Molecular assemblies of highly PEG-ylated phospholipids are important in many biomedical applications. We have studied sterically stabilized micelles (SSMs) of self-assembled DSPE–PEG2000 in pure water and isotonic HEPES-buffered saline solution. The observed SSM sizes of 2–15 nm largely depend on the solvent and the lipid concentration used. The critical micelle concentration of DSPE–PEG2000 is 10 times higher in water than in buffer, and the viscosity of the dispersion dramatically increases with the lipid concentration. To explain the experimentally observed results, we performed atomistic molecular dynamics simulations of solvated SSMs. Our modeling revealed that the observed assemblies have very different aggregation numbers (N(agg) ≈ 90 in saline solution and N(agg)< 8 in water) because of very different screening of their charged PO4(–) groups. We also demonstrate that the micelle cores can inflate and their coronas can fluctuate strongly, thus allowing storage and delivery of molecules with different chemistries.

OBJECTIVE: Diabetes is known to be associated with alterations in metabolic parameters. The aim of this study is to investigate whether Ramadan fasting can affect these metabolic parameters in non-insulin dependent diabetes mellitus (NIDDM) patients. METHODS: This study was conducted in the outpatient Clinic of Jordan University Hospital, Amman, Jordan in February of 1415 Hijra year (1995 Gregorian). Forty-four NIDDM male patients volunteered for this study. Patients fasted the month of Ramadan and few metabolic parameters were recorded. Body weight, fasting blood sugar (FBS), glycosylated hemoglobin (HbA1c), triglycerides (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C) were measured, before, at mid- and at the end- of Ramadan. Detailed energy intakes were also recorded. RESULTS: Patients mean age were 52+/-9 years (range 35-75). Patients showed a statistically significant reduction in their body weight, FBS, HbA1c, and TG levels by the end of Ramadan (1.57 kg, 31 mg/dl, 0.85%, and 35 mg/dl). Other parameters such as TC, LDL-C, HDL-C were not affected by Ramadan fasting. The total daily energy intake remained unchanged including the qualitative components of nutrients. CONCLUSION: Muslim NIDDM patients showed a trend towards better glycemic control following Ramadan fasting. However, the pre-Ramadan existed dyslipidemia was sustained or even worsened following Ramadan fasting.

Actin depolymerizing factor (ADF) from 19-day embryonic chick brains has been purified to greater than 98% homogeneity with a yield of 7.2 mg/100 g of brain. Quantitative immunoblotting with a monospecific antibody to ADF indicated that ADF comprises 0.3% of the total brain protein, resulting in an actual purification yield of about 20%. Brain ADF migrates as a single polypeptide of 19,000 kDa on SDS-containing polyacrylamide gels. The molecular weight of the native protein determined from sedimentation equilibrium in buffers containing from 50 to 200 mM KCl is 20,000. The secondary structure of ADF calculated from the circular dichroic spectrum consists of about 22% alpha-helix, 24% beta-sheet, and 18% beta-turn. ADF contains a blocked N-terminus, a single tryptophan residue located about one-third of the way from one end of the protein, and six cysteine residues (all in reduced form in the native protein). All six cysteine residues could be chemically modified with eosinylmaleimide under nondenaturing conditions; however, ADF activity was lost when more than one cysteine residue was modified. ADF microheterogeneity has been observed upon nonequilibrium pH gradient electrophoresis in polyacrylamide gels containing 9 M urea, the major isoform having a pI of congruent to 7.9-8.0. ADF can interact with either monomeric or filamentous actin to give a complex which can be isolated by gel filtration chromatography. Both major and minor isoforms of the ADF are found in the complex. Assembly-competent actin and active ADF can both be recovered from the complex by chromatography on ATP-saturated DEAE-cellulose.(ABSTRACT TRUNCATED AT 250 WORDS)