Multimodal imaging of hemorrhagic transformation biomarkers in an ischemic stroke model

Hemorrhagic transformation of ischemic stroke has devastating consequences, with high mortality and poor functional outcomes. Animal models of ischemic stroke also demonstrate the potential for hemorrhagic transformation, which complicates biochemical characterization, treatment studies, and hinders poststroke functional outcomes in affected subjects. The incidence of hemorrhagic transformation of ischemic stroke in animal model research is not commonly reported. The postmortem brain of such cases presents a complex milieu of biomarkers due to the presence of healthy cells, regions of varying degrees of ischemia, dead and dying cells, dysregulated metabolites, and blood components (especially reactive Fe species released from lysed erythrocytes). To improve the characterization of hemorrhage biomarkers on an ischemic stroke background, we have employed a combination of histology, X-ray fluorescence imaging (XFI), and Fourier transform infrared (FTIR) spectroscopic imaging to assess 122 photothrombotic (ischemic) stroke brains. Rapid freezing preserves brain biomarkers in situ and minimizes metabolic artifacts due to postmortem ischemia. Analysis revealed that 25% of the photothrombotic models had clear signs of hemorrhagic transformation. The XFI and FTIR metabolites provided a quantitative method to differentiate key metabolic regions in these models. Across all hemorrhage cases, it was possible to consistently differentiate otherwise healthy tissue from other metabolically distinct regions, including the ischemic infarct, the ischemic penumbra, blood vessels, sites of hemorrhage, and a region surrounding the hemorrhage core that contained elevated lipid oxidation. Chemical speciation of deposited Fe demonstrates the presence of heme-Fe and accumulation of ferritin.

Human dendritic cells adenovirally-engineered to express three defined tumor antigens promote broad adaptive and innate immunity

Dendritic cell (DC) immunotherapy has shown a promising ability to promote anti-tumor immunity in vitro and in vivo. Many trials have tested single epitopes and single antigens to activate single T cell specificities, and often CD8(+) T cells only. We previously found that determinant spreading and breadth of antitumor immunity correlates with improved clinical response. Therefore, to promote activation and expansion of polyclonal, multiple antigen-specific CD8(+) T cells, as well as provide cognate help from antigen-specific CD4(+) T cells, we have created an adenovirus encoding three full length melanoma tumor antigens (tyrosinase, MART-1 and MAGE-A6, "AdVTMM"). We previously showed that adenovirus (AdV)-mediated antigen engineering of human DC is superior to peptide pulsing for T cell activation, and has positive biological effects on the DC, allowing for efficient activation of not only antigen-specific CD8(+) and CD4(+) T cells, but also NK cells. Here we describe the cloning and testing of "AdVTMM2," an E1/E3-deleted AdV encoding the three melanoma antigens. This novel three-antigen virus expresses mRNA and protein for all antigens, and AdVTMM-transduced DC activate both CD8(+) and CD4(+) T cells which recognize melanoma tumor cells more efficiently than single antigen AdV. Addition of physiological levels of interferon-α (IFNα) further amplifies melanoma antigen-specific T cell activation. NK cells are also activated, and show cytotoxic activity. Vaccination with multi-antigen engineered DC may provide for superior adaptive and innate immunity and ultimately, improved antitumor responses.

Intraarticular measurement of forces acting on the canine medial meniscus during motion

Meniscal injuries are currently under much clinical investigation. With regard to tissue engineering strategies for meniscal repair or replacement, the direct measurement of forces applied on the meniscus, during range of motion, could provide important information. This in vitro study using canine cadaver limbs evaluated the possibility of measuring the tibial reaction force, at the medial meniscal level, with film pressure sensors.

The sensors were placed between the medial meniscus and the tibial plateau. With different preloads of the stifle, in proportion to the dog’s total body weight measurements were taken under constant motion with intact and artificially transected cranial cruciate ligament. With an intact cranial cruciate ligament the force peak, under the cranial horn, was found in extension, and under the caudal horn in flexion. Transection of the cranial cruciate ligament led to a rise in mean force under both of the horns. The rise in mean force was higher under the caudal horn compared to the cranial horn. Transection of the cranial cruciate ligament resulted in an altered curve pattern under the caudal medial meniscal horn, which was most apparent with the highest preloads. The sensors were easy to apply, the results substantiated commonly accepted biomechanical predictions and the experimental set-up was found to be a useful tool for the investigation of forces acting on the menisci.

A thin film pressure sensor was implanted under the cranial and caudal medial meniscal horn in 18 canine cadaver stifles and the forces recorded during a constant range of motion with intact and artificially transected cranial cruciate ligaments. The results reflected biomechanical predictions, and the experimental set-up was found to be a useful tool in the investigation of forces acting on the menisci.

