Novel sulfated glucomannan-barium-alginate microcapsules in islet transplantation: significantly decreased the secretion of monocyte chemotactic protein 1 and improved the activity of islet in rats

The sulfated glucomannan can be used to filter the heparin-binding properties of cytokines. In this study, novel sulfated glucomannan-barium-alginate (SGA) microcapsules were prepared to encapsulate islets with barium-alginate (ABa) and calcium alginate-poly-l-lysine (APA) microcapsules as controls. SD rat islets were purified as donor cells to Lewis rats that had been treated with streptozotocin. Intraperitoneal transplantation was performed with about 3000 islet equivalent (IEQ) rat. At week three after transplantation, the concentrations of monocyte chemotactic protein-1 (MCP-1), interleukin (IL)-1 beta, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha in intraperitoneal fluid were determined using ELISA. At week 8, the islet cell mass in the abdominal microcapsules was excised to test insulin release. The EB-FDA fluorescence staining method was used to observe the functional activity of the islet cells. Compared with ABa and APA microcapsules, SGA microcapsules showed significantly decreased MCP-1 secretion by beta-cells. Also, the concentrations of cytokines IL-1beta, IFN-gamma, and TNF-alpha were decreased significantly. The activity of the transplanted islets was significantly improved in SGA microcapsules, which shielded against cytokines better than ABa or APA microcapsules and may serve as novel method.

Receptor crosstalk: reprogramming B cell receptor signalling to an alternate pathway results in expression and secretion of the autoimmunity-associated cytokine, osteopontin

Receptor crosstalk: reprogramming B cell receptor signalling to an alternate pathway results in expression and secretion of the autoimmunity-associated cytokine, osteopontin (Review). J Intern Med 2009; 265: 632-643.Intracellular signalling emanating from the B-cell antigen receptor is considered to follow a discrete course that requires participation by a set of mediators, grouped together as the signalosome, in order for downstream events to occur. Recent work indicates that this paradigm is true only for naïve B cells. Following engagement of the IL-4 receptor, a new, alternate pathway for B-cell receptor (BCR)-triggered intracellular signalling is established that bypasses the need for signalosome elements and operates in parallel with the classical, signalosome-dependent pathway. Reliance on Lyn and sensitivity to rottlerin by the former, but not the latter, distinguishes these two pathways. The advent of alternate pathway signalling leads to production and secretion by B cells of osteopontin (Opn). As Opn is a polyclonal B-cell activator that is strongly associated with a number of autoimmune diseases including lupus and rheumatoid arthritis, this novel finding is likely to be clinically relevant. Our results highlight the potential role of B-cell-derived Opn in immunity and autoimmunity and suggest that stress-related IL-4 expression might act to strengthen immunoglobulin secretion at the risk of autoantibody formation. Further, these results illustrate receptor crosstalk in the form of reprogramming, whereby engagement of one receptor (IL-4R) produces an effect that persists after the original ligand (IL-4) is removed and results in alteration of the pathway, and outcome, of signalling via a second receptor (BCR) following its activation.

Quantitative detection of cytokeratin 20 mRNA in urine samples as diagnostic tools for bladder cancer by real-time PCR

AIM

To determine and compare cytokeratin 20 (CK20) mRNA expression in urine of patients with transitional cell carcinomas of bladder (TCCB), urological benign diseases, and healthy volunteers.

METHODS

Taqman probe was designed according to the sequence of CK20 cloned gene. The quantitative PCR reaction system was optimized and evaluated. The CK20 mRNA level was screened by real-time polymerase chain reaction (RT-PCR) in 95 urine samples and analyzed according to the following parameters: urinary cytology, nuclear matrix protein 22 (NMP22) expression, tumor stage and grade.

