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Biomedical subjects

C Gebhardt

Publications and source records attributed to C Gebhardt.

At least 55 records · Page 3Linked to original sources
PubMed1997

Structural organization, expression and promoter activity of a cold-stress-inducible gene of potato (Solanum tuberosum L.)

Cold storage of potato tubers at 4 degrees C is associated with the accumulation of several cold-induced transcripts. By using a previously characterized cDNA (CI7) as probe, we isolated and sequenced the corresponding ci7 gene. The putative promoter of ci7 contains sequence elements that have been shown to mediate expression of stress-responsive genes of Arabidopsis thaliana. CI7 transcripts were differentially induced in response to cold, drought, high salt or exogenous ABA treatment in potato tubers and leaves. Whereas accumulation of CI7 transcript during cold storage occurred within days, induction of CI7 transcript in response to drought, ABA and salt occurred rapidly within few hours. In tubers, accumulation of CI7 protein in response to abiotic stresses and ABA was small when compared to transcript levels. In leaves, the CI7 protein was undetectable after all treatments tested. 3 kb of the 5'-flanking ci7 promoter region were fused to the GUS reporter gene and introduced into S. tuberosum plants. The analysis of tubers of independent transgenic lines did not reveal significant induction of enzymatic GUS activity in response to low temperature. When RNA gel blotting was used to analyze the level of induction of the GUS gene driven by the ci7 promoter, the heterologous GUS fusion was, however, strongly responsive to low temperature. Nuclear run-on transcription studies of the ci7 gene, in comparison with RNA gel blot analyses of the transgenic plants, indicated that most of the temperature-regulated expression of the ci7 gene in tubers may be accounted for by post-transcriptional control mechanisms.

Abscisic Acid↗
PubMed1997

Expression patterns and promoter activity of the cold-regulated gene ci21A of potato.

Storage of potato (Solanum tuberosum) tubers at 4 degrees C is associated with the accumulation of several transcripts. DNA sequence analysis of cDNA clone CI21, which corresponds to one of the cold-induced transcripts, revealed high homology to transcripts of tomato (Lycopersicon esculentum) and wild potato (Solanum chacoense) induced by ripening and water stress. Two homologous, nonallelic genes, ci21A and ci21B, were isolated and sequenced. Northern blot analysis showed that CI21 transcripts were present at the highest levels in cold-stored tubers, at lower levels in stems and roots, and at the lowest levels in leaves and tubers stored at room temperature. Treatment with abscisic acid, heat, and a high concentration of salt had no marked effect on CI21 transcript levels in tubers and leaves. Drought was the only stress treatment that induced CI21 transcripts in leaves, but it did not do so in tubers. Western blot analysis detected CI21 protein only in tubers. Chimeric gene constructs between the putative ci21A promoter region and the uidA reporter gene were tested in transgenic potato plants for induction of beta-glucuronidase activity by low temperature. A 2-fold increase of beta-glucuronidase activity in response to tuber storage at 4 degrees C was observed for fragments between 380 and 2000 bp of the ci21A promoter region.

Amino Acid Sequence↗
PubMed1997

[Acute pancreatitis--conservative versus surgical therapy].

Based on own studies and on results of other centers the multiorgan failure (MOF) resp. the systemic inflammatory response syndrome (SIRS) in acute necrotizing pancreatitis seems to be no longer an compelling reason for surgery in the absence of proven infection of pancreatic necrosis. Growing experience of continuous veno-venous hemofiltration (CVVH) facilitates successful conservative treatment of-formerly often lethal-cases of serious necrotizing pancreatitis. If infection of necrosis is documented surgical intervention should be performed. Our present regime of therapy of necrotizing pancreatitis consists in conservative intensive medical treatment, immediately after admission; a pancreas penetrating antibiotic medication starting on admission; early use of continuous veno-venous hemofiltration if MOF or SIRS occurs, surgical intervention, if infection of necrosis is proved. Other indications for surgery are massive bleeding or bowel perforation due to tryptic lesions.

Acute Disease↗
PubMed1997

[Discontinuity resection in therapy of complicated sigmoid diverticulitis].

