Distortion of the gizzard in Cyprus pigeons (Columba livia) associated with Hadjelia truncata infestation.

Hadjelia truncata is well recognised as an avian parasite but is rarely reported as pathogenic. This paper describes severe disease in pigeons due to this parasite and is the first to describe the condition in Cyprus. The morphology of the parasite and the associated lesions are described and illustrated and the pathogenesis of the condition is discussed.

Cooperioides antidorca from intestinal nodules in Gazella thomsoni and G. granti in Kenya.

Examination of nodules from the intestine of Gazella thomsoni and G. granti in Kenya revealed the presence of the trichostrongylid nematode Cooperioides antidorca. Nodules from the two hosts were histologically similar and took the form of chronic inflammatory lesions extending through the wall of the gut from the submucosa into the muscular layers. There was some necrosis around the parasite located in the centre of the nodule, a varying population of inflammatory cells and a varying degree of fibrous tissue encapsulation. One nodule possessed an aperture into the lumen of the gut and there was also evidence of serosal proliferation, probably due to the parasitic lesion penetrating the deeper layers of the wall. The morphology of Cooperioides antidorca recovered from the nodules was examined by scanning electron microscopy and is briefly described.

Studies on the induction of cholangiofibrosis by coumarin in the rat.

The histogenesis of coumarin-induced cholangiofibrosis in the rat has been determined. Proliferation of ductal structures was preceded by extensive damage to hepatocytes in the centrilobular region. Focal proliferation of ducts and fibrous tissue was present at 3 months and typical areas of cholangiofibrosis at 6 months. By 18 months the lesion was extensive and contained areas showing bizarre histological features suggestive of malignancy although no evidence of extra-hepatic metastasis was found. The lesion in animals returned to standard diet showed varying degrees of involution with extensive atrophy and fibrosis. A number of parameters of hepatic mixed function oxidase activity were reduced during the initial treatment period, at later times there was recovery of some microsomal enzyme activities. The activity of gamma-glutamyltransferase and the hepatic content of non-protein sulphydryl groups, in contrast, were raised throughout the treatment period.

Oestrogen and progesterone receptors and their relationship to histological grades of epithelial tumours of the magnum region of the oviduct of the domestic fowl.

Tumours of the proprial tubular glands of the magnum region of the oviduct of the domestic fowl (Gallus domesticus) were found to contain receptors for oestrogen and progesterone. The distribution of the receptors in the cytosol and nucleus of the tumour cells was similar to that of the normal magnum under oestrogen stimulation. Receptor content showed a positive correlation with increasing clinical stage and histological grade, i.e., malignancy and undifferentiation of the tumours. These tumours are unusual for hormonally responsive tumours in that their receptor mechanism remains intact with loss of differentiation.

Spontaneous occurrence and experimental induction of leiomyoma of the ventral ligament of the oviduct of the hen.

Leiomyoma of the ventral ligament (VL) of the oviduct is a common tumour of the domestic fowl which occurs in specific pathogen free hens and commercial breeding hens at the end of the first laying season, with prevalence varying from 0 to 60 per cent in different lines and breeds. To investigate the aetiological role of steroid sex hormones in this tumour, subcutaneous implants of diethylstilboestrol (DES), progesterone (P) and DES combined with P (DESP), were administered to chickens at three-week intervals, starting from eight weeks old. DESP produced hyperplasia and leiomyoma of the VL but DES alone produced only hyperplasia. P alone induced neither hyperplasia nor leiomyoma. DESP started to induce leiomyomas within five weeks of the onset of treatment and after 32 weeks of treatment 75 per cent of the DESP group had developed leiomyomas, compared with none in the control group. The results suggest that continuous DESP-treatment can induce hyperplasia and leiomyomas independent of ovarian involvement. The leiomyomas possessed receptors for oestradiol and P. A role of P as a cocardinogen is indicated. These experiments provide the first example of synergism between an oestrogen and progesterone in tumorigenesis in the fowl.

Histochemical studies on the zona reticularis of stress-susceptible pigs.

During an investigation into the role of the adrenal gland in stress susceptibility of pigs, the large lipid masses in the inner zona reticularis were seen to be particularly related to sex differences, although stress-susceptible castrates had significantly more lipid in this zone than had stress-resistant castrates. Significant histochemical differences were also found in the activity of glucose-6-phosphate dehydrogenase and succinic dehydrogenase between the sexes and between castrates of differing susceptibility to stress. The differences in histochemical activity suggest a different origin for some of the adrenocortical cells in the inner zona reticularis.

Cortical hyperplasia of the adrenal gland in the dog.

A survey of the adrenal glands of 151 dogs revealed 33 cases of nodular cortical hyperplasia and six cases of diffuse cortical hyperplasia. The gross, microscopic and ultrastructural changes seen in these two forms of the condition are compared. Detailed measurements indicate that a morphometric study is of some value in establishing a post mortem diagnosis of hyperadrenocorticalism. Cell counts show that, despite differences revealed by histological examination, cellular hypertrophy may be in important feature in both nodular and diffuse 'hyperplasia'. Electron micrography suggests that the ultrastructural changes in nodular hyperplasia are of a degenerative nature while in diffuse hyperplasia the increased quantity of endoplasmic reticulum present and the appearance of the other organelles indicate hyperactivity. This correlates well with the clinical evidence of hyperadrenocorticalism seen in the latter condition.

Tumours of the adrenal gland and paraganglia.

This classification is arranged in two parts in order to take into account the different origins, structures, and functions of the cortex and medulla. The tabular classification is a simplified version of that suggested for adrenal tumours in man, and includes cortical adenoma and carcinoma, phaeochromocytoma, chemodectoma, neurofibroma, ganglioneuroma and ganglioneuroblastoma, and neuroblastoma. A detailed functional classification is not given, since the hormonal activity of many adrenal tumours in animals is less well known than it is in man. Of the tumour-like lesions listed, cortical hyperplasia is particularly important in several species.