RESULTS

For 60 TCCB patients urinary cytology was positive in 28 (46.7%), control group had no false-positive results (specificity 100%). CK20 expression was positive in RT-PCR of 51 cases (85%) of TCCB, but control group was positive in 2 cases (specificity 94.3%) with a cutoff value of crossover point (CT) = 30. Two methods have significant variation in sensitivity (p < 0.001), NMP22 expression was positive in 47 cases (78.3%), but control group was positive in 9 cases (specificity 85%). In the simultaneous evaluation of CK20 and NMP22 mRNA expression, there were 54 positive cases (90%). CK20 mRNA values in TCCB group (mean 27712.57 copies/microl) were significantly higher than in non-cancer disease urological group (mean 74.45 copies/microl) and control group (mean 8.47 copies/microl) (p < 0.001, p < 0.001, respectively). CK20 mRNA values increased gradually with higher tumor grade and stage: G1 differs significantly from G2 (p = 0.016); T(is) /T(a) differs significantly from T(1-2) (p = 0.022).

CONCLUSION

Our results indicate that CK20 mRNA expression could be regarded as a potential marker for TCCB. We demonstrated correlation between CK20 expression and the clinicopathologic features of TCCB (tumor stage and grade); simultaneous use of CK20 and NMP22 markers will elevate the sensitivity of the method. CK20 RT-PCR is a sensitive, quantitative, rapid and specific method to detect free cancer cells in the urine, and could be recommended for be wide application in the diagnostics of TCCB and evaluation of therapeutic effect.

Atomistic simulation of voids effect on nanoindentation

In this paper, spherical voids effect on the first dislocation emission of single-crystal Cu in nanoindentation is investigated by means of the atomistic simulation. The results show that there are two opposite effects on dislocation emission resulting from the stable voids in matrix. The existence of voids can lower or heighten the load needed to nucleate the first dislocation. The relative distance between the void and the indenter, and the void size play an important role in the yield load of the first dislocation emission in nanoindentation.

Reductions in tumor RNA integrity associated with clinical response to epirubicin/docetaxel chemotherapy in breast cancer patients

Abstract #6068

Background: Optimal doses and dosing intervals for neoadjuvant anthracycline/taxane chemotherapy are poorly studied. Moreover, biomarkers for measuring response to such combination regimens are unknown. This study investigated these issues in sequential phase I/II cohorts of women with locally advanced or inflammatory breast cancer treated with epirubicin and docetaxel with pegfilgrastim support at 3- or 2-weekly intervals in association with the NCIC-CTG MA.22 clinical trial.&#x2028; Methods: Accrual has been completed for the 3-weekly regimen (maximum tolerated dose: epirubicin 105 mg/m2, taxotere 75 mg/m2), and continues for the phase II portion of the 2-weekly regimen. Six core biopsies were obtained from 50 patients pre-, mid-, and post-treatment. Immunohistochemical staining was performed to determine baseline levels of ER, PR, HER2 and Topo II expressed as % positive stain. Tumour RNA integrity (RIN) and tumor extent were measured pre-, mid- and post-treatment by capillary electrophoresis and light microscopy after haematoxylin/eosin staining, respectively. Associations between maximum and average RIN at the three time points and tumour extent, clinical response, pathologic complete response, or baseline levels of ER, PR, HER2 and Topo II were assessed using Spearman correlation coefficients after data transformation to improve symmetry and stabilize variances. The association between both RIN and tumour extent, and baseline drug dose was assessed using a 1-way ANOVA.&#x2028; Results: Low mid-treatment maximum RIN was associated with high drug dose level (p=0.05) and eventual pathologic complete response (p=0.01). Post-treatment, low maximum and average RIN were found to be associated with low tumor extent (p=0.004 and p=0.01, respectively). As well, low average RIN was significantly associated with clinical complete response post-treatment (p=0.01). As expected, post-treatment low tumor extent was significantly associated with pathologic complete response (p=0.01). High pre-treatment Topo II levels were also significantly associated with high RIN (p = 0.03). No association was observed between RIN and HER2, ER or PR.&#x2028; Discussion: The association of RIN with tumour extent, pathologic complete response, clinical response, a known risk factor (Topo II), and drug dose suggests that the RIN may represent an important new biomarker for measuring response to anthracycline/taxane combinations (and possible other chemotherapy regimens) in breast cancer patients.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6068.

