Differential involvement of Th1 or Th17 cells in pathogenic autoimmune processes triggered by different TLR ligands (129.22)

We have previously shown that various TLR ligands are capable of converting naïve CD4 cells specific to hen egg lysozyme (HEL) to become effector cells that initiate inflammation in eyes of recipient mice expressing HEL in their lens. In addition, our data revealed that pertussis toxin (PTX) is superior to all other tested TLR ligands in this activity. Here, we examined the involvement of Th1 or Th17 cells in the pathogenic processes triggered by different TLR ligands. Using qPCR, we found that eyes of PTX-treated recipients expressed both IL-17 and IL-22 transcripts ~15, ~10 and ~6 fold higher than eyes from recipients treated with poly (I:C) (PIC), CpG oligodeoxynucleotide (CpG), or LPS, respectively. Although inflamed eyes from PTX-treated mice also expressed IFN-γ more than eyes of the other groups, the differences were markedly lower: ~5, ~ 4 and ~ 4 fold, respectively. Furthermore, intracellular staining of infiltrating cells collected from the inflamed eyes revealed that cells stained for IL-17 were ~5 fold higher than cells stained for IFN-γ in eyes of PTX-treated mice, ~2 fold higher in eyes of the LPS group, approximately equal in the PIC group, but ~2 fold lower in the CPG group.

Polarized TCR-Transgenic Th17 Cells Resemble Th1 Cells in Their Capacity to Adoptively Transfer Ocular Inflammation, but Differ in Other Biological Activities (130.44)

The role of Th17 lymphocytes in immunopathogenic processes has been well established, although little is known about their mode of action and other biological activities. Here, we prepared polarized populations of TCR-transgenic (Tg) Th1 or Th17 cells specific against hen egg lysozyme (HEL) and compared each line for its capacity to adoptively transfer ocular inflammation into Tg recipients expressing lens-associated HEL, as well as for other biological activities. To establish each line, naive CD4+ cells were cultured in the presence of HEL and "cocktails" containing cytokines and antibodies known to drive polarization to Th1 or Th17. Successful polarization of Th1 and Th17 lines was confirmed by intracellular expression and release into the culture medium of IFNγ or IL17, respectively. Surface marker expression was determined by flow cytometry of cultured cells. Recipient eyes were examined histologically. Polarized cells were also tested for their capacity to induce splenomegaly in recipient mice (Chen et al JI 2006). Our results showed that Th1 and Th17 cells were similarly immunopathogenic, transferring ocular inflammation at doses as low as 0.2 million. Histological comparison of eyes from each group, however, revealed slight although discernible differences between Th1 and Th17 recipients. The two populations also differed in their expression of surface markers, particularly in CD49d and CD62L. Finally, Th17 cells were remarkably less efficient than Th1 cells in their capacity to induce splenomegaly in recipient mice.

Receptor tyrosine kinase inhibitors AG013764 and AG013711 reduce choroidal neovascularization in rat eye

Age-related macular degeneration (AMD) is the major cause of blindness for people over 60. In the "wet" form of AMD compounds targeting growth factor signaling pathways such as VEGF have been a major focus for therapeutic interventions. In a previously developed rat model of CNV, we utilized two receptor tyrosine kinase inhibitors (RTKi) to block VEGFR-1, VEGFR-2 and PDGFR signaling following the establishment of CNV. AAV-VEGF(165) was injected into the subretinal space of rats at postnatal days 15-17. Six weeks later, a suspension of RTK inhibitors, AG013764 or AG013711, was injected intraperitoneally (IP, twice daily) or intravitreally (every five days) over a two week period. FITC-dextran whole-mounts of RPE-choroid-sclera were prepared after the animals were sacrificed. CNV area was quantified using Neurolucida to measure the hyperfluorescence on FITC-dextran whole-mounts. Histology and immunohistochemistry were performed as described previously. VEGF expression in control and treated eyes was confirmed by immunohistochemistry and histological sections indicated recovery of retinal morphology and CNV reduction in treated eyes. In the animals IP injected with AG013764 or AG013711 the mean CNV level was reduced by 25 to 33% compared to control, but this effect did not achieve statistical significance. Intravitreal injections of AG013764 or AG013711 reduced the level of CNV by approximately 60% compared to control (p<0.005 or p<0.05, respectively). These data show that two RTK inhibitors, AG013764 or AG013711, delivered intravitreally, significantly reduce blood vessel proliferation in this AAV-VEGF(165) model of CNV.

