Cryptosporidium spp. is a protozoan parasite that infects the gastrointestinal epithelium and causes diarrhoeal disease worldwide. It is one of the most common pathogens responsible for moderate to severe diarrhoea in children younger than 2 years. Because of the ‘minimally invasive’ nature of Cryptosporidium infection, mucosal epithelial cells are critical to the host's anti-Cryptosporidium immunity. Gastrointestinal epithelial cells not only provide the first and most rapid defence against Cryptosporidium infection, they also mobilize immune effector cells to the infection site to activate adaptive immunity. Recent advances in genomic research have revealed the existence of a large number of non-protein-coding RNA transcripts, so called non-coding RNAs (ncRNAs), in mammalian cells. Some ncRNAs may be key regulators for diverse biological functions, including innate immune responses. Specifically, ncRNAs may modulate epithelial immune responses at every step of the innate immune network following Cryptosporidium infection, including production of antimicrobial molecules, expression of cytokines/chemokines, release of epithelial cell-derived exosomes, and feedback regulation of immune homoeostasis. This review briefly summarizes the current science on ncRNA regulation of innate immunity to Cryptosporidium, with a focus on microRNA-associated epithelial immune responses.

The posterior esophagus of Bulla striata, running from the gizzard to the stomach, was investigated with light and electron microscopy to obtain new data for a comparative analysis of the digestive system in cephalaspidean opisthobranchs. In this species, the posterior esophagus can be divided into two regions. In the first, the epithelium is formed by columnar cells with apical microvilli embedded in a cuticle. Many epithelial and subepithelial secretory cells are present in this region. In both, electron-lucent secretory vesicles containing filaments and a peripheral round mass of secretory material fill the cytoplasm. These acid mucus-secreting cells may also contain a few dense secretory vesicles. In the second part of the posterior esophagus, the cuticle is absent and the epithelium is ciliated. In this region, epithelial cells may contain larger lipid droplets and glycogen reserves. Subepithelial secretory cells are not present, and in epithelial secretory cells the number of dense vesicles increases, but most secretory cells still contain some electron-lucent vesicles. These cells secrete a mixture of proteins and acid polysaccharides and should be considered seromucous. The secretory cells of the posterior esophagus are significantly different from those previously reported in the anterior esophagus of this herbivorous species.

Nutrition modulates both production and composition of milk. Milk composition was studied in rats chronically fed a diet without additional lipids, and therefore eating only traces of the recommended supply of essential polyunsaturated fatty acid. Despite a large decrease in milk-protein synthesis, only protein composition, but not protein concentration, was found to change in the milk of rats following a lipid-deprived diet. Correlatively, we observed a substantial increase in the lactose concentration of milk. Analysis of milk proteins by two-dimensional electrophoresis demonstrated that the relative proportion of the various molecular forms of κ-casein, an O-glycosylated protein, was modified in the milk of rats receiving the lipid-deprived diet. In tissues, differences in the two-dimensional pattern of κ-casein between control and lipid-deprived rats were similar, if not identical. In contrast to κ-casein, the molecular forms of α-lactalbumin, an N-glycosylated protein, were not affected by the diet. These data provide evidence that O-glycosylation of milk proteins in the secretory pathway of mammary epithelial cells is modulated by the lipid content of experimental diets.

