It has recently been suggested that a substitution of glutamine for arginine at residue 3500 of apolipoprotein (apo) B-100 causes familial defective apo B-100 (FDB), an autosomal, dominantly inherited disorder, which leads to increased serum cholesterol levels. From a sample of 243 patients from Munich with type IIa hyperlipoproteinemia (HL), we have identified eight individuals with the apo B-100 arginine(3500)----glutamine mutation. In a group of 57 subjects with defective low density lipoprotein receptor (LDLR), no mutant apo B alleles were detected. The frequency of FDB in patients with type IIa HL was estimated to be 3%. In the kindreds of three of the probands, 10 additional carriers of the apo B mutation were identified. Clinical and biochemical data reveal a striking similarity between patients with FDB and those with a defect in the LDLR gene. Our data support previous findings that FDB is a serious disorder causing premature atherosclerosis.

Adult↗

PubMedDate not supplied

Arterial deepvenous difference of lipoproteins in skeletal muscle of patients in postoperative state: effects of medium chain triglyceride emulsion.

The effect of fat infusion with medium chain triglycerides (MCT) and long chain triglycerides (LCT) on serum lipoproteins before and after passage through the skeletal muscle was investigated with the forearm technic in eight patients after abdominal operation. All lipoprotein fractions were enriched with triglycerides and phospholipids from infused artificial fat particles with the consequence of significantly increased ratios of TG/PL and TG/apo B in VLDL, of TG/apo B in LDL and TG/apo A-I in HDL. Uptake and release of lipoprotein components by skeletal muscle are given by arterial-deepvenous differences considering the blood flow rates. The positive arterial-deepvenous difference of VLDL triglycerides after 4-hr infusion is interpreted as cleavage and uptake of infused MCT by the muscle. The release of LDL is more pronounced after the fat infusion than before, suggesting a degradation and enhanced catabolism of artificial fat particles. HDL release may be also a consequence of catabolism of artificial TG/PL-particles. These results indicate an uptake of MCT/LCT emulsion by the skeletal muscle.

Adult↗

PubMedDate not supplied

Odd-numbered medium-chain triglycerides (trinonanoin) in total parenteral nutrition: effects on parameters of fat metabolism in rabbits.

Odd-numbered medium-chain triglycerides (MCTs) might combine the advantages of "usual" MCTs applied in clinical nutrition with lower ketogenic action and the release of three carbon units. To test subacute toxicity, trinonanoin/long-chain triglyceride (LCT) (7/3 wt/wt) fat emulsions were given to rabbits (n = 8) for 11 days (7 h/d) within a total parenteral nutrition regimen at a dose of 46.5% of total daily energy. Comparisons were made with rabbits receiving equicaloric amounts of MCT/LCT (7/3, wt/wt) or pure LCT fat emulsions, as well as with orally fed controls. The trinonanoin/LCT emulsion was well tolerated by all animals. Body weight changes showed no statistically significant differences between groups. The enzymatic determination of triglycerides, non-esterified fatty acids, and free glycerol concentrations in plasma samples revealed similar results for both MCT groups. However, ketone body concentrations (3-hydroxybutyrate) were significantly lower after trinonanoin/LCT emulsion administration. In the trinonanoin/LCT group, the plasma concentrations of propionic acid as well as of other short-chain fatty acids continuously increased; on days 10 and 11, elevated amounts of propionic acid were also detected in the urine. The histologic examination of the gut mucosa revealed no distinct differences between groups. On the basis of the presented data, the trinonanoin/LCT emulsion showed no inferiority to "usual" MCT/LCT emulsions. The lower ketogenic effect as well as the marked increase in plasma short-chain fatty acid concentrations may encourage further testing of this substrate for total parenteral nutrition.

3-Hydroxybutyric Acid↗

PubMedDate not supplied

Efficacy of different triglycerides in total parenteral nutrition for preventing atrophy of the gut in traumatized rats.

BACKGROUND: The efficacy of different fat emulsions as components of a total parenteral nutrition (TPN) regimen on the integrity of the gut was assessed in traumatized rats. With the release of the short-chain fatty acids butyric or propionic acid during the hydrolysis of a structured triglyceride containing butyric acid (C4-L-C4-TG) or the beta-oxidation of nonanoic acid from trinonanoin (C9TG), respectively, the infusion of these two triglycerides was supposed to reveal positive effects against the TPN-induced atrophy of the intestine. METHODS: After 3 days of fiber-free liquid diet, rats were traumatized (laparotomy) and catheterized. Afterwards they received equicaloric TPN that delivered 1008 kJ (241 kcal)/kg of body weight per day and 30% nonprotein calories as fat emulsion. The four fat emulsions tested in four groups of six animals contained either long-chain triglycerides (LCT), medium-chain triglycerides (MCT)-LCT (1:1), C9TG/LCT (1:1) or C4-L-C4-TG. Animals of a control group were infused with isovolemic 0.9% NaCl solution and were offered oral standard chow. RESULTS: After 7 days of MCT/LCT administration, the mass-to-length ratio of the total small bowel as well as the masses of mucosa/submucosa and muscularis/serosa in 10-cm segments of the distal half of the small bowel were significantly higher than that found in the other TPN groups or not different from controls. Histometric measurement of the villus height in the ileum revealed no statistically significant differences from controls for the rats of the MCT/LCT and C4-L-C4-TG groups. In the colon, no statistically significant differences between TPN groups were found for either parameter. CONCLUSIONS: Within the tested fatty substrates the MCT/LCT fat emulsion revealed less structural impairments in the distal half of the small bowel regarding mucosa/submucosa (mass and villus height), but also muscularis/ serosa (mass).

Animals↗

PubMedDate not supplied

Characterization of subtypes of hypertension in CAPD patients by cyclic guanosine monophosphate.

OBJECTIVE: While most hypertensive patients with end-stage renal disease normalize high blood pressure with fluid removal by continuous ambulatory peritoneal dialysis (CAPD), there is a significant proportion of CAPD patients whose blood pressure can be controlled only by antihypertensive drugs. METHOD AND PATIENTS: To study the hypothesis that such patients are still volume overloaded, we used plasma cyclic guanosine monophosphate (cGMP) as a marker for hydration status. Thirty-two CAPD patients were divided into 3 groups: group 1, normotensive patients (n = 12); group 2, hypertensive patients who normalized their blood pressure with fluid removal (n = 12); group 3, hypertensive patients whose blood pressure was refractory to intensified fluid removal (n = 8). RESULTS: Mean cGMP levels were significantly higher in dialysis-sensitive hypertension (27 +/- 5 pmol/mL) than in dialysis-refractory hypertension (15 +/- 2 pmol/mL), or in normotensive patients (13 +/- 4 pmol/mL). Reduction of excess fluid in volume overloaded hypertensive CAPD patients resulted in a normalization of cGMP levels (14 +/- 8 pmol/mL), but did not affect this volume marker in patients with dialysis-resistant hypertension (10 +/- 4 pmol/mL). CONCLUSION: Plasma cGMP levels are elevated in volume overload-induced hypertension complicating CAPD. Hypertensive CAPD patients whose plasma cGMP levels are within normal limits have raised blood pressure refractory to volume removal. Our findings are consistent with the hypothesis that inadequate removal of excess volume plays a major role in a subset of patients with CAPD hypertension.

Blood Pressure↗