Muscular architecture and VIP-like immunoreactive nerves in the gastroduodenal junction of the chicken

The muscular architecture and the distribution of nerves with vasoactive intestinal polypeptide-like (VIP-like) immunoreactivity were examined in the gastroduodenal junction of the chicken. Both the outer and the inner muscle layers (tunica muscularis) and the muscularis mucosae were examined. The inner muscle layer was divided into two parts, namely its inner and outer parts. The outer muscle layer was not present in the pyloric part but was found in the proventriculus and the duodenum. The muscle strands of the outer muscle layer ran longitudinally but were absent at the isthmus and the pylorus. Most of the outer part of the inner muscle layer was located in or close to the pyloric part. The muscle strands in the outer part connected the pyloric part with other regions, namely the craniodorsal muscle, the tendinous centres and the isthmus. The inner part of the inner muscle layer was widely distributed in the stomach. In the pyloric part, the muscle strands of this layer followed a circular or spiral course. The muscularis mucosae was not present in the caudodorsal and cranioventral muscles of the gizzard. In addition, VIP-like immunoreactive nerve fibres were predominantly distributed in the inner part of inner muscle layer of the pyloric part. These results suggest that the ventriculopyloric orifice and the pyloric part itself constrict with a sphincter-like action.Abbreviations VIP vasoactive intestinal polypeptide     

Iron content of rat serum ferritin.

The serum ferritin concentration was significantly higher in female than in male rats, reflecting higher iron stores in females than in males. The mean iron/protein ratio of serum ferritin was 0.018+/-0.008 (SD) (microg of Fe/microg of protein) in female rats and 0.011+/-0.011 in male rats, being much lower than that of liver ferritin (0.233+/-0.014 in females and 0.227+/-0.020 in males). Iron loading of rats significantly increased serum ferritin concentration, but did not influence the iron content of serum ferritin. These results indicate that rat serum ferritin contains only a small amount of iron independent of body iron stores.     

Case of calcifying epithelial odontogenic tumour in a dog

A 12-year-old male shih tzu dog was diagnosed as having a calcifying epithelial odontogenic tumour. One and a half years prior to presentation, a mass was noticed on the right mandible by the owners. Radiography revealed irregular, faintly radiopaque material within the tumour. A right hemimandibulectomy was performed, based on the clinical diagnosis of osteosarcoma. Histopathological evaluation of the mandibular mass showed that it was composed of a polyhedral odontogenic epithelial cell nest, fibrous stroma, homogeneous eosinophilic material and rounded calcifying material. The eosinophilic material was visualised by staining with Congo red, and observed under green birefringence by polarisation microscopy. Although the tumour had not recurred 12 months after surgery, the dog was euthanased because of aspiratic pharyngitis. The literature on the clinical behaviour of calcifying epithelial odontogenic tumours in dogs and cats is reviewed.     

Arrhythmias in newborn thoroughbred foals.

Foetal electrocardiograms (ECG) were obtained from 39 of 50 Thoroughbred foaling mares close to delivery. The 50 newborn foals were studied electrocardiographically during their adaptive period, immediately after birth. In 48 foals there were paroxysmal arrhythmias or mixed arrhythmias. The most common arrhythmias were sinus arrhythmias including wandering pacemaker (32/50) and atrial premature contraction (30/50). The others observed were atrial fibrillation (15/50), ventricular premature contraction (10/50), partial atrioventricular block (7/50), ventricular tachycardia (4/50), atrial tachycardia (3/50) and idioventricular rhythm (1/50). The duration of the arrhythmias was approximately 5 min, and in all cases the arrhythmia disappeared within 15 min of birth. From foetal ECG recordings, no indication of the likelihood of neonatal arrhythmias was detected. With the exception of 2 cases, all foals have continued to grow and develop normally. These arrhythmias are considered normal physiological processes in newborn Thoroughbred foals during the adaptive period to extra-uterine life. High vagal tone and hypoxaemia at birth are probably the main contributing factors.     

Relationship between the development of the gubernaculum and the testicular descent in the rat fetus: macroscopic and light and electron microscopic observation

The gubernaculum consists of the gubernacular cord connected with the vas deferens and the gubernacular bulb connected with the retroabdominal wall. The cord was first distinguished on day 15 of gestation. Its length reached the peak on day 16, followed by a reduction until day 18 to be almost constant thereafter. The bulb was first distinguished on day 16, and its length was steadily increased toward term. The testis began to descend with a reduced length of the cord. By day 19, the testis descended close to the caudal part of the bulb by the sharp bending of the cord. Microscopically, the bulb consisted at first of a centrally located mesenchymal mass and of a covering layer of myoblasts. Thereafter, the mesenchymal mass was gradually shifted toward the cranial part of the bulb, trailing loose mesenchymal tissue in the caudal part of the bulb. On day 19, the mass was decreased in cell population but increased in amount of collagen fibers. It is suggested that the testicular descent starts on day 16 together with the commencement of shortening of the gubernacular cord and enlargement of the gubernacular bulb.     

Prevalence of Mycoplasma gallisepticum and M. synoviae in commercial layers in southern and central California

The prevalence of Mycoplasma gallisepticum (MG) and M. synoviae (MS) in commercial pullet and layer flocks in Southern and Central California was estimated by testing serum and egg-yolk samples from 360 sample flocks in Southern California and 41 sample flocks in Central California. Data relating to potential risk factors associated with MG and MS infections were collected. The estimated true prevalence rate of MG was 73% in Southern California and 3% in Central California. The estimated true prevalence rate of MS was 91% in Southern California and 32% in Central California. Compared with uninfected flocks, MG-infected flocks in Southern California were significantly older and were medicated less (P less than 0.05). More managements were under a multiple-age system, more flocks had molted, more were vaccinated with F-strain, and more had concurrent infection with MS (P less than 0.05). Only one sample flock in Central California was MG-infected; none were vaccinated with F-strain. In Southern California, MS-infected flocks were older than uninfected flocks, more had molted, more were medicated, and more had concurrent infection with MG (P less than 0.05). In Central California, MS-infected flocks did not differ significantly from uninfected flocks in any factor examined; the lack of statistical significance may be due to small sample size.     

The pathogenesis of infectious bursal disease: serologic, histopathologic, and clinical chemical observations

Infectious bursal disease in 35-day-old specific-pathogen-free (SPF) chickens was characterized clinically by its acute onset and brief duration. Clinical signs included depression, anorexia, diarrhea, and polyuria. A detectable precipitin antibody response occurred between 3 and 5 days postinoculation. Evaluation of pooled serum samples obtained from infectious bursal disease virus (IBDV)-infected chickens revealed transient changes in potassium, cholesterol, uric acid, lactate dehydrogenase, serum glutamic-oxalic transaminase, and serum proteins. Individual serum samples analyzed for uric acid concentration indicated that several IBDV-infected chickens had serum uric acid concentrations above the normal comparison range. Histopathologic examination of lymphoid and nonlymphoid tissues from IBDV-infected SPF chickens affirmed that the predominant lesion was lymphoid necrosis in the bursa of Fabricius. Other lymphoid organs were much less severely affected and possessed greater regenerative potential. Nonspecific and relatively mild changes were found in the liver and kidney: hepatic lipidosis and necrosis, renal intratubular crystalline deposits (probably urates), and increased ectopic lymphoid foci. There was no evidence of immune-complex-mediated arteritis/vasculitis in the sartorius muscle or any other tissue examined. Histopathologic and ultrastructural evidence of glomerulonephritis was rare but compatible with acute immune complexemia.