Pelvic fractures in the dog and cat: a classification system and review of 556 cases

A system for the classification of pelvic fractures in small animals is described. The system is based on a review of 556 cases and adapted from the AO/ASIF classification system for fractures of long bones in humans and small animals. A coding method was created to encompass the multiple sites in pelvic fractures, and associate fracture location and morphology with complexity of therapy and prognosis. The classification is based on criteria derived from standard radiographs and well-defined in a glossary of terms. Illustrations of fracture configurations given by the codes facilitate the designation of codes to cases. This article introduces the classification system and reports the findings when applied to 556 cases of pelvic fractures.

Molecular cloning of plane pollen allergen Pla a 3 and its utility as diagnostic marker for peach associated plane pollen allergy

BACKGROUND

Non-specific lipid transfer proteins (nsLTP) are considered to provoke allergic symptoms to plane tree pollen, which are frequently associated with peach allergy.

OBJECTIVE

The objective was to clone the cDNA of plane pollen nsLTP Pla a 3, to characterize IgE-binding and allergenic potency of recombinant Pla a 3 in comparison to its natural counterpart and peach nsLTP Pru p 3.

METHODS

Natural Pla a 3 was purified from plane pollen and analysed by mass spectrometry (MS). Recombinant Pla a 3 was characterized by SDS-PAGE and CD spectroscopy. Specific IgE to extract, components of plane pollen and Pru p 3 was measured by ImmunoCAP in sera of patients allergic to either plane pollen (n = 10), peach (n = 15) or both (n = 15). Biological potency of the proteins was investigated by in vitro mediator release assays and IgE cross-reactivity by competitive ELISA.

RESULTS

Two Pla a 3 isoforms were identified. Recombinant Pla a 3 showed high purity, structural integrity, IgE-binding capacity comparable to nPla a 3 and biological potency. Sensitization to plane pollen extract was confirmed in 24/25 plane pollen allergics. The frequency of sensitization to Pla a 3 was 53% among patients allergic to both plane pollen and peach and 10% among plane pollen allergics tolerating peach where most patients were sensitized to Pla a 1. Pla a 3 and Pru p 3 showed strong bi-directional IgE cross-reactivity in patients allergic to peach and plane pollen, but not in peach allergics tolerating plane pollen. Levels of IgE-binding were generally higher to Pru p 3 than to Pla a 3.

CONCLUSION

Sensitization to Pla a 3 is relevant in a subgroup of plane pollen allergics with concomitant peach allergy. IgE testing with Pla a 3 may serve as a marker to identify plane pollen allergic patients at risk of LTP-mediated food reactions and thereby improve in vitro diagnostic procedures.

Initial operation of a newly developed multichord motional Stark effect diagnostic in KSTAR

A photo-elastic modulator based 25-chord motional Stark effect (MSE) diagnostic has been successfully developed and commissioned in Korea Superconducting Tokamak Advanced Research. The diagnostic measures the radial magnetic pitch angle profile of the Stark splitting of a D-alpha line at 656.1 nm by the electric field associated with the neutral deuterium heating beam. A tangential view of the neutral beam provides a good spatial resolution of 1-3 cm for covering the major radius from 1.74 m to 2.28 m, and the time resolution is achieved at 10 ms. An in-vessel calibration before the vacuum closing as well as an in situ calibration during the tokamak operation was performed by means of specially designed polarized lighting sources. In this work, we present the final design of the installed MSE diagnostic and the first results of the commissioning.

Cellular sentinels for heat shock protein-peptide complexes in vivo. (P4270)

Heat shock proteins (HSPs), such as gp96, harvested from cancer cells elicit potent anti-tumor immunity in mice and in patients with cancer. HSPs in the extracellular environment, released by cells or introduced through vaccination, are taken up by antigen presenting cells of the immune system, which allows for cross-presentation of the HSP-chaperoned peptides to T-cells. The goal of this study is to identify the subset(s) of cells that sample HSPs in vivo prior to initiating T cell responses. By vaccinating mice with fluorescent-labeled gp96, cells in the draining lymph node (dLN) that engage extracellular HSPs have been explored in a time and dose dependent manner. Our results show that CD4+CD11b+ cells are the predominant cells that internalized the HSP in the subcapsular region of the dLN while CD11c+CD8+ cells, which have been shown by other groups to be the major cross-priming dendritic cells, did not significantly internalize the HSP at any time points. Other CD11c+ cells did not appreciably internalize HSP until 24+ hours after. Internalization corresponded to higher CD91 expression by the CD4+CD11b+ cell subset. The functional capabilities of the CD4+CD11b+ and CD11c+ cells in T cell priming are examined. These studies illustrate how HSPs act to alert the immune system to cellular damage and will be useful for optimizing HSP-based vaccination regimes by identifying possible cellular targets.

