Search Results - (Author, Cooperation:C. Gebhardt)

2013-05-11

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2018-01-18

The American Society for Microbiology (ASM)

0022-538X

1098-5514

Medicine

2011-10-29

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Calcium/chemistry ; Calmodulin/*chemistry ; Kinetics ; Markov Chains ; Optical Tweezers ; Protein Conformation ; Protein Folding ; Protein Structure, Tertiary ; Thermodynamics

0005-2736

(Electron microscopy) ; Membrane protein ; Membrane structure ; Phase separation ; Picture analysis

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] The observation that clusters of neutral H2O () or SO2 (ref. 5) molecules, on impact with essentially any solid surface, can decay efficiently into positively and negatively charged fragments has defied explanation, not least because the kinetic energy ...

Electronic Resource

0014-5793

Anoxia ; Heart cell ; K"A"T"P channel ; Patch clamp

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0196-9781

''Incretin'' deficiency ; Conscious Beagle dog ; Entero-insular axis of insulin ; Oral and intravenous glucose administration ; Pancreas atrophy ; Pancreatic duct occlusion ; Somatostatin ; VIP ; VIP is no ''incretin''

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1432-2323

Springer Online Journal Archives 1860-2000

Medicine

Résumé L'article analyse 117 duodénopancréatectomies pour pancréatite chronique, 49 partielles et 68 totales. La mortalité opératoire a été 8.2% pour les résections partielles et de 20.6% pour les totales. Les opérés ont été suivis pendant 6 1/2 années: 76% des résections partielles et 63% des totales ont continué à boire autant d'alcool qu'avant l'intervention. Avant pancréatectomie totale, 42% des malades étaient diabétiques; après cette opération, tous avaient un diabète, difficile à équilibrer à l'insuline dans 75% des cas qui ont souffert d'épisodes répétés de choc hypoglycémique. La mortalité tardive a été de 20.4% après duodénopancréatectomie partielle et de 19.1% après résection totale. Après pancréatectomie totale, 50% des décès tardifs ont été dus aux accidents d'hypoglycémie. A la fin de la période de follow-up, la survie du groupe pancréatectomie totale est de 11% inférieure à celle des résections partielles. La pancréactectomie totale n'est justifiée que chez les malades qui ont, avant l'intervention, un diabète exigeant l'administration d'insuline. Nous décrivons une nouvelle technique qui réalise, après résection de la tête du pancréas, une occlusion des canaux pancréatiques par injection d'une solution d'acides aminés à prise rapide, ce qui entraîne après quelques semaines une atrophie du pancréas exocrine. Cette technique a été utilisée chez 39 malades, avec 2.5% de décès et 7.6% de complications postopératoires. Nous estimons que cette nouvelle technique peut réduire nettement le risque opératoire de la duodénopancréatectomie partielle pour pancréatite chronique et améliorer les résultats à long terme.

Abstract This is a report of 117 pancreaticoduodenectomies performed for chronic pancreatitis, of which 49 were partial and 68 were total. The operative mortality rate of partial pancreaticoduodenectomy was 8.2% and of total pancreatectomy was 20.6%. During a follow-up period of 6 1/2 years, 76% and 63% of the surgical patients, respectively, continued to drink alcohol as heavily as before. Prior to total pancreatectomy, only 42% of the patients had diabetes. After total extirpation of the organ, all had diabetes and 75% were very difficult to stabilize with insulin, experiencing repeated episodes of hypoglycemic shock. The additional late mortality rate was 20.4% following partial pancreaticoduodenectomy and 19.1% after total resection. After total pancreatectomy, 50% of the late deaths were due to hypoglycemia. After total pancreatectomy, 11% fewer patients were still alive at the end of the follow-up period than after partial pancreaticoduodenectomy. Total pancreatectomy is justified only in patients who already have diabetes requiring insulin. A new technique is described in which, following resection of the head of the pancreas, the duct system is occluded by injection of a rapidly hardening amino acid solution, leading to atrophy of the excretory pancreas within a few weeks. This procedure has been carried out in 39 patients with a mortality rate of 2.5% and postoperative complications in 7.6%. We believe that the immediate risk of partial pancreaticoduodenectomy in chronic pancreatitis can be decreased markedly and the late results improved by this new technique.