A total of 112 patients were operated on for severe complicated sigmoid diverticulitis, Hartmann's procedure was performed due to local or generalised peritonitis, 80% to them as emergency surgery. There was a mortality of 18.8% due to the sepsis or other complications. Sixty-two of the remaining 80 patients underwent a restorative procedure without any mortality and low morbidity (11 died after discharge not related to the colon disease). Resection and primary anastomsis is always the first choice, but in cases of severe peritonitis there is no discomfort or risk for the patient if Hartmann's procedure with restorative surgery is chosen.

Adult↗
PubMed1996

A PCR-based approach for isolating pathogen resistance genes from potato with potential for wide application in plants.

Plant genes for pathogen resistance can be used to engineer disease resistant crops. Oligonucleotides were designed from sequence motifs conserved between resistance genes of tobacco and Arabidopsis thaliana and used as PCR primers in potato DNA. Amplification products were obtained that were homologous to known resistance genes and linked without recombination with the nematode resistance locus Gro1 and the Phytophthora infestans resistance locus R7 of potato. Map positions of PCR-derived potato gene fragments were also correlated with resistance loci of the related tomato and tobacco genomes. Our results indicate that plant resistance genes that are effective against nematodes, fungi, viruses and bacteria may be isolated based on common sequence motifs and PCR methodology.

Amino Acid Sequence↗
PubMed1996

[The significance of lymph- and hemangiosis carcinomatosa in colorectal carcinoma].

Between 1.1.1988 and 31.12.1989 306 patients underwent curative surgery for colorectal cancer at the surgical center of Nurnberg City hospital. The pathohistological findings showed that a carcinomatous lymphangiosis and hemangiosis (LH+) was present in 57 (18.6%) cases. The rate of metachronic metastases of the liver was significantly higher (38.2% vs. 19.6% p < 0.001) compared to patients without lymphangiosis and hemangiosis (LH-). There were also significant differences between the survival rates (5-year survival rate 50% vs. 63% p < 0.02). Analysing the lymph node stage and LH+ situation it was found that carcinomatous lymphangiosis and hemangiosis were already present in 7.2% of patients who didn't have tumorous infiltration of the lymph nodes (p NO/LH+). The 5-year survival rate was bad in both groups (54% vs. 49%).

Aged↗
PubMed1996

[Distal stenosis of the choledochus in chronic pancreatitis: endoscopic drainage or operation?].

With the less invasive techniques for complications regarding chronic pancreatitis, such as tubular choledochostenosis, the endoscopic transpapillary bile drainage therapy by means of endoprosthesis has undergone an enlargement of its indications range. Blocked and dislocated prostheses, however, further raise the already existing possibility of septic complications. With 15 out of 43 patients undergoing medium-term endodrainage treatment, we observed different resulting conditions of chronic cholestasis, such as abscess-forming cholangitis, hepatic abscesses, retroperitoneal phlegmon and sepsis up to biliary cirrhosis. Thus, in the case of chronic pancreatitis we still regard choledochostenosis- which, due to scarring, is mostly fixed-as a primary indication for operation.

Adult↗
PubMed1996

[Extensive surgery of colorectal carcinoma in the elderly--a justified therapy approach].

Over a 5-year period 1232 patients were operated on for carcinoma of the colon or rectum, 828 had curative surgery without and only 69 with resection of other organs. About half of the patients were 70 or more years old, but the older patients, especially in the extended resected cases, had the same or better 5-year survival and the same rate of complications or mortality. The overall prognosis depends on the complete resection of the tumor, the involvement of lymph nodes and the number of general risk factors, but not on the age of the patient.

Aged↗
PubMed1996

[Lymph- and haemangiosis carcinomatosa--an important prognostic factor in non-small-cell bronchial carcinoma (NSCLC)].

Between 1 Jan 1984-1 Jan 1990, 199 patients underwent curative (R0) surgery for non-small cell lung cancer. The pathohistological findings showed that a carcinomatous lymphangiosis and haemangiosis (L/H pos.) were present in 26 patients. In six patients, no lymph node metastases were detected. The median (22 mo. vs. 74 mo.) and 5-year survival (25% vs. 41%) were significantly (p < 0.001) higher compared to patients with and without lymphangiosis and haemangiosis carcinomatosa (L/H neg.). There were also significant (p < 0.05) differences in the survival time between pNO L/H neg. and pNO L/H pos. patients (median 74 mo. vs. 15 mo.-5 years 43% vs. 0%).

Capillaries↗
PubMed1995

A high-resolution map of the vicinity of the R1 locus on chromosome V of potato based on RFLP and AFLP markers.