Cellular sentinels for Heat Shock Protein-peptide complexes in vivo. (52.15)

Heat shock proteins (HSPs), such as gp96, harvested from cancer cells elicit potent anti-tumor immunity in mice and in patients with cancer. HSPs in the extracellular environment, released by cells or introduced through vaccination, are taken up by antigen presenting cells of the immune system, which allows for cross-presentation of the HSP-chaperoned peptides to T-cells. The goal of this study is to identify the subset(s) of cells that sample HSPs in vivo prior to initiating T cell responses. By vaccinating mice with fluorescent-labeled gp96, cells in the draining lymph node (dLN) that engage extracellular HSPs have been explored in a time and dose dependent manner. Our results show that CD4+CD11b+ cells are the predominant cells that internalized the HSP in the subcapsular region of the dLN while total CD11c+ cells internalized minor amounts of HSP. Upon further subtyping, CD8+CD11c+ cells, which have been shown by other groups to be the major cross-priming dendritic cells, did not significantly internalize the HSP. The ability of the CD4+CD11b+ and CD11c+ cells to prime T cells is examined to demonstrate cross-presenting function following internalization. These studies illustrate how HSPs act to alert the immune system of cellular damage and will be useful for optimizing HSP-based vaccination regimes by identifying possible cellular targets.

Francisella tularensis LVS-induced Interleukin-12 p40 cytokine production mediates dendritic cell migration through IL-12 Receptor β1

Three cytokines use the IL-12p40 cytokine subunit namely: IL-12p70 (IL-12-comprised of IL-12p40 and IL-12p35), IL-23 (comprised of the IL-12p40 and IL-23p19 subunits) and homodimeric IL-12p40 (IL-12(p40)(2)). Following activation, immature dendritic cells (DCs) upregulate the chemokine receptor Chemokine-C-Receptor 7 (CCR7), and migrate in response to homeostatic chemokines such as chemokine (C-C motif) ligand 19 (CCL19). Induction of the cytokine IL-12p40 in response to pathogen-exposure, likely in its homodimeric form, is one of the primary events that mediates migration of DCs in response to CCL19. Here we show that following exposure to Francisella tularensis Live Vaccine Strain (LVS), DCs produce IL-12p40 and promote the migration of DCs to the chemokine CCL19 in an IL-12Rβ1- and IL-12p(40)(2)-dependent manner. Induction of IL-12p40 and resulting chemokine responsiveness in DCs is TLR2-dependent and coincides with the uptake of F. tularensis LVS and activation of DCs. Importantly, we show that IL-12Rβ1 signaling is required for DC migration from the lung to the draining lymph node following F. tularensis LVS exposure and coincides with accumulation of IL-12p40 expressing DCs in the draining lymph nodes. Together, these findings illustrate that IL-12p40 is induced rapidly in response to F. tularensis LVS and is required for DC migration through an IL-12Rβ1-IL-12(p40)(2) dependent mechanism.

Cellular sentinels for Heat Shock Protein-peptide complexes in vivo. (100.1)

Heat shock proteins (HSPs) released into the extra cellular environment via cell death or through vaccination are taken up by antigen presenting cells of the immune system. HSP-chaperoned peptides are then cross-presented for priming of specific T cell responses. Our goal is to identify the subset(s) of cells that sample HSPs in vivo and then initiate T cell priming. By introducing a fluorescent labeled HSP into mice, cells in the draining lymph node that engage extracellular HSP have been identified. Our data demonstrate that CD4+CD11c+ dendritic cells (DC) are the predominant cells that internalize the HSP, while CD8+CD11c+ DCs did not significantly internalize the HSP. The localization of these cells within the lymph node and their ability to prime T cells are examined. These studies illustrate how HSPs act to alert the immune system of cellular damage and will be useful for optimizing HSP-based vaccination regimes in clinical studies of cancer patients.

In vivo analysis of cellular sentinels for extracellular Heat Shock Protein-peptide complexes. (101.2)

Heat shock proteins are expressed in all cells and chaperone protein and peptide cargoes within cells. Based on their abundance and intracellular localization, HSPs in the extracellular environment have been described as indicators of cellular/membrane damage. Thus, the immune system is designed to detect HSPs in the extracellular environment (either released from dying cells or by immunization) by cell surface receptors such as CD91. Our goal is to identify the subset(s) of antigen presenting cells that detect extracellular HSPs and initiate the immune response. By introducing fluorescent labeled HSPs into mice, cells in the draining lymph node that engage extracellular HSP can be tracked. Our data demonstrates that the CD4+CD11c+ dendritic cells are the predominant antigen presenting cell that internalizes the HSP. The ability of these cells to cross-present HSP-chaperoned peptides and provide co-stimulation is under investigation. These studies will be important for understanding how endogenous HSPs act to alert the immune system of cellular damage and for optimizing immunization regimens with HSP-based vaccines.

