Metabolic responses to high-fat diets rich in n-3 or n-6 long-chain polyunsaturated fatty acids in mice selected for either high body weight or leanness explain different health outcomes

Background

Increasing evidence suggests that diets high in polyunsaturated fatty acids (PUFA) confer health benefits by improving insulin sensitivity and lipid metabolism in liver, muscle and adipose tissue.

Methods

The present study investigates metabolic responses in two different lines of mice either selected for high body weight (DU6) leading to rapid obesity development, or selected for high treadmill performance (DUhTP) leading to a lean phenotype. At 29 days of age the mice were fed standard chow (7.2% fat, 25.7% protein), or a high-fat diet rich in n-3 PUFA (n-3 HFD, 27.7% fat, 19% protein) or a high-fat diet rich in n-6 PUFA (n-6 HFD, 27.7% fat, 18.6% protein) for 8 weeks. The aim of the study was to determine the effect of these PUFA-rich high-fat diets on the fatty acid profile and on the protein expression of key components of insulin signalling pathways.

Results

Plasma concentrations of leptin and insulin were higher in DU6 in comparison with DUhTP mice. The high-fat diets stimulated a strong increase in leptin levels and body fat only in DU6 mice. Muscle and liver fatty acid composition were clearly changed by dietary lipid composition. In both lines of mice n-3 HFD feeding significantly reduced the hepatic insulin receptor β protein concentration which may explain decreased insulin action in liver. In contrast, protein kinase C ζ expression increased strongly in abdominal fat of n-3 HFD fed DUhTP mice, indicating enhanced insulin sensitivity in adipose tissue.

Conclusions

A diet high in n-3 PUFA may facilitate a shift from fuel deposition in liver to fuel storage as fat in adipose tissue in mice. Tissue specific changes in insulin sensitivity may describe, at least in part, the health improving properties of dietary n-3 PUFA. However, important genotype-diet interactions may explain why such diets have little effect in some population groups.     

Increased nuchal translucency and adverse pregnancy outcomes

Objective: To assess the adverse outcome in pregnancies with raised Nuchal translucency measurement.

Methods: This retrospective study was conducted at the Aga Khan University Hospital, Karachi, Pakistan between January 2001 and December 2015. Women attending the Fetal Medicine unit for first trimester screening by Nuchal translucency were included in the study. All pregnancies were followed up till delivery. Those with incomplete information about the delivery were excluded from the analysis. Pregnancy outcome was observed in normal Nuchal translucency measurements and in raised Nuchal translucency measurements.

Results: Out of the 1941 fetuses, there were 54 (2.8%) with raised Nuchal translucency measurement. Adverse pregnancy outcome was found in 32 (59.3%) of fetuses with raised Nuchal translucency measurement. Invasive testing was done in 15 (27.8%) of pregnancies with raised Nuchal translucency measurement. Among them there were nine (16.7%) cases with abnormal karyotype. It included six (11.1%) cases of trisomy 21, three (5.6%) cases of trisomy 13 and 18.

Conclusion: Raised Nuchal translucency measurement is associated with adverse pregnancy outcome. One in three fetuses are affected by it. Live birth in this group where there is no aneuploidy is around 3.7%.     

A time-series analysis of any short-term effects of meteorological and air pollution factors on preterm births in London, UK

Although much is known about the incidence and burden of preterm birth, its biological mechanisms are not well understood. While several studies have suggested that high levels of air pollution or exposure to particular climatic factors may be associated with an increased risk of preterm birth, other studies do not support such an association. To determine whether exposure to various environmental factors place a large London-based population at higher risk for preterm birth, we analyzed 482,568 births that occurred between 1988 and 2000 from the St. Mary's Maternity Information System database. Using an ecological study design, any short-term associations between preterm birth and various environmental factors were investigated using time-series regression techniques. Environmental exposures included air pollution (ambient ozone and PM(10)) and climatic factors (temperature, rainfall, sunshine, relative humidity, barometric pressure, and largest drop in barometric pressure). In addition to exposure on the day of birth, cumulative exposure up to 1 week before birth was investigated. The risk of preterm birth did not increase with exposure to the levels of ambient air pollution or meteorological factors experienced by this population. Cumulative exposure from 0 to 6 days before birth also did not show any significant effect on the risk of preterm birth. This large study, covering 13 years, suggests that there is no association between preterm births and recent exposure to ambient air pollution or recent changes in the weather.     

Altered states of consciousness profile: an Afro-centric intrapsychic evaluation tool

In an effort to develop an Afro-centric intrapsychic evaluation tool, the Community Mental Health Council, Inc., Altered States of Consciousness Research Team, developed a structured interview used to quantify and qualify the 17 states of consciousness¹ that occurred in black control, precare, and aftercare subjects. Differences were noted in the three groups as to the incidence, prevalence, and quality of the various states of consciousness. It was also noted that the profile obtained from the interviews yielded a sharp clinical picture of the subjects'' total intrapsychic propensities.     

Reduced lower extremity vibratory perception in osteoarthritis of the knee

OBJECTIVE: Vibratory perception threshold (VPT) assesses a distinct yet related sensory pathway that has been associated with neuropathic arthropathy but has not been assessed in knee osteoarthritis (OA). The purpose of this study was to evaluate VPT in subjects with knee OA to determine whether the lower extremity afferent deficits observed in knee OA involve more than just proprioception. METHODS: Twenty-seven individuals with symptomatic and radiographic knee OA were compared with 14 age-matched normal subjects. VPT was assessed using a biothesiometer. Five sites of the lower extremity were evaluated. VPT of OA subjects was compared with VPT of normal subjects. RESULTS: VPT of the OA subjects was significantly reduced at all 5 testing sites compared with normal subjects (P<0.05 at all sites). VPT scores (mean+/-SEM volts) for OA subjects and normal subjects were as follows: first metatarsophalangeal joint (15.0+/-1.9 versus 6.4+/-0.9), medial malleolus (22.0+/-2.2 versus 12.3+/-1.4), lateral malleolus (22.3+/-2.0 versus 10.4+/-0.8), medial femoral condyle (25.8+/-1.8 versus 15.9+/-1.9), and lateral femoral condyle (27+/-1.9 versus 18.9+/-2.4). CONCLUSION: This was the first study to evaluate VPT in OA and demonstrate that VPT is reduced at the lower extremity of subjects with knee OA. The noted deficits in VPT may have significant implications in the neuromechanical pathophysiology of OA. VPT is a simple and reliable technique to measure sensory deficits in subjects with OA of the knee.