Medicare managed care. How physicians can make it better

The federal government is attempting to control anticipated, increased Medicare health care costs by providing the senior population with incentives to encourage their movement into managed care programs. For-profit corporate HMOs that currently dominate the managed care arena are coming under increased competitive pressure at a time when their perception of profiteering is undergoing increased public scrutiny. If physicians are to take advantage of this window of opportunity and successfully enter the Medicare managed care marketplace, they must identify the major deficiencies existing in the current model, and fashion a new product that divests itself of the profit orientation of current corporate HMOs. A nonprofit version of a highly integrated, multispecialty provider service organization (PSO) provides an appropriate model to effectively compete with the corporate HMO. The ideal physician-controlled managed care model must: develop a responsive policy board structure; create practice guidelines that decrease variation in physician practice; achieve an appropriate balance between primary and specialty medical care; and adopt a quality-assurance program that effectively addresses both process and outcome data.     

Bulk melts bring flexibly better metal powders

Advanced melt technology has helped a US powder manufacturer produce more consistent PM materials with enhanced properties…     

Ultrasonics may make an impact in nano powders

Researchers in Switzerland say that the development of new transducers has opened the way to commercial production of nanostructured metal powders by double ultrasonic atomisation...     

Blown to atoms: how to make metal powders

Before anything can be manufactured from metal powder, the powder itself has to be made. Most powders are made by the automisation of molten metal. John Dunkley looks at the major atomisation method in use...     

The chronic non-healing wound: how to make it better

Chronic wounds are a commonly encountered problem. An understanding of their aetiology, combined with a systematic approach to their management, is fundamental to achieving an optimal environment for healing to take place.     

Finer powder additions can make harder, tougher steels

Reducing the size of nickel powder particles admixed to prealloyed molybdenum steel powder can make significant differences to toughness and hardness…     

Hereditary angioedema. Complex symptoms can make diagnosis difficult

Although rare, hereditary angioedema is a potentially life-threatening disorder that can be difficult to diagnose. It is characterized by a deficiency in C1 esterase inhibitor (C1 INH). Manifestations include gastrointestinal, subcutaneous, and respiratory edema. Factors that trigger episodes vary. Symptoms typically last 48 to 72 hours, but they can last 4 hours to 1 week. Treatment includes prophylactic therapy with attenuated androgens or antifibrinolytic agents. Acute episodes can be medical emergencies, and airway management is a major concern. The treatment of choice in an acute episode is administration of plasma concentrate of C1 INH.     

Plasma metanephrine measurements make the diagnosis of pheochromocytoma easier

A study where plasma metanephrine and normetanephrine concentrations in 51 patients with hypertension and 62 healthy normotensives were compared with those in 52 patients with histologically confirmed phaeochromocytoma showed measurement of the two variables to constitute a test that reliably excludes the presence of phaeochromocytoma in cases where both values are normal. Other currently available tests (e.g., plasma catecholamine assay) can yield false-negative results in some patients with the tumour, and thus do not reliably exclude its presence in unaffected patients. Accordingly, as a missed diagnosis can have disastrous consequences for the patient, hitherto the exclusion of phaeochromocytoma has typically entailed multiple and repeated tests which are time-consuming and costly. The advantage of the plasma metanephrine-normetanephrine test is that, as it does not yield false-negative results, a negative test result reliably excludes the presence of phaeochromocytoma in suspected cases, and no further tests are necessary.     

Ethics consultants and surrogates: can we do better?

We present here a new algorithm for functional site analysis. It is based on four main assumptions: each variation of nucleotide composition makes a different contribution to the overall binding free energy of interaction between a functional site and another molecule; nonfunctioning site-like regions (pseudosites) are absent or rare in genomes; there may be errors in the sample of sites; and nucleotides of different site positions are considered to be mutually dependent. In this algorithm, the site set is divided into subsets, each described by a certain consensus. Donor splice sites of the human protein-coding genes were analyzed. Comparing the results with other methods of donor splice site prediction has demonstrated a more accurate prediction of consensus sequences AG/GU(A,G), G/GUnAG, /GU(A,G)AG, /GU(A,G)nGU, and G/GUA than is achieved by weight matrix and consensus (A,C)AG/GU(A,G)AGU with mismatches. The probability of the first type error, E1, for the obtained consensus set was about 0.05, and the probability of the second type error, E2, was 0.15. The analysis demonstrated that accuracy of the functional site prediction could be improved if one takes into account correlations between the site positions. The accuracy of prediction by using human consensus sequences was tested on sequences from different organisms. Some differences in consensus sequences for the plant Arabidopsis sp., the invertebrate Caenorhabditis sp., and the fungus Aspergillus sp. were revealed. For the yeast Saccharomyces sp. only one conservative consensus, /GUA(U,A,C)G(U,A,C), was revealed (E1 = 0.03, E2 = 0.03). Yeast is a very interesting model to use for analysis of molecular mechanisms of splicing.     

Radiotherapy planning for lung cancer: can we do better?

Modern radiotherapy planning and treatment techniques allow the delivery of treatment with considerable geographic and dosimetric precision. Uncertainties and variability in the radiotherapy process prior to this stage, that is, localization of the target volume, has received little systematic study. The results of a planning study in non-small cell carcinoma of the lung are presented to highlight the possible variability in the planning process, both at an inter-clinician and intra-clinician level. The implications of this survey, both in terms of treatment outcome and training issues, are discussed.