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E Thies

Publications and source records attributed to E Thies.

11 recordsLinked to original sources
PubMed1992

Transgenic mice generated by pronuclear injection of a yeast artificial chromosome.

Transgenic mice have become invaluable for analysing gene function and regulation in vivo. However, the size of constructs injected has been limited by the cloning capacity of conventional vectors, a constraint that could be overcome with yeast artificial chromosomes (YACs). We investigated the feasibility of making transgenic mice with YACs by pronuclear injection of a small YAC carrying a gene encoding tyrosinase. Use of a vector with a conditional centromere allowed fifteenfold amplification of the YAC in yeast and its recovery in high yield. The albino phenotype of the recipient mice was rescued demonstrating the correct expression of the tyrosine gene from the construct. Furthermore, the telomeric sequences added by the yeast integrated into the mouse genome and did not reduce efficiency of integration. Using this technique future experiments with longer YACs will allow the expression of gene complexes such as Hox and the globin gene clusters to be analysed in transgenic animals.

Animals↗
PubMed1992

Chromosome jumping from flanking markers defines the minimal region for alf/hsdr-1 within the albino-deletion complex.

The locus alf/hsdr-1, defined by the albino-deletion complex on mouse chromosome 7, is essential for neonatal survival. Animals homozygous for a subset of the deletions die shortly after birth due to impaired gene expression in liver parenchymal cells and kidney proximal tubular cells. Here, we describe a detailed analysis of the region containing alf/hsdr-1 by means of chromosome jumping from flanking markers. Three chromosome jumping libraries based on the restriction enzymes XmaI and SalI were constructed. Isolation of eight jumping clones distributed over 450 kb allowed more than 240 kb to be cloned in genomic lambda and cosmid libraries. Five of the probes map within the minimal genetic interval for alf/hsdr-1, which is defined by the proximal borders of the deletions c10R75M and c11DSD. The breakpoints of these deletions were precisely mapped, which allowed alf/hsdr-1 to be localized to a 310-kb interval.

Albinism↗
PubMed1992

Deficiency of an enzyme of tyrosine metabolism underlies altered gene expression in newborn liver of lethal albino mice.

Mice homozygous for albino deletions encompassing the locus alf/hsdr-1 die shortly after birth. Lethality is thought to be the consequence of hypoglycemia, which results from the failure to activate hormone-dependent genes in liver and kidney encoding enzymes important for gluconeogenesis. Within the region in which alf/hsdr-1 has been defined by physical mapping, we identified the gene encoding fumarylacetoacetate hydrolase (FAH), an enzyme of tyrosine metabolism. Lack of FAH activity should lead to accumulation of toxic tyrosine metabolites. In man, genetically determined FAH deficiency is the primary defect in tyrosinemia type I, a fatal liver disease of infants. Northern blot and in situ hybridization analysis of mouse tissues showed that the cell types that normally express FAH correspond to those that exhibit a phenotype in alf/hsdr-1 deletion mice. Moreover, we could mimic aspects of the alf/hsdr-1 deletion phenotype in vitro by treating primary hepatocyte cultures with an intermediate of tyrosine metabolism. These findings strongly suggest that alf/hsdr-1 encodes FAH and that absence of FAH is responsible for neonatal lethality in albino deletion mice. Mechanisms by which this metabolic defect might bring about alterations in gene expression characteristic of the alf/hsdr-1 deletion phenotype are discussed.

Amino Acid Sequence↗
PubMed1992

Multiple effects on liver-specific gene expression in albino lethal mice caused by deficiency of an enzyme in tyrosine metabolism.

alf/hsdr-1 is a locus in the mouse defined by albino deletions to be essential for neonatal viability. Homozygous deletion of alf/hsdr-1 leads to a pleiotropic phenotype in liver and kidney, including impaired perinatal activation of hormone-dependent genes, and the induction of detoxifying enzymes and early-response genes. To elucidate the molecular basis of this complex phenotype, we have identified the gene mapping at alf/hsdr-1 by positional cloning, using overlapping albino locus deletions to define the location of alf/hsdr-1. The gene encodes fumarylacetoacetate hydrolase, FAH, an enzyme of tyrosine metabolism. Genetically determined FAH deficiency in man leads to a severe liver failure in infants. In mice, we find that the normal sites of expression of FAH correlate tightly with cell-types which display abnormalities in albino lethal mice. The identification of the Fah gene as a candidate for alf/hsdr-1 offers a novel explanation for the complex phenotype, one into which all aspects can be accommodated. The phenotype can now be understood as a sequence of responses to toxic electrophilic metabolites.

Animals↗
PubMed1990

Expression of glutathione S-transferases in normal gastric mucosa and in gastric tumors.