Interleukin-17 is required for T helper 1 cell immunity and host resistance to the intracellular pathogen Francisella tularensis

The importance of T helper type 1 (Th1) cell immunity in host resistance to the intracellular bacterium Francisella tularensis is well established. However, the relative roles of interleukin (IL)-12-Th1 and IL-23-Th17 cell responses in immunity to F. tularensis have not been studied. The IL-23-Th17 cell pathway is critical for protective immunity against extracellular bacterial infections. In contrast, the IL-23-Th17 cell pathway is dispensable for protection against intracellular pathogens such as Mycobacteria. Here we show that the IL-23-Th17 pathway regulates the IL-12-Th1 cell pathway and was required for protective immunity against F.tularensis live vaccine strain. We show that IL-17A, but not IL-17F or IL-22, induced IL-12 production in dendritic cells and mediated Th1 responses. Furthermore, we show that IL-17A also induced IL-12 and interferon-gamma production in macrophages and mediated bacterial killing. Together, these findings illustrate a biological function for IL-17A in regulating IL-12-Th1 cell immunity and host responses to an intracellular pathogen.

Retrospective study of indications for and outcome of perineal urethrostomy in cats

OBJECTIVES

To evaluate indications for and outcome of perineal urethrostomy in cats.

METHODS

The medical records of 59 cats that had undergone perineal urethrostomy were evaluated. Short-term follow up information (for a period of four weeks following surgery) was available for all of the cats. Long-term follow up information (for a period of at least four months) was available for 39 cats.

RESULTS

Early complications occurred in 25.4 per cent of cats and late complications were observed in 28.2 per cent of cats. The most frequent late complication was recurring bacterial urinary tract Infection.

CLINICAL SIGNIFICANCE

Despite frequent complications and recurring signs of lower urinary tract disease, 32.2 per cent of the cats had a disease-free long-term outcome (mean four years, median 3.9 years), and 88.6 per cent of clients interviewed thought that their cats had a good quality of life after surgery.

Glenoid dysplasia and bicipital tenosynovitis in a Maine coon cat

This report describes a rare case of bicipital tenosynovitis in a Maine coon cat. The cat, a three-and-half-year-old neutered female, presented with chronic weightbearing lameness of the left forelimb. Flexion of the left glenohumeral joint and extension of the left cubital joint were resented, and palpation of the biceps brachii tendon in the bicipital groove elicited pain. A mild incongruity of the joint with mild degenerative changes was seen radiographically. Glenohumeral joint dysplasia was suspected. Ultrasound examination revealed marked thickening of the bicipital tendon and moderate effusion of the left bicipital tendon sheath. Positive contrast radiography of the joint confirmed dilation of the tendon sheath. A tentative diagnosis of bicipital tenosynovitis was made and confirmed on arthrotomy. Surgical removal of osteophytes resulted in the cat being free from pain but a mild lameness recurred six months after surgery.

Tagging and validation of a major quantitative trait locus for leaf rust resistance and leaf tip necrosis in winter wheat cultivar forno

ABSTRACT A major leaf rust (Puccinia triticina) resistance quantitative trait locus (QTL) (QLrP.sfr-7DS) previously has been described on chromosome 7DS in the winter wheat (Triticum aestivum) cv. Forno. It was detected in a population of single-seed descent (SSD) lines derived from the cross Arina x Forno. QLrP.sfr-7DS conferred a durable and slow-rusting resistance phenotype, co-segregated with a QTL for leaf tip necrosis (LTN) and was mapped close to Xgwm295 at a very similar location as the adult plant leaf rust resistance gene Lr34 found in some spring wheat lines. Here, we describe the validation of this QTL by mapping it to the same chromosomal region close to Xgwm295 on chromosome 7DS in a population of SSD lines from the winter wheat x spelt (T. spelta) cross Forno x Oberkulmer. In both populations, the log of the likelihood ratio curves for leaf rust resistance and LTN peaked at identical or very similar locations, indicating that both traits are due to the same gene. We have improved the genetic map in the target region of QLrP.sfr-7DS using microsatellite and expressed sequence tag (EST) markers. Two EST loci (Xsfr.BF473324 and Xsfr.BE493812) define a genetic interval of 7.6 centimorgans containing QLrP.sfr-7DS, a considerably more precise genetic location for this QTL than previously described both in spring and winter wheat. The identified genetic interval is physically located in the distal 39% of chromosome 7DS. Single-marker analysis identified Xsfr.BF473324 and Xgwm1220 as the most informative loci for QLrP.sfr-7DS and QLtn.sfr-7DS. In the rice genome, the two ESTs flanking the QLrP.sfr-7DS/QLtn.sfr-7DS chromosomal segment in wheat are conserved on chromosome 6S in a region colinear with wheat chromosome 7DS. There, they define a physical region of three rice bacterial artificial chromosomes spanning approximately 300 kb.

