Body composition in the dog. I. Findings in the normal animal

Soy Phosphatidylinositol-Containing Lipid Nanoparticle Prolongs the Plasma Survival and Hemostatic Efficacy of B-domain-Deleted Recombinant Canine Factor VIII in Hemophilia A Dogs

Soy phosphatidylinositol (PI)-containing lipid nanoparticles prolong plasma survival, improve hemostatic efficacy, and decrease immunogenicity of human B-domain-deleted factor VIII (BDD FVIII) in hemophilia A (HA) mice. We hypothesize that PI-associated BDD FVIII is more potent than the free protein and, using mathematical modeling, have projected that PI-associated BDD FVIII could be used for once-weekly prophylactic dosing in patients. To facilitate translation to the clinic, comparative plasma survival and ex vivo efficacy of PI-associated recombinant canine FVIII (PI-rcFVIII) were evaluated in HA dogs. Two HA dogs were administered a 50-U/kg intravenous dose of free or PI-rcFVIII. rcFVIII activity measurements and ex vivo efficacy analyses such as whole blood clotting time and thromboelastography were conducted on recovered plasma and whole blood samples. PI association decreased clearance (∼25%) and increased plasma exposure (∼1.4-fold) of rcFVIII. PI-rcFVIII-treated animals had prolonged improvements in whole blood clotting time and thromboelastography parameters compared to free rcFVIII-treated animals. Because rcFVIII is a BDD form of FVIII, these studies provide proof of principle that observations with human BDD FVIII in mice translate to higher animal species. In addition, PI-rcFVIII has potential applications in canine HA management and as a bypass therapy in inhibitor-positive HA patients.

Saline-induced natriuresis and renal blood flow in conscious dogs: effects of sodium infusion rate and concentration

AIM

This study focused on static and dynamic changes in total renal blood flow (RBF) during volume expansion and tested whether a change in RBF characteristics is a necessary effector mechanism in saline-induced natriuresis.

METHODS

The aortic flow subtraction technique was used to measure RBF continuously. Identical amounts of NaCl (2.4 mmol kg(-1)) were given as slow isotonic (Iso, 120 min), slow hypertonic (Hyper, 120 min), and rapid isotonic loads (IsoRapid, 30 min).

RESULTS

During Iso and IsoRapid, arterial blood pressure increased slightly (6-7 mmHg), and during Hyper it remained unchanged. Iso and Hyper increased sodium excretion (4 +/- 1 to 57 +/- 27 and 10 +/- 4 to 79 +/- 28 micromol min(-1), respectively) and decreased plasma renin activity (by 38% and 29%), angiotensin II (by 56% and 58%) and aldosterone (by 47% and 65%), while RBF remained unchanged. IsoRapid caused a similar increase in sodium excretion (to 72 +/- 19 micromol min(-1)), a similar decrease in renin system activity, but a 15% elevation of RBF (282 +/- 22 to 324 +/- 35 mL min(-1)). Selected frequency domain parameters of RBF autoregulation did not change in response to any load.

CONCLUSIONS

In response to slow saline loading simulating daily sodium intake, the rate of sodium excretion may increase 10-20-fold without any change in mean arterial blood pressure or in RBF. Regulatory responses to changes in total body NaCl levels appears, therefore, to be mediated primarily by neurohumoral mechanisms and may occur independent of changes in arterial pressure or RBF.

Water turnover evaluated by the tritiated water method and by the nutritional method in European hedgehog (Erinaceus europaeus L.)

The total body water (TBW), the fractional water turnover rate (WTR), and the water flux rates (WFR) were studied for the first time by the tritiated-water method in 10 hedgehogs under laboratory conditions during the year. To validate this method, we compared the result to the nutritional method. The TBW varied inversely with body mass (BM) during both the active and the hibernation periods. The WTR varied from 16% to 21% during the hibernation period and after the reproduction. The higher values (from 22% to 26%) were recorded during the reproduction period and during the preparation for hibernation. The same variations in WFR were recorded during the active and hibernation period. The net gain or loss of water followed the gain and loss of BM. The tritiated water (THO) method has been validated by the fact that the same variations in WFR during each month have been measured by the THO method and the nutritional method. Moreover, the THO method can be used to estimate the changes in energy metabolism of hedgehogs in relation with the seasons.

Hypothermic anesthesia attenuates postoperative proteolysis

The catabolic response that commonly occurs after major operation is characterized by net skeletal muscle proteolysis and accelerated nitrogen excretion. This response was absent in patients undergoing cardiac surgical procedures associated with the combination of cardiopulmonary bypass, narcotic anesthesia, neuromuscular blockade, and hypothermia. Forearm nitrogen release was 422 +/- 492 nmol/100 ml X min on the first postoperative day, approximately 25% of preoperative values (1677 +/- 411, p less than 0.05). Nitrogen excretion and the degree of negative nitrogen balance were comparable to levels observed in nonstressed, fasting subjects. The potential role of hypothermia, high-dose fentanyl anesthesia, and neuromuscular blockade in modifying the catabolic response to laparotomy and retroperitoneal dissection was further evaluated in animal studies. Six hours after operation, amino acid nitrogen release from the hindquarter was 84% less than control values (p less than 0.05). Nitrogen excretion and urea production were also reduced compared to normothermic controls. It is concluded that the combination of hypothermia, narcotic anesthesia, and neuromuscular blockade attenuates the catabolic response to injury and thus may be useful in the care of critically ill surgical patients.

Effects of single, repeated and massive mannitol infusion in the dog: structural and functional changes in kidney and brain

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Dieldrin poisoning in dogs: relation to obesity and treatment

Keane, William T., Zavon, Mitchell R., and Witherup, Samuel H. (1969).Brit. J. industr. Med.,26, 338-341. Dieldrin poisoning in dogs: relation to obesity and treatment. The time interval required for poisoning to result in mammals from the prolonged absorption of a relatively constant amount of dieldrin, a chlorinated hydrocarbon insecticide, is directly related to obesity. This relationship should be applicable regardless of the route of absorption of dieldrin (ingestion, inhalation, or percutaneous). Forced feeding of a high calorific value food appears to have a place in the treatment of dieldrin poisoning and, by extension, in the treatment of poisoning from many other chlorinated hydrocarbon insecticides.

The management, function and histology of long functioning renal allografts in dogs on immunosuppressive drug therapy

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