Comparison of a phospholipid-based protein-free surfactant and a natural bovine surfactant (SURVANTA) during pressure and volume-controlled ventilation in an improved rabbit fetus model.

During pressure- or volume-controlled ventilation different surfactant preparations were compared in an improved rabbit fetus model. Based on a self-designed software program, this model enables on-line registration of lung mechanics and heart rate in up to ten fetuses. Using a commercially available bovine lung surfactant (SURVANTA) as standard, we compared animals treated with a protein-free surfactant preparation containing only phospholipids, PL (dipalmitoylphosphatidylcholine:palmitoyloleoylphosphatidylglycerol++ +, DPPC:POPG 70:30) plus palmitic acid (PA) with an untreated ventilated control group. During pressure-controlled ventilation the insufflation pressure (IP) was decreased and increased stepwise with and without positive end-expiratory pressure (PEEP). SURVANTA was significantly more potent than PL plus PA and both differed significantly from the untreated controls. With additional PEEP the differences between SURVANTA and PL+PA disappeared but the differences to the controls were still present. We found that, with additional PEEP, active natural surfactants lead to ECG-irregularities, which indicates that PEEP influences pulmonary and cardiovascular function and compromises the benefits of surfactant therapy. Also during volume-controlled ventilation SURVANTA was superior to PL+PA and the untreated controls. In order to raise the level of activity of pure PL mixtures to that of natural bovine surfactants, we suggest that a surface active protein (probably SP-C) must be added to such mixtures.

Anatomy of the prepubic tendon in the horse, cow, sheep, goat, and dog.

Analyses of the fibers in the prepubic tendon of the horse and ruminants have shown that it is composed of the crossed and uncrossed tendons of origin of the pectineus muscles, the pelvic tendons of the rectus and obliquus abdominis muscles, and the tendons of origin of the cranial parts of the gracilis muscles. Pelvic attachments of the linea alba and the yellow abdominal tunic are incorporated in it. It is not a transverse ligament, and it is not homologous to the human superior (cranial) pubic ligament. The dog differs in 4 respects: (1) the pectineus tendons do not cross, but each originates from the pubic bone of the same side; (2) an iliopubic cartilage is intercalated in the prepubic tendon on each side at the junction of the pectineus tendon and the abdominal and pelvic tendons of the external oblique at the caudal angle of the superficial inguinal ring; (3) in some dogs, the caudal border of the aponeurosis of the transversus abdominis joins the prepubic tendon; (4) the gracilis tendon does not extend to the prepubic tendon. The clinical anatomy was described, illustrated, and compared between species. Conflicting descriptions in the literature were discussed and resolved by new approaches to the dissection. Studies of the inguinal region in the cat and pig were reviewed. A table of nomenclature is included.

Volvulus of the bovine abomasum and omasum.

Two cows with right-side volvulus (torsion) of the abomasum and omasum were embalmed, and the viscera were dissected to study the topography and mechanisms of the condition. In both cases, the abomasum and omasum were greatly distended and formed a loop with the cranial part of the duodenum. The loop was twisted 360 degrees counter-clockwise, as viewed from the rear or from the right, around an axis through the lesser omentum. The reticulum was drawn caudally on the right side of the rumen by its attachment to the fundus of the abomasum. Study of a model of the stomach and omenta indicated that the more probable mode of rotation was in a sagittal plane. The mode of rotation made no difference in the result or in the method of reduction, which was deflation and rotation in the opposite direction. pressure and tension damage to the ventral vagal trunk and to the blood vessels would indicate a guarded prognosis.

Pharyngeal trauma in cattle.

Four cases of pharyngeal trauma in cattle due to improper administration of oral medications are discussed. These cases presented for suspected gastro-intestinal disorders and anorexia. Physical findings included copious drooling of saliva, pharyngeal pain, extended head and neck, forestomach stasis, fever, dysphagia, and pneumonia. Diagnosis was made by manual examination of the oral cavity or endoscopy. Ancillary diagnostic aids included clinical pathology and radiography. Hemograms were consistent with infection, serum electrolytes were normal. Radiographs in 3 of 4 did reveal significant evidence of retropharyngeal cellulitis. The signs of dysphagia and forestomach dysfunction were explained by either a pain induced inhibition of swallowing and eructation or direct involvement of the vagus nerve itself in the retropharyngeal region. An additional consequence of laryngeal motor dysfunction was aspiration pneumonia. Response to treatment with broad spectrum antibiotics, analgesics and symptomatic supportive care over a 7 to 14 day period was good.

Histochemical localization of adenosine triphosphatase activity in bovine ruminal epithelium.

A fine-structural histochemical technique was used to localize magnesium-dependent adenosine triphosphatase (Mg-ATPase) activity in ruminal mucosa. Precipitate appeared on the cytoplasmic surface of the plasmalemma in cells of the upper stratum spinosum, the stratum granulosum, and the deepest layer of the stratum corneum. This ATPase activity was sensitive to glutaraldehyde fixation and possibly to ouabain, but was unaffected by sodium and potassium. The preponderance of Mg-ATPase activity in bovine ruminal epithelium may make it impossible to detect sodium-potassium-activated adenosine triphosphatase ((Na + K)-ATPase) activity histochemically. A Mg-ATPase activity also occurred in mitochondria of the stratum spinosum and stratum granulosum. None of the ruminal sections hydrolyzed adenosine diphosphate, inosine triphosphate, or beta-glycerophosphate when these compounds were used as substitute substrates for adenosine triphosphate. When adenosine-5'-monophosphate was the available substrate, a reaction product appeared in the same layers as Mg-ATPase activity, but the reaction product was confined to the intercellular space.