Optimal control of vancomycin-resistant enterococci using preventive care and treatment of infections.

The rising prevalence of vancomycin-resistant enterococci (VRE) is a major health problem in intensive care units (ICU) because of its association with increased mortality and high health care costs. We present a mathematical framework for determining cost-effective strategies for prevention and treatment of VRE in the ICU. A system of five ordinary differential equations describes the movement of ICU patients in and out of five VRE-related states.

Evaluating IMRT and VMAT dose accuracy: practical examples of failure to detect systematic errors when applying a commonly used metric and action levels.

Purpose: This study (1) examines a variety of real-world cases where systematic errors were not detected by widely accepted methods for IMRT/VMAT dosimetric accuracy evaluation, and (2) drills-down to identify failure modes and their corresponding means for detection, diagnosis, and mitigation. The primary goal of detailing these case studies is to explore different, more sensitive methods and metrics that could be used more effectively for evaluating accuracy of dose algorithms, delivery systems, and QA devices.

Methods: The authors present seven real-world case studies representing a variety of combinations of the treatment planning system (TPS), linac, delivery modality, and systematic error type.

Vancomycin-resistant enterococci colonization-infection model: parameter impacts and outbreak risks.

Vancomycin-resistant enterococci (VRE) infections have been linked to increased mortality and costs. A new model of a VRE-infested intensive care unit (ICU) is introduced. It incorporates critical features including the difference between colonization and infection, the role of special preventive care treatment cycles, fitness cost, and antibiotic use.

The metabonomics of aging and development in the rat: an investigation into the effect of age on the profile of endogenous metabolites in the urine of male rats using 1H NMR and HPLC-TOF MS.

The effect of aging and development in male Wistar-derived rats on the profile of endogenous metabolites excreted in the urine was investigated using both (1)H NMR spectroscopy and HPLC-TOF MS using electrospray ionisation (ESI). The endogenous metabolites were profiled in samples collected from male rats every two weeks from just after weaning at 4 weeks up to 20 weeks of age. Multivariate data analysis enabled clusters to be visualised within the data according to age, with urine collected at 4 and 6 weeks showing the greatest differences by both analytical techniques.

New guidelines from the National Cholesterol Education Program: what is the impact on risk assessment?

The National Cholesterol Education Program has developed a set of guidelines for optimal levels of serum lipids that are recommended to reduce the risk of coronary artery disease. This article compares those values to lipid levels found in insurance applicants.

Children's rights: a decade of dispute.

Aim: This paper attempts to raise issues surrounding children's rights against a backdrop of ethical principles and their subsequent interpretation and application in practice.

Method: Key words have been used to search a selection of electronic databases and a range of 'grey' literature has been reviewed.

Background: Over a decade ago the United Nations (1989) Convention on the Rights of the Child was ratified, with the exception of two member states (UNICEF 2000).

Underwriting lethal genetic diseases.

There are thousands of single gene deposits that cause increased morbidity or mortality risks. Few have complete penetrance leading to certain death. Most can be underwritten with affordable increases in premium; many at standard rates.

A genetic testing code of practice for insurers.

The Association of British Insurers has issued a Genetic Testing Code of Practice. The document consists of a forward and six parts, namely; Code of Practice, Statement of Duties of our Insurance Company's Chief Medical Director, Statement of the ABI Genetics advisors responsibilities, Principals of the adjudication system, the legal and ethical framework and confidentiality guidelines.

Proposal: a position for the insurance industry on genetic testing.

Proposed legislation to limit the use of genetic test results in insurance underwriting has appeared with increasing frequency at the state and federal level. The proponents seek to protect consumers from unfair discrimination by insurers. Can we not develop a proactive approach, acknowledging that we do not need to do prospective testing while we assert that we must retain the current status of equivalency of information between the underwriter and the applicant?

Classification of disorders of GM2 ganglioside hydrolysis using 3H-GM2 as substrate.

Rates of GM2 ganglioside hydrolysis by fibroblasts from normal controls and patients with GM2 gangliosidosis were measured in situ, with cells growing in tissue culture by assaying the decrease in cell-incorporated 3H-GM2 over time, and in vitro by assaying the rate of 3H-GM2 hydrolysis using fibroblast extracts in the presence of no additives, sodium taurocholate, and GM2 activator protein. In tissue culture, normal cells hydrolyzed cell-incorporated GM2 while fibroblasts from patients with GM2 gangliosidosis did not. The half life of GM2 in normal fibroblasts was 78 hours.

GM2 ganglioside activator occurs in multiple forms.

The protein which activates the hydrolysis of GM2 ganglioside by hexosaminidase A was purified from human kidney. The GM2 activator had a molecular mass of 28 kDa by gel filtration and was resolved into three major bands using polyacrylamide gel electrophoresis in the presence of SDS with molecular masses of 23, 22 and 21 kDa. These three bands corresponded respectively to strongly binding, weakly binding and non-binding fractions of GM2 activator chromatographed through concanavalin A-Sepharose, indicating that GM2 activator exists in multiple glycosylated forms.

Molecular heterogeneity in the infantile and juvenile forms of Sandhoff disease (O-variant GM2 gangliosidosis).

There are two major beta-hexosaminidase, EC 3.2.1.

Isolation of cDNA clones coding for the alpha-subunit of human beta-hexosaminidase. Extensive homology between the alpha- and beta-subunits and studies on Tay-Sachs disease.

The lysosomal beta-hexosaminidases (N-acetyl-beta-glucosaminidase, EC 3.2.1.

Characterization by nuclear magnetic resonance of the concanavalin A binding oligosaccharide on the beta b chain of placental beta-hexosaminidase B: lectin binding to the separated polypeptide chains of hexosaminidases A and B.

The type and distribution of the oligosaccharides on each polypeptide of human placental beta-hexosaminidases A (alpha (beta a beta b)) and B (2(beta a beta b)) were examined. The denatured polypeptides were separated by isoelectric focussing in a polyacrylamide slab gel and each gel was then overlaid with 125I-labelled lectins. The study indicated that the beta a chain contains negligible carbohydrate, the beta b chain contains both the high-mannose and a complex type oligosaccharide, and the alpha chain contains predominantly high-mannose or hybrid type moieties.

HPLC analysis of urinary sulfatide: an aid in the diagnosis of metachromatic leukodystrophy.

Metachromatic leukodystrophy (MLD) presents as six separate variant forms, four allelic and two non-allelic. It is diagnosed in the laboratory by a decrease in the fibroblast or leukocyte arylsulfatase A activity, generally against an artificial substrate. Since residual enzyme activity is not always an indicator of presence or absence of disease, it may be helpful to supplement this information with that of the presence or absence of sulfatide storage in the body.