Hugh Y. Elder

Optimum conditions for cryoquenching of small tissue blocks in liquid coolants.

Three approaches were taken with the aim of defining the optimum conditions for rapid cryopreservation in liquid quenchants. In a theoretical approach, two mathematical models were used. The first is of value in defining the absolute maximum rates of cooling which could be achieved at various depths in the tissues. The second highlights the poor thermal properties of liquid coolants and therefore emphasizes the essential requirement for vigorous quenchant mixing and rapid specimen entry.

Cytology of carcinus haemocytes and their function in carbohydrate metabolism

Abstract 1. 1. Haemocytes of the common shore crab, Carcinus maenas, have been examined under the light and electron microscopes. 2. 2. Two morphologically distinct cell types are observed and the cytology of each has been described. 3. 3. Histochemical analysis confirms the presence of a large glycogen store and of an acid polysaccharide component (which may be chitin) in one of the cell types. 4. 4. Preliminary analysis suggests that haemocytes may contain glucose-6-phosphatase, and since it is known that the blood polysaccharide fraction incorporates radioactive glucose, a central role for haemocytes in the metabolism of carbohydrates is strongly suggested .

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.

Comparative studies of the ultrastructure of the sebaceous gland

Three-dimensional reconstructions and ultrastructural evidence on the sebaceous glands of man and domestic animals indicate that sebum is produced from a column of developing and degenerating cell populations derived from peripheral progenitor cells at the base of the lobe in a manner analogous to hair growth. The remainder of the peripheral cells apparently have no direct involvement with sebocyte production; those towards the neck of the gland contribute keratin to the secretory product.

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.

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.

Vacuolar-type H+ -ATPase distribution in unstimulated and acetylcholine-activated isolated human eccrine sweat glands.

The presence and cellular distribution of subunits of the V1 sector of the vacuolar-type H+-ATPase (V-ATPase) was investigated in isolated human eccrine sweat glands. In every instance, V-ATPase was located in the cytoplasm and apical membranes of the luminal cells of the reabsorptive duct segment. In the secretory coil, both diffuse and perinuclear staining was demonstrated in the secretory cells, with additional expression at the apical and basolateral membranes and on the intercellular canaliculi. There was no detectable difference in V-ATPase expression as a result of prior application of 100 µM acetylcholine.

Changes in the Ultrastructure of the Gill Epithelium of Patella Vulgata after Exposure to North Sea Crude Oil and Dispersants

Intertidal organisms are particularly prone to the effects of both crude oil and to the chemicals commonly used to disperse the oil, following an oil spill at sea (Smith, 1968). A large body of literature now exists on the lethal effects of crude oil and dispersants but little progress has been made towards elucidating the toxic mode of action of these chemicals, nor to understanding what effects they exert when present in sub-lethal concentrations. Since the gills of aquatic animals are generally the most delicate of the epithelia exposed to the environment, it is likely that they will be most prone to damage by pollutants. Whilst previous workers using light microscopy (e.g. Clark, Finley & Gibson, 1974; Blanton & Robinson, 1973) have reported gross damage to the gills of mussels and fish following exposure to crude oil, there was no information available on the nature of the cellular damage at the ultrastructural level. In this study, we describe the nature of the lesions produced in the gills of the common intertidal limpet Patella vulgata following exposure to the water soluble fraction of North Sea crude oil and to the dispersants BP 1100 X and BP 1100 WD. A description of the ultrastructure of normal gill plates of Patella has been published previously (Nuwayhid, Davies & Elder, 1978).

Gill structure in the common limpet Patella vulgata

The gills of Patella consist of a row of triangular shaped leaflets suspended from the roof of the pallial groove. The surface of each gill is thrown into a series of transverse furrows. Tufts of cilia are irregularly distributed over the surface and generate a current of water which flows in the opposite direction to the flow of blood within. The central part of the gill comprises a large haemocoelic space traversed by trabeculae which contain muscle fibres and suggesting that the flow of blood through the gill may be under nervous control. A blood channel runs around the periphery of the gill. The epithelial layer bounding the blood space comprises a single layer of columnar epithelial cells. The outer surface is protected by a structured mucopolysaccharide glycocalyx held in place by a dense mat of microvilli. The cells contain clearly defined mitochondria, Golgi complex, lysosomes, rough and smooth endoplasmic reticulum. In addition, the non-ciliated cells are characterized by a layer of membrane-bound granules, of unknown function, in the apical cytoplasm. Phagocytes are frequently found associated with the basement membrane. They contain large membrane-bound granules and appear to move outwards between the epithelial cells to expel the granules at the outer surface of the gill. It is possible that the gill has an excretory as well as respiratory role in the physiology of the animal.