Electronic Resource

1432-2323

Springer Online Journal Archives 1860-2000

Medicine

Résumé Le cancer gastrique précoce est défini par un carcinome dont la localisation est limitée à la muqueuse et la sous muqueuse. En fonction de cette définition on peut considérer 2 types de carcinome le cancer muqueux et le cancer sous muqueux. L'existence ou non de métastases ganglionnaires n'est pas à prendre en considération dans la définition. Les progrès les plus marqués dans la détection du cancer de l'estomac ont été faits au Japon depuis 1960. Dès maintenant, près de 30% de tous les malades qui présentènt un cancer de l'estomac sont traités à un stade précoce dans ce pays. Cependant, en Europe, des progrès ont été également atteints. Avant la pratique de l'endoscopie le taux des cancers traités à un stade précoce était inférieur à 3%. Depuis lors il s'est élevé à 6% dans la plupart des pays européens et a même atteint 16% dans notre formation hospitalière. Le diagnostic de cancer précoce est établi le plus souvent par endoscopie. Le taux de fiabilité de la gastroscopie est d'environ 92% (Rösch) et atteint même 98% lorsque l'endoscopie est compétée par la biopsie. En raison du fait que le cancer de l'estomac est multifocal dans plus de 10%, l'endoscopiste doit systématiquement rechercher une seconde ou une troisième localisation au niveau de la totalité de l'estomac. Pour établir fermement le diagnostic de cancer en présence d'une ulcération, de multiples prélèvements doivent être effectués aussi bien au niveau du fond que des bords de l'ulcération. Les lésions ulcéreuses malignes pouvant régresser de temps en temps et même cicatrisées les prélèvements doivent être faits en présence de lésions cicatricielles. Lorsque les lésions revêtent un type polypöide, une large excision est nécessaire pour établir le diagnostic. Dans quelques cas choisie, elle représente une méthode thérapeutique.

Abstract In the last 10 years, 130 patients with early gastric carcinoma were operated on at the Surgical University Clinic of Erlangen. The ulcerous type was the most frequent (85%) and had the best prognosis with a 5-year survival rate of 87% excluding operative mortality, and 100% when agecorrected.

Electronic Resource

1432-2242

Key words Chromosome identification ; Physical mapping ; FISH ; BAC ; Molecular cytogenetics ; Potato

Springer Online Journal Archives 1860-2000

Biology

Abstract  Reliable and easy to use techniques for chromosome identification are critical for many aspects of cytogenetic research. Unfortunately, such techniques are not available in many plant species, especially those with a large number of small chromosomes. Here we demonstrate that fluorescence in situ hybridization (FISH) signals derived from bacterial artificial chromosomes (BACs) can be used as chromosome-specific cytogenetic DNA markers for chromosome identification in potato. We screened a potato BAC library using genetically mapped restriction fragment length polymorphism markers as probes. The identified BAC clones were then labeled as probes for FISH analysis. A set of 12 chromosome-specific BAC clones were isolated and the FISH signals derived from these BAC clones serve as convenient and reliable cytological markers for potato chromosome identification. We mapped the 5S rRNA genes, the 45S rRNA genes, and a potato late blight resistance gene to three specific potato chromosomes using the chromosome-specific BAC clones.

