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Biomedical subjects

R R Jones

Publications and source records attributed to R R Jones.

8 recordsLinked to original sources

Increased sensory neuropeptides in nodular prurigo: a quantitative immunohistochemical analysis.

Seven patients with nodular prurigo, five patients with lichenified eczema and seven control volunteers were studied immunohistochemically using antisera to the pan-neuronal marker protein gene product 9.5 (PGP), and the neuropeptides calcitonin gene-related peptide (CGRP), substance P (SP), tyrosine hydroxylase (TH), vasoactive intestinal polypeptide (VIP) and the C-flanking region of neuropeptide Y (C-PON). PGP-, CGRP- and SP-immunoreactivities were also evaluated using image analysis quantification, and the data compared by statistical analysis. No significant changes were noted in the lichenified skin of patients with chronic eczema, compared with the control groups. In contrast, a significant increase in PGP immunoreactive nerve fibers was seen in lesional skin of all nodular prurigo cases studied, when compared with non-lesional skin from the same patient or from control subjects (P < 0.001). In one case massive neural hyperplasia was also identified. Staining for CGRP and SP showed a large increase of immunoreactive nerves in lesional skin of nodular prurigo patients, which closely paralleled that of PGP. Staining with VIP, C-PON and TH was similar in both lesional and non-lesional skin. These results indicate that neural changes in nodular prurigo are associated with an increase of sensory neuropeptides, which could be related to the intense pruritus which accompanies nodular prurigo. The absence of significant changes in lichenified skin suggests that the increase in CGRP- and SP-immunoreactive nerve fibres is a characteristic feature of nodular prurigo and may be important in its pathogenesis.

Adult

Ozone depletion and its effects on human populations.

Concern about the ozone-depleting potential of man-made chemicals has led the United Nations to control their usage. Under the present arrangements, fully halogenated chlorofluorocarbons, halons and carbon tetrachloride will be phased out by the year 2000, and methylchloroform by the year 2005. Even so, atmospheric chlorine is expected to rise to seven times its natural level, so further ozone losses and greater ultraviolet B (UVB) exposure can be expected over heavily populated areas of the globe. Calculating changes in skin cancer incidence is a two-stage process which must take account of the increase in biologically effective UVB that results from an ozone loss of 1% (optical amplification factor, OAF) and the percentage increase in skin cancer incidence that results from a 1% increase in annual UV dose (biological amplification factor, BAF). Epidemiological data provide a BAF value of approximately 1.7 for basal cell carcinoma and 3.0 for squamous cell carcinoma. The absorption spectrum of ozone and the increased carcinogenic impact of UV radiation around 300 nm results in a value for OAF of approximately 1.6%; thus a 10% loss of ozone, if sufficiently sustained, would eventually increase the incidence of basal and squamous cell carcinomas by almost 30% and 50%, respectively. Dermatologists, therefore, need to look carefully at the environment in order to safeguard the health of future generations.

Air Pollution

The clinicopathological features of familial cylindromas and trichoepitheliomas (Brooke-Spiegler syndrome): a report of two families.

We have studied four patients from two families and obtained the clinical data from four other affected family members who demonstrated the coexistence of multiple cylindromas and trichoepitheliomas. An autosomal dominant pattern of inheritance with variable penetrance was exhibited in both families, with a female to male ratio of 3:1. The clinical and pathological features of this rare association are discussed.

Adult

Complement abnormalities in diffuse plane xanthomatosis with paraproteinaemia.

Paraproteinaemia may be associated with xanthomatous skin deposits and these can arise in the absence of elevated lipid levels. Two cases of benign monoclonal gammopathy with diffuse plane xanthomatosis are reported. Case 1 exhibited hypolipidaemia and a functional deficiency of C1 esterase inhibitor. Case 2 showed a normal lipoprotein profile, abnormal platelet aggregation, and a cutaneous vasculitis with evidence of complement consumption via the classical pathway. The significance of these abnormalities is discussed.

Aged

Warfarin skin necrosis. The role of factor VII.

Necrosis of cutaneous and subcutaneous tissue is a rare complication of therapy of with oral anticoagulants, and is related to the use of loading-dose regimes. Three cases are reported, and demonstrate that the principal histopathological feature is thrombosis within the subcutaneous vasculature. The effect of large doses of anticoagulant on the levels of the vitamin K dependent clotting factors provides a satisfactory model for the temporal sequence of events in this syndrome. The occurrence of intravascular thrombosis with low or absent levels of Factor VII indicates that the intrinsic clotting system is of primary importance in venous thrombosis. This complication of anticoagulant therapy is not seen if loading-dose regimes are avoided.

Aged

Patterns of total and ionized calcium and other electrolytes in plasma during and after general surgery.

Thirteen patients were studied during two hours of anaesthesia for abdmonial operations and for an hour post-operatively. Serial venous blood samples were taken for determination of plasma total and ionized calcium, acid-base variables, Na, K, Mg, PO4 total proteins and parathyroid hormone. One group of patients received 5 per cent dextrose/water and the other 5 per cent dextrose in Ringer's solution, at 250 ml per hour. Total and ionized calcium levels decreased toward the end of operation and an hour later, associated with respiratory alkalosis. Parathyroid hormone increased at the end of operation, as an effect of the decreased ionized calcium. The general effect was mild haemodilution with all the other electrolytes decreasing, as did total protein concentration.

Adult

Cystic cavum veli interpositi associated with normal or low pressure hydrocephalus.

A new clinical syndrome, characterized by progressive increase in head size (without intracranial hypertension), variable delay in milestones, moderate ventricular dilation, and the presence of a cavum veli interpositi is herein described. The arteriographic and venographic signs are suggestive, but not diagnostic, of the presence of a cavum veli interpositi. Pneumoencephalography, with adequate filling of the subarachnoid spaces and ventricles, is essential to confirming the diagnosis. Cerebrospinal fluid shunting appears to result in an improvement, but the results cannot as yet be considered definitive since only 10 of our 29 patients were shunted.

Cerebral Ventricles