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Biomedical subjects

H Schuster

Publications and source records attributed to H Schuster.

At least 181 records · Page 10Linked to original sources
PubMed1977

DNA synthesis in an Escherichia coli dna B dnaC mutant.

An Escherichia coli K12 dnaB dnaC mutant was constructed by P1 transduction of the dnaC allele into a dnaB recipient stain. dnaB dnaC transductant were discriminated from dnaB mutants by their inability to grow at 40 degree C after lysogenization with phage P1bac. The dnaB dnaC mutant character was verified by 1. P1 transduction, and 2. by in vitro complementation with dnaB and dnaC wild type protein fractions. DNA synthesis was studied in strains containing dnaB, dnaB dnaC alleles in an otherwise uniform genetic background with the dnaB character either unsuppressed or suppressed by P1bac prophage. Degradation at 42 degree C of [3H]-thymidine pulse-labeled DNA in dnaB and dnaB dnaC mutants is suppressed by P1bac. However, unlike the dnaC mutant, the P1bac lysogen of the dnaB dnaC mutant exhibits an abrupt cessation of DNA synthesis and less residual cell divisions at 42 degree C indicating an inhibition of DNA chain elongation rather than a defect in DNA initiation. It is suggested that denaturation of the dnaB protein effects the dnaC function.

Coliphages↗
PubMed1977

Bone-to-bone, joint-to-bone and joint-to-joint ratios in normal and diseased skeletal states using region-of-interest technique and bone-seeking radiopharmaceuticals.

Bone-to-bone, iliosacral joint-to-os sacrum and joint-to-joint ratios were computed using the region-of-interest technique 2 to 3 hrs. after injection of 99mTc Sn-methylene-diphosphonate or 99mTc Sn-pyrophosphate in 139 patients with skeletal diseases (bone tumours, degenerative changes of the spine and joints, inflammatory changes of joints) as well as in 123 patients with normal skeletal states. In the latter group, iliosacral joint-to-os sacrum ratios decreased with increasing age of the patients. In patients with osseous metastases of the spine ratios of 0.80 to 4.0 occurred ( reference area second vertebra below or above the affected vertebra). In degenerative changes of the spine values of 0.80 to 1.69 were computed. These results show, that 74% of the spine metastases could not be differentiated from benign changes of the spine by determining their relative amounts of bone uptake. In bone tumours of the extremities and in rheumatoid or gouty arthritis of the small joints (hands and feet) the highest ratios, i.e. contrasts, occurred referring to a contralateral reference area. Osteoarthritic and inflammatory alterations of the big joints could not be differentiated because of percentual distribution of the increased joint-to-joint ratios turned out to be nearly identical.

Adult↗
PubMed1977

[Extraneural metastases of anaplastic gliomas (author's transl)].

8 cases are reported of anaplastic cerebral gliomas with metastases outside the neuraxis, which were seen among about 1600 gliomas. The series included 4 males and 4 females ranging in age from 5 to 58 years at the time of death. There were 2 children with anaplastic ependymomas, one adult with oligodendroglioma, and 5 young or middle-aged adults with astrocytomas grade III or IV. All patients had one or more craniotomies, and 5 had radiotherapy before the appearance of remote tumor deposits. The survival times ranged from 7 to 31 months in cases with gliomas grade II, and from 8 to 18 months in high-grade astrocytomas. All tumors showed invasion of the meninges and/or ventricle walls, and in 4 cases they transgressed the dura and surrounding bone or soft tissues. In 6 autopsy cases there was widespread dissemination of gliomas through the CSF pathways. Remote metastases involved regional or distant lymph nodes in 7, the lungs in 2, the vertebrae, lungs, pleura, parotis and mediastinum in one patient each. The possible pathways for distant spread of intracranial gliomas and the factors which are considered responsible for their rare occurrence are discussed.

Adolescent↗
PubMed1976

Extracranial metastases of anaplastic cerebral gliomas.

