Nasal dissemination of a single-clone IgH-rearranged conjunctival MALT lymphoma through the nasolacrimal duct: A case report.

The aim of the present study was to report a rare case of single-clone, immunoglobulin heavy chain (IgH)-rearranged mucosa-associated lymphoid tissue (MALT) lymphoma in the conjunctiva, with nasal cavity dissemination through the nasolacrimal duct. A 24-year-old female was diagnosed with MALT lymphoma of the nasal cavity at the Department of Otolaryngology, Wan Fang Medical Center, Taipei Medical University (Tapei, Taiwan) in October 2008. A biopsy of the relapsing conjunctival lesion revealed a MALT lymphoma by pathological staining, while a single-clone, IgH-rearranged tumor lesion in the nasal cavity and conjunctiva was confirmed using continuous sinus computed tomography scans and polymerase chain reaction. Tumor lesions were negative for Helicobacter pylori and Chlamydia infection, but exhibited bilateral neck lymph node dissemination. A combination of radiation therapy (a total dosage of 46.8 Gray, in two phases covering the left lacrimal sac, nasal cavity and bilateral neck region) and topical ciprofloxacin plus steroid (0.3% ciprofloxacin 4 times a day and betamethasone eye ointment before sleep for 1 month) was provided as an effective therapeutic strategy, and no recurrence was found in the next 3 years. The nasolacrimal duct serves as a channel for conjunctival tumor spreading and is easily neglected. IgH-involved translocation in MALT lymphoma is a factor in the progression of the disease, and aggressive combination therapy is essential for a high-risk, disseminated IgH-rearranged MALT lymphoma.

Graphene matrix for signal enhancement in ambient plasma assisted laser desorption ionization mass spectrometry.

In this work, the signal intensity of ambient plasma assisted laser desorption ionization mass spectrometry (PALDI-MS) was significantly increased with graphene as matrix. The graphene functions as a substrate to trap analytes, absorb energy from the visible laser irradiation and transfer energy to the analytes to facilitate the laser desorption process. The desorbed analytes are further ionized by helium plasma and analyzed by MS. Compared with a traditional organic matrix, α-cyano-4-hydroxycinnamic acid (CHCA), graphene exhibited much higher desorption efficiency for most of the compounds benefitting from the strong optical absorption at 532nm. The performance has been confirmed by the facile analysis of more than forty compounds with various structures. Additionally, this method was successfully applied to distinguish three kinds of Chinese tea leaves by detecting the endogenous caffeine and theanine, which proved the utility, facility and convenience of this method for rapid screening of main components in real samples.

[Clinical value of seminal paraoxonase-1 activity evaluation in the diagnosis of male infertility].

OBJECTIVE: To investigate the changes in seminal paraoxonase-1 (PON-1) activity in infertile male patients and assess the clinical value of seminal PON-1 examination in the diagnosis of male infertility. METHODS: Seminal PON-1 activity was detected by spectrophotometric method in the semen samples from 270 infertile male patients and 50 health fertile males (control), and the semen parameters were analyzed using a computer-assisted semen analysis system. RESULTS: In the male infertility group, seminal PON-1 activity was 1.22∓0.76 U/L in the patients with normal semen parameters and 0.64∓0.54 in the patients with abnormal semen parameters, both significantly lower than that of the control group (3.17∓0.89 U/L, P<0.01). In patients with asthenospermia, the declined sperm motility was associated with decreased seminal PON-1 activity, which showed significant differences between patients with mild, moderate, and severe asthenospermia. Seminal PON-1 activity was positively correlated with the percentage of sperm viability (P<0.01), but inversely with the percentage of morphologically abnormal sperm (P<0.01). According to ROC curves, the area of seminal PON-1 activity under the curve was 0.907, showing a statistical significance (P<0.01). CONCLUSION: The detection of seminal PON-1 activity can provide a laboratory evidence for the diagnosis of male infertility.

Membrane-based continuous remover of trifluoroacetic acid in mobile phase for LC-ESI-MS analysis of small molecules and proteins.

We developed a "continuous" trifluoroacetic acid (TFA) remover based on electrodialysis with bipolar membrane for online coupling of liquid chromatography (LC) and electrospray ionization mass spectrometry (ESI-MS) using TFA containing mobile phase. With the TFA remover as an interface, the TFA anion in the mobile phase was removed based on electrodialysis mechanism, and meanwhile, the anion exchange membrane was self-regenerated by the hydroxide ions produced by the bipolar membrane. So the remover could continuously work without any additional regeneration process. The established LC-TFA remover-MS system has been successfully applied for the qualitative and quantitative analysis of small molecules as well as proteins.

