Effect of calmodulin on the activity of NAD-kinase from rabbit liver

It has been shown that rabbit liver NAD-kinase is a Ca(2+)-dependent, calmodulin-regulated enzyme. Differences were found between the sensitivity of the alpha- and beta-forms of the enzyme to calmodulin. The maximal activation of the NAD-kinase alpha-form was observed at a calmodulin/NAD-kinase ratio equal to 2, that of the beta-form--at 4. Further increases in the above parameter (up to 10) had no effect on the activity of the alpha-form, whereas that of the beta-form dropped down to the initial (basal) level.     

Restoration of squamous mucosa after ablation of Barrett's esophageal epithelium

BACKGROUND: Antireflux therapy has generally failed to induce regression of Barrett's epithelium. It was hypothesized that squamous epithelium could be restored if the columnar tissue was ablated while gastric acid secretion was suppressed. METHODS: Ten white men with Barrett's esophagus received 40 mg of omeprazole daily. Thereafter, every 2-5 weeks they underwent videotaped endoscopies to argon laser photoablate columnar tissue, obtain biopsy specimens, and assess results. Squamous re-epithelialization was assessed by correlation of videotapes and directed biopsies. RESULTS: Patients had one to eight areas ablated, totaling 0.5-12.0 cm2. Videotape assessments were corroborated by biopsy in all but one instance. Thirty-eight of 40 treatment locations partially or completely re-epithelialized with squamous tissue. Squamous regrowth appeared to occur by spread from contiguous squamous borders and de novo from glandular tissue. Regrowth was influenced by the extent of squamous borders and completeness of ablations. Nonablated glandular tissue persisted beneath squamous epithelium. CONCLUSIONS: Ablation of Barrett's epithelium and suppression of acid secretion facilitated squamous re-epithelialization. A progenitor cell within the metaplastic tissue has the potential to differentiate normally.     

Constructions of particular random processes

This paper reviews how to construct sets of random numbers with particular amplitude distributions and correlations among values. These constructions support both high-fidelity Monte Carlo simulation and analytic design studies. A variety of constructions is presented to free engineering models from “white or normal” limitations embodied in many current simulations. The methods support constructions of conventional stationary and normally distributed processes, nonstationary, nonnormal signal and interference waveforms, nonhomogeneous random scenes, nonhomogeneous volumetric clutter realizations, and snapshots of randomly evolving, nonhomogeneous scenes. Each case will have specified amplitude statistics, e.g., normal, log-normal, uniform, Weibull, or discrete amplitude statistics; and selected correlation, e.g., white, pink, or patchy statistics, clouds. or speckles. Sets of random numbers with correlation, nonstationarities, various tails for the amplitude distributions, and multimodal distributions can be constructed. The paper emphasizes aspects of probability theory necessary to engineering modeling     

Emergent Properties of the BT SDH Network

When planning an SDH network, explicit structure, such as rings or a network hierarchy, is often imposed to allow for easier network protection and management. Decisions on node connectivity are also heavily dependent on available transmission capacity and network geography, as well as the demands placed on the SDH transport layer. The strictly imposed structure therefore makes it unlikely for unplanned properties to appear but here we describe how the BT SDH network exhibits emergent power-law properties in a range of metrics. These properties are similar to those previously found in the Internet, but the Internet in contrast is not globally planned, has adaptive elements such as dynamic routing and peering agreements, lacks explicit imposed structure, and is less coupled to transmission topologies.This paper shows that even with a wide range of restrictions and controls the BT SDH network topology follows power-laws and we offer possible sources for them, concentrating on the possible effect of adjacent network layers. The existence of these properties has wide implications in network modelling, as well as network scaling, growth, and robustness analysis.     

Perfluorocarbons are effective oxygen carriers in cardiopulmonary bypass

Intravascular perfluorochemical (PFC) emulsions together with a high oxygen (O2) tension may increase the delivery of dissolved O2 to useful levels. A severely anemic model of cardiopulmonary bypass (CPB) was used to test the hypothesis that a novel PFC emulsion (PFCE; Oxygent [Alliance Pharmaceutical Corp., San Diego, CA] 90% w/v perflubron) used at a high PO2 during bypass delivers sufficient O2 to ameliorate hypoxic myocardial contractile dysfunction. Acutely anemic dogs (N = 42; hematocrit = 15.8 +/- 0.6% [mean +/- SEM] before CPB and 10.9 +/- 0.1% during CPB) were divided into four groups. Group 1 was a control (n = 12). As CPB was initiated, groups 2 (n = 10), 3 (n = 10), and 4 (n = 10) had 1.35 g PFC.kg-1, 2.7 g PFC.kg-1, or 5.4 g PFC.kg-1 added via the venous return cannula. Pre-CPB and post-CPB cardiac function was measured by the first derivative of left ventricular pressure (dP/dtmax). The dP/dtmax on separation from CPB was: group 1, 619 +/- 96; group 2, 738 +/- 56; group 3, 782 +/- 101; and group 4, 828 +/- 100 (p < 0.05 groups 3 and 4 versus group 1). Mortality during the first hour after separation from CPB was higher in group 1 than in PFCE treated dogs; however, this trend did not attain statistical significance (p < 0.065). The PFC dose was higher in survivors than in nonsurvivors (2.6 +/- 0.4 g PFC.kg-1 versus 1.2 +/- 0.5 g PFC.kg-1; p < 0.05). A PFCE used at a high PO2 provides sufficient physically dissolved O2 to relieve myocardial hypoxic injury in a severely anemic model of CPB. Current PFCEs are effective O2 carriers. This finding suggests that they can be used as a temporary erythrocyte substitute to diminish the need for allogeneic transfusions during cardiac operations.     

Psychosocial functioning in children of alcoholic fathers.

T. Jacob and K. Leonard (1986) reported that children of alcoholic fathers were comparable to children of depressed fathers in their psychosocial functioning. These results, however, were based on a relatively homogeneous sample. In the current study, previous results were extended by examining a sample of alcoholic fathers who were not screened for additional paternal psychiatric disorders or for major maternal psychopathology. Children in the unscreened and screened samples could not be distinguished in their functioning, and the majority of children of alcoholic fathers were functioning in the normal range of the Child Behavior Checklist. Given the heterogeneous adjustment in children of alcoholic fathers, the authors examined a range of factors that might protect against or exacerbate the risk associated with paternal alcoholism. Maternal depression and certain demographic characteristics were associated with poorer child functioning, particularly for male children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Designing circuits with partial scan

In this scan design methodology, only selected faults are targeted for detection. These faults are those not detected by the designer's functional vectors. The test generator decides exactly which flip-flops should be scanned using one of two methods. In the first method, all possible tests are generated for each target fault, and the set of tests requiring the fewest flip-flops is selected. In the second method, only one test is generated for each fault, and the use of flip-flops is avoided as much as possible during test generation. Examples of actual VLSI circuits show a savings of at least a 40% in full-scan overhead