Electronic Resource

1432-2242

Solanum tuberosum ; P. infestans ; Resistance ; Dihaploid induction ; RFLP mapping

Springer Online Journal Archives 1860-2000

Biology

Abstract In potato, 11 resistance alleles (R1–R11) are known which confer race-specific resistance to the fungus Phytophthora infestans. R1 has been mapped previously to potato chromosome V and R3 to chromosome XI. Here we report on the localization of the R6 and R7 alleles on the genetic map of potato. Differential resistant strains of tetraploid Solanum tuberosum, clones MaR6 and MaR7, were used as parental plants for the parthenogenetic induction and selection of diploid genotypes containing the R6 or the R7 resistance allele to P. infestans. One resistant dihaploid from MaR7 could be used directly as a parent to produce diploid F1 progeny suitable for phenotypic and RFLP analysis. MaR6 did not produce useful dihaploids directly. After crossing MaR6 with a tetraploid susceptible genotype, resistant F1 clones were selected. The resistant genotypes were then used as parents for the induction of dihaploids. Six dihaploids bearing R6 were identified that could be crossed with a diploid susceptible genotype. Two diploid F1 populations, segregating for R6 and R7, respectively, were analysed with RFLP markers known to be linked with previously identified R genes. Markers linked with R3 were found also to be linked with R6 and R7. The resistance alleles R6 and R7 mapped to a similar distal position on chromosome XI as the R3 allele.

Electronic Resource

1432-2242

Key words Plants ; Disease resistance ; Host-pathogen interaction ; Synchytriumendobioticum ; Potato

Springer Online Journal Archives 1860-2000

Biology

Abstract  The fungus Synchytrium endobioticum, the causal agent of potato wart disease, is subject to world-wide quarKantine regulations due to the production of persistent resting spores and lack of effective chemical control measures. The selection of Synchytrium-resistant potato cultivars may be facilitated by using markers closely linked with a resistance gene or by transferring a cloned gene for resistance into susceptible cultivars. Sen1, a gene for resistance to Synchytrium endobioticum race 1, was localized on potato chromosome XI in a genomic region which is related to the tobacco genome segment harbouring the N gene for resistance to TMV. Using N as probe, we isolated homologous cDNA clones from a Synchytrium-resistant potato line. The N-homologous sequences of potato identified by RFLP mapping a family of resistance gene-like sequences closely linked with the Sen1 locus. Sequence analysis of two full-length N-homologous cDNA clones revealed the presence of structural domains associated with resistance gene function. One clone (Nl-25) encodes a polypeptide of 61 kDa and harbours a Toll-interleukin like region (TIR) and a putative nucleotide binding site (NBS). The other clone (Nl-27) encodes a polypeptide of 95 kDa and harbours besides the TIR and NBS domains five imperfect leucine-rich repeats (LRRs). Both clones have at their amino terminus a conserved stretch of serine residues that was also found in the N gene, the RPP5 gene from Arabidopsis thaliana and several other resistance gene homologues, suggesting a function in the resistance response. Cloning of the disease resistance locus based on map position and the establishment of PCR-based marker assays to assist selection of wart resistant potato genotypes are discussed.

Electronic Resource

1432-2242

RFLP ; Solanum ; Phylogenetic analysis

Springer Online Journal Archives 1860-2000

Biology

Summary Phylogenetic relationships between 14 wild and 3 cultivatedSolanum species, including the European potato,Solanum tuberosum ssp.tuberosum, were inferred using DNA restriction fragment length polymorphisms (RFLPs) as discriminating characters. Phenetic trees were obtained based on distance matrices as well as on parsimony methods, which were not significantly altered either by the computational method used, or by the individual plant genotypes or RFLP markers chosen for the analysis. The reliability of the tree topologies was assessed and, as expected, it increased with the number of polymorphic restriction fragments scored. The individual genotypes within each species, the different species themselves, and the main branches of the trees were clearly separated from each other. The least reliable parts in the trees were the positions of closely related species within the main clusters.S. tuberosum spp.tuberosum formed one group closely related withS. tuberosum spp.andigena,S. stenotomum, andS. canasense. This was well separated from a second group formed byS. sparsipilum,berthaultii,kurtzianum,gourlayi,vernei,spegazzinii,chacoense, andmegistacrolobum. Two further branches were formed byS. demissum andS. acaule, and byS. polyadenium,S. pinnatisectum,S. stoloniferum, andS. etuberosum. The phenetic trees presented here supported the description of relationships amongSolanum species based on biosystematic studies, with the exception of the placement ofS. chacoense andS. megistacrolobum.