A new endophytic taxane-production fungus from Taxus chinensis

More than 50 kinds of endophytic fungi associated with Taxus chinensis, were isolated and examined as potential source of the imposing anticancer drug taxol. Of these, 4 isolates show ability to produce taxane when measured with the competitive inhibition enzyme immunoassay method. The most promising clone, DA10, identified as Mucor rouxianus sp., is the first rouxianus reported as taxol-production fungus. The presence of taxol and its important precursors, such as 10-diacetyl baccatinIII (10-DAB) and baccatinIII, in the culture of this fungus was confirmed by reactivity with taxane-specific monoclonal antibody, comparative chromatographic and mass spectrometric behavior, cytotoxity to liver carcinoma 7402, and molecular cloning of kernel fragment of taxadiene synthase gene.

Expression and hormonal regulation of IL-11Ralpha in canine uterus during early pregnancy

Embryo implantation is critical for the successful establishment of pregnancy. Interleukin-11 (IL-11) is essential for adequate decidualization in the mouse and human via binding to the specific IL-11 receptor alpha (IL-11Ralpha). But the expression and regulation of IL-11 and IL-11Ralpha in the canine endometrium remain unknown. The aim of this study was to investigate the differential expression of IL-11Ralpha in canine uterus during early pregnancy and its regulation under different conditions by in situ hybridization. Interleukin-11Ralpha mRNA was mainly localized in glandular epithelium in canine uterus. There was a low level of IL-11Ralpha expression in the glandular epithelium on days 6, 12 and 17 of pregnancy. On day 20 of pregnancy when embryo implanted, IL-11Ralpha mRNA was highly expressed in the glandular epithelium surrounding the embryo, but not in the luminal epithelium and stroma. On day 23 of pregnancy, the expression of IL-11Ralpha mRNA maintained a constant level compared with the expression of day 20 and increased on day 28 of pregnancy. During the oestrous cycle, a high level of IL-11Ralpha mRNA expression was seen in the oestrous uterus. Progesterone slightly induced the expression of IL-11Ralpha mRNA in the ovariectomized canine uterus. These results suggest that IL-11Ralpha expression is closely related to canine implantation and up-regulated by progesterone.

Needle track seeding following biopsy of liver lesions in the diagnosis of hepatocellular cancer: a systematic review and meta-analysis

BACKGROUND

Needle biopsy of a suspicious liver lesion could guide management in the setting of equivocal imaging and serology, although it is not recommended generally because there is the possibility of tumour dissemination outside the liver. The incidence of needle track seeding following biopsy of a suspicious liver lesion is ill-defined, however.

METHODS

A systematic review and meta-analysis of observational studies published before March 2007 was performed. Studies that reported on needle tract seeding following biopsy of suspicious liver lesions were identified. Lesions suspected of being hepatocelleular cancer (HCC) were considered. Data on the type of needle biopsy, diagnosis, incidence of needle track seeding duration to seeding, follow-up and impact on outcome were tabulated.

RESULTS

Eight studies identified by systematic review on biopsy of HCC were included in a meta-analysis. The pooled estimate of a patient with seeding per 100 patients with HCC was 0.027 (95% confidence interval (CI) 0.018 to 0.040). There was no difference whether a fixed or random effects model was used. Q was 4.802 with 7 degrees of freedom, p = 0.684; thus the observed heterogeneity was compatible with variation by chance alone. The pooled estimate of a patient with seeding per 100 patients per year was 0.009 (95% CI 0.006 to 0.013), p = 0.686.

CONCLUSIONS

In this systematic review we have shown that the incidence of needle tract tumour seeding following biopsy of a HCC is 2.7% overall, or 0.9% per year.

Customizing kernel functions for SVM-based hyperspectral image classification

Previous research applying kernel methods such as support vector machines (SVMs) to hyperspectral image classification has achieved performance competitive with the best available algorithms. However, few efforts have been made to extend SVMs to cover the specific requirements of hyperspectral image classification, for example, by building tailor-made kernels. Observation of real-life spectral imagery from the AVIRIS hyperspectral sensor shows that the useful information for classification is not equally distributed across bands, which provides potential to enhance the SVM's performance through exploring different kernel functions. Spectrally weighted kernels are, therefore, proposed, and a set of particular weights is chosen by either optimizing an estimate of generalization error or evaluating each band's utility level. To assess the effectiveness of the proposed method, experiments are carried out on the publicly available 92AV3C dataset collected from the 220-dimensional AVIRIS hyperspectral sensor. Results indicate that the method is generally effective in improving performance: spectral weighting based on learning weights by gradient descent is found to be slightly better than an alternative method based on estimating "relevance" between band information and ground truth.

