Cost effectiveness and the choice of ‘best environmental options’

‘Best’ environmental options can be identified by standard techniques of economic analysis. However, the concept of ‘best’ will depend on the nature of the damage avoided by the use of different control types, the secondary cross-media effects of using environmental control, and the costs of control.

Control cost estimation does present problems but these can be largely overcome. However, damage estimates have been notoriously difficult to generate. To overcome some of the intractible problems, an alternative approach is suggested which is less powerful but more operational.     

The distribution of parenterally administered antibody to CEA in colorectal xenografts. Preliminary findings

Autoradiography was used to identify the distribution of parenterally administered anti-CEA in human colorectal tumours xenografted to nude mice. Four xenograft lines were studied: three mucinous adenocarcinomas of various degrees of differentiation and one undifferentiated tumour. 125Iodine-labelled, affinity purified goat anti-CEA was given intravenously to xenograft-bearing mice, who were killed at intervals thereafter up to 7 days. Autoradiograms were prepared by both conventional methods and the Appleton 'diffusible compound' technique which is designed to avoid possible translocation and extraction of labelled antibody tracer during tissue processing. Control experiments were done using a non-specific goat gamma-globulin. By combining autoradiography with a PAP-immunoperoxidase method of demonstrating CEA, anti-CEA was found to be preferentially retained at extracellular sites of CEA-positive material within viable tumour areas. Cell surface retention was not observed. At all times following administration more antibody was detected within necrotic areas, extracellular spaces and stromal connective tissue than within the tumour cell compartment. These preliminary results are discussed in relation to the possibility of using anti-CEA as a carrier to deliver chemotherapeutic agents into colorectal tumours. The suitability of diffusible compound and conventional autoradiography for studies of this nature are also examined.     

A second-order double-sampled delta-sigma modulator usingadditive-error switching

A second-order double-sampled delta-sigma modulator is described. It uses an additive-error switching scheme to convert capacitor mismatch into an additive out-of-band tone that can be removed by a digital filter. With a sampling rate of 5 MHz and an oversampling ratio of 256, the maximum measured signal-to-noise-and-distortion ratio (SNDR) is 86.3 dB, and the total harmonic distortion is -88.7 dB when the input is 2 dB below full scale. The modulator is fully differential, occupies 5 mm², and dissipates 13 mW     

Long-term mechanical circulatory support system reliability recommendation: American Society for Artificial Internal Organs and The Society of Thoracic Surgeons: long-term mechanical circulatory support system reliability recommendation

Jointly developed by members of the American Society for Artificial Internal Organs and the Society of Thoracic Surgeons along with staff from the Food and Drug Administration, the National Heart, Lung and Blood Institute and other experts, this recommendation describes the reliability considerations and goals for Investigational Device Exemption and Premarket Approval submissions for long-term, mechanical circulatory support systems. The recommendation includes a definition of system failure, a discussion of an appropriate reliability model, a suggested in vitro reliability test plan, reliability considerations for animal implantation tests, in vitro and animal in vivo performance goals, the qualification of design changes during the Investigational Device Exemption clinical trial, the development of a Failure Modes Effects and Criticality Analysis, and the reliability information for surgeons and patient candidates. The document will be periodically reviewed to assess its timeliness and appropriateness within five years.     

An Interleave Principle for Demonstrating concurrent Programs

Although they want to know whether their concurrent programs are working properly, programmers may not need a rigorous proof of correctness.     

Identification of a novel receptor tyrosine kinase expressed in acute myeloid leukemic blasts

Using the polymerase chain reaction with degenerate oligonucleotides derived from conserved motifs within the catalytic kinase domain of protein tyrosine kinases, and RNA extracted from embryonic stem cells, sequences that encode a segment of the kinase domain of several potentially novel receptor tyrosine kinases (RTKs) have been identified. One of these was selected for further study because in Northern analysis it hybridized to RNA from multipotential hematopoietic cell lines, but not from lines representative of lineage-committed cells. A cDNA for this receptor, designated developmental tyrosine kinase (DTK), was isolated and encodes a protein with structural similarities to AXL. Together these receptors form a new class of RTK. DTK is expressed in a number of human leukemic cell lines, and in the blasts of 6 of 11 patients with acute myeloid leukemia (AML) analyzed. The structure of DTK suggests that it may function as a cell adhesion molecule, and mediate cell-to-cell or cell-matrix interactions between hematopoietic cells and their respective microenvironments.     

Vigilance and cardiovascular reactivity to subsequent stressors in men: A preliminary study.

Understanding moderators of acute responses to stress has implications for a variety of outcomes in health psychology. The present study investigated the role of sustained search for potential threat in acute cardiovascular stress responses. As a means of manipulating vigilance for threat in the laboratory, male participants (N?=?30) were randomly assigned to search, on a computer screen, for statements that were negative, positive, or occurring at known intervals. Relative to participants in the other search conditions, participants in the negative search condition had significantly higher systolic and diastolic blood pressure responses during subsequent stressors. These results encourage a closer look at the effects of vigilance for threat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The distribution of Nematospiroides dubius within the small intestine of laboratory mice

Recent reports have suggested the use of intravenous 201T1 (thallium-201) for myocardial imaging with the gamma scintillation camera. In order to better appreciate the possible utility of this agent in humans we examined its distribution and kinetics in 13 patients and in six mongrel dogs, three with experimental coronary artery occlusion. In addition, 201T1 was compared to 86Rb (rubidium-86) in 84 rats. In the rat heart, the concentration of 201T1 was 30% higher than that of 86Rb ten minutes after injection. Moreover, myocardium-to-blood ratios for 201T1 averaged 51:1, but only 32:1 for 86Rb ten minutes after administration. In the dog heart, the distribution of 201T1 paralleled that of radioiodinated (131I) albumin particles injected into the left atrium and, thus, appears to be related to regional blood flow. Its concentration in ischemic regions decreased to 32.3% of the normally perfused myocardium. In the patients with a recent or old myocardial infarction, areas of decreased 201T1 uptake were easily identified and corresponded in location to that by ECG. Repeat scans 24 hours after the initial injection showed a significant retention of 201T1 by the myocardium. 201T1 blood levels in humans 15 minutes after injection were low (averaging 1.06% +/- 0.41% SD of the total dose per liter) and these levels decreased with a biological half-life of 3.1 +/- 0.7 days. Twenty-four hour urinary excretion rates ranged from 0.6 to 6.5% of the total dose and appeared related to urinary flow and the concentation of 201T1 in blood. Because of the higher target to background ratios, 201T1 compares favorably with radioactive rubidium. 201T1 in diagnostic doses remained without detectable adverse effects and appears promising as an agent for visualizing abnormal regional myocardial perfusion in patients with coronary artery disease.