T helper cell population and eosinophilia in nasal polyps

OBJECTIVE

To analyze the immunological pattern of nasal polyposis in patients with and without allergy, the percentages of CD4+ cells expressing intracellular interferon-gamma and interleukin-4 (T helper [T(H)] type 1 and 2 cells) were measured by flow cytometry in samples from patients with nasal polyps.

METHODS

Samples from 32 patients (16 atopic, 16 nonatopic) were studied. The fresh nasal polyp samples were prepared in single cell suspension for flow cytometry. Eosinophils were counted in hematoxylin-and-eosin-stained sections of all the samples.

RESULTS

T(H)1 cells were predominant in all the nasal polyps, with no significant differences in the mean (+/-SD) percentages of T(H)1 cells between the 2 groups (46.28% +/- 14.95% vs 38.25% +/- 9.16%, P > .05). The mean percentage of T(H)2 cells in the polyps from the atopic patient group was significantly greater than in polyps from nonatopic group (7.34% +/- 2.54% vs 0.63% +/- 0.31%, respectively; P < .01); the eosinophil count was significantly higher in atopic patient polyp samples (54.5 +/- 15.76 eosinophils/HPF) than in nonatopic ones (14.38 +/- 5.6 eosinophils/HPF, P < .01). The mean percentage of T(H)1 cell correlated with eosinophil count in the polyp samples overall (r = 0.80, P < .01).

CONCLUSIONS

T(H)1 cells were predominant in nasal polyp tissue. Polyps from atopic patients had more T(H)2 cells and eosinophils than nonatopic patients' polyps did. Eosinophil recruitment in nasal polyposis is probably associated with T(H)2 cell infiltration. Nonatopic and atopic patients' polyps have different immunological patterns.

A novel NADP+-dependent L-1-amino-2-propanol dehydrogenase from Rhodococcus erythropolis MAK154: a promising enzyme for the production of double chiral aminoalcohols

AIM

A novel NADP(+)-dependent L-1-amino-2-propanol dehydrogenase was isolated from Rhodococcus erythropolis MAK154, and characterized.

METHODS AND RESULTS

The enzyme was inducibly produced on cultivation with aminoalcohols such as 1-amino-2-propanol, 1-amino-2-butanol and 2-aminocyclohexanol. The enzyme catalyses the NADP(+)-dependent oxidation of several aminoalcohols, and also the NADPH-dependent asymmetric reduction of an aminoketone compound to a double chiral aminoalcohol, d-pseudoephedrine. Amino acid sequence analysis showed that the enzyme might belong to the short-chain dehydrogenase/reductase family.

CONCLUSIONS

NADP(+)-dependent L-1-amino-2-propanol dehydrogenase isolated from R. erythropolis MAK154 reversibly catalysed dehydrogenation of aminoalcohols, and exhibited a unique sterospecifity for the reduction reaction.

SIGNIFICANCE AND IMPACT OF THE STUDY

The enzyme is a promising catalyst for the production of double chiral compound, d-pseudoephedrine, from prochiral substrate.

Translational proteomics: developing a predictive capacity -- a review

Over the past decade, proteomics has undergone a rapid development and radiation, diversifying across the biochemical landscape. While no single technique yet delivers complete proteomic coverage, application-specific adaptations afford significant opportunity for discovery and the development of predictive capacity (e.g. surrogate biomarker and clinical diagnostics). Targeted proteomic approaches, protein profiling strategies using affinity capture mass spectrometry and solution array represent realistic opportunities to deliver predictive capacity. The aim of this review is to provide an overview of proteomic technologies and how the outcomes delivered by such platforms may be translated into applications of predictive utility in clinical and basic science. In particular, recent applications in protein/peptide profiling (solid-phase affinity capture mass spectrometry and the targeted approach of antibody arrays) and the opportunities they afford researchers within the discipline of reproductive biology to develop new diagnostic and prognostic tests and surrogate biomarkers to improve the delivery of women's health care are considered.