Bioactive natural products from endophytes: a review

Endophytes, microorganisms that reside in the internal tissues of living plants without causing any immediate overt negative effects, have been found in every plant species examined to date and recognized as potential sources of novel natural products for exploitation in medicine, agriculture, and industry with more and more bioactive natural products isolated from the microorganisms. In this review, we focus mainly on bioactive natural products from endophytic microorganisms by their different functional roles. The prospect and facing problems of isolating natural products from endophytes are also discussed.

Temperature effects on the enantioselectivity of basic analytes in capillary EKC using sulfated beta-CDs as chiral selectors

The thermodynamic processes were investigated to reveal the temperature effects during chiral separation by capillary EKC with reversed polarity mode using sulfated beta-CD (S-beta-CD) as chiral selectors. The temperature effects on enantioselectivities of basic analytes (ephedrine, norephedrine, synephrine, and epinephrine) were investigated in detail over a temperature range of 20-60 degrees C. An increase of the capillary temperature produced the decrease of enantioselectivities for ephedrine and norephedrine, but increase of enantioselectivities for synephrine and epinephrine. The thermodynamic variations showed that the interactions between the basic analytes and chiral selectors were always enthalpy- driven. However, the difference in enthalpy and entropy showed that the enantioseparation was an enthalpy-driven process for ephedrine and norephedrine, but an entropydriven process for synephrine and epinephrine. Just because of the different driving forces, there exist two kinds of temperature effects on enantioselectivities mentioned above.

Functional analysis of the Arabidopsis PHT4 family of intracellular phosphate transporters

The transport of phosphate (Pi) between subcellular compartments is central to metabolic regulation. Although some of the transporters involved in controlling the intracellular distribution of Pi have been identified in plants, others are predicted from genetic, biochemical and bioinformatics studies. Heterologous expression in yeast, and gene expression and localization in plants were used to characterize all six members of an Arabidopsis thaliana membrane transporter family designated here as PHT4. PHT4 proteins share similarity with SLC17/type I Pi transporters, a diverse group of animal proteins involved in the transport of Pi, organic anions and chloride. All of the PHT4 proteins mediate Pi transport in yeast with high specificity. Bioinformatic analysis and localization of PHT4-GFP fusion proteins indicate that five of the proteins are targeted to the plastid envelope, and the sixth resides in the Golgi apparatus. PHT4 genes are expressed in both roots and leaves, although two of the genes are expressed predominantly in leaves and one mostly in roots. These expression patterns, together with Pi transport activities and subcellular locations, suggest roles for PHT4 proteins in the transport of Pi between the cytosol and chloroplasts, heterotrophic plastids and the Golgi apparatus.

[Development of on-line sample preparation coupled with liquid chromatography-mass spectrometry for analysis of small molecules in biofluids]

On-line liquid chromatography-mass spectrometry (LC-MS) is a highly sensitive, highly selective and high throughput method for the analysis of small molecules in biofluids. The developments, characterizations and applications of pre-column, on-line LC-MS method and its configuration in the recent five years are reviewed.

[Recent advances in enantiomeric separation of chiral environmental pollutants by capillary electrophoresis]

Capillary electrophoresis (CE) is an effective analytical tool in chiral separation. This review article is focused on the major developments in the recent applications of CE to the enantioseparation of the chiral environmental pollutants in the past decade. Developments are classified according to the types of chiral pollutants, i. e. phenoxyalkanoic acid herbicides, organophosphorus/organochlorine/pyrethroid pesticides, triazole fungicides, polychlorinated biphenyls (PCBs). The advances in enantiomeric separation of the above-mentioned chiral pollutants by CE are reviewed. In addition, the emerging chiral pollutants are highlighted and the prospects of CE in the analysis of chiral environmental pollutants are also drafted.

