The composition of lipids in intestinal digesta of young pigs receiving diets containing tallow and tallow fatty acids

Three semipurified diets containing a low level of fat or 10 percent of either beef tallow or beef tallow free fatty acids were fed to young pigs. Jejunal digesta was sampled 1.5, 2.5, 3.5, and 4.5 h after feeding by aspiration through tubes leading from the jejunal lumen to the exterior. The samples were forced through Millipore filters (1 x 10(-7) m pore size) to separate aqueous phase and oil phase lipid. The total and aqueous phase lipid was separated into triglyceride, monoglyceride, and free fatty acid, and the fatty acid composition of each fraction determined. The concentration of aqueous phase lipid was not influenced by diet, although the concentration of the oil phase lipid was generally higher for the addition of fat to the diets; the increase was greater for the beef tallow free fatty acid diet than for the beef tallow diet. Free fatty acids were the predominant component of the aqueous phase lipid along with some monoglyceride and traces of triglyceride. The major component of the oil phastions of triglyceride and monoglyceride. These must have been derived from endogenously secreted lipid in the case of the tallow fatty acid diet. Thus, the lower digestibility of completely hydrolyzed beef tallow than of conventional beef tallow was not due to an absence of monoglyceride in the intestinal lumen. The proportion of stearic acid in the jejunal digesta was greater than in the dietary lipid, whereas there were lower proportions of palmitic and oleic acids in the jejunal digesta than in the diet; the effect being most pronounced for the tallow free fatty acid diet. The ratio of oleic to palmitic acid in the aqueous phase was less than in the lipid phase suggesting preferential uptake of oleic acid from the micelle by the intestinal mucosa.     

Metastatic retinoblastoma and L-phenylalanine mustard-dianhydrogalactitol

Retinoblastomas heterotransplanted to nude mice were shown to be sensitive to a combination of phenylalanine mustard and dianhydrogalactitol. A patient with metastatic retinoblastoma was treated with this combination and had a significant response with complete clinical clearance of her bone marrow and metastatic tumors. However, the patient's response was similar to that observed in nude mice; recurrences of tumors developed after complete clinical remission.     

Occurrence of amyloid-related serum proteins in patients with benign monoclonal gammopathy

The serum protein SAA, which is related to the amyloid fibril protein AA, was detected by double immunodiffusion using anti-protein AA antiserum. The SAA level was elevated in 16 to 32 patients with benign monoclonal gammopathy (BMG). In addition, two BMG sera reacted with an antiserum to amyloid fibril protein of immunoglobulin light-chain type, V lambdaI (EF), and one reacted with antiamyloid protein VlambdaV (AR). The reactivity of the BMG sera with antisera to the various amyloid fibril proteins was strikingly similar to that of 35 sera from patients with myelomatosis. In the age group of 50--70 years the proportion of SAA-positive sera in BMG (53%) and myelomatosis (56%) was strikingly higher than that of the normal controls (5%). In older subjects (70--90 years), however, the frequency of SAA in BMG or myelomatosis, although increased (53%--54%), was not significantly greater than that of a control group of apparently healthy individuals (44%).     

Septic arthritis: an explanation

Arterial blood-gases and lung volumes were measured in 48 patients before and after upper abdominal surgery. There was no significant difference between the results of 25 patients ventilated with oxygen and nitrogen during anaesthesia compared with a comparable group which received oxygen and nitrous oxide.     

Selection of monocular or binocular strabismus surgery

A hypothesis is proposed which attributes the dynamic behaviour of the excitable biological membrane to postulated thermal vibrations of polar molecules in the membrane. It is suggested that these vibrations constitute the physical pumping mechanism for active transport and are also the seat of excitability. To illustrate the latter property the construction of a working mechanical model of coupled oscillators is described producing impulses which resemble the behaviour of the nerve impulse in all major aspects. A reinterpretation of this and some other prominent properties of the membrane is attempted in the light of the hypothesis.     

The use of porous granular hydroxyapatite in secondary orbitocranial reconstruction

The search for the ideal bone-graft substitute has been the focus of many research and clinical studies. Hydroxyapatite is one such material that combines osseointegration with maintenance of implant volume and excellent durability. We present our experience in 29 patients ranging in age from 3 to 22 years (mean age 10.5 years) who underwent secondary orbitocranial reconstruction of large contour defects utilizing porous granular hydroxyapatite. Follow-up ranges from 6 to 72 months (mean 30 months). Indications for secondary surgery included residual bony contour defects of the frontal bone, temporal areas, and superior orbital rims that were present 12 months or more after initial surgery. There was one infection secondary to a chronic seroma necessitating removal of the porous hydroxyapatite, and one patient required revision for underfilling and another for overfilling. Excellent permanent contour improvement was obtained with a smooth skin surface in the remainder of our patients. The contour corrections have been long lasting, without evidence of porous hydroxyapatite resorption or migration.     