Glutathione S-transferases from both normal gastric mucosa and its matched gastric tumors from 10 different patients were investigated. The transferases were purified and subsequently the isoenzyme composition was studied. Glutathione S-transferase (GST)-pi was present in all specimens in large amounts. Class alpha GSTs were present in 9 out of 10 normal specimens and in six tumors. In malignant tissue, expression of GST-pi was increased at the expense of class alpha GST. In six patients, the ratio GST-pi/GST-alpha was higher in tumorous versus normal tissue. On a Western blot, using a monoclonal antibody, GST-mu was shown to be present in both normal and malignant tissue from four patients, the other six patients completely missed the enzyme in their gastric tissue. When present, GST-mu amounts to only a few per cent of total GST protein. GST-pi was quantified by densitometric analysis of Western blots, treated with a monoclonal antibody against GST-pi. Both total GST enzyme activity as well as the absolute amounts of GST-pi protein were significantly higher in the tumors, as compared to its matched normal mucosa. The importance of this overexpression of GST-pi was previously unknown. However, the frequent occurrence of this phenomenon in many refractory tumors, and as shown now also in gastric cancers, suggests a role for GST-pi in the mechanism of anti-cancer drug resistance.

Adult↗
PubMed1990

[Management of ruptured aortic aneurysms in routine service of a surgical department].

In the year 1989 859 patients with infrarenal aortic aneurysms were treated in the Hessen county (5.6 mill inhabitants) (private survey). 64% of the ruptured aneurysms were operated in 24 departments for general surgery and 36% were operated in the 7 departments for vascular surgery. Corresponding numbers for elective operations are 55% respectively 45%. The results after resection of the aneurysms in our 22 patients with ruptured aneurysms (1986-1989) reveal a letality of 50%. No patient arriving at our clinic alive was excluded from operation. Letality in electively operated patients (n = 131) during the same period was 2.3% (n = 3).

Aged↗
PubMed1988

Glutathione and GSH-dependent enzymes in the gastrointestinal mucosa of the rat.

The mucosal glutathione content of the gastrointestinal wall amounted to 50-60% of its concentration in the liver. GSH S-aryltransferase activity (CDNB) was very low in the glandular stomach, colon and rectum amounting to only 5% of liver enzyme activity. There was a marked postpyloric increase in GSH S-aryltransferase activity with an oral-aboral decline along the small intestine. GSH peroxidase was much lower in the mucosa of the small and large intestine as compared to the stomach or liver, whereas GSSG reductase was more than twice as high in the gastrointestinal mucosa as compared to the liver showing a gradual increase in activity from proximal to distal segments. The low GSH S-transferase activities found in the stomach, colon and rectum may account for the high and exclusive susceptibility of these segments to carcinogenesis and the deficient inducibility of these enzymes in the gastrointestinal wall may reflect an insufficient adaption towards higher exposure to toxic or even carcinogenic xenobiotics.

Animals↗
PubMed1986

Parathyroid localization.

Twenty-nine consecutive patients with suspected primary hyperparathyroidism were examined preoperatively using ultrasound, sonographically guided fine needle aspiration, and aspirate immunostaining for PTH. In 25 patients, localization of enlarged parathyroid glands was successful. In 2 patients, the tumors were located retrosternally and, thus, could not be detected by ultrasound. One patient had a multinodular goiter which impeded localization. In 1 patient with renal osteodystrophy, 2 enlarged parathyroid glands in the neck were not visualized preoperatively. Cytology was not diagnostic, although some cytological features were suggestive of parathyroid cells. Immunostaining of the aspirated smears for PTH, however, correctly diagnosed all preoperatively localized lesions. Ultrasound should be the routine procedure of choice for preoperative localization of abnormal parathyroid glands in primary hyperparathyroidism. Fine needle aspiration and immunocytochemistry can supply confirmation, if necessary.

Adolescent↗
PubMed1985

[Therapy of recurrent colorectal cancers].

Colorectal cancers treated for cure by operative means show tumour recurrences and metastases in about 20% of the patients. Of these colon or rectal cancers 75 and 90% respectively can be only operated for palliation. These patients have a better prognosis than those operated primarily for palliation. 25% of the cases especially with suture line recurrences can be operated upon radically enough and exhibit a total five year survival rate of 50%.

Colectomy↗
PubMed1985

[Endoscopic injections around gastrointestinal hemorrhages in the stomach and duodenum].

Besides the method of laser coagulation and electrocoagulation the endoscopic injection therapy of gastrointestinal bleeding in the stomach and in the duodenum seems to be a successful, inexpensive and simple method. In our hospital 62 pat. were treated by endoscopic injection therapy since 1978. A definitive hemostasis could be achieved in 83%, while the method did not succeed in 17% of patients.

Adult↗