Study of the enantioseparation of imazaquin and enantioselective degradation in field soils by CZE

A fast, simple, and sensitive CE method was developed to study the separation and degradation of imazaquin enantiomers in field soils. The parameters pH and concentration of the buffer electrolyte, type and concentration of the chiral selectors, applied voltage, and temperature of the CE system were investigated. Sodium hydrogen phosphate (50 mM) at pH 10.1 containing 30 mM hydroxypropyl-beta-CD (HP-beta-CD) was found to be the suitable BGE. The reliable determination for imazaquin enantiomers was obtained at 20 kV applied voltage, 15 degrees C separation system, and detection at 214 nm. Under the optimal conditions, the LODs (S/N = 3) were 0.0097 and 0.0098 mg/kg; linearity ranged from 0.019 to 1.24 and 0.020 to 1.26 mg/kg for the first-eluting peak of imazaquin (imazaquin-I) and the second-eluting peak of imazaquin (imazaquin-II) in soil, respectively. The precision in terms of the percentage of RSD (%RSD) calculated from peak area was not greater than 5%. With the suitable characteristics of the present method, it was applied to the study of enantioselective degradation in field soil. According to the calculated values of the enantiomer ratio (ER) and the rate constant of degradation (k), the results suggested that the degradation rate of the two enantiomers were slightly different, and that the pH of the soil had a strong influence on the rate of degradation.

Role of salicylic acid in alleviating oxidative damage in rice roots (Oryza sativa) subjected to cadmium stress

Time-dependent changes in enzymatic and non-enzymatic antioxidants, and lipid peroxidation were investigated in roots of rice (Oryza sativa) grown hydroponically with Cd, with or without pretreatment of salicylic acid (SA). Exposure to 50 microM Cd significantly decreased root growth, and activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), but increased the concentrations of H(2)O(2), malondialdehyde (MDA), ascorbic acid (AsA), glutathione (GSH) and non-protein thiols (NPT). However, pretreatment with 10 microM SA enhanced the activities of antioxidant enzymes and the concentrations of non-enzymatic antioxidants, but lowered the concentrations of H(2)O(2) and MDA in the Cd-stressed rice compared with the Cd treatment alone. Pretreatment with SA alleviated the Cd-induced inhibition of root growth. The results showed that pretreatment with SA enhanced the antioxidant defense activities in Cd-stressed rice, thus alleviating Cd-induced oxidative damage and enhancing Cd tolerance. The possible mechanism of SA-induced H(2)O(2) signaling in mediating Cd tolerance was discussed.

Strengthening tight junctions of retinal microvascular endothelial cells by pericytes under normoxia and hypoxia involving angiopoietin-1 signal way

PURPOSE

To determine the effects of pericytes and angiopoietin-1 on the expression of occludin and zonula occludens-1 (ZO-1) in retinal endothelial cells (ECs) under both normoxic and hypoxic conditions.

METHODS

Rat primary retinal microvascular ECs were cultured under normoxia or hypoxia in either absence or presence of pericytes conditioned medium (PCM). PCM was pretreated with or without angiopoietin-1 neutralizing antibody. Immuofluorescent staining, Western blot and RT-PCR were used to detect the alterations of occludin and ZO-1 expression.

RESULTS

Under normoxia, PCM strengthened occludin and ZO-1 immunofluorescent staining at cytomembrane as well as increased their expression at both protein and mRNA level. When pretreated with angiopoietin-1 neutralizing antibody, occludin upregulation induced by PCM was significantly blocked at protein level (62%) and mRNA level (34%). Under hypoxia, the continuity of occludin and ZO-1 staining at cell boundaries was disrupted consistent with a decrease of their protein level by 31 and 27%, respectively. Also occludin and ZO-1 mRNA level decreased by 46 and 57%, respectively. PCM was observed to partially increase expression of occludin at protein and mRNA level. Angiopoietin-1 antibody slightly inhibited (16%) PCM induced occludin mRNA increase under hypoxia.