QTL analysis of resistance to Fusarium head blight in Swiss winter wheat (Triticum aestivum L.)

Fusarium head blight (FHB) of wheat is a widespread and destructive disease which occurs in humid and semi-humid areas. FHB epidemics can cause serious yield and quality losses under favorable climatic conditions, but the major concern is the contamination of grains with mycotoxins. Resistance to FHB is quantitatively inherited and greatly influenced by the environment. Its evaluation is costly and time-consuming. The genetic basis of FHB resistance has mainly been studied in spring wheat. The objective of this study was to map quantitative trait loci (QTLs) for resistance to FHB in a population of 240 recombinant inbred lines (RILs) derived from a cross between the two Swiss winter wheat cultivars Arina (resistant) and Forno (susceptible). The RILs were genotyped with microsatellite and RFLP markers. The resulting genetic map comprises 380 loci and spans 3,086 cM. The 240 RILs were evaluated for resistance to FHB in six field trials over 3 years. Composite interval mapping (CIM) analyses carried out on FHB AUDPC (i.e. mean values across six environments) revealed eight QTLs which altogether explained 47% of the phenotypic variance. The three main QTLs were mapped on the long arms of chromosomes 6D ( R(2)=22%), 5B ( R(2)=14%) and 4A ( R(2)=10%). The QTL detected on 5B originated from the susceptible parent Forno. Other QTLs with smaller effects on FHB resistance were detected on chromosomes 2AL, 3AL, 3BL, 3DS and 5AL.

Desfluran bei akute intermittierender Porphyrie

Despite the low incidence of the acute porphyrias, a profound knowledge of the disease is essential for anaesthesiologists, as a variety of perioperatively administered drugs are potential triggers of an acute attack. There is an ongoing discussion about the use of volatile anaesthetics in porphyrias, but halothane and isoflurane seem to be safe. There is no clinical data or case report about the use of desflurane in this specific patient group, but its fast and relatively unchanged elimination and the minimal induction of the cytochrome P 450 system seem to be favorable in this setting. We report the use of desflurane in a patient with acute intermittent porphyria, scheduled for hemihepatectomy. To minimize perioperative distress by pain or the need for postoperative mechanical ventilation, we chose a balanced anaesthesia technique with desflurane, sufentanil and atracurium in combination with a continuous epidural analgesia (bupivacain and fentanyl) for the postoperative period. Preoperatively the porphyrin precursors were analyzed in serum and urine and postoperatively the 24 h-urine was screened every 2 days until postoperative day 6 to monitor the porphyria activity. The preoperative data showed high concentrations of porphyrin precursor excretion, confirming the diagnosis of AIP. The postoperative data in the 24 h-urine were significantly lower than preoperative levels and reached normal levels at postoperative day 5. There were no clinical symptoms of a porphyric attack during the postoperative hospitalization. The patient was discharged on postoperative day 21 in excellent condition. We conclude that our perioperative management prevented an acute porphyric attack in this case. Desflurane might be a valuable alternative to other hypnotics in patients with AIP.

Dissection of quantitative and durable leaf rust resistance in Swiss winter wheat reveals a major resistance QTL in the Lr34 chromosomal region

The Swiss winter bread wheat cv. 'Forno' has a highly effective, durable and quantitative leaf rust ( Puccinia triticina Eriks.) resistance which is associated with leaf tip necrosis (LTN). We studied 240 single seed descent lines of an 'ArinaxForno' F(5:7 )population to identify and map quantitative trait loci (QTLs) for leaf rust resistance and LTN. Percentage of infected leaf area (%) and the response to infection (RI) were evaluated in seven field trials and were transformed to the area under the disease progress curves (AUDPC). Using composite interval mapping and LOD >4.4, we identified eight chromosomal regions specifically associated with resistance. The largest and most consistent leaf rust resistance locus was identified on the short arm of chromosome 7D (32.6% of variance explained for AUDPC_% and 42.6% for AUDPC_RI) together with the major QTL for LTN ( R(2)=55.6%) in the same chromosomal region as Lr34 ( Xgwm295). A second major leaf rust resistance QTL ( R(2)=28% and 31.5%, respectively) was located on chromosome arm 1BS close to Xgwm604 and was not associated with LTN. Additional minor QTLs for LTN (2DL, 3DL, 4BS and 5AL) and leaf rust resistance were identified. These latter QTLs might correspond to the leaf rust resistance genes Lr2 or Lr22 (2DS) and Lr14a (7BL).