Electronic Resource

1432-2242

Tomato ; Lycopersicon esculentum ; Root knot nematode resistance ; Meloidogyne ; RFLP markers

Springer Online Journal Archives 1860-2000

Biology

Summary The Mi gene originating from the wild tomato species Lycopersicon peruvianum confers resistance to all major root knot nematodes (Meloidogyne spp.). This single dominant gene is located on chromosome 6 and is very closely linked to the acid phosphatase-1 (Aps-1) locus. Resistance to nematodes has been introgressed into various cultivars of the cultivated tomato (L. esculentum), in many cultivars along with the linked L. peruvianum Aps-1 1 allele. By using a pair of nearly isogenic lines differing in a small chromosomal region containing the Mi and Aps-1 loci, we have identified two RFLP markers, GP79 and H6A2c2, which are located in the introgressed L. peruvianum region. Analysis of a test panel of 51 L. esculentum genotypes of various origins indicated that GP79 is very tightly linked to the Mi gene and allows both homozygous and heterozygous nematode-resistant genotypes to be distinguished from susceptible genotypes, irrespective of their Aps-1 alleles. Marker H6A2c2 is linked to the Aps-1 locus and is capable of discriminating between the L. peruvianum Aps-1 1 allele and the L. esculentum Aps-1 3 and Aps-1 + alleles. In combination, these RFLP markers may provide a powerful tool in breeding tomatoes for nematode resistance.

Electronic Resource

1432-2242

RFLP ; Potato ; Tomato ; Genetic maps

Springer Online Journal Archives 1860-2000

Biology

Summary An RFLP linkage map of the potato is presented which comprises 304 loci derived from 230 DNA probes and one morphological marker (tuber skin color). The self-incompatibility locus of potato was mapped to chromosome I, which is homoeologous to tomato chromosome I. By mapping chromosome-specific tomato RFLP markers in potato and, vice versa, potato markers in tomato, the different potato and tomato RFLP maps were aligned to each other and the similarity of the potato and tomato genome was confirmed. The numbers given to the 12 potato chromosomes are now in accordance with the established tomato nomenclature. Comparisons between potato RFLP maps derived from different genetic backgrounds revealed conservation of marker order but differences in chromosome and total map length. In particular, significant reduction of map length was observed in interspecific compared to intraspecific crosses. The distribution of regions with distorted segregation ratios in the genome was analyzed for four potato parents. The most prominent distortion of recombination was found to be caused by the self-incompatibility locus.

Electronic Resource

1432-2242

Solanum spegazzinii ; Globodera rostochi ensis ; Nematode resistance ; QTL ; RFLP

Springer Online Journal Archives 1860-2000

Biology

Abstract We report the identification and mapping of two quantitative trait loci (QTLs) of Solanum spegazzinii BGRC, accession 8218-15, involved in resistance to the potato cyst-nematode Globodera rostochiensis pathotype Ro1, by means of restriction fragment length polymorphisms (RFLPs). For this purpose we crossed a susceptible diploid S. tuberosum with the resistant S. spegazzinii, and tested the F1 population for resistance to the Ro1 pathotype. Since the F1 segregated for the resistance, the S. spegazzinii parent was concluded to be heterozygous at the nematode resistance loci. For the mapping of the resistance loci we made use of RFLP markers segregating for S. spegazzinii alleles in the F1. One hundred and seven RFLP markers were tested in combination with four different restriction enzymes; 29 of these displayed a heterozygous RFLP pattern within S. spegazzinii and were used for mapping. Analysis of variance (ANOVA) was applied to test the association of the RFLP patterns of these markers with nematode resistance. Two QTLs involved in disease resistance to Globodera rostochiensis pathotype Ro1 were identified and mapped to chromosomes 10 and 11 respectively.

