TAG-1 can mediate homophilic binding, but neurite outgrowth on TAG-1 requires an L1-like molecule and beta 1 integrins

Subsets of axons in the embryonic nervous system transiently express the glycoprotein TAG-1, a member of the subfamily of immunoglobulin (Ig)-like proteins that contain both C2 class Ig and fibronectin type III domains. TAG-1 is attached to the cell surface by a glycosylphosphatidylinositol linkage and is secreted by neurons. In vitro studies have shown that substrate-bound TAG-1 promotes neurite outgrowth. We have examined the nature of axonal receptors that mediate the neurite-outgrowth promoting properties of TAG-1. Although TAG-1 can mediate homophilic binding, neurite outgrowth on a substrate of TAG-1 does not depend on the presence of TAG-1 on the axonal surface. Instead, neurite outgrowth on TAG-1 is inhibited by polyclonal antibodies directed against L1 and, independently, by polyclonal and monoclonal antibodies against beta 1-containing integrins. These results provide evidence that TAG-1 can interact with cell surfaces in both a homophilic and heterophilic manner and suggest that neurite extension on TAG-1 requires the function of both integrins and an L1-like molecule.     

Heparin Use in Daily Hemodialysis

More frequent dialysis is thought to be associated with increased heparin requirements; however, limited data are available which compare heparin requirements of conventional to daily dialysis. Objectives: To determine differences in heparin dose during conventional thrice‐weekly dialysis (CHD) compared to daily hemodialysis (DHD). Methods: All patients within the daily home hemodialysis at the Northwest Kidney Centers were evaluated for heparin dose both pre‐ and post initiation of daily hemodialysis. Patients on DHD received an initial bolus of heparin, without a continuous heparin drip, and supplemental heparin midway through the dialysis run as needed to maintain adequate activated clotting times (ACTs). CHD patients received a heparin bolus, followed by initiation of heparin drip as needed to maintain adequate ACTs. Results: Of the 1117 patients who dialyze at the NKC, 55% were Caucasian, 21% African‐American, 20% Asian/Pacific Islander, and 35% were of other ethnicity. The majority of patients were greater than 60 years (56%), while 36% ranged from 40–60 years and 13% ranged from 20–40 years. Male patients constituted 54% of patients. Diabetes was the primary cause of renal disease (36%), followed by hypertension (21%) and glomerular disease (18%). Of those patients in the home hemodialysis program (n = 45), 10 patients started daily home hemodialysis using the Aksys daily home hemodialysis system. Of those, the majority was male (100%), Caucasian (78.8%) with an average age of 46.7 ± 18 years. Glomerulonephritis was the primary cause of end‐stage renal disease (40%), while the percentages of other diseases were similar [Alport's syndrome (20%), hypertension (20%) and diabetes (10%)]. Compared to initial DHD heparin requirements (10,111 ± 2219 units), CHD heparin dose requirements (6833 ± 2715 units) were significantly lower (p = 0.045); however, total heparin needs were similar between groups (10,166 ± 4380 units vs. 10,778 ± 2959 units) (p = 0.324). Conclusion: Although patients initiating DHD have greater initial heparin requirements than when on CHD, total heparin doses remain similar to those required on conventional thrice‐weekly hemodialysis. Greater initial heparin doses required during short daily dialysis appear safe compared to those of conventional dialysis.     

Nonstarter lactobacilli isolated from soft and semihard Argentinean cheeses: genetic characterization and resistance to biological barriers