The aim of this study was to analyse the tissue surrounding prematurely extruded ventilation tubes (grommets). Thirty-one ventilation tubes, including 21 Shah and six Shepherd tubes, that had been extruded naturally into the ear canal were examined. After formalin fixation, material adhering to the tubes was retrieved and processed to paraffin wax. Five tubes were processed for scanning electron microscope (SEM) analysis. Sections were stained using histochemical methods for collagen, keratin and keratohyaline. In addition, the presence of collagen (type I and III), keratin, vimentin, fibronectin, tenascin, factor VIII-related antigen, CD31 and CD45 was tested for by immunohistochemistry. Results showed that all specimens consisted of an acellular fibrous material, oriented in concentric rings parallel to the tube surface that was often associated with small collections of CD45+ inflammatory cells. Two specimens contained collagen that was detectable by histochemical and immunohistological methods. Twelve specimens contained identifiable desquamated epithelial cells containing keratin and keratohyaline. Only one specimen stained positively for connective tissue markers (vimentin, fibrous fibronectin, tenascin) or showed the presence of vascular epithelium. SEM revealed adherent clusters or sheets of plate-like structures, consistent with the presence of epithelial squames, on three of the five ventilation tubes examined. It is concluded that tissue retained on extruded grommets consists of orthokeratinitizing epithelium infiltrated by inflammatory cells, a finding that is consistent with the theory that tube extrusion occurs as a result of squamous epithelial proliferation, medial migration, differentiation and desquamation. epithelial cells containing keratin and keratohyaline. Only one specimen stained positively for connective tissue markers (vimentin, fibrous fibronectin, tenascin) or showed the presence of vascular epithelium. SEM revealed adherent clusters or sheets of plate-like structures, consistent with the presence of epithelial squames, on three of the five ventilation tubes examined. It is concluded that issue retained on extruded grommets consists of orthokeratinitizing epithelium infiltrated by inflammatory cells, a finding that is consistent with the theory that tube extrusion occurs as a result of squamos epithelial proliferation, medial migration, differentiation and desquamation.

Epithelial-myoepithelial carcinoma (EMC) is a rare biphasic tumour of the salivary glands typically arising in the parotid. Fine needle aspiration cytology is widely used in the initial investigation of salivary gland swellings and whilst the cytological features of this tumour have been described they are not well recognized. This report describes the clinicopathological features of a case of epithelial-myoepithelial carcinoma of the parotid gland and highlights the importance of awareness of this tumour in the differential diagnosis of biphasic tumours on fine needle aspiration cytology.

The peptidergic and noradrenergic innervation of rat and human thymus was investigated by immunohistochemistry at the light and electron microscopical level (avidin-biotin-complex, sucrose-phosphate-glyoxylic-acid, and immunogold techniques). The distribution of noradrenergic neural profiles, and positive immunoreactivity for calcitonin gene-related peptide (CGRP), tyrosine hydroxylase (TH) and neuropeptide Y (NPY) is described in female rats during ageing, and in human children. In the neonatal rat thymus, the arteries and septa are well supplied by fine varicose nerves. In older animals (2 wk–1 y) the number of septa and blood vessels increase and consequently also the innervation. No nerves were found in the cortex. Apart from the innervation of the septal areas, immunoreactivity for CGRP and TH was present in thymic cells. Except for the young rats (neonatal–14 d), all rats showed CGRP positivity in subcapsular/perivascular epithelial cells (type 1 cells). All rat thymuses also contained a few TH positive cells in the medulla, which could only be confirmed as epithelial cells (type 6 cells) in children. Type 1 cells in the human thymus were not CGRP positive, but as in the rat, there were similar TH positive cells in the medulla. It was concluded that in addition to nerves containing CGRP, noradrenaline or dopamine, epithelial cells also contain these transmitters. They could therefore act on different cells (compared with neural targets) in a paracrine manner.

A new technique for the treatment of severe epistaxis associated with hereditary haemorrhagic telangiectasia is described. The nasal septum and inferior turbinates, surgically denuded of respiratory epithelium, were grafted using autografts of cultured epithelial sheets derived from buccal epithelium. All patients upon whom this technique has been used have shown considerable lessening in the frequency and severity of their epistaxes although two patients received grafts on two occasions, in each case approximately three months apart. It is postulated that a nasal lining of stratified squamous epithelium is likely to be more resistant to trauma than the normal respiratory type, and this is supported by the observation that bleeds very seldom occur from the oral cavity in this syndrome.