An integrative genetic linkage map of winter wheat (Triticum aestivum L.)

We constructed a genetic linkage map based on a cross between two Swiss winter wheat ( Triticum aestivum L.) varieties, Arina and Forno. Two-hundred and forty F(5) single-seed descent (SSD)-derived lines were analysed with 112 restriction fragment length polymorphism (RFLP) anonymous probes, 18 wheat cDNA clones coding for putative stress or defence-related proteins and 179 simple-sequence repeat (SSR) primer-pairs. The 309 markers revealed 396 segregating loci. Linkage analysis defined 27 linkage groups that could all be assigned to chromosomes or chromosome arms. The resulting genetic map comprises 380 loci and spans 3,086 cM with 1,131 cM for the A genome, 920 cM for the B genome and 1,036 cM for the D genome. Seventeen percent of the loci showed a significant ( P < 0.05) deviation from a 1:1 ratio, most of them in favour of the Arina alleles. This map enabled the mapping of QTLs for resistance against several fungal diseases such as Stagonospora glume blotch, leaf rust and Fusarium head blight. It will also be very useful for wheat genetic mapping, as it combines RFLP and SSR markers that were previously located on separate maps.

Detection of QTLs for Stagonospora glume blotch resistance in Swiss winter wheat

Stagonospora nodorum is the causal agent of the Stagonospora glume blotch disease in hexaploid wheat. The Swiss winter bread wheat cv. 'Arina' has a highly effective, durable and quantitative glume blotch resistance. We studied 240 single seed descent (SSD)-derived lines of an 'Arina x Forno' F(5:7) population to identify and map quantitative trait loci (QTLs) for glume blotch resistance under natural infestation. Using composite interval mapping (CIM) and LOD>4.5, we detected two chromosomal regions on chromosome arms 3BS and 4BL which were specifically associated with glume blotch resistance. These identified QTLs were designated QSng.sfr-3BS and QSng.sfr-4BL, respectively. QSng.sfr-3BS peaked at the locus Xgwm389 in the telomeric region of the short arm of chromosome 3B and explained 31.2% of the observed phenotypic variance for the resistance within the population. The responsible QSng.sfr-3BS allele originated from the resistant parent 'Arina'. The QTL QSng.sfr-4BL (19.1%) mapped to chromosome arm 4BL ('Forno' allele) very close to two known genes, TaMlo and a catalase ( Cat). Both QTL alleles combined could enhance the resistance level by about 50%. Additionally, they showed significant epistatic effects (4.4%). We found PCR-based microsatellite markers closely linked to QSng.sfr-3BS (gwm389) and QSng.sfr-4BL (gwm251) which make marker-assisted selection (MAS) for Stagonospora glume blotch resistance feasible. We also found one resistance QTL, QSng.sfr-5BL, on the long arm of chromosome 5B which overlapped with QTLs for plant height as well as heading time.

Urethral entrapment following pelvic fracture fixation in a dog

An 18-month-old female crossbred dog was presented with a unilateral sacroiliac luxation and separation of the pelvic symphysis. Surgical correction of the luxation with screw fixation led to entrapment of the urethra between the symphyseal parts of the two hemipelves.

Molecular markers as a tool to verify sexual and apomictic off-spring of intraspecific crosses in Hypericum perforatum

The aim of this project was to establish RAPD markers to determine the percentage of sexual off-spring of the facultative apomictic plant species H. perforatum. We did reciprocal crosses between four different accessions (A x B, B x A, C x D, D x C) by mechanical emasculation and hand pollination. Genomic DNA of the parents and the off-spring was isolated and PCR conditions were optimized in order to obtain reproducible bands with RAPD markers. Of the 260 screened RAPD primers 127 revealed polymorphism between the parental lines of A and B, whereas 53 revealed no amplification products. Each progeny was tested for the presence of paternal bands with three primers. We found no sexual off-spring among the 22 progenies of A x B, the nine progenies of B x A and the ten progenies of D x C. However, we detected six sexual off-spring among the 45 progenies of C x D. We have proved that RAPD markers can be used to distinguish between sexual and apomictic off-spring in H. perforatum and that sexual off-spring can be obtained from intraspecific crosses. The percentage of sexual progeny might depend on the genotype of the parental lines.