Nonstarter lactic acid bacteria isolated from Argentinean cheeses were identified and characterized by focusing on their resistance to biological barriers, along with other physiological features of potential interest, in the search for future probiotic organisms. Lactobacilli were enumerated and isolated from semihard and soft cheeses made with multistrain Streptococcus thermophilus starters. Lactobacilli counts in 1-week-old cheeses were between 10(5) and 10(7) CFU/g and then reached 10(7) CFU/ g in all 1-month samples, while streptococci were always above 10(9) CFU/g. A total number of 22 lactobacilli isolates were retained, identified, and characterized by in vitro tests. Species identity was determined by carbohydrate metabolism and species-specific PCR assays. Genetic diversity was explored by random amplified polymorphic DNA (RAPD) PCR analysis. The Lactobacillus strains were assigned to the species L. casei, L. plantarum, L. rhamnosus, L. curvatus, L. fermentum, and L. perolens. All the strains studied tolerated 25 ppm of lysozyme, and most of them showed resistance to 0.3% bile. After incubation in gastric solution (pH 2.0), counts decreased by several log units, ranging from 3.2 to 7.0. The strains were able to grow in the presence of bile salts, but only three isolates were capable of deconjugation. The nonstarter lactobacilli that were assayed fermented the prebiotic substrates (especially lactulose and inulin). Some strains showed high cell hydrophobicity and beta-galactosidase activity, as well as inhibitory activity against pathogenic bacteria. It was concluded that most of the lactobacilli isolated in this study demonstrated resistance to biological barriers and physiological characteristics compatible with probiotic properties, which make them suitable for further research in in vivo studies aimed at identifying new probiotic organisms.     

Autocrine inhibition of the epidermal growth factor receptor by intracellular expression of a single-chain antibody

A gene encoding a single-chain antibody which specifically binds the human epidermal growth factor (EGF) receptor has been constructed and expressed intracellularly. The single-chain antibody is derived from monoclonal antibody 225 which competes with EGF for binding to the extracellular domain of the receptor. The single-chain antibody was provided with a signal peptide to direct it to the secretory pathway and was expressed in EGF receptor transformed NIH/3T3 fibroblasts. EGF induced activation of its receptor was reduced in these cells. In addition, EGF-induced anchorage-independent growth of the cells was inhibited. The data suggest that the single-chain antibody functions in an autocrine fashion to inhibit the activity of the EGF receptor.     

Proteolytic activity of three probiotic strains in semi-hard cheese as single and mixed cultures: Lactobacillus acidophilus,Lactobacillus paracasei and Bifidobacterium lactis

The influence of three probiotic strains (Lactobacillus acidophilus, Lactobacillus paracasei and Bifidobacterium lactis) in semi-hard cheese proteolysis patterns was assessed. Probiotics were inoculated both as single cultures and as a three-strain mix, and added to milk either after a pre-incubation step or directly to the vat. B. lactis did not show any effect on proteolysis of cheeses, while L. paracasei showed limited impact at the end of the ripening. In contrast, L. acidophilus significantly influenced secondary proteolysis from the beginning of ripening, causing an increase in the levels of small nitrogen-containing compounds and free amino acids and changes in the peptide profiles. The effect of Lactobacillus acidophilus on peptidolysis was more noticeable when it was added to cheese–milk after pre-incubation in an enriched milk fat substrate. Similar results obtained with the three-strain mixed culture, suggesting that L. acidophilus played a major role in secondary proteolysis of probiotic cheeses in this trial.     

Thermal Annealing of Gold Thin Films on the Structure and Surface Morphology Using RF Magnetron Sputtering

Gold(Au)thin films were deposited on SiO2 substrate under argon(Ar)gas environment using RF(radio frequency)magnetron sputtering at room temperature for various...     

Effects of STN DBS on memory guided force control in Parkinson's disease (June 2007).

This study examined the control of elbow force in nine patients with Parkinson's disease when visual feedback was available and when visual feedback was removed to determine how medication (Meds) and unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) affect memory guided force control. Patients were examined in each of four treatment conditions: 1) off treatment; 2) Meds; 3) STN DBS; and 4) Meds plus STN DBS. With visual feedback available, there was no difference in force output across treatment conditions. When visual feedback was removed force output drifted under the target in both the off-treatment and the Meds conditions. However, when on STN DBS or Meds plus STN DBS force output drifted above the target. As such, only STN DBS had a significant effect on force output in the vision removed condition. Increased force output when on STN DBS may have occurred due to disruptions in the basal ganglia-thalamo-cortical circuitry. We suggest that modulation of output of the internal segment of the globus pallidus by STN DBS may drive the effect of STN DBS on memory guided force control.