CONCLUSION

Pericytes improved the integrity of endothelial barrier through inducing occludin and ZO-1 expression at protein and mRNA level under normoxia. Under hypoxia, pericytes could partially reverse occludin decrease. These protecting effects of pericytes on endothelial barrier were at least in part mediated by angiopoietin-1.

Simultaneous enantioseparation of antiparkinsonian medication Rotigotine and related chiral impurities by capillary zone electrophoresis using dual cyclodextrin system

A dual cyclodextrin (CD) system consisting of sulfated beta-CD (S-beta-CD) and methyl-beta-CD (M-beta-CD) modified capillary zone electrophoresis (CZE) method was proposed to separate the antiparkinsonian drug Rotigotine ((-)-(S)-2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin) and related chiral impurities (2-(N-propylamino)-5-hydroxytetralin, 2-(N-propylamino)-5-methoxytetralin). The method was optimized by varying the CD type, the buffer pH, individual CD concentration of the dual system and the ionic strength of background electrolyte. Under the optimum conditions, i.e. 2% (w/v) S-beta-CD and 2% (w/v) M-beta-CD in 100mM sodium phosphate (pH 2.5) as the running buffer, separation voltage -20 kV, detected at 200 nm and temperature controlled at 20 degrees C, a satisfactory separation of the six analytes was accomplished. The optimized method was validated for specificity, precision, linearity, accuracy and stability using sodium benzenesulfonate as the internal standard. The relative standard deviation for migration time was less than 0.58%, and 3.78% for peak area ratio. The linearity ranged from 0.005 to 0.25 mM. The recovery ranged from 95.9% to 108.3%. The limits of detection and limits of quantification for each enantiomer were 0.003 and 0.01 mM, respectively. This method was utilized for evaluating the chiral purity of five batches of Rotigotine.

Pooled analysis of data from multiple quantitative trait locus mapping populations

Quantitative trait locus (QTL) analysis on pooled data from multiple populations (pooled analysis) provides a means for evaluating, as a whole, evidence for existence of a QTL from different studies and examining differences in gene effect of a QTL among different populations. Objectives of this study were to: (1) develop a method for pooled analysis and (2) conduct pooled analysis on data from two soybean mapping populations. Least square interval mapping was extended for pooled analysis by inclusion of populations and cofactor markers as indicator variables and covariate variables separately in the multiple linear models. The general linear test approach was applied for detecting a QTL. Single population-based and pooled analyses were conducted on data from two F(2:3) mapping populations, Hamilton (susceptible) x PI 90763 (resistant) and Magellan (susceptible) x PI 404198A (resistant), for resistance to soybean cyst nematode (SCN) in soybean. It was demonstrated that where a QTL was shared among populations, pooled analysis showed increased LOD values on the QTL candidate region over single population analyses. Where a QTL was not shared among populations, however, the pooled analysis showed decreased LOD values on the QTL candidate region over single population analyses. Pooled analysis on data from genetically similar populations may have higher power of QTL detection than single population-based analyses. QTLs were identified by pooled analysis on linkage groups (LGs) G, B1 and J for resistance to SCN race 2 whereas QTLs on LGs G, B1 and E for resistance to SCN race 5 in soybean PI 90763 and PI 404198A. QTLs on LG G and B1 were identified in both PI 90763 and PI 404198A whereas QTLs on LG E and J were identified in PI 90763 only. QTLs on LGs G and B1 for resistance to race 2 may be the same or closely linked with QTLs on LG G and B1 for resistance to race 5, respectively. It was further demonstrated that QTLs on G and B1 carried by PI 90763 were not significantly different in gene effect from QTLs on LGs G and B1 in PI 404198A, respectively.

