Contact guidance requires spatial control of leading-edge protrusion.

In vivo, geometric cues from the extracellular matrix (ECM) are critical for the regulation of cell shape, adhesion, and migration. During contact guidance, the fibrillar architecture of the ECM promotes an elongated cell shape and migration along the fibrils. The subcellular mechanisms by which cells sense ECM geometry and translate it into changes in shape and migration direction are not understood. Here we pattern linear fibronectin features to mimic fibrillar ECM and elucidate the mechanisms of contact guidance. By systematically varying patterned line spacing, we show that a 2-µm spacing is sufficient to promote cell shape elongation and migration parallel to the ECM, or contact guidance. As line spacing is increased, contact guidance increases without affecting migration speed. To elucidate the subcellular mechanisms of contact guidance, we analyze quantitatively protrusion dynamics and find that the structured ECM orients cellular protrusions parallel to the ECM. This spatial organization of protrusion relies on myosin II contractility, and feedback between adhesion and Rac-mediated protrusive activity, such that we find Arp2/3 inhibition can promote contact guidance. Together our data support a model for contact guidance in which the ECM enforces spatial constraints on the lamellipodia that result in cell shape elongation and enforce migration direction.

Review of brucellosis cases from laboratory exposures in the United States in 2008 to 2011 and improved strategies for disease prevention.

Five laboratory-acquired brucellosis (LAB) cases that occurred in the United States between 2008 and 2011 are presented. The Centers for Disease Control and Prevention (CDC) reviewed the recommendations published in 2008 and the published literature to identify strategies to further prevent LAB. The improved prevention strategies are described.

Person-centred planning: factors associated with successful outcomes for people with intellectual disabilities.

BACKGROUND: Recent research in the USA and UK indicates that person-centred planning (PCP) can lead to improvements in lifestyle-related outcomes for people with intellectual disabilities (ID). It is clear, however, that the introduction of PCP does not have an equal impact for all participants. The aim of the present paper was to identify factors associated with the probability of delivering a plan and with improvements in outcomes for those who did receive a plan. METHODS: Information on the life experiences of participants was collected over a period of approximately 2 years for a cohort of 93 adults with ID. RESULTS: There were powerful inequalities in both access to and the efficacy of PCP in relation to participant characteristics, contextual factors and elements of the PCP process. CONCLUSIONS: Results are discussed in relation to implications for policy and practice for increasing the effectiveness of PCP and reducing inequalities in the life experiences of people with ID.

Evaluation of a new computer intervention to teach people with autism or Asperger syndrome to recognize and predict emotions in others.

This randomized controlled trial looked at the effect of a new computer program designed to teach people with autistic spectrum disorders to better recognize and predict emotional responses in others. Two groups of 11 children (age 12-18) with autism or Asperger syndrome at two special schools participated: one group used the computer program for 10 half-hour sessions over 2 weeks. Within-program data showed a significant reduction in errors made from first to last use. Students were assessed pre- and post-intervention using facial expression photographs, cartoons depicting emotion-laden situations, and non-literal stories. Scores were not related to age or verbal ability. The experimental group made gains relative to the control group on all three measures. Gains correlated significantly with the number of times the computer program was used and results suggest positive effects. Further research could assess whether these gains generalized into real life or improved performance on theory of mind measures.

The manufacturing process for recombinant factor IX.

Advances in recombinant DNA manufacturing technology have now made possible the production of a highly purified and active recombinant factor IX (rFIX) product. Recombinant factor IX was developed by (1) stable insertion of the genes for both factor IX and PACE-SOL (a truncated, soluble serine protease needed to enhance the capacity of cells to remove the amino-terminal propeptide from rFIX) into Chinese hamster ovary cells; (2) selection of a cell line that was capable of expressing high amounts of active rFIX while growing in bioreactors containing a completely defined culture medium that does not contain blood or plasma products; and (3) inclusion of four independent chromatography steps, none of which require monoclonal antibodies. Furthermore, rFIX has been extensively tested to demonstrate similarity to plasma-derived factor IX and has been shown to be a consistent, high-purity product. For example, a high-specific-activity product (276+/-23 IU/mg) has been consistently produced throughout 65 consecutive batches from five consecutive manufacturing campaigns. Thus, rFIX offers a consistent and high-purity source of factor IX treatment for patients with hemophilia B.

CHO DUKX cell lineages preadapted to growth in serum-free suspension culture enable rapid development of cell culture processes for the manufacture of recombinant proteins.

