritoneal macrophages. Conversely, gene expression of TNF-alpha in tissues elevated markedly after acute insults. There were positive correlations between lipopolysaccharide levels and LBP/CD14 mRNA as well as TNF-alpha mRNA expression in tissues. Similar results were also obtained between CD14, TNF-alpha mRNA expression in liver tissue and liver function parameters, and between pulmonary TNF-alpha mRNA and myeloperoxidase activities (p < 0.01).

CONCLUSION

Thermal injury per se can markedly up-regulate both LBP and CD14 gene expression in various organs. Excessive LBP and CD14 mRNA expression might be associated with enhanced synthesis and release of TNF-alpha stimulated by endotoxin translocation after major burns.

The significance of changes in high mobility group-1 protein mRNA expression in rats after thermal injury

There has been a widespread impression that tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) mediate the toxicity of high doses of lipopolysaccharide (LPS, endotoxin) and are key factors in septic shock. However, the clinical efficacy of treatment with antagonists of TNF-alpha and IL-1beta is still controversial, suggesting that mediators other than TNF-alpha and IL-1beta might contribute causally to endotoxin-induced death. Recent studies implicated high mobility group-1 (HMG-1) protein as a late mediator of endotoxin lethality in mice. However, the role of HMG-1 in mediating multiple organ damage-associating trauma has not been studied. This study was designed to investigate changes in HMG-1 gene expression in vital organs, and its potential role in mediating multiple organ damage following major burns. Wistar rats were subjected to a 35 percent full-thickness thermal injury, and randomly divided into three groups as follows: normal controls (n = 7), thermal injury (n = 24), and recombinant bactericidal/permeability-increasing protein (rBPI21) treatment (n = 12). Tissue samples from liver and lungs were collected to measure tissue endotoxin levels and HMG-1 mRNA expression. In addition, blood samples were obtained for measurement of organ function parameters. Our data demonstrated a significant increase in HMG-1 gene expression in tissues at 24 h postburn, which remained markedly elevated up to 72 h after thermal injury (P< 0.05-0.01). Treatment with rBPI21 could significantly decrease tissue HMG-1 mRNA expression in the liver and lung (P < 0.01). In addition, there were high positive correlations between hepatic HMG-1 mRNA and serum aminoleucine transferase (ALT) and aspartate aminotransferase (AST) levels, and also between pulmonary HMG-1 mRNA and myeloperoxidase activities (P < 0.05-0.01). Taken together, these findings indicate that thermal injury per se can markedly enhance HMG-1 gene expression in various organs. Up-regulation of HMG-1 expression may be involved in the pathogenesis of endogenous endotoxin-mediated multiple organ damage secondary to major burns.

Effect of recombinant bactericidal/permeability-increasing protein on endotoxin translocation and lipopolysaccharide-binding protein/CD14 expression in rats after thermal injury

OBJECTIVE

To investigate the potential mechanisms underlying the in vivo effect of recombinant bactericidal/permeability-increasing protein (rBPI21) on endogenous bacteria or endotoxin translocation and lipopolysaccharide-binding protein/CD14 expression secondary to thermal injury.

DESIGN

Prospective, randomized, controlled animal study.

SETTING

College hospital animal research laboratory.

SUBJECTS

Thirty-six male Wistar rats weighing 250-300 g.

INTERVENTIONS

The rats were anesthetized, and a 35% total body surface area full-thickness burn was created. Animals were randomized to receive treatment with either rBPI21 or the control protein (albumin). rBPI21 (2 mg/kg body wt, BPI group) or a protein control preparation (burn group) in the same dose was administered in an intravenous bolus at 30 mins and 4 hrs after thermal injury. All animals were killed at 12 and 24 hrs postburn (six to ten rats for each interval). In addition, eight rats were taken as normal controls.

MEASUREMENT AND MAIN RESULTS

Our data showed that treatment with rBPI21 was effective in preventing endotoxin translocation secondary to severe burns. Meanwhile, tissue lipopolysaccharide-binding protein, CD14, and tumor necrosis factor-alpha mRNA expression in various organs were inhibited markedly by rBPI21 secondary to acute insults (p <.05-.01). Furthermore, significant reduction in serum aminoleucine transferase concentrations and elevation in intestinal diamine oxidase activities in the rBPI21-treated group were found compared with controls (p <.05-.01).

CONCLUSIONS

These findings indicate that endotoxin accumulated in local sites after thermal injury can markedly up-regulate lipopolysaccharide-binding protein/CD14 and tumor necrosis factor-alpha mRNA expression in various organs. Meanwhile, up-regulation of lipopolysaccharide-binding protein/CD14 expression would be the major molecular mechanism of increasing sensitivity to endogenous endotoxin response after burns. Early treatment with rBPI21may be effective in attenuating multiple organ damage resulting from gut-origin endotoxin translocation. This might be associated with the down-regulation effects of tissue lipopolysaccharide-binding protein and CD14 gene expression by the use of rBPI21.