D. McEwan Jenkinson

Comparative physiology of sweating.

In the following short review an attempt has been made to collate recent work on the sweat glands of different species. Information on these glands is, however, limited and it has been necessary to generalize from sparse evidence; most of the physiological information, for example, has been obtained from study of domestic and only a few wild animals. It is hoped, however, that, in spite of the dangers of generalization, by presenting the available data in comparative terms it will provoke discussion and a challenging of present views.

The effect of washing on the thickness of the stratum-corneum in normal and atopic individuals

The thickness of, and number of cell layers in, the stratum corneum and the living epidermis were determined on frozen sections of washed and unwashed skin from normal and atopic individuals of both sexes. The stratum corneum of aropic patients was thinner and had fewer layers of dead cells and intercellular lipid than normal, although the living epidermis was thicker. Regular washing with soap and water had no appreciable effect on the dimensions of the living epidermis of either group but caused a reduction in the number of cell layers and the amount of sudanophilic material in the stratum corneum of both. In atopic patients little surface lipid remained, suggesting that washing with soap and water may be detrimental to the barrier function of the stratum corneum in such patients.

Ultrastructure of the hyperhidrotic eccrine sweat gland

Background Hyperhidrosis is the secretion of inappropriately large amounts of sweat by eccrine glands; it can be very debilitating. Little is known of the causes of primary hyperhidrosis.

Seasonal Changes in the Skin Glands of the Goat

SUMMARY Regional and sex differences in the histology of the skin glands of the British Saanen goat are described. The sebaceous glands of the general body surface of the male were observed to increase in size at the beginning of the rutting period. This increase, which was much more pronounced on the neck of the animal, was associated with differences in the chemical composition of the skin lipids on the foreparts of the body. No comparable change was observed in the female or castrated male. The diameters of the sweat glands of male, female and castrated goats did not exhibit a seasonal variation. It is probable that multilobular sebaceous glands situated between the horns and the bilobular sebaceous glands of the head and neck are involved in the production of the substance causing the rutting odour or its precursor.

The effects of thermal stimulation on the ultrastructure of the human atrichial sweat gland. I. The fundus

Ultrastructural examination of sweat glands from the human loin before and during heat‐induced activity indicated that the sweat is formed from the contents of disrupted cells as well as from the products of secretion. The principal secretory processes appear to be fluid transport and exocytosis of vesicles. However, configurations suggesting microapocrine secretion were also observed. It is concluded that the mechanisms involved in sweat production in man are fundamentally similar to those in animals and the terms ‘apocrine’ and ‘eccrine’ should be discarded. The myocpithelial cells which were contracted at the onset of sweating appeared to be under less tension after 3 h of continuous activity.

Serum and skin surface antibody responses to intradermal vaccination of cattle with Dermatophilus congolensis.

SUMMARY The specific antibody titres and concentrations of IgG1, IgG2, IgA and IgM in skin washings and serum from cattle were compared before and after intradermal vaccination with an epidermal pathogen, Dermatophilus congolensis. Vaccination induced a rise in serum antibody titres for the IgG subclasses and a fall in the serum IgA titre. At the skin surface, however, increased antibody levels were demonstrated for IgG1, IgA and IgM. Although no increase in IgG2 antibody titre occurred on the skin, the concentration of this subclass increased in both the serum and skin washings. The concentrations of IgG1 and IgM in the washings fell. These findings support the concept of peripheral secretory or transport systems at the skin surface capable of differentiating between classes of antibody.

Location of the microflora in the skin of cattle.

SUMMARY Using histological techniques the bovine skin microflora was found in the intercellular spaces of the outer stratum corneum and in the hair follicle infundibula. It was composed mainly of bacteria although yeasts and filamentous fungi were also observed. The bacteria and yeasts were generally found in mixed microcolonies closely associated with sebaceous lipid.

Effects of topically‐applied antiperspirant on sweat gland function

In subjects exposed to a hot environment, short‐term topical pretreatment with aluminium zirconium tetrachlorhydrate delayed the onset of visible sweating although it failed to prevent the response. The delay was considered most probably to be due to the occlusivc action, in the duct within the upper epidermis, of aluminium‐containing conglomerates, which disappear after continuous sweating. However, microanalytical evidence indicated that ionic transport within the fundus secretory cells was also modified.

Automated image segmentation and serial section reconstruction in microscopy

A technique for automatic 3‐D reconstruction of specifically stained features in televised serial histological sections has been developed using an image analyser. Images which included these features were individually converted to binary images, compiled, displayed to show the 3‐D morphology and used to quantify the structure. The criteria necessary for producing valid reconstructions and the problems associated with the manipulation of images of fine detail, particularly those containing several thousand features, are illustrated by examples from skin.

The Topography of the Skin Surface of Cattle and Sheep

SUMMARY The skin surface of cattle and sheep was observed by scanning electron microscopy. In both species the hair pores were well protected by layers of squames permeated with an amorphous material which appeared to be sebaceous lipid. Lipid was generally found only at the margins of the epidermal squames in the interfollicular region of cattle and it was concluded that sebum does not flow across the skin but acts as a surface sealant. A similar system seems to operate at the surface of sheep skin although more lipid was present on the squames.