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Biomedical subjects

N Hess

Publications and source records attributed to N Hess.

13 recordsLinked to original sources
PubMed1988

Integration into the cellular genome of a Friend murine leukaemia virus containing a selectable marker reveals a clonal origin of erythroleukaemia.

We have constructed a selectable Friend murine leukaemia virus (F-MuLV) with a suppressor tRNA (supF) gene integrated into the proviral long terminal repeat. The viral construct was infectious and pathogenic and retained the marker gene when growing in vitro or in vivo. Only a few integration sites of the provirus were detected by Southern blot analysis of the DNA of erythroleukaemic cells. These results indicate that F-MuLV-induced erythroleukaemia is of clonal origin and suggest that insertional mutagenesis is involved in pathogenesis.

Animals↗
PubMed1987

Autocrine stimulation after transfer of the granulocyte/macrophage colony-stimulating factor gene and autonomous growth are distinct but interdependent steps in the oncogenic pathway.

Autocrine stimulation of cells by aberrant synthesis of growth factor may lead to malignant transformation, either as a direct consequence of endogenous factor production or as a first step of a series of successive events. Introduction of the granulocyte/macrophage colony-stimulating factor (GM-CSF) cDNA clone into a vector based on the myeloproliferative sarcoma virus allowed efficient transfer and expression of GM-CSF in factor-dependent myeloid cell lines (FDC-P1 and FDC-P2). Factor-independent growth was acquired when the vector was introduced into the GM-CSF-responsive FDC-P1 cell line but not the multi-CSF-dependent FDC-P2 line. Nonlinear clonability in the absence of exogenous growth factor and growth inhibition by GM-CSF antiserum support a model of autocrine stimulation that requires interaction of factor and receptor at the outer membrane. However, many, but not all, infected FDC-P1 cells acquired subsequently a second mutation that abrogated the requirement of GM-CSF secretion and external interaction. The nature of the second step, which presumably leads to tumorigenicity of these cells, is not well understood, but its frequency could be correlated with the level of GM-CSF released by an individual cell clone.

Animals↗
PubMed1987

King Lear and some anxieties of old age.

The experience of ageing and the resulting emotional difficulties of elderly patients have only recently begun to be understood from a psychodynamic perspective. This paper draws on two sources, literary (Shakespeare's King Lear) and clinical (consultations with elderly patients in primary care) to highlight a fundamental anxiety of old age: the dread of being abandoned to a state of utter helplessness. This state is felt to be caused by the catastrophes of old age, such as stroke and dementia. The defence against this anxiety is often a narcissistic tyranny.

Aged↗
PubMed1976

A low molecular weight substance obtained from serum which has luteinizing hormone like activity ("mini LH").

A low molecular weight substance of 1000-2000 daltons has been isolated in dialysates of normal human serum which, on testing in a radio-immunoassay, a radioligand receptorassay and an in-vitro bioassay exhibited LH activity comparable to the range of LH activity found in normal serum. The substance was heat labile. Its reactivity in a RIA suggests peptide nature. No "mini LH" activity could be derived from LH-free serum samples of hypophysectomized patients.

Biological Assay↗
PubMed1976

Existence of big and little forms of luteinizing hormone in human serum.

Serum fractions from normal subjects obtained by gel chromatography have been investigated using three different assay systems: radioimmunoassay (RIA), radioligand receptor assay (RRA), and testosterone production assay (TPA). The bulk of immunoassayable and "bioassayable" LH-activity was found in two fractions differing widely in their molecular size. The slower moving component, designated as "little" LH, migrated identical to the radioiodinated pituitary hormone (LER 960) with a molecular weight of about 30,000, while "big" LH appeared in an elution volume consistent with a molecular weight range between 140,000 and 180,000. Concordance was seen between the LH-activities measured in all three assay systems. The RRA/RIA ratio varied between 1.6 and 8.9, the RRA/TPA ratio was close to unity. Treatment with 6 M urea and 0.1% mercaptoethanol and also, exposure to different pH values and salt concentrations did not change the elution position of the two LH components. Also, "big" and "little" LH appeared unaltered after re-filtration and no conversion each other could be found. In another experiment injection of gonadotrophin releasing hormone (Gn-RH) into a male induced a profound shift of LH towards the low molecular weight species. Kinetic uptake studies with "big" and "little" LH using RRA showed identical affinities to the receptor preparation. Ion exchange chromatography of serum, however, did not give two LH components, indicating no major differences in charge properties. This finding could be confirmed by preparative gel isoelectric focusing. The RRA potencies following gel filtration were in good agreement with that applied to the column, however, the immunological activities exceeded that of loaded by a factor 3-4. A new aspect of serum LH heterogeneity is the finding of a low molecular substance (mol. weight approximately 1000) in the outer dialysate of serum, which has LH like activity in all three assay systems.

Adult↗
PubMed1976

Amnesia for random shapes following unilateral and bilateral electronvulsive shock therapy.

Three 16-point shapes were shown to 15 patients before undergoing either unilateral or bilateral electroconvulsive therapy. They were then tested for recognition following therapy. The same subjects were similarly tested for recognition memory with no intervening shock. Analysis of variance indicated no significant differential effects of the two methods of electroshock application.

Adult↗