A corrinoid-dependent catabolic pathway for growth of a Methylobacterium strain with chloromethane

Methylobacterium sp. strain CM4, an aerobic methylotrophic alpha-proteobacterium, is able to grow with chloromethane as a carbon and energy source. Mutants of this strain that still grew with methanol, methylamine, or formate, but were unable to grow with chloromethane, were previously obtained by miniTn5 mutagenesis. The transposon insertion sites in six of these mutants mapped to two distinct DNA fragments. The sequences of these fragments, which extended over more than 17 kb, were determined. Sequence analysis, mutant properties, and measurements of enzyme activity in cell-free extracts allowed the definition of a multistep pathway for the conversion of chloromethane to formate. The methyl group of chloromethane is first transferred by the protein CmuA (cmu: chloromethane utilization) to a corrinoid protein, from where it is transferred to H4folate by CmuB. Both CmuA and CmuB display sequence similarity to methyltransferases of methanogenic archaea. In its C-terminal part, CmuA is also very similar to corrinoid-binding proteins, indicating that it is a bifunctional protein consisting of two domains that are expressed as separate polypeptides in methyl transfer systems of methanogens. The methyl group derived from chloromethane is then processed by means of pterine-linked intermediates to formate by a pathway that appears to be distinct from those already described in Methylobacterium. Remarkable features of this pathway for the catabolism of chloromethane thus include the involvement of a corrinoid-dependent methyltransferase system for dehalogenation in an aerobe and a set of enzymes specifically involved in funneling the C1 moiety derived from chloromethane into central metabolism.

Comparative mapping of the two wheat leaf rust resistance loci Lr1 and Lr10 in rice and barley

The wheat genome is large, hexaploid, and contains a high amount of repetitive sequences. In order to isolate agronomically important genes from wheat by map-based cloning, a simpler model of the genome must be used for identifying candidate genes. The objective of this study was to comparatively map the genomic regions of two wheat leaf rust disease resistance loci, Lr1 and Lr10, in the putative model genomes of rice and barley. Two probes cosegregating with the Lr1 gene on chromosome 5DL of wheat were studied. The rice sequences corresponding to the two probes were isolated and mapped. The two probes mapped to two different rice chromosomes, indicating that the organization of the region orthologous to Lr1 is different in rice and wheat. In contrast, synteny was conserved between wheat and barley in this chromosomal region. The Lrk10 gene cosegregated with Lr10 on chromosome 1AS in wheat. The rice gene corresponding to Lrk10 was mapped on rice chromosome 1, where it occurred in many copies. This region on rice chromosome 1 corresponds to the distal part of the group 3S chromosomes in Triticeae. The synteny is conserved between rice chromosome 1 and the Triticeae group 3S chromosomes up to the telomere of the chromosomes. On group 3S chromosomes, we found a gene that is partially homologous to Lrk10. We conclude that in the genomic regions studied, there is limited and only partially useful synteny between wheat and rice. Therefore, barley should also be considered as a model genome for isolating the Lr1 and Lr10 genes from wheat.

Metabolism of Dichloromethane by the Strict Anaerobe Dehalobacterium formicoaceticum

The metabolism of dichloromethane by Dehalobacterium formicoaceticum in cell suspensions and crude cell extracts was investigated. The organism is a strictly anaerobic gram-positive bacterium that utilizes exclusively dichloromethane as a growth substrate and ferments this compound to formate and acetate in a molar ratio of 2:1. When [C]dichloromethane was degraded by cell suspensions, formate, the methyl group of acetate, and minor amounts of methanol were labeled, but there was no nuclear magnetic resonance signal corresponding to the carboxyl group of acetate. This finding and previously established carbon and electron balances suggested that dichloromethane was converted to methylene tetrahydrofolate, of which two-thirds was oxidized to formate while one-third gave rise to acetate by incorporation of CO(2) from the medium in the acetyl coenzyme A synthase reaction. When crude desalted extracts were incubated in the presence of dichloromethane, tetrahydrofolate, ATP, methyl viologen, and molecular hydrogen, dichloromethane and tetrahydrofolate were consumed, with the concomitant formation of stoichiometric amounts of methylene tetrahydrofolate. The in vitro transfer of the methylene group of dichloromethane onto tetrahydrofolate required substoichiometric amounts of ATP. The reaction was inhibited in a light-reversible fashion by 20 muM propyl iodide, thus suggesting involvement of a Co(I) corrinoid in the anoxic dehalogenation of dichloromethane. D. formicoaceticum exhibited normal growth with 0.8 mM sodium in the medium, and crude extracts contained ATPase activity that was partially inhibited by N,N'-dicyclohexylcarbodiimide and azide. During growth with dichloromethane, the organism thus may conserve energy not only by substrate-level phosphorylation but also by a chemiosmotic mechanism involving a sodium-independent F(0)F(1)-type ATP synthase.

Genetic and physical characterization of the LR1 leaf rust resistance locus in wheat (Triticum aestivum L.)