Identification of QTLs associated with resistance to soybean cyst nematode races 2, 3 and 5 in soybean PI 90763

Soybean cyst nematode (SCN) is a major soybean pest throughout the soybean growing regions in the world, including the USA. Soybean PI 90763 is an important SCN resistance source. It is resistant to several SCN populations including races 2, 3 and 5. But its genetics of resistance is not well known. The objectives of this study were to: (1) confirm quantitative trait loci (QTLs) for resistance to SCN race 3 in PI 90763 and (2) identify QTLs for resistance to SCN races 2 and 5. QTLs were searched in Hamilton x PI 90763 F(2:3)populations using 193 polymorphic simple sequence repeats (SSRs) covering 20 linkage groups (LGs). QTLs for resistance to SCN were identified on LGs A2, B1, E, G, J and L. The same QTL was suggested for resistance to different SCN races where their 1-LOD support intervals of QTL positions highly overlapped. The QTL on LG G was associated with resistance to races 2, 3 and 5. The QTL on LG B1 was associated with resistance to races 2 and 5. The QTL on LG J was associated with resistance to races 2 and 3. The QTLs on LGs A2 and L were associated with resistance to race 3. The QTL on LG E was associated with resistance to race 5. We conclude that LGs A2 and B1 may represent an important distinction between resistance to SCN race 3 and resistance to SCN races 2 and 5 in soybean.

Identification of QTLs associated with resistance to soybean cyst nematode races 2, 3 and 5 in soybean PI 90763

Soybean cyst nematode (SCN) is a major soybean pest throughout the soybean growing regions in the world, including the USA. Soybean PI 90763 is an important SCN resistance source. It is resistant to several SCN populations including races 2, 3 and 5. But its genetics of resistance is not well known. The objectives of this study were to: (1) confirm quantitative trait loci (QTLs) for resistance to SCN race 3 in PI 90763 and (2) identify QTLs for resistance to SCN races 2 and 5. QTLs were searched in Hamilton x PI 90763 F(2:3)populations using 193 polymorphic simple sequence repeats (SSRs) covering 20 linkage groups (LGs). QTLs for resistance to SCN were identified on LGs A2, B1, E, G, J and L. The same QTL was suggested for resistance to different SCN races where their 1-LOD support intervals of QTL positions highly overlapped. The QTL on LG G was associated with resistance to races 2, 3 and 5. The QTL on LG B1 was associated with resistance to races 2 and 5. The QTL on LG J was associated with resistance to races 2 and 3. The QTLs on LGs A2 and L were associated with resistance to race 3. The QTL on LG E was associated with resistance to race 5. We conclude that LGs A2 and B1 may represent an important distinction between resistance to SCN race 3 and resistance to SCN races 2 and 5 in soybean.

Multi-wavelength mid-infrared micro-spectral imaging using semiconductor lasers

Infrared (IR, 3-12-microm) microscopic spectral imaging is an important analytical technique. Many current instruments employ thermal IR light sources, which suffer the problem of low brightness and high noise. This paper evaluates the system engineering merit in using semiconductor lasers, which offer orders-of-magnitude-higher power, brightness, and lower noise. A microscopic spectral imaging system using semiconductor lasers (quantum cascade) as illuminators, and focal plane array detectors demonstrated a high signal-to-noise ratio (> 20 dB) at video frame rate for a large illuminated area. The comparative advantages of laser vs. thermal light source are analyzed and demonstrated. Microscopic spectral imaging with fixed-wavelength and tunable lasers of 4.6-, 5.1-, 6-, and 9.3-microm wavelength was applied to a number of representative samples that consist of biological tissues (plant and animal), solid material (a stack of laminated polymers), and liquid chemical (benzene). Transmission spectral images with approximately 30-dB dynamic range were obtained with clear evidence of spectral features for different samples. The potential of more advanced systems with a wide coverage of spectral bands is discussed.

[Preparation of DNA probe for Cryptosporidium parvum]

AIM

To prepare a probe with high specificity and sensitivity for the detection of Cryptosporidium parvum.

METHODS

Using PCR method, a fragment from the DNA of C. parvum was amplified. The PCR product, 452 bp DNA, was labeled with hapten digoxigenin.

RESULTS

Examination of sensitivity showed that the DNA probe could detect as low as 2 pg DNA from C. parvum. The dot-blot hybridizition assay showed that the probe hybridized with the DNA of C. parvum, but not hybridized with DNA of E. histolytica, G. lamblia, E. coli and D. bacilli.

CONCLUSION

The probe was highly specific and sensitive for the detection of C. parvum.