Using an adaptive strategy, Chinese hamster ovary (CHO) cell lines were developed that are capable of robust growth in serum-free suspension culture. These preadapted derivatives of the commonly used strain of CHO cells (CHO DUKX), termed PA-DUKX, were used for the introduction and stable expression of several heterologous human genes. A significant advantage of recombinant PA-DUKX cells was their ability to readily resume growth in serum-free suspension culture after transfection and amplification of heterologous genes. Expression of recombinant human proteins in PA-DUKX cells was quantitatively similar to that of lineages generated using conventional CHO DUKX cells. In addition, recombinant human proteins expressed by transfected PA-DUKX lineages were shown to be biochemically and structurally similar to those expressed in CHO DUKX cells, PA-DUKX host cell technology provides an opportunity for reducing the time and resources required to develop large-scale, suspension culture-based manufacturing processes employing serum-free medium. (c) 1996 John Wiley & Sons, Inc.

Social categorization and group homogeneity: changes in the perceived applicability of stereotype content as a function of comparative context and trait favourableness.

Using the Katz-Braly checklist subjects (N = 65) assigned five traits to a national group and estimated the percentage of group members who had those traits. This was either an in-group (Australians) or an out-group (Americans), and subjects either judged that group alone (one-group conditions) or also estimated the percentage of people from the other nation (the United States or Australia, respectively) who had those same traits (two-group conditions). Across one-group conditions there was a significant out-group homogeneity effect with traits being seen to apply to more Americans than Australians, but there was no such effect across the two-group conditions. These findings were predicted on the basis of self-categorization theory's analysis of the role of comparative context in determining level of social categorization. Across two-group conditions non-stereotypic traits were also applied to fewer in-group than out-group members. This result suggests that trait favourableness is an important normative-motivational determinant of perceived homogeneity. A second experiment (N = 297) confirmed this point through an additional manipulation of the favourableness of checklist traits. This study also replicated the effect for comparative context. Implications for the analysis of social categorization, perceived group homogeneity and stereotyping are discussed.

Effect of gamma-thio-ATP on dog stomach smooth muscle membranes.

The effect of gamma-Thio-ATP on high affinity ATPase and on the ATP-dependent Ca-uptake of a plasma membrane fraction prepared from the dog stomach smooth muscle was examined. gamma-Thio-ATP did not act as a substrate for the ATP-dependent Ca-uptake and was only a poor substrate for the high affinity Ca-ATPase reaction. The compound, however, reversibly inhibited the uptake and the ATPase.

Calcium channel antagonist binding and pharmacology in rat uterine smooth muscle.

The calcium channel antagonists altered Ca-dependence of high K+-contractions of the estrogen dominant rat myometrium with the following pA2 values: PN-200-110, 10.63; nitrendipine, 9.56; nifedipine, 9.41; D-600, 9.05; and diltiazem, 7.57. Specific binding of 3H-nitrendipine occurred to the isolated plasma membrane vesicles with Kd of 0.1 to 0.3 nM and was inhibited by PN-200-110, nitrendipine, nifedipine and D-600, and slightly activated by diltiazem. The binding studies and the contractility studies were in excellent agreement for the three dihydropyridines, but not for D-600 and diltiazem.

Solubilization of a high affinity CA-ATPase from dog antrum smooth muscle.

A Mg-independent high affinity Ca-ATPase has recently been reported to be present in the plasma membranes of smooth muscle. This enzyme has now been solubilized using deoxycholate. The membrane-bound and the solubilized enzymes resemble each other in Km for Ca2+, and inhibition by fluphenazine. The solubilized enzyme is, however, more sensitive to inhibition by Mg2+ than the membrane bound enzyme. Radiation inactivation analysis shows that whereas the membrane-bound enzyme had a target size of 98,000 +/- 4,000 Daltons, the solubilized enzyme was only 70,000, +/- 7,000 Daltons.

Target size of 5'-nucleotidase in smooth muscle.

Target size of the 5'-nucleotidase in six different smooth muscles was determined by radiation inactivation. The enzyme in the soluble fraction of rat myometrium and vas deferens gave a target size of approximately 80,000 daltons. The plasma membrane bound 5'-nucleotidase however, gave target size of 80,000 to 110,000 daltons in rat gastric fundus and vas deferens and dog stomach and ileum, 135,000 daltons in rat mesenteric artery and 210,000 daltons in rat myometrium.

Calcium pump, high-affinity Ca2+-ATPase, and other ATPases in dog antrum smooth muscle plasma membrane.

The plasma membrane-enriched fraction from dog antrum smooth muscle is enriched in ATP-dependent azide-insensitive Ca2+ uptake (0.3-0.4 microM Ca2+ required for half-maximal activity), a high-affinity Ca2+-ATPase (Km of 0.3-0.8 microM for Ca2+), a low-affinity Ca2+-ATPase (Km for 250-400 microM for Ca2+), and a Mg2+-ATPase. Studies using membranes washed with EDTA and assay media treated with Chelex 100 showed that the high-affinity Ca2+-ATPase did not depend on contaminating Mg2+. Thus, whereas the ATP-dependent Ca2+ uptake had an absolute requirement for Mg2+, the Ca2+-ATPases did not. Studies using gamma-irradiation showed that the protein responsible for the ATP-dependent Ca2+ uptake was inactivated at significantly lower doses of radiation than the three ATPases. The Ca2+ uptake and the high-affinity Ca2+-ATPase also differed in their inhibition by calmodulin antagonists and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid. Thus it is unlikely that the high-affinity Ca2+-ATPase by itself is responsible for the ATP-dependent Ca2+ uptake.