The objective of this study was to characterize the leaf rust resistance locus Lr1 in wheat. Restriction fragment length polymorphism (RFLP) analysis was performed on the resistant line Lr1/6* Thatcher and the susceptible varieties Thatcher and Frisal, as well as on the segregating F2 populations. Seventeen out of 37 RFLP probes mapping to group 5 chromosomes showed polymorphism between Lr1/6* Thatcher and Frisal, whereas 11 probes were polymorphic between the near-isogenic lines (NILs) Lr1/6* Thatcher and Thatcher. Three of these probes were linked to the resistance gene in the segregating F2 populations. One probe (pTAG621) showed very tight linkage to Lr1 and mapped to a single-copy region on chromosome 5D. The map location of pTAG621 at the end of the long arm of chromosome 5D was confirmed by the absence of the band in the nulli-tetrasomic line N5DT5B of Chinese Spring and a set of deletion lines of Chinese Spring lacking the distal part of 5DL. Twenty-seven breeding lines containing the Lr1 resistance gene in different genetic backgrounds showed the same band as Lr1/6* Thatcher when hybridized with pTAG621. The RFLP marker was converted to a sequence-tagged-site marker using polymerase chain reaction (PCR) amplification. Sequencing of the specific fragment amplified from both NILs revealed point mutations as well as small insertion/deletion events. These were used to design primers that allowed amplification of a specific product only from the resistant line Lr1/6* Thatcher. This STS, specific for the Lr1 resistance gene, will allow efficient selection for the disease resistance gene in wheat breeding programmes. In addition, the identification of a D-genome-specific probe tightly linked to Lr1 should ultimately provide the basis for positional cloning of the gene.

Spectral properties of human placental aldose reductase and aldehyde reductase II

Circular dichroism and fluorescence spectra of aldose reductase (E.C.1.1.1.21) and aldehyde reductase II (E.C.1.1.1.19) purified to homogeneity from human placenta have been studied. The alpha helical content of aldose reductase and aldehyde reductase II was 51% and 56%, respectively, whereas no beta helical structure was found in either case. In the case of aldose reductase, the secondary structure was unaffected at alkaline pH (9.5), whereas a drastic alteration in the structure was observed at 58 degrees C. The secondary structure of aldehyde reductase II, on the other hand, remained unaffected at higher pH and temperature.

Comparative studies of beta s-crystallins from human, bovine, rat and rabbit lenses

Soluble extracts from young bovine, human, rat and rabbit lenses were fractionated by high resolution size-exclusion chromatography to demonstrate the existence of three discrete size-classes of monomeric crystallins in each species. These were identified by ion exchange chromatography, amino acid analysis, SDS electrophoresis and isoelectric focusing as the beta s-, gamma A- and gamma B-crystallins. Conventional SDS electrophoretic analysis of these proteins revealed apparent Mr values of about 23kD, 22kD and 19kD, respectively. Similar analysis in the presence of 6 M urea showed the proteins all co-migrated with an apparent Mr of about 20,500, which is far more consistent with the molecular weights calculated from beta s- and gamma-crystallin sequence data. Amino acid compositions of all the beta s samples indicate a high degree of homology to the bovine protein, whose sequence is known. The different species beta s-crystallins showed other general similarities in size, charge, thiol content and secondary structural properties. On the other hand, near UV CD and fluorescence emission and energy transfer measurements indicate that these proteins have subtle yet significant differences in their tertiary structures. Unlike the gamma-crystallins, the secondary structure of all of the beta s samples is completely denatured in the presence of 8 M urea at 20 degrees C.

High-molecular-weight protein aggregates of calf and cow lens: spectroscopic evaluation

To gain insight into the molecular features of the high-molecular-weight (HMW) fraction of soluble lens proteins and their changes in aging, we isolated this fraction from the nucleus of calf and cow lenses and measured fluorescence and circular dichroism (CD) properties of the samples. Not only was there an increase in the HMW fraction in the older lens, but there was also an age-related difference in tertiary structure that was clearly manifested in the fluorescence and CD parameters. The far-u.v. CD of low- and high-molecular-weight proteins do not differ significantly in band position and magnitude, but the near-u.v. CD of HMW protein does differ distinctly from that of all other crystallins (alpha, beta and gamma); the entire CD spectrum of this protein is displayed in the negative region. Millipore filtration further revealed that HMW aggregates are essentially a polydisperse population of different conformation (tertiary structure) and that these aggregates are associated by non-convalent interactions. This association is caused mainly by the apolar (hydrophobic) nature of the constituent protein. alpha-Crystallin has more hydrophobic domain along the peptide chain that do other crystallins and thus is likely to be the predominant protein in HMW aggregates.