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Biomedical subjects

K Wolf

Publications and source records attributed to K Wolf.

At least 163 records · Page 9Linked to original sources
PubMed1988

Two changes of the same nucleotide confer resistance to diuron and antimycin in the mitochondrial cytochrome b gene of Schizosaccharomyces pombe.

Diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) and antimycin, both inhibitors of mitochondrial respiration, block electron flow between cytochromes b and c1. Mutants resistant to either drug have been selected using Schizosaccharomyces pombe strains with an extrachromosomally inherited mutator. In analogy to Saccharomyces cerevisiae these mutational sites were assumed to map in the cytochrome b gene. DNA sequence analysis showed that two changes in the same nucleotide are responsible for resistance to antimycin and diuron. Analysis of resistant and sensitive progeny of crosses between the mutants and the wild type confirmed the correlation between mutational alteration and resistant phenotype.

Amino Acid Sequence↗
PubMed1988

Two distinct mechanisms for deletion in mitochondrial DNA of Schizosaccharomyces pombe mutator strains. Slipped mispairing mediated by direct repeats and erroneous intron splicing.

Mutator strains of the fission yeast Schizosaccharomyces pombe produce mitochondrial respiratory deficient mutants at a high rate, and roughly 20% of these mutants carry deletions in the range of 50 to 1500 base-pairs. To elucidate the mechanism of deletion we have sequenced ten deletion mutants in the mosaic gene encoding apocytochrome b (cob) and three in the split gene coding for the first subunit of cytochrome c oxidase (cox1). Of 13 deletions, ten are correlated with the presence of direct repeats, which could promote deletions by slipped mispairing during DNA replication. In some of these mutants, the termini are located in possible DNA secondary structures. In three independently isolated mutants with identical deletions in the cob gene, the 5' deletion endpoint coincides with the 3' splice point of the intron, whereas the 3' endpoint of the deletion exhibits pronounced homology with the 5' splice point of the intron. This result suggests that these deletions might be initiated by erroneous RNA splicing.

Base Sequence↗
PubMed1988

Epithelial thymus tumors--therapy and prognosis.

One hundred and two patients with epithelial thymoma (ET) and carcinoma have undergone surgical treatment since 1957. In this series thymomas were classified according to Masaoka's clinical staging criteria (encapsulated, invasive) and according to Müller-Hermelink's histological criteria of the resected specimens (medullary and cortical differentiation) and compared to clinical symptoms and survival rates (mean follow-up time 66.4 months). We found that it is not always possible to differentiate intraoperatively fibrous adhesions from infiltrations of the thymic capsule or to recognise thymus carcinoma as such macroscopically if they have not already infiltrated the organ's capsule. All ETs with cortical differentiation after thymectomy showed a malignant course; in contrary ETs with medullary differentiation we found without relapses of metastases. ETs with both histological types (hybrid typs) and cortical dominance took in only two out of 57 cases a malignant course though five of them showed an invasion into the capsule according to clinical staging criteria stage II. Therefore classifying ETs only into two categories, encapsulated and invasive, according to surgical and gross findings, seems to be not always possible and insufficient for the clinical assessment of the malignity and prognosis.

Adult↗
PubMed1987

The proximal and distal tarsal tunnel syndromes. An anatomical study.

Clinical and electromyographic studies in the tarsal tunnel syndrome may suggest compression of only one of the two terminal branches of the posterior tibial nerve. This anatomical study demonstrates the structures which may cause isolated damage to either the medial plantar or the lateral plantar nerves. A surgical approach to the tarsal tunnel is described.

Ankle Joint↗
PubMed1987

Distribution of mitochondrial introns in the species Schizosaccharomyces pombe and the origin of the group II intron in the gene encoding apocytochrome b.

The mitochondrial genome size of 26 different Schizosaccharomyces pombe strains varies between 17.6 and 24.6 kilobase pairs due to the presence or absence of introns. One of these is the group II intron in the gene encoding apocytochrome b (cob: intron cobI1). Partial DNA sequences of continuous cob genes from six strains (including strain EF1: Trinkl et al. 1985) revealed identical nucleotide sequence in the region where the group II intron is inserted in the mosaic form of the gene. In contrast, analysis of the mosaic cob gene in strain UCD-FstI revealed several base pair changes in the exon regions flanking the splice point, compared with the continuous genes and with the mosaic cob gene in strain 50 (Lang et al. 1985). The base pair differences between the exons of the two mosaic cob genes and the identity of exons in all continuous cob genes argue in favour of the two cob introns in strains 50 and UCD-FstI as independent later acquisitions of the genes, rather than loss of the intron from a common mosaic ancestor of all strains. Other introns present in some but not all strain include two group I introns without open reading frame in the gene encoding subunit 1 of cytochrome c oxidase (cox1: introns cox1I2a and cox1I3), and two group I introns with open reading frames in the same gene (introns cox1I1 and cox1I2b).

Apoproteins↗
PubMed1987

[Tarsal tunnel syndrome].

The natural history, diagnosis, and therapy of tarsal tunnel syndrome are given. Anatomical studies corresponding to the clinical picture and electrodiagnostic findings show two different narrow points in tarsal tunnel. Operative treatment should take into account the compression of the posterior tibial nerve by the flexor retinaculum and also of the plantar nerves under the abductor hallucis.

Ankle↗
PubMed1987

[Value of intra-arterial digital subtraction angiography in microvascular anastomosis in tissue transplantation].

The technique of selective intraarterial digital subtraction angiography is less time-consuming and requires less contrast medium than conventional angiography thus reducing both the invasiveness and the risk associated with angiography. With this method both the morphology and the functional status of the vasculature can be determined. Anatomic variations in the blood supply which influence the operative technique can thus be known preoperatively and no longer threaten the success of the operation.

Angiography↗
PubMed1987

[Late results in transplantation of free or pedicled radical flaps].

The free and pedicled forearm flap is well suited to cover large skin defects on the head, neck and extremities. It offers advantages in terms of size, shape, colour, skin thickness and a wide range of usage with combined tissue transfer. 31 patients with free or pedicled flaps were reexamined. The parameters of reexamination were blood flow, pulse, capillary return, and colour of skin. In half of the cases there was no restriction of blood flow; only one parameter showed signs of less blood flow. Every flap revealed pulse and good capillary return. Esthetic parameters were colour, hairgrowth and skin niveau differences. In 22 patients the results were esthetically satisfactory. The donor area was evaluated with respect to hand circulation in which the selected parameters were cold sensitivity, claudication, and the results of thermography.

Adult↗