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Biomedical subjects

I Scott

Publications and source records attributed to I Scott.

72 records · Page 4Linked to original sources
PubMed1994

Application of angiogenic oligosaccharides of hyaluronan increases blood vessel numbers in rat skin.

Angiogenic oligosaccharides of hyaluronan were applied to the backs of young, adult male rats and the number of blood vessels, within a depth of 136 microns beneath the base of the epidermis, were evaluated. Application of hyaluronan oligosaccharides significantly increased the mean number of blood vessels/mm skin length in six of 11 treated rats when compared with controls. Application of radiolabeled hyaluronan oligosaccharides to skin of one rat demonstrated a penetration to a depth of approximately 800 microns, suggesting that the blood vessels beneath the epidermis would be exposed to the hyaluronan. Hyaluronan has previously been shown to stimulate endothelial cell proliferation; we demonstrate here that these hyaluronan oligosaccharides also specifically stimulate endothelial cell migration. This action of hyaluronan oligosaccharides may prove useful in retarding blood vessel paucity and degeneration observed during the ageing process and following radiotherapy.

Animals↗
PubMed1993

Gas exchange in a three-compartment lung model analyzed by forcing sinusoids of N2O.

A mathematical gas exchange model, using sinusoidal forcing functions of inert inspired gas (A. Zwart, R. C. Seagrave, and A. Van Dieren. J. Appl. Physiol. 41: 419-424, 1976), has been extended by us to include dead space (VD), a single alveolar compartment (VA) perfused with blood flow (Qp), and a shunt (Qs). In this new work we use N2O as the indicator gas in the mathematical model and in the experimental studies, in low enough concentrations [<6% (vol/vol)] to avoid anesthetic effects. Mathematical relationships between the inspired and expired N2O gas partial pressures, the blood gas N2O partial pressures, and their variation with forcing frequency are derived for a continuous ventilation uptake and a conventional anesthetic gas distribution model. We show that these gas and blood gas N2O relationships give direct derivation of cardiorespiratory parameters such as VA, Qp, the dead space-to-total ventilation ratio (VD/VT), and the shunt-to-total blood flow ratio (Qs/QT) without altering the subject's oxygenation and that they are essentially free from recirculation effects at high forcing frequencies > or = 2 min-1. Theoretical results from the model are presented for a wide range of forcing frequencies between 2 x 10(-2) and 10 min-1 (sinusoid periods 30-0.1 min), and these show that VA, Qp, and VD/VT can all be measured by N2O forcing frequencies > or = 1 min-1. We also present results from five animal studies, with an experimental inspired gas forcing frequency range of 0.125 to 2 min-1, which show qualitative agreement with the predictions of the continuous ventilation model. During these animal studies both mass spectrometric N2O respiratory gas measurements and intravascular polarographic arterial and mixed venous blood N2O partial pressure measurements were made, and examples of these in vivo measurements are presented, together with examples of the calculations derived from them.

Animals↗
PubMed1992

The metabolic output of avian (Sturnus vulgaris, Calidris alpina) adipose tissue liver and skeletal muscle: implications for BMR/body mass relationships.

1. The oxygen uptake rate of avian adipose tissue, liver and skeletal muscle slices were measured. 2. The energy consumption of fat was less than one tenth that of liver and muscle. 3. Thus, interspecific allometric equations for the prediction of basal metabolic rate from body mass will not be accurate throughout the avian annual cycle unless changes in body composition are taken into account.

Adipose Tissue↗
PubMed1990

Rumpshaker mouse: a new X-linked mutation affecting myelination: evidence for a defect in PLP expression.

This report describes a new X-linked mutation in mice, named rumpshaker (rsh) which is associated with hypomyelination of the central nervous system. Myelination commences appropriately but the majority of sheaths fail to develop normally. Oligodendrocytes are increased in number and have prominent Golgi apparatus, rough endoplasmic reticulum and free ribosomes. Occasional cisternae of rough endoplasmic reticulum are distended. Some dense lamellar inclusions occur in oligodendrocytes but overall, degenerative changes and cell death are uncommon. Immunostaining demonstrates a major defect in expression of PLP DM-20. Using site-specific antisera directed at different portions of the PLP/DM-20 molecule, the major defect appears to be with PLP where virtually no myelin sheaths are positive. Antiserum against the C-terminal common to PLP and DM-20 shows reduced but definite myelin staining. Genetic analysis indicates a locus at or close to the PLP/jimpy (jp) locus. The rsh mutation, however, differs from jp in that affected mice have normal longevity, can breed, produce substantially more myelin and have increased numbers of oligodendrocytes.

Animals↗
PubMed1988

Phaeochromocytoma and cardiomyopathy.

This case report describes a patient who presented with severe biventricular cardiac failure and shock, whose cardiac function returned to normal after the removal of a noradrenaline-secreting benign phaeochromocytoma. A catecholamine-induced cardiomyopathy with cardiogenic shock, rather than catecholamine-mediated peripheral vasoconstriction alone, is postulated as a mechanism to account for the marked hypoperfusion.

Adrenal Gland Neoplasms↗
PubMed1986

Regression of aneurysmal bone cyst following open biopsy.

Aneurysmal bone cysts are well described but relatively rare bone lesions. Histological diagnosis is usually obtained before definitive treatment. We report a patient with aneurysmal bone cyst regression after excisional biopsy and prior to preoperative embolization. This was also a patient with the William syndrome. This has not previously been reported, nor is there any known association between aneurysmal bone cyst and the William syndrome.

Adult↗
PubMed1985

The occurrence of profilaggrin and its processing in cultured keratinocytes.

An affinity-purified antibody to rat filaggrin detects filaggrin and profilaggrin in extracts of newborn rat epidermis, and a monoclonal antibody to human filaggrin, HF-1, detects the two proteins in extracts of human epidermis. Immunohistologic studies show that HF-1 reacts with keratohyaline granules of human epidermis and those seen in cultured human keratinocytes. Immunoblotting studies have demonstrated that profilaggrin is synthesized in both cultured human keratinocytes and in a long-lived line of cultured rat keratinocytes, but only in the latter is the protein processed to a product of the molecular weight of filaggrin.

Animals↗
PubMedDate not supplied

Nurses' attitudes to pain control and the use of pain assessment scales.

The key to effective pain control is accurate assessment and, more importantly, the belief that what patients state about their pain is true. This research study investigates nurses' attitudes to pain and its assessment, and reveals why pain control continues to be an inconsistent affair.

Attitude of Health Personnel↗
PubMedDate not supplied

Sustainable change.

In the first of a series of four reports, the author outlines the driving factors behind radical changes that took place in care delivery at Leicester Royal Infirmary. Future reports will focus on the nurses' role in change programmes, the importance of education in successful change and examples of process change in gynaecology and endoscopy.

Hospital Restructuring↗