The R1 allele confers on potato a race-specific resistance to Phytophthora infestans. The corresponding genetic locus maps on chromosome V in a region in which several other resistance genes are also located. As part of a strategy for cloning R1, a high-resolution genetic map was constructed for the segment of chromosome V that is bordered by the RFLP loci GP21 and GP179 and includes the R1 locus. Bulked segregant analysis and markers based on amplified fragment length polymorphisms (AFLP markers) were used to select molecular markers closely linked to R1. Twenty-nine of approximately 3200 informative AFLP loci displayed linkage to the R1 locus. Based on the genotypic analysis of 461 gametes, eight loci mapped within the GP21-GP179 interval. Two of those could not be separated from R1 by recombination. For genotyping large numbers of plants with respect to the flanking markers GP21 and GP179 PCR based assays were also developed which allowed marker-assisted selection of plants with genotypes Rr and rr and of recombinant plants.

Alleles↗
PubMed1995

Marker enrichment and high-resolution map of the segment of potato chromosome VII harbouring the nematode resistance gene Gro1.

The dominant allele Gro1 confers on potato resistance to the root cyst nematode Globodera rostochiensis. The Gro1 locus has been mapped to chromosome VII on the genetic map of potato, using RFLP markers. This makes possible the cloning of Gro1 based on its map position. As part of this strategy we have constructed a high-resolution genetic map of the chromosome segment surrounding Gro1, based on RFLP, RAPD and AFLP markers. RAPD and AFLP markers closely linked to Gro1 were selected by bulked segregant analysis and mapped relative to the Gro1 locus in a segregating population of 1105 plants. Three RFLP and one RAPD marker were found to be inseparable from the Gro1 locus. Two AFLP markers were identified that flanked Gro1 at genetic distances of 0.6 cM and 0.8 cM, respectively. A genetic distance of 1 cM in the Gro1 region corresponds to a physical distance of ca. 100 kb as estimated by long-range restriction analysis. Marker-assisted selection for nematode resistance was accomplished in the course of constructing the high-resolution map. Plants carrying the resistance allele Gro1 could be distinguished from susceptible plants by marker assays based on the polymerase chain reaction (PCR).

Animals↗
PubMed1995

Isolation, characterization and RFLP linkage mapping of a DNA repeat family of Solanum spegazzinii by which chromosome ends can be localized on the genetic map of potato.

In a random sample of 2263 cloned genomic DNA fragments of the wild potato species Solanum spegazzinii six related, highly repetitive fragments (SPG repeat family) were identified that were present in much higher copy numbers in S. spegazzinii when compared with the closely related cultivated potato S. tuberosum. The SPG repeat family was organized in long arrays of multiple copies. Cross hybridization experiments with 29 wild and cultivated Solanum species and with the related tomato showed specificity of the SPG repeat family for tuber-bearing Solanum species. Among tuber bearing Solanum species a high degree of variation was observed for restriction fragment length and copy number. The variation in copy number was not correlated with established taxonomic relationships between tuber-bearing Solanum species. DNA sequence analysis revealed a subrepeat structure of 120-140 base pairs embedded in longer repeat units of variable length. Length polymorphisms between highly repeated restriction fragments detected by the SPG probes were used for segregation- and linkage analysis in four mapping populations of potato, for which RFLP maps had been constructed. Twelve loci were identified, eleven of which mapped to the distal ends of nine linkage groups. All the evidence suggested that the SPG repeat family represents a satellite repeat members of which are localized in the subtelomeric region of potato chromosomes. The SPG repeat family could be used, therefore, for completing the genetic map of potato.

Base Sequence↗
PubMed1995

Molecular cloning and characterization of a soluble inorganic pyrophosphatase in potato.