Subcellular distribution of dihydropyridine isothiocyanate binding in guinea-pig ileal smooth muscle.

The subcellular distribution of the 3H--2,6-dimethyl-3,5-dicarbomethoxy-4(2-isothiocyano) phenyl-1,4-dihydropyridine (DPSCN) binding to guinea-pig ileal smooth muscle was studied by subcellular fractionation. Initial experiments on subcellular fractionation of 3H-DPSCN-labelled tissues by differential centrifugation showed that there was an excellent correlation between the levels of the label present in a fraction and the plasma membrane marker phosphodiesterase I (r = 0.98) but not between the label and the putative endoplasmic reticulum marker NADPH: cytochrome-c-reductase (r = 0.56) or the inner mitochondrial marker cytochrome-c-oxidase (r = 0.36). Centrifugation of the microsomes on a continuous sucrose density gradient showed an excellent correlation of the migration of the label with phosphodiesterase I activity (r = 0.93) but not with the activities of NADPH: cytochrome-c-reductase (r = 0.66) or cytochrome-c-oxidase (r = 0.44). Treatment of microsomes with digitonin (1 mg/ml) followed by centrifugation on continuous sucrose density gradients increased the weighted mean densities of the phosphodiesterase activity (plasma membrane marker) and the labelling by similar magnitudes (0.04 to 0.06 g/ml). The weighted mean densities of NADPH: cytochrome-c-reductase and the cytochrome-c-oxidase were not altered significantly. It is concluded that in the guinea-pig ileal smooth muscle, DPSCN labels the plasma membrane specifically.

Studies on canine gastric antrum smooth muscle: preparation and characterization of a plasma membrane enriched fraction.

A method is described for preparation of large amounts of a plasma membrane (PM) enriched fraction from the smooth muscle of dog antrum. It consists of preparing microsomes, treating them with ATP + EGTA + Mg, centrifuging in 30% sucrose and then centrifuging the resulting supernatant in 15% sucrose to yield the plasma membrane enriched fraction P6. The subcellular fractions obtained at various steps during purification were characterized by: 5'-nucleotidase and phosphodiesterase I as plasma membrane markers; cytochrome c oxidase as an inner mitochondrial marker; NADPH-cytochrome c reductase as a putative endoplasmic reticulum marker; electron microscopy; polyacrylamide sodium dodecyl sulfate slab gel electrophoresis. The distribution of ATP-dependent and independent Ca uptake in presence and absence of azide and the effect of 5 mM oxalate or 25 mM phosphate on this uptake was also examined. The fraction P6 consists of mostly smooth surface vesicles 164.3 +/- 7.2 nm in diameter, has an exclusion volume of 9.7 microL/mg for [3H]inulin and 11.1 microL/mg for [3H]sucrose. P6 is maximally enriched in the ATP-dependent azide-insensitive Ca-uptake capacity and as compared with the postnuclear supernatant (S1) it shows a very small percent stimulation by oxalate and phosphate. The ATP-dependent Ca uptake by the P6 fraction occurs optimally at pH 7.0-7.4 and is much larger than the ATP-independent Ca uptake. At pH 7.1, the ATP-dependent Ca uptake occurs with a Km of 0.27 microM and a Hill coefficient greater than 2 for Ca2+. Half maximum binding of Ca2+ occurred at 300 microM Ca2+. Ca ionophores A23187 and ionomycin inhibited the ATP-dependent Ca uptake, and if added after the uptake, these caused a release of the accumulated Ca2+. From these and other data it is concluded that this PM preparation contains a Ca transport system which can lead to formation of greater than 1000-fold Ca2+ concentration gradient across the vesicle membrane in 1 min when extravesicular Ca2+ concentration is 0.3 microM. Thus this preparation is an extremely useful material for studying the mechanism of action of the Ca pump in smooth muscle plasma membrane.

Renal displacement visualized on myocardial scintigram: case report.

Myocardial scinitgrams, using 99mTc-stannous pyrophosphate, showed an acute posterior infarction and an abnormally placed left kidney in a 24-year-old hypertensive man; Further study revealed that the kidney was displaced by a mass later proven to be a pheochromocytoma. The latter was the cause of his hypertension and probably instigated the acute myocardial infarction.