Measuring EGJ opening patterns using high resolution intraluminal impedance

The aim of this study was to adapt impedance methodology to study esophagogastric junction (EGJ) sphincter opening and compare opening patterns of the EGJ during deglutitive LES relaxation (dLESR) and transient LES relaxation (tLESR). We studied eight healthy subjects with a novel 12-lumen combined impedance/manometry catheter, the main element of which was a 6 cm sleeve sensor with six side hole sensors and six impedance rings spaced at 1 cm increments along its length. Subjects underwent an air infusion protocol after standard assessment and data tracings and isocontour plots were analysed to assess opening characteristics of the EGJ during dLESRs and tLESRs. Our results revealed that during dLESR the opening pattern was top to bottom, occurred in 0-2.7 s and in 29 of 35 (83%) cases the leading edge of the bolus was liquid. Opening during tLESR began between -7.8 and +8.6 s relative to the onset of nadir LES relaxation. The opening pattern during tLESR was bottom to top, occurred in 0-7.7 s, and in 22 of 29 (76%) the leading edge was liquid. These results support that impedance monitoring can be adapted to identify sphincter opening, to distinguish sphincter opening from sphincter relaxation, and to determine luminal contents during the opening period.

Design and analysis of annular antenna arrays with different reflectors

The design and performance of annular antenna arrays with reflectors is presented. Arrays with three shapes of reflectors are analysed and simulated. These include the corner reflector, the circular reflector and the elliptical reflector. Power-density distributions within the annular arrays with and without reflectors are obtained by using the FDTD method. Also, the image theory method is used to verify the FDTD results in one case. By comparing the power-density distribution pattern of all four of the array designs (three with different reflectors, one without reflector), it is readily seen in each case that the array with reflectors yields better power-efficiency than the array without reflectors and the elliptical reflector yields the best performance. Comparisons of each array are made using 4, 6 and 8 antennae in the annular array. By using the optimized results of the elliptical reflector, the requirement for the input-power level to each antenna is greatly reduced.

Establishment of immunoglobulin M(IgM)-immunosorbent agglutination assay (ISAGA) for diagnosis of toxoplasmosis

AIM

To establish an immunosorbent agglutination assay (ISAGA) for detection of IgM antibodies against Toxoplasma gondii.

METHODS

In the ISAGA, wells of microtiter plates were coated with anti-human IgM antibodies and sealed with 1% bovine serum albumin. After the test sera were added and incubated, the plates were washed, T. gondii tachyzoite antigen suspension was added, and incubated overnight at 37 degrees C. The ISAGA results were evaluated by comparing with those detected by Danish ISAGA and ELISA and those detected by slide enzyme immunoassay (S-EIA).

RESULTS

Forty-four sera from Danish pregnant women were tested by the IgM-ISAGA, 41(93.2%) were consistent with the Danish results. Sixty-seven sera from Danish and Shanghai pregnant women were detected by IgM-IgM-ISAGA and S-EIA, the total consistency rate was 92.5%. A significant correlation was found between the titers of the ISAGA and S-EIA, with a Pearson correlation coefficient of 0.589(P < 0.001). The titers of ISAGA were eighteen times higher than those of S-EIA. This method enables the detection of IgM antibodies as low as approximately 0.08 IU/ml.

CONCLUSION

The IgM-ISAGA is therefore sensitive, specific, easy to perform, and is useful for mass screening and diagnosing recent Toxoplasma infection or reactivation.

Reduced tLESR elicitation in response to gastric distension in fundoplication patients

Transient lower esophageal sphincter relaxations (tLESRs) are vagally mediated in response to gastric cardiac distension. Nine volunteers, eight gastroesophageal reflux disease (GERD) patients, and eight fundoplication patients were studied. Manometry with an assembly that included a barostat bag was done for 1 h with and 1 h without barostat distension to 8 mmHg. Recordings were scored for tLESRs and barostat bag volume. Fundoplication patients had fewer tLESRs (0.4 +/- 0.3/h) than either normal subjects (2.4 +/- 0.5/h) or GERD patients (2.0 +/- 0.3/h). The tLESRs rate increased significantly in normal subjects (5.8 +/- 0.9/h) and GERD patients (5.4 +/- 0.8/h) during distension but not in the fundoplication group. All groups exhibited similar gastric accommodation (change in volume/change in pressure) in response to distension. Fundoplication patients exhibit a lower tLESR rate at rest and a marked attenuation of the response to gastric distension compared with either controls or GERD patients. Gastric accommodation was not impaired with fundoplication. This suggests that the receptive field for triggering tLESRs is contained within a wider field for elicitation of gastric receptive relaxation and that only the first is affected by fundoplication.