A cDNA clone encoding a soluble inorganic pyrophosphatase (EC 3.6.1.1) of potato (Solanum tuberosum L.) was isolated by screening a developing tuber library with a heterologous probe. The central domain of the encoded polypeptide is nearly identical at the sequence level with its Arabidopsis homolog (J.J. Kieber and E.R. Signer [1991] Plant Mol Biol 16: 345-348). Computer-assisted analysis of the potato, Arabidopsis, and Escherichia coli soluble pyrophosphatases indicated a remarkably conserved organization of the hydrophobic protein domains. The enzymatic function of the potato protein could be deduced from the presence of amino acid residues highly conserved in soluble pyrophosphatases and was confirmed by its capacity to complement a thermosensitive pyrophosphatase mutation in E. coli. The potato polypeptide was purified from complemented bacterial cells and its pyrophosphatase activity was shown to be strictly dependent on Mg2+ and strongly inhibited by Ca2+. The subcellular location of the potato pyrophosphatase is unknown. Structure analysis of the N-terminal protein domain failed to recognize typical transit peptides and the calculated molecular mass of the polypeptide (24 kD) is significantly inferior to the values reported for the plastidic (alkaline) or mitochondrial pyrophosphatases in plants (28-42 kD). Two unlinked loci could be mapped by restriction fragment length polymorphism analysis in the potato genome using the full-length cDNA as probe.

Amino Acid Sequence↗
PubMed1995

[Repeat liver resection in colorectal liver metastases].

For patients with recurrent operable liver metastases from colorectal cancer operative resection is the only chance of getting rid of their tumorous disease for a longer time. As there are not therapeutic alternatives more and more authors are reporting on repeated resections of liver metastases. From 1986 to 1994 we performed 12 recurrent liver resections with curative intent in 8 patients suffering from liver metastases of colorectal cancer: 4 synchronous and 4 metachronous metastases were removed, the primary procedure being anatomic hemihepatectomy in 5 cases and segmentectomy or bisegmentectomy in 3 cases. The mean time interval between the first and the second resections was 14 (4-23) months. Two patients underwent 4 consecutive liver resections because of recurrent metastases. In these cases the interval between the second, third and fourth procedures was 10 months. The postoperative complication rate was 16% and not a single patient died in hospital. Three patients died an average of 28 (9-54) months after the last liver resection, and the other 5 patients are still alive after an average of 14 (4-28) months: 3 are free of tumor and 2 have recurrent metastases in the liver. Compared with untreated or only locally treated cases, patients in whom operative risk is low can achieve prolonged survival times after resections of colorectal metastases to the liver.

Adult↗
PubMed1994

ATP-sensitive K+ channels in heart muscle cells first open and subsequently close at maintained anoxia.

In ventricular myocardial cells of the guinea pig and the mouse, anoxia caused after a mean latency of 439 +/- 141 s and 129 +/- 23 s (mean +/- S.E.M.), respectively, a large current through KATP-channels. This current disappeared within several seconds when reoxygenating the cells but decayed also completely at maintained anoxia. The kinetics of the latter process, however, were much slower and obeyed an approximately monoexponential time course with time constants in the range of 30 s. The results suggest that in the ischaemic myocardium KATP-channels contribute only to the initial phase of extracellular K+ accumulation.

Adenosine Triphosphate↗
PubMed1994

[Enterocolic fistula due to foreign body perforation].

A 26-year-old man reported diarrhoea, abdominal pain and weight loss (16 kg in 3 weeks). Ultrasonography and computed tomography showed a 5 x 5 cm abnormal rosette-shaped mass with surrounding infiltration in the area of the left colic flexure. Laboratory tests indicated a florid inflammation. Coloscopy and double-contrast radiology of the colon revealed a fistula at the junction between sigmoid and descending colon. At laparotomy a large tumorous mass was found (18 x 15 x 10 cm), which was removed completely by partial resection of small intestine and colon. Histological examination revealed occlusion of an intestinal loop by a plastic foreign body (probably the cap of a household cleaner bottle). The patient would not provide any explanation of the circumstances leading to its ingestion.

Adult↗
PubMed1994

[Multivisceral resection of advanced colorectal cancer].

From 1 September to 1 January 1990, a total of 1232 patients underwent surgery for colorectal cancer. Resection was performed on 1112 (90.3%) patients. It was curative in 917 cases and palliative in 195. Multivisceral resection was necessary 82 times because of tumour infiltration of adjacent organs (curative: 69 cases; palliative: 13 cases). The complication rate (26.7% vs 27.5%) and mortality rate (3.4% vs 2.9%) were similar to those for curative resections without multivisceral extension. The 5-year survival rate was also similar in the two groups (58% vs 55%). These results show that curative multivisceral resections can lead to the same long-term results as conventional curative resections. These data are encouraging, and tumour infiltration of neighbouring organs should not be taken to demonstrate inoperability.

Abdominal Neoplasms↗