Electronic Resource

1432-2242

Bilateral sexual polyploidization ; FDR ; SDR ; Recombination rate

Springer Online Journal Archives 1860-2000

Biology

Abstract The heterozygosity transmitted through 2n gametes in potato was evaluated by following the segregation of RFLP markers in tetraploid progeny from bilateral sexual polyploidization in a cross between two diploid (2x) interspecific hybrids which produce 2n SDR eggs or 2n FDR pollen. Out of 84 probe/enzyme combinations tested, 23 revealed polymorphism between the parents and were heterozygous in at least one of the parents. These probes characterized 13 loci distributed on five different chromosomes of the potato RFLP map. The heterozygosity transmitted through SDR and FDR gametes was estimated to be 31.8% and 71.4%, respectively. Two different indices (LH and RHI) were used to select plants showing a high level of heterozygosity in the tetraploid progeny. The recombination events and the centromere positions were estimated for chromosomes I, VI and VII, following the segregation ratios of SDR or FDR gametes produced by the parents. A different recombination rate was observed between the two interspecific hybrids.

Electronic Resource

1432-2242

Key words  Solanum tuberosum  ;  P. infestans  ;  Resistance  ;  Dihaploid induction  ;  RFLP mapping

Springer Online Journal Archives 1860-2000

Biology

Abstract   In potato, 11 resistance alleles (R1–R11) are known which confer race-specific resistance to the fungus Phytophthora infestans. R1 has been mapped previously to potato chromosome V and R3 to chromosome XI. Here we report on the localization of the R6 and R7 alleles on the genetic map of potato. Differential resistant strains of tetraploid Solanum tuberosum, clones MaR6 and MaR7, were used as parental plants for the parthenogenetic induction and selection of diploid genotypes containing the R6 or the R7 resistance allele to P. infestans. One resistant dihaploid from MaR7 could be used directly as a parent to produce diploid F1 progeny suitable for phenotypic and RFLP analysis. MaR6 did not produce useful dihaploids directly. After crossing MaR6 with a tetraploid susceptible genotype, resistant F1 clones were selected. The resistant genotypes were then used as parents for the induction of dihaploids. Six dihaploids bearing R6 were identified that could be crossed with a diploid susceptible genotype. Two diploid F1 populations, segregating for R6 and R7, respectively, were analysed with RFLP markers known to be linked with previously identified R genes. Markers linked with R3 were found also to be linked with R6 and R7. The resistance alleles R6 and R7 mapped to a similar distal position on chromosome XI as the R3 allele.

Electronic Resource

1432-2242

Key words Potato ; YAC library ; Disease resistance ; R1 ; Gro1

Springer Online Journal Archives 1860-2000

Biology

Abstract  A yeast artificial chromosome (YAC) library was constructed from high-molecular-weight DNA of potato (Solanum tuberosum). Potato DNA fragments obtained after complete digestion with four different rare-cutter restriction enzymes were cloned using the pYAC-RC vector. The library consists of 21 408 YAC clones with an average insertion size of 140 kb. The frequency of YAC clones having insertions of chloroplast or mitochondrial DNA was estimated to be 0.5% and 0.3%, respectively. The YAC library was screened by PCR with 11 DNA markers detecting single genes or small gene families in the potato genome. YACs for 8 of the 11 markers were detected in the library. Using 2 markers that are linked to the resistance genes R1 and Gro1 of potato, we isolated two individual YAC clones. One of these YAC clones was found to harbour one member of a small family of candidate genes for the nematode resistance gene Gro1.

Electronic Resource