Ion-exchange-membrane-based enzyme micro-reactor coupled online with liquid chromatography-mass spectrometry for protein analysis.

In this article, we developed a membrane-based enzyme micro-reactor by directly using commercial polystyrene-divinylbenzene cation-exchange membrane as the support for trypsin immobilization via electrostatic and hydrophobic interactions and successfully applied it for protein digestion. The construction of the reactor can be simply achieved by continuously pumping trypsin solution through the reactor for only 2 min, which was much faster than the other enzyme immobilization methods. In addition, the membrane reactor could be rapidly regenerated within 35 min, resulting in a "new" reactor for the digestion of every protein sample, completely eliminating the cross-interference of different protein samples. The amount and the activity of immobilized trypsin were measured, and the repeatability of the reactor was tested, with an RSD of 3.2% for the sequence coverage of cytochrome c in ten digestion replicates. An integrated platform for protein analysis, including online protein digestion and peptide separation and detection, was established by coupling the membrane enzyme reactor with liquid chromatography-quadrupole time-of-flight mass spectrometry. The performance of the platform was evaluated using cytochrome c, myoglobin, and bovine serum albumin, showing that even in the short digestion time of several seconds the obtained sequence coverages was comparable to or higher than that with in-solution digestion. The system was also successfully used for the analysis of proteins from yeast cell lysate.

Determination of dissociation constants of aristolochic acid I and II by capillary electrophoresis with carboxymethyl chitosan-coated capillary.

Aristolochic acid-I and aristolochic acid-II have been proved to be the main bioactive and toxic component in Aristolochia plants. As a result, the determination of their dissociation constants, which are important property parameters for weak acids, is highly desired for related pharmacological and toxicological studies. In this work, the dissociation constant values of aristolochic acid-I and aristolochic acid-II were determined by capillary electrophoresis using carboxymethyl chitosan-coated capillary, based on their electrophoretic mobilities by using nonlinear regression as well as linear regression, showing that the two models give comparable results. The data were also compared with those obtained by capillary electrophoresis with polybrene-coated capillary, and no conspicuous difference was observed. The correlation coefficients were all higher than 0.998 for both linear and nonlinear regression model. The pKa values were found to be 3.3±0.1 for aristolochic acid-I and 3.2±0.1 for aristolochic acid-II.

Improvement of reproducibility and sensitivity of CE analysis by using the capillary coated dynamically with carboxymethyl chitosan.

Analysis reproducibility and detection sensitivity of capillary electrophoresis (CE) are often questioned by applied scientists, which has hindered its application as a routine method. To address these issues, a simple, precise, and reproducible dynamic coating method was developed by applying carboxymethyl chitosan (CMC) dynamic coating on fused silica capillary. The proposed coating was accomplished by simply rinsing the capillary with CMC solution for 1 min in between runs, with no regeneration procedure or buffer additives needed. Electroosmotic flow could be well controlled by adjusting the pH of background electrolyte, and the adsorption of analytes onto the capillary inner wall was effectively eliminated. The main parameters of the coating condition were optimized, and extensive applications of these CMC-dynamically coated capillaries in CE separations were then firmly confirmed. By using proteins, aristolochic acids, and inorganic anions as model analytes, the coating showed a good stability, high reproducibility, as well as improved sensitivity. Baseline separations could be obtained with high efficiency. The reduced adsorption was impressively effective for basic proteins, with an average plate number of 90,000/m for each protein, apart from the good resolution on the chromatogram. A high sensitive detection of α-lactalbumin was achieved with a limit of detection (S/N = 3) of 3.5 nM, and the number of theoretical plates was as high as 1,200,000/m. In addition, the combination of the CMC coating with nonaqueous CE and CE-mass spectrometry proved to be practical. All results showed that the CMC-dynamically coated capillary has special properties and obvious superiority over the uncoated ones for CE analysis.

CE-MS analysis of heroin and its basic impurities using a charged polymer-protected gold nanoparticle-coated capillary.