Seven cases are reported of anaplastic cerebral gliomas with metastases outside the neuraxis, seen among about 1500 gliomas. There were two children with anaplastic ependymomas, one adult with oligodendroglioma, and four young to middle-aged adults with astrocytomas grade III and IV. All patients had one or more craniotomies, and four had radiotherapy prior to the appearance of distant tumour deposits. The survival times ranged from 7 to 31 months in cases with gliomas grade II, and from 8 to 18 months with high grade astrocytomas. All seven tumours showed invasion of the meninges, ventricular walls, or both, and in four cases they transgressed the dura and surrounding bone or soft tissues. In six autopsy cases there was widespread dissemination of gliomas through the CSF pathways. Distant metastases involved regional or distant lymph nodes in six patients, the lungs in two, and the vertebrae, pleura, liver, or mediastinum in one patient each. The possible pathways for distant spread or intracranial gliomas and the factors which are considered responsible are briefly discussed.

Adolescent↗
PubMed1976

[Extra-intracranial anastomosis technic].

This is a report about the author's surgical experiences with extra-intracranial anastomosis. Special attention is drawn to various technical measures for avoiding postoperative complications. It seems very important to leave around the temporal superficial artery a mantle of connective tissue to preserve the vascular supply of the vessel wall and to facilitate safe manipulation of the artery. Further more the report deals with the bloodflow direction in the temporal superficial artery in relation to the middle cerebral artery- the flow should be directed to the trunk of the middle cerebral artery in order to effect an optimal perfusion of the supplying area of the middle cerebral artery. Approx. 8 to 10 mm should hold the incision in both arteries, end of temporal superficial and side of middle cerebral, to attain a wide opened junction between both arteries and to prevent obstruction. Attention is called to the risk of skin necrosis when using both, frontal and parietal branches of the temporal superficial artery. High value is set on covering the bone and dura deficiency with muscle lobe to prevent spreading and fistula of cerebral spinal fluid.

Arteriovenous Shunt, Surgical↗
PubMed1975

phiX174 DNA-dependent DNA synthesis in vitro: requirement for P1 ban protein in dnaB mutant extracts of Escherichia coli.

Ammonium sulfate fractionation of crude extracts of E. coli yields a soluble enzyme fraction (about 25-fold purification) that catalyzes the conversion of phiX174 single-stranded DNA to duplex DNA. The reaction is rifampicin-resistant, requires single-stranded DNA, Mg++, deoxynucleoside triphosphates, and ATP, and is stimulated by KCl. Such soluble enzyme fractions were prepared from E. coli strains carrying the prophage mutant P1bac, in which the viral dnaB analog (ban) protein is expressed constitutively, or P1bacban, in which the expression of ban protein is prevented. DNA-synthesizing activity of ban protein containing fractions from wild-type or dnaB(P1bac) lysogens was more temperature-resistant than that from E. coli containing only wild-type dnaB protein, whereas that from dnaB(P1bacban) lysogens of dnaB cells was extremely thermolabile. It is suggested that the temperature-resistant DNA synthesis with fractions from P1bac lysogens is mediated by the P1 ban protein.

Bacterial Proteins↗
PubMed1975

[The importance of the histological structure of the superficial temporal artery for the functioning of the arterial extra-intracranian anastomosis].

After extra-intracranial anastomosis one could find a considerable dilatation of the superficial temporal artery in a relatively short period of time. This vessel as well as other arteries of the circulatory system were examined histologically. On the basis of a large amount of autopsy material the atherosclerotic changes of the different vessels were correlated. Thus it turned out that the superficial temporal artery revealed another type of atherosclerotic changes. A type which exhibited hardly any calcification, but shows an increase of elastic fibers which make dilatation of the vessel possible despite of its thickened wall and primarily narrowed lumen.

Adult↗
PubMed1973

Prophage induction by high temperature in thermosensitive dna mutants lysogenic for bacteriophage lambda.

High-temperature treatment of thermosensitive dna mutants lysogenic for phage lambda leads to prophage induction and release of phage (at the permissive temperature) in elongation-defective mutants of the genotypes dnaB, dnaE, and dnaG. In initiation-defective mutants no prophage induction occurs at 42 C in mutants of the genotype dnaA, whereas with a dnaC mutant as well as with strain HfrH 252 (map position not yet known) phages are released at 42 C. DNA degradation at the replication fork at 42 C is observed in all dnaB(lambda) mutants tested, but not in mutants of the genotypes dnaE(lambda) and dnaG(lambda). Therefore, degradation of replication fork DNA is not a prerequisite for prophage induction.

Coliphages↗