Simultaneous quantification of seven active metabolites of roxifiban in human plasma by LC/MS/MS in the presence of an interfering displacer at millimolar concentrations

Roxifiban (DMP 754) is a glycoprotein (GP) IIb/IIIa antagonist. Following oral administration to humans, roxifiban is metabolized to its primary active zwitterionic form, XV459, and several minor, active, hydrolyzed and hydroxylated metabolites, namely, M1a (DPC-AD3508), M1b (DPC-AD6128), M2 (SW156), M3 (DPC-AG2185), M8a (DPC-AF5814), and M8b (DPC-AF5818). Quantification of these metabolites in humans was not workable with a previous analytical method due to ion suppression of at least four of the analytes by a competitive displacer, DMP 728. This compound, which is another GP IIb/IIIa antagonist with very high affinity for the platelet receptor, was added to harvested blood samples in millimolar quantity to liberate XV459 from the GP IIb/IIIa receptor. An automated ion exchange solid phase extraction (IX-SPE) procedure was developed to selectively extract the seven metabolites of roxifiban and its deuterated internal standard while specifically excluding DMP 728. Among the six hydroxylation metabolites, there were two pairs of epimeric diastereomers (M1a/M1b and M8a/M8b) and one pair of geometric isomers (M2/M3), corresponding to three critical chromatographic pairs that needed to be base-line resolved because of the lack of specificity of MS/MS detection for these isomers. A new LC/MS/MS assay was developed to simultaneously quantify the seven metabolites in human plasma. The assay method was validated under GLP conditions over the concentration range of 0.5 to 80 nM for each of the analytes and successfully applied to assaying approximately 500 plasma samples from clinical trials.

The effect of glucagon-induced gastric relaxation on TLOSR frequency

This study aimed to determine the effect of glucagon-induced gastric relaxation on the frequency of transient lower oesophageal sphincter relaxations (TLOSRs). Eight normal subjects (four male, age 18-52 y) were studied after a 6-h fast using a combined manometric barostat assembly. The recording was divided into two 1-h sessions: (1) a baseline period with the barostat set at minimal distending pressure (MDP) + 2 mmHg and (2) a period with continuous glucagon or placebo infusion with barostat set at MDP + 2 mmHg. Patients were studied on two different days and randomly received glucagon (4.8 microg kg(-1) bolus followed by 9.6 microg kg(-1) h(-1) infusion) on 1 day and placebo (saline) on another. Lower oesophageal sphincter (LOS) pressure, frequency of TLOSRs, and barostat bag volumes were determined for both placebo and glucagon infusion. Glucagon induced significant fundal relaxation compared with placebo (P < 0.05) and significantly decreased baseline LEOS pressure (P < 0.05). The frequency of TLOSRs was not altered by glucagon infusion compared with placebo. Despite causing substantial proximal stomach relaxation, glucagon did not increase TLOSR frequency. This suggests that the relevant gastric mechanoreceptors responsible for triggering TLOSRs do not respond to passive elongation.

Distinct patterns of oesophageal shortening during primary peristalsis, secondary peristalsis and transient lower oesophageal sphincter relaxation

This study characterized oesophageal shortening during secondary peristalsis and transient lower oesophageal sphincter relaxation (TLOSR) in an attempt to determine its contribution to the opening mechanism. Eight healthy subjects (four males, 26 +/- 1 years) had metal clips affixed at 0, +3, and +8 cm relative to the squamocolumnar junction (SCJ), defining two distal oesophageal segments. Axial clip movement was assessed with concurrent videofluoroscopy and manometry during primary peristalsis, secondary peristalsis and TLOSR. Clip-defined oesophageal segment length change was measured at 0.5-s intervals. The magnitude of the most distal segment shortening was least with TLOSR, greatest with primary peristalsis and intermediate with secondary peristalsis. Conversely, maximal overall oesophageal shortening during TLOSR, evidenced by SCJ movement, was similar to that during primary peristalsis. In 3/12 TLOSRs, the moment of LOS opening and gas reflux was optimally imaged; SCJ excursion was 0.3 +/- 0.1 cm prior to LOS opening and 1.4 +/- 0.7 cm immediately after gas reflux. The segmental pattern of oesophageal shortening was distinct during primary peristalsis, secondary peristalsis and TLOSR. During TLOSR, significant elevation of the SCJ occurred only after LOS opening, suggesting that this was a consequence of oesophageal distension induced by gas reflux rather than a component of the opening mechanism.