The first application of charged polymer-protected gold nanoparticles (Au NPs) as semi-permanent capillary coating in CE-MS was presented. Poly(diallyldimethylammonium chloride) (PDDA) was the only reducing and stabilizing agent for Au NPs preparation. Stable and repeatable coating with good tolerance to 0.1 M HCl, methanol, and ACN was obtained via a simple rinsing procedure. Au NPs enhanced the coating stability toward flushing by methanol, improved the run-to-run and capillary-to-capillary repeatabilities, and improved the separation efficiency of heroin and its basic impurities for tracing geographical origins of illicit samples. Baseline resolution of eight heroin-related alkaloids was achieved on the PDDA-protected Au NPs-coated capillary under the optimum conditions: 120 mM ammonium acetate (pH 5.2) with addition of 13% methanol, separation temperature 20 degrees C, applied voltage -20 kV, and capillary effective length 60.0 cm. CE-MS analysis with run-to-run RSDs (n=5) of migration time in the range of 0.43-0.62% and RSDs (n=5) of peak area in the range of 1.49-4.68% was obtained. The established CE-MS method would offer sensitive detection and confident identification of heroin and related compounds and provide an alternative to LC-MS and GC-MS for illicit drug control.

Chiral separation of raltitrexed by cyclodextrin-modified micellar electrokinetic chromatography.

A rapid and effective method was developed for the chiral separation of raltitrexed (RD) enantiomers by carboxymethyl-beta-cyclodextrin (CM-beta-CD)-modified micellar electrokinetic chromatography (MEKC). Optimization of conditions including the type and concentration of the chiral selector, concentration of sodium dodecyl sulfate (SDS), pH and concentration of the background electrolyte (BGE), capillary temperature, and applied voltage was investigated. The enantiomers of raltitrexed could be separated with satisfactory resolution and linear response by using 75 mM Tris-phosphate at pH 8.0 containing 30 mM SDS and 8 mM CM-beta-CD as buffer system. Furthermore, the usefulness of this method was demonstrated in a purity test of a real synthetic drug sample.

[Recent advances in the detection of recombinant human erythropoiesis and its analogs in doping control].

Recombinant human erythropoietin (rhEPO) is one of hormone dopings. In the recent years, it has been always misused in endurance competition sports. It is extremely difficult to discriminate between the natural endogenous erythropoietin (EPO) and recombinant exogenous hormone because they have identical amino acid sequences, and EPO has a relatively short half-life and very low concentration in blood or urine. In this paper, the research progress on the analysis and detection of rhEPO and its analogs by direct and indirect methods are reviewed. Future direction and prospects of the detection of rhEPO in doping control are discussed based on the research of our group.

Fragmentation pathways of heroin-related alkaloids revealed by ion trap and quadrupole time-of-flight tandem mass spectrometry.

The electrospray ionization (ESI) ion trap and quadrupole time-of-flight (QqToF) mass spectra of heroin and seven related alkaloids, i.e., morphine, codeine, O-6-monoacetylmorphine (6-MAM), thebaine, acetylcodeine, papaverine and narcotine, have been extensively investigated in this work. The ESI mass spectrometric fragmentation pathways of protonated 6-MAM, heroin, acetylcodeine, and thebaine were comprehensively elucidated for the first time with the aid of high-resolution mass spectrometry. It was found that cleavage of the piperidine ring was the featured fragmentation route of six of the compounds, although not of papaverine and narcotine. In addition, a simple high-performance liquid chromatography (HPLC)-based separation method gave baseline resolution of all eight components. This study could play an important role in the screening for these alkaloids in different matrices by HPLC coupled to tandem mass spectrometry (MS/MS).

[Some advances and prospects in fingerprintings of traditional Chinese medicines].

The quality control standards are the key points in the modernization of traditional Chinese medicines (TCM), and in recent years, the fingerprinting techniques play an increasingly important role, including fingerprintings based on gas chromatography, liquid chromatography, capillary electrophoresis, spectroscopic methods, and so on. Some advances in this area in the past few years are reviewed and some prospects are discussed in this article.

Online concentration of aristolochic acid I and II in Chinese medicine preparations by micellar electrokinetic chromatography.

In this study, an online concentration method in micellar electrokinetic chromatography (MEKC) applying field-enhanced sample injection (FESI) mode was developed for the detection of aristolochic acids (AAs) in Chinese medicine preparations. AA-I and AA-II were baseline separated with high separation efficiency, and 100-fold enhancement of the detection sensitivity was achieved compared with those obtained from normal capillary zone electrophoresis (CZE) or simple MEKC method. The proposed method was successfully applied for the determination of AAs in Chinese medicine preparations.

Rapid determination of C12-C26 non-derivatized fatty acids in human serum by fast gas chromatography.

