The Monoglyceride Pathway of Fat Absorption in Man

The absorption of fat was studied in five male subjects with cannulation of the thoracic duct in the neck by the administration of doubly labeled monoglycerides, or triglyceride as well as labeled free glycerol or labeled free oleic acid, by gastric or duodenal intubation.Total recoveries of the administered glyceride radioactivity from the lymph lipids ranged from 35 to 53% for the glycerol label (tritium) and from 35 to 57% for the fatty acid label ((14)C). The recovery of administered radioactive free glycerol in lymph lipids was only 4.1%, even when given in mixture with bile salts, fatty acid, and monoglyceride.A comparison of the isotope ratios of the two components (glycerol and fatty acid) of the lymph glycerides with the ratios of these components of the original meal glyceride showed little change during the initial period of fat absorption, indicating that the doubly labeled monoglycerides passed into the lymph intact. During the later part of the period of major fat absorption, the ratios in lymph lipids changed due to loss of glycerol representation, indicating monoglyceride hydrolysis and portal venous diversion of free glycerol.Confirmation of the intact nature of 2-monoglyceride during absorption was made by analyzing the amount and position of the labeled fatty acid in the lymph triglycerides. The percentage of labeled fatty acid in the various positions of the lymph triglycerides was virtually identical with that of the meal during the initial period of fat absorption and then changed reflecting isomerization of fatty acids and subsequent complete hydrolysis of the glycerides.The 2-monoglyceride pathway appears to be the major route of fat absorption for man during normal digestion and absorption of dietary triglyceride.     

C-reactive protein modulates vagal heart rate control in patients with coronary artery disease

Systemic inflammation is associated with sympathetic cardiac activation and decreased HRV (heart rate variability) in subjects at high risk of CAD (coronary artery disease). In the present study, we examined the influence of systemic inflammation, measured by CRP (C-reactive protein), on vagal HR (heart rate) control during behavioural relaxation in patients with CAD. It was hypothesized that CRP would be associated with decreased vagal HR modulation. Consecutive patients were screened 2 weeks prior to elective PTCA (percutaneous transluminal coronary angioplasty). The study was comprised of 29 subjects who represented the first and fourth quartiles of the CRP distribution: Low (0.47+/-0.07 microg/ml)- and High (8.19+/-1.95 microg/ml)-CRP groups respectively. Vagal HR control was quantified as RR high-frequency spectral power (0.15 to 0.40 Hz), and was assessed in log-transformed absolute units (logHF power). Near-IR particle immunoassay was used to determine high-sensitivity CRP concentration. Assessment entailed 5 min of silent reading and self-guided behavioural relaxation. RR logHF power was decreased in the High-CRP group across both assessment procedures (P=0.032). Behavioural relaxation increased RR logHF power for both the Low- and High-CRP groups (P=0.033). Hierarchical linear regression determined that CRP accounted for 18.9% of the variance in RR logHF power during behavioural relaxation (P=0.03), independent of baseline RR interval, cardiac medication, respiratory logHF power and body mass index. In conclusion, patients with CAD had augmented vagal HR control with behavioural relaxation, but this effect was moderated by the severity of CRP. Therefore it may be advisable to assess systemic inflammation in interventions aimed at improving neurocardiac regulation in patients with CAD.     

Impairment of the Growth of Plasmodium Falciparum in HbEE Erythrocytes

HbE is a β-chain mutant frequently found among inhabitants of Southeast Asia and surrounding territories. We find that Plasmodium falciparum multiplies more slowly in erythrocytes from individuals homozygous for HbE than in cells from HbA individuals. In contrast, this parasite grows normally in erythrocytes heterozygous for HbE. This is the first direct evidence that suggests what has been suspected on the basis of circumstantial data, that HbE-containing erythrocytes might be advantageous to the carrier in regions with endemic malaria.     

Should Cannabinoids Be Added to Multimodal Pain Regimens After Total Hip and Knee Arthroplasty?

Background

This study investigated the effects of dronabinol on pain, nausea, and length of stay following total joint arthroplasty (TJA).