Malignant histiocytosis and other causes of death in Bernese mountain dogs in Denmark.

To determine the causes of death in Bernese mountain dogs, to assess the prevalence of malignant histiocytosis in the Danish Bernese mountain dog population, and to assess whether a hereditary pattern for this disease exists, 756 questionnaires were sent to members of the Danish Bernese Mountain Dog Club requesting information regarding the life span and causes of death of their dogs. A response rate of 57.7 per cent was achieved, giving information for 812 dogs, of which 290 had died. The average life span was 7.1 years. The most prevalent causes of death were neoplasia (42.1 per cent), old age (10.3 per cent), kidney disease (6.9 per cent), infection (5.9 per cent), skeletal problems (5.2 per cent), heart disease (3.8 per cent) and behavioural causes (3.5 per cent). Thirteen dogs were diagnosed with malignant histiocytosis, 11 of which were genealogically related.

Oesophageal heat transfer properties indication of segmental blood flow changes during distension.

The pain perception to distension of the oesophagus can be explained by activation of receptors responding to mechanical deformation or to distension-induced ischaemia. The aim of this study was to develop a new method for detection of changes in segmental blood flow during distension based on measurement of heat transfer. A bag was distended in the distal oesophagus of six healthy subjects followed by cooling or heating of the bag fluid to 5 or 60 degrees C. After equilibrium, the temperature was allowed to change back to body temperature. The temperature was recorded together with intraluminal ultrasound imaging, allowing assessment of the heat transfer properties at different bag volumes. The heat transfer constants were higher after heating the bag than after cooling the bag (Tukey, P < 0.05). The heat transfer constants after heating the bag decreased as function of bag volumes whereas the heat transfer during cooling was not affected by the bag volume (F = 0.9, P = 0.4). The findings indicate that segmental blood flow can be assessed indirectly by calculating the heat transfer properties. Distension induced a drop in regional blood flow. Hence, ischaemia may contribute to distension-induced pain. Furthermore, heat increased segmental blood flow and cold decreased segmental blood flow. This method may in the future be used to explore the mechanisms behind oesophageal pain.

Sensation and distribution of stress and deformation in the human oesophagus.

Evaluation of the distribution of stresses and strains in relation to distension-induced sensation in the human oesophagus is valuable for understanding oesophageal biomechanics and mechano-sensation. In 12 healthy volunteers a specially designed oesophageal bag containing an endoscopic ultrasound probe was inflated to the moderate pain level. Ultrasound images, bag pressure and perceived sensation were recorded before and after pharmacological relaxation of the smooth muscle with butylscopolamine. The oesophagus was assumed to be circular and thick-walled. Distension induced a tensile circumferential stretch, radial compression and longitudinal shortening. Both circumferential strain and stress were highest at the mucosal surface and decreased throughout the wall. The stiffness increased throughout the wall and was highest at the outer surface (P < 0.001). The decrease in stiffness in response to butylscopolamine was non-significant. The infused volume (P = 0.012) and circumferential stress (P < 0.001) were most closely associated with the distension-induced sensation (adjusted R2 = 0.88). The perceived sensation was highly individual but was unaffected by butylscopolamine (P > 0.08). The present study provides a method for computation of the stress-strain distribution throughout the wall and the mechano-sensory interaction in the human oesophagus. In the future, this may be useful for understanding of mechanoreceptor responses and generation of symptoms in visceral organs in health and in disease.