The pancreas in diabetes mellitus. The echographic aspects

Forty patients with diabetes mellitus (25 with insulin-dependent and 15 with non-insulin dependent diabetes) were studied by means of US in order to evaluate possible volumetric alterations in the pancreas and their eventual progression over time. Thirty healthy subjects were also studied as a control group. The following variables were recorded: thickness of the head, body and tail of the pancreas and area of its head. The patients were also divided into 5 groups according to the age of diabetes (< 1, > 1, > 7, > 14, > 21 years). The results showed 25 IDDM patients to exhibit significant reduction in these variables relative to controls (p < = 0.01), especially in the body (average reduction -40%) and tail (average reduction -20%) of the pancreas. NIDDM patients exhibited non-significant reductions in pancreatic size. The study of the 5 groups of IDDM patients, divided according to the duration of diabetes, revealed all pancreatic variables to reduce more than in controls within a year since diagnosis, to exhibit relative increase during the next 7 years and finally to reduce again in the following years. These results show that anatomic damage to the pancreas occurs within the first year of diabetes. Moreover, IDDM was seen to alter the normal proportions among the single anatomic structures forming the pancreas, especially relative to two anatomic ratios--i.e., head/body and tail/body pancreatic thickness. The relative values in IDDM patients were markedly higher than those in controls (p < 0.001). The patients were again divided into 5 groups according to the age of diabetes: the values of the above ratios in the course of diabetes greatly differed from those observed in controls--i.e., they increased within the first year of diabetes, were steady during the next 7 years, and returned to normal values after 21 years of diabetes, which meant the return to the normal anatomic ratios among the three parts of the pancreas.     

Novel Engineered Ion Channel Provides Controllable Ion Permeability for Polyelectrolyte Microcapsules Coated with a Lipid Membrane

The development of nanostructured microcapsules based on a biomimetic lipid bilayer membrane (BLM) coating of poly(sodium styrenesulfonate) (PSS)/poly(allylamine hydrochloride) (PAH) polyelectrolyte hollow microcapsules is reported. A novel engineered ion channel, gramicidin (bis‐gA), incorporated into the lipid membrane coating provides a functional capability to control transport across the microcapsule wall. The microcapsules provide transport and permeation for drug‐analog neutral species, as well as positively and negatively charged ionic species. This controlled transport can be tuned for selective release biomimetically by controlling the gating of incorporated bis‐gA ion channels. This system provides a platform for the creation of “smart” biomimetic delivery vessels for the effective and selective therapeutic delivery and targeting of drugs.     

Study of Some Experimental Parameters in the Synthesis of Triacylglycerols with CLA Isomers and Structural Analysis

The present research deals with the synthesis of structured triacylglycerols (TAG) by enzymatic treatment of sn-1,3-diacylglycerol (sn-1,3-DAG) with conjugated linoleic acid (CLA) isomers using the immobilized lipase from Rhizomucor miehei (Lipozyme^® IM) under different experimental conditions. In particular, the influence of reaction parameters, such as temperature, enzymatic load, reaction time and DAG/CLA ratio has been evaluated using an experimental design software with a screening objective. Two responses have been selected, they are the percentage of CLA isomers in total TAG and in the sn-2- position and a three-level-4-factor fractional factorial experimental design was used to screen the variables. The results showed that the selected experimental variables have an influence on the enzymatic reaction, in particular, the DAG/CLA substrate ratio and the temperature, both of which inversely correlated with CLA incorporation, but also the enzymatic load and the reaction time, both directly correlated with CLA incorporation. The best results for CLA isomer % content both in total TAG (46.3%) and in the sn-2- position (52.2%) were obtained at 40 °C for 96 h, with 20% enzymatic load and a 0.5 reactive ratio.     

Using human and model performance to compare MRI reconstructions

Magnetic resonance imaging (MRI) reconstruction techniques are often validated with signal-to-noise ratio (SNR), contrast-to-noise ratio, and mean-to-standard-deviation ratio measured on example images. We present human and model observers as a novel approach to evaluating reconstructions for low-SNR magnetic resonance (MR) images. We measured human and channelized Hotelling observers in a two-alternative forced-choice signal-known-exactly detection task on synthetic MR images. We compared three reconstructions: magnitude, wavelet-based denoising, and phase-corrected real. Human observers performed approximately equally using all three reconstructions. The model observer showed very close agreement with the humans over the range of images. These results contradict previous predictions in the literature based on SNR. Thus, we propose that human observer studies are important for validating MRI reconstructions. The model's performance indicates that it may provide an alternative to human studies.     

Stereospecific analysis of triacylglycerol and phospholipid fractions of four freshwater fish species: Salmo trutta, Ictalurus punctatus, Ictalurus melas and Micropterus salmoides

The fatty acid compositions and the positional distributions of fatty acid in triacylglycerol (TAGs) and phospholipid (PLs) fractions of four cultured freshwater fish species (Salmo trutta, Ictalurus punctatus, Ictalurus melas and Micropterus salmoides) were investigated. As regards the TAGs fraction, the S. trutta (trout) and I. punctatus (channel catfish) species had the highest % content in n3 polyunsaturated fatty acids (PUFAs) and the lowest n6/n3 ratio; this ratio resulted always lower than 1 in all the considered fish species. The PLs fraction of the considered fish was very interesting because of the high percentage of PUFAs, both in phosphatidylcholines and in phosphatidylethanolamines. The fatty acid distribution among the three sn-positions of the glycerol backbone was non-random; generally, both n6 and n3 PUFAs were mainly distributed between sn-2- and sn-3-positions of TAGs while the contents in sn-1-position were generally lower; in PLs fraction these fatty acids preferred the sn-2-position.     

Use of Lactobacillus plantarum fermentation products in bread-making to prevent Bacillus subtilis ropy spoilage

Four fermentation products (FPs) of the lactic acid bacterium Lactobacillus plantarum ITM21B were screened for their anti-Bacillus activity in vitro and in bread-making trials. Results of the storage tests performed with loaves prepared with an FP or calcium propionate demonstrated that after 3 days at 30 degrees C, gross spoilage was evident in only the control loaves, which contained Bacillus subtilis at numbers of about 10(9) cfu/g. The highest inhibitory activity was shown by DM-FP obtained by growing L. plantarum in a defined medium (DM). Significantly, this medium contained an amino acceptor of the aminoacid transamination, namely alpha-ketoglutaric acid, and an aminoacid pool. With loaves prepared using the DM-acid mixture which simulated the DM-FP composition, the same reduction of ropy spoilage as with DM-FP was obtained after 3 days, while the efficacy of the mixture decreased after 7 days. This result suggests the potential involvement of some unknown metabolites in the inhibitory activity of DM-FP. In baked products made with flour based media (M1-FP, M2-FP, M3-FP), no ropy symptoms were noticeable after 3 days storage although a considerable Bacillus count was detected. DM-FP was as effective as calcium propionate (0.3% w/w, based on flour mass) in prolonging the Bacillus free-shelf life of yeast-leavened bread for 7 days.