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Biomedical subjects

W Lindstrom

Publications and source records attributed to W Lindstrom.

6 recordsLinked to original sources
PubMed1999

DNA bending by EcoRI DNA methyltransferase accelerates base flipping but compromises specificity.

EcoRI DNA methyltransferase was previously shown to bend its cognate DNA sequence by 52 degrees and stabilize the target adenine in an extrahelical orientation. We describe the characterization of an EcoRI DNA methyltransferase mutant in which histidine 235 was selectively replaced with asparagine. Steady-state kinetic and thermodynamic parameters for the H235N mutant revealed only minor functional consequences: DNA binding affinity (KDDNA) was reduced 10-fold, and kcat was decreased 30%. However, in direct contrast to the wild type enzyme, DNA bending within the mutant enzyme-DNA complexes was not observed by scanning force microscopy. The bending-deficient mutant showed enhanced discrimination against the methylation at nontarget sequence DNA. This enhancement of enzyme discrimination was accompanied by a change in the rate-limiting catalytic step. No presteady-state burst of product formation was observed, indicating that the chemistry step (or prior event) had become rate-limiting for methylation. Direct observation of the base flipping transition showed that the lack of burst kinetics was entirely due to slower base flipping. The combined data show that DNA bending contributes to the correct assembly of the enzyme-DNA complex to accelerate base flipping and that slowing the rate of this precatalytic isomerization can enhance specificity.

Amino Acid Sequence↗
PubMed1998

Cost-benefit analysis for the treatment of severe obesity.

Cost-benefit and cost-effectiveness analyses (CEAs) are only now beginning to be used by business, government, and policymakers to evaluate various medical treatments. The evolution of why CEAs are being demanded is reviewed. To date, a formal CEA of obesity treatments has not been published. This article outlines how a CEA is performed, reviews data relevant to setting up a formal CEA of medical and surgical obesity treatments, and lists published reports that demonstrate the effectiveness of surgical obesity treatments. The general level of discrimination that society allows the obese to suffer also allows medical insurance companies, businesses, and government to not provide many obese Americans with obesity treatments that have established a level of effectiveness far surpassing many other forms of medical therapy. CEAs of obesity treatments, by themselves, cannot be expected to reverse this discrimination. This type of data, however, provides individual obese patients and their physicians with evidence to challenge policymakers' decisions, especially when cost-effective obesity treatments are excluded or placed at a lower priority than treatments with less proven effectiveness.

Cost-Benefit Analysis↗
PubMed1997

Maximizing your chances of getting an insurance approval the first time.

BACKGROUND: Support staffs for any bariatric surgeon are confronted with daily requests for information, rejections and non responses. Although we are only in control of one-half of the process (with the insurer holding the other cards), there are specific things which can be done to minimize the amount of time spent on each individual claim and maximize your chances of getting it done the first time. METHODS: This paper explores an attorney/obesity rights advocate's various approaches which successfully lead to the overturning of denials by an insurance company or HMO. Implementing such techniques by the surgeon's office may assist some patients in getting approved without having to hire counsel. RESULTS: By standardizing certain repetitively sought information, utilizing existing technology and creating comprehensive checklists, providers can comprehensively process patient claims with an eye toward providing all necessary information from the start. In addition, 'local knowledge' of the propensities of particular insurers must be documented and kept in mind so that inevitable requests for additional information can be minimized. Lastly, a 'crash course' in insurance law may assist your patients' chances to get approved. CONCLUSIONS: Some denials will not be overturned without the assistance of qualified counsel. However, some potential denials can be defeated before they start by carefully documenting files, using technology to provide ample information for the insurance company decision makers, knowing some basic insurance law and by actively seeking your patient's involvement in their claims.

Gastric Bypass↗