Preoperative amiodarone as prophylaxis against atrial fibrillation after heart surgery

BACKGROUND: Atrial fibrillation occurs commonly after open-heart surgery and may delay hospital discharge. The purpose of this study was to assess the use of preoperative amiodarone as prophylaxis against atrial fibrillation after cardiac surgery. METHODS: In this double-blind, randomized study, 124 patients were given either oral amiodarone (64 patients) or placebo (60 patients) for a minimum of seven days before elective cardiac surgery. Therapy consisted of 600 mg of amiodarone per day for seven days, then 200 mg per day until the day of discharge from the hospital. The mean (+/-SD) preoperative total dose of amiodarone was 4.8+/-0.96 g over a period of 13+/-7 days. RESULTS: Postoperative atrial fibrillation occurred in 16 of the 64 patients in the amiodarone group (25 percent) and 32 of the 60 patients in the placebo group (53 percent) (P=0.003). Patients in the amiodarone group were hospitalized for significantly fewer days than were patients in the placebo group (6.5+/-2.6 vs. 7.9+/-4.3 days, P=0.04). Nonfatal postoperative complications occurred in eight amiodarone-treated patients (12 percent) and in six patients receiving placebo (10 percent, P=0.78). Fatal postoperative complications occurred in three patients who received amiodarone (5 percent) and in two who received placebo (3 percent, P= 1.00). Total hospitalization costs were significantly less for the amiodarone group than for the placebo group ($18,375+/-$13,863 vs. $26,491+/-$23,837, P=0.03). CONCLUSIONS: Preoperative oral amiodarone in patients undergoing complex cardiac surgery is well tolerated and significantly reduces the incidence of postoperative atrial fibrillation and the duration and cost of hospitalization.     

Intestinal nematode parasites, cytokines and effector mechanisms

Laboratory models of intestinal nematode infection have played an important role in developing our understanding of the immune mechanisms that operate against infectious agents. The type of helper T cell response that develops following infection with intestinal nematode parasites is critical to the outcome of infection. The early events that mediate polarisation of the helper T cell subsets towards either Th1 or Th2 during intestinal nematode infection are not well characterised, but it is likely that multiple factors influence the induction of a Th1 or Th2 type response, just as multiple effector mechanisms are involved in worm expulsion. Costimulatory molecules have been shown to be important in driving T helper cell development down a specific pathway as has the immediate cytokine environment during T cell activation. If helper T cells of the Th2 type gain ascendancy then a protective immune response ensues, mediated by Th2 type cytokines and the effector mechanisms they control. In contrast, if an inappropriate Th1 type response predominates the ability to expel infection is compromised. Equally important is the observation that multiple potential effector mechanisms are stimulated by nematode infection, with a unique combination operating against the parasite depending on nematode species and its life cycle stage. Despite the close association between intestinal nematode infection and the generation of eosinophilia, mastocytosis and IgE it has been difficult to consistently demonstrate a role for these effector cells/molecules in resistance to nematode parasites, although mast cells are clearly important in some cases. It therefore seems that, in general, less classical Th2 controlled effector mechanisms, which remain poorly defined, are probably important in resistance to nematode parasites. Thus, our understanding of both the induction and effector phases remains incomplete and will remain an intense area of interest in the coming years.     

Synthesis, biological activity, and molecular modeling of selective 5-HT(2C/2B) receptor antagonists

The synthesis and biological activity are reported for a series of analogues of the previously published indole urea 2 (SB-206553), designed to probe the 5-HT(2C) receptor binding site. Small molecule modeling studies have been used to define a region in space which is allowed at the 5-HT(2C) receptor but disallowed at the 5-HT(2A) receptor. In a complementary approach, docking of 2 into our model of the 5-HT(2C) receptor has allowed us to propose a novel primary binding interaction for this series of diaryl ureas, involving a potential double hydrogen-bonding interaction between the urea carbonyl oxygen of the ligand and two serine residues in the receptor. The difference of two valine residues in the 5-HT(2C) receptor for leucine residues in the 5-HT(2A) receptor is believed to account for the observed 5-HT(2C)/5-HT(2A) selectivity with 2.