The concentration of long-chain fatty acids (LCFAs) in human serum is closely related to human health. It is therefore important to develop a fast, low-cost, efficient method for their determination. In this study, by using fast temperature programming and micro-bore short capillary columns, a fast gas chromatography method was developed for the direct analysis of non-derivatized LCFAs including n-dodecanoic acid to n-hexacosanic acid (C12:0-C26:0, even numbers only), linoleic acid (C18:2), oleic acid (C18:1), and erucic acid (C22:1) within 4.0 min. Method optimization including extraction and separation conditions is considered, and the analysis of real serum samples is presented. The results show that ten LCFAs were well separated with sufficient resolution, and the detection limit was in the range of 2.8-9.6 microg/mL. The reproducibility (RSD) for both intra-day and inter-day determination was always less than 15%, and the recoveries for these LCFAs were from 63.1 to 97.0%.

[Determination of underivatized long-chain fatty acids in edible oils by fast gas chromatography].

A fast gas chromatography (GC) method with short micro-bore capillary column was developed for the determination of underivatized long-chain fatty acids (LCFAs) in edible oils. Baseline separation of eight kinds of LCFAs (dodecanoic acid, tetradecanoic acid, palmitic acid, oleic acid, stearic acid, eicosanic acid, erudcic acid, behenic acid) was achieved within 2 min with high resolution performance. The linear correlation coefficients for underivatized LCFAs were higher than 0. 988 and detection limits (at signal-to-noise of 3:1 ) were 2. 80 -9. 60 mg/L. The method is easy and low-cost and has the ability to achieve an accurate determination of the LCFAs in three edible oils.

A comparative study of micellar and microemulsion EKC for the analysis of benzoylurea insecticides and their analogs.

An investigation of the basic factors which govern the microemulsion EKC (MEEKC) and MEKC for the separation of four benzoylurea (BU) insecticides and their four analogs was carried out. In MEEKC, the separation of eight BU compounds was optimized by changing the microemulsion composition, such as concentration of SDS, octane, n-butanol, and isopropanol percentages, as well as capillary temperature. Separation optimization was also carried out for MEKC, showing that ACN and a high level of another additive gamma-CD were needed to achieve effective separation of these analytes. Although separation with baseline resolution was achieved by either MEEKC or MEKC methods, the separation selectivity resulting from the proposed MEEKC method was completely different from that of MEKC. In addition, analytical time in MEEKC was longer than that in MEKC, but in view of theoretical plate numbers, detection limits, and reproducibility, both methods were effective for the analysis of BU insecticides and their analogs.

Growth inhibitory effects of gastric cancer cells with an increase in S phase and alkaline phosphatase activity repression by aloe-emodin.

Aloe-emodin is a novel active compound found in the root and rhizome of Rheum palmatum. To investigate the effects and mechanisms of aloe-emodin on human gastric cancer, MGC-803 cells were treated with 2.5, 5, 10, 20 and 40 microM aloe-emodin for 1-5 d. The results showed that aloe-emodin inhibited the growth of cancer cells in a dose-dependent manner with an increase in S phase and in the proportion of cells cycling at a higher ploidy level (>G2/M). Moreover, the alkaline phosphatase (ALP) activity, an indicator of cell differentiation, was found decreased. This is one of the first to focus on the effect of ALP activity in human gastric carcinomas cells treated by aloe-emodin. These results indicate that aloe-emodin has a potential value for the treatment of gastric cancer and its mechanisms are by means of cell cycle interruption and induce differentiation.

Applications of nanomaterials in liquid chromatography: opportunities for separation with high efficiency and selectivity.

During recent decades, great efforts have been made to improve the chemical stability, selectivity, and separation efficiency of stationary phases in liquid chromatography. Significant progress has been achieved, especially after the introduction of nanomaterials into separation science. This review covers the applications of nanomaterials playing various roles in liquid chromatography. Future possibilities for developing nanomaterial-based stationary phases are also discussed.

Fragmentation study of hexanitrostilbene by ion trap multiple mass spectrometry and analysis by liquid chromatography/mass spectrometry.

The fragmentation pathways of three explosive compounds with similar structures, hexanitrostilbene (HNS), cyclotrimethylene trinitramine (RDX), and 2,4,6-trinitrotoluene (TNT), have been investigated by multiple mass spectrometry (MSn, n = 1, 2, 3) with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) sources. The electron capture mechanism for these compounds in negative ion APCI and ESI mode differs from the usual negative ion mechanism, deprotonation or addition of other species. This was shown for HNS and TNT, which both gave a [M]- anion but not a [M-H]- ion in APCI, and the [M]- anion of HNS was observed in ESI. The quantitative analysis of HNS was performed by liquid chromatography (LC)/ESI-MS, and the results obtained by the internal standard (ISTD) method were compared with those from the external standard (ESTD) method, demonstrating that both quantitation approaches are useful, with good sensitivity, reproducibility and linearity, and ESTD is preferable in routine applications.