The inherent cellular level of reactive oxygen species: one of the mechanisms determining apoptotic susceptibility of leukemic cells to arsenic trioxide

Though reactive oxygen species (ROS) has been noticed to be involved in arsenic trioxide (As(2)O(3))-induced apoptosis of tumor cells, its role in apoptosis signaling remained to be elucidated. The objective of this work was to explore the association of the inherent cellular ROS level with the susceptibility of the tumor cells to apoptosis induction by As(2)O(3). Low concentration of As(2)O(3) was administered to cultured leukemic cell lines NB4, U937, HL60 and K562. The difference in apoptotic sensitivity was displayed among four cell types. ROS probes were incubated with the cells in the absence of As(2)O(3), and ROS was thus quantified relatively by flow cytometry. We manifested, in four cell types, the inherently existed difference in whole ROS quantity, and a positive correlation between the inherent ROS level and their apoptotic sensitivity to As(2)O(3). Furthermore, by interference using a ROS producer, we demonstrated that an elevation of ROS level would sensitize the cells to As(2)O(3)-induced apoptosis. The results of the present work suggested that the inherent ROS level might be determinative in tumor cells for their apoptotic susceptibility to As(2)O(3).

Structure and dynamics of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase

Folates are essential for life. Unlike mammals, most microorganisms must synthesize folates de novo. 6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) catalyzes pyrophosphoryl transfer from ATP to 6-hydroxymethyl-7,8-dihydropterin (HP), the first reaction in folate pathway, and therefore, is an ideal target for developing novel antimicrobial agents. Because of its small size and high thermal stability, E. coli HPPK is also an excellent model enzyme for studying the mechanisms of enzymatic pyrophosphoryl transfer. We have determined the crystal structures of HPPK in the unligated form and in complex with HP, two Mg2+ ions, and AMPCPP (an ATP analog that inhibits the enzymatic reaction). Comparison of the two crystal structures reveals dramatic conformational changes of three flexible loops and many side chains and possible roles of the active site residues.

[Weak signal detection in every heart cycle]

In this article, a new approach is introduced to lowering the myo-electronic noise in weak ECG signals. We use artificial neural network to make the noise be white, and then we adopt an adaptive filter of which the reference signal is achieved by extracting from other ECG cycle. The outcome is the reduction of both white noise and non-white noise in ECG signal. Satisfactory results have been achieved by using this method in the experiment of late potential detection.

Comparison of structural changes of cell surface carbohydrates in the eustachian tube epithelium of chinchillas infected with a Streptococcus pneumoniae neuraminidase-deficient mutant or its isogenic parent strain

Six different lectin probes were used to examine alterations of the cell surface carbohydrates in the chinchilla eustachian tube (ET) lumen subsequent to the intranasal (i.n.) challenge with the Streptococcus pneumoniae parent strain, D39, or its isogenic derivative, DeltaNA1, which is deficient in neuraminidase NanA. The labelling pattern revealed that the binding of wheat germ agglutinin (WGA), Erythrina cristagalli lectin (ECL), peanut agglutinin (PNA), Bandeiraea simplicifolia lectin II (BSL II) and succinylated wheat germ agglutinin (SWGA) were increased in the lumenal surface of the ET in the D39 inoculated cohort compared to the uninfected control, which indicated that N-acetylglucosamine (GlcNAc) and D-galactose residues were exposed. Concurrently, decreased labelling with Sambucus nigra agglutinin (SNA) indicated that there were few sialic acid residues remaining in the ET epithelium subsequent to i.n. inoculation with D39. The DeltaNA1 neuraminidase deficient mutant, however, did not induce any significant changes in the lectin labelling patterns, and was comparable to that of the control cohort. We propose that products of the nanA gene have a significant impact on the changes of the carbohydrate moieties in the ET epithelium and may be responsible for the previously reported increased ability of the D39 parent to colonize the nasopharynx and invade the middle ear.

A three-dimensional model of the human facilitative glucose transporter Glut1

The human facilitative transporter Glut1 is the major glucose transporter present in all human cells, has a central role in metabolism, and is an archetype of the superfamily of major protein facilitators. Here we describe a three-dimensional structure of Glut1 based on helical packing schemes proposed for lactose permease and Glut1 and predictions of secondary structure, and refined using energy minimization, molecular dynamics simulations, and quality and environmental scores. The Ramachandran scores and the stereochemical quality of the structure obtained were as good as those for the known structures of the KcsA K(+) channel and aquaporin 1. We found two channels in Glut1. One of them traverses the structure completely, and is lined by many residues known to be solvent-accessible. Since it is delimited by the QLS motif and by several well conserved residues, it may serve as the substrate transport pathway. To validate our structure, we determined the distance between these channels and all the residues for which mutations are known. From the locations of sugar transporter signatures, motifs, and residues important to the transport function, we find that this Glut1 structure is consistent with mutagenesis and biochemical studies. It also accounts for functional deficits in seven pathogenic mutants.