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Biomedical subjects

S D Wood

Publications and source records attributed to S D Wood.

At least 19 recordsLinked to original sources
PubMed1999

Structure of the native (unligated) mannose-specific bulb lectin from Scilla campanulata (bluebell) at 1.7 A resolution.

The X-ray crystal structure of native Scilla campanulata agglutinin, a mannose-specific lectin from bluebell bulbs and a member of the Liliaceae family, has been determined by molecular replacement and refined to an R value of 0.186 at 1.7 A resolution. The lectin crystallizes in space group P21212 with unit-cell parameters a = 70. 42, b = 92.95, c = 46.64 A. The unit cell contains eight protein molecules of Mr = 13143 Da (119 amino-acid residues). The asymmetric unit comprises two chemically identical molecules, A and B, related by a non-crystallographic twofold axis perpendicular to c. This dimer further associates by crystallographic twofold symmetry to form a tetramer. The fold of the polypeptide backbone closely resembles that found in the lectins from Galanthus nivalis (snowdrop) and Hippeastrum (amaryllis) and contains a threefold symmetric beta-prism made up of three antiparallel four-stranded beta-sheets. Each of the four-stranded beta-sheets (I, II and III) possesses a potential saccharide-binding site containing conserved residues; however, site II has two mutations relative to sites I and III which may prevent ligation at this site. Our study provides the first accurate and detailed description of a native (unligated) structure from this superfamily of mannose-specific bulb lectins and will allow comparisons with a number of lectin-saccharide complexes which have already been determined or are currently under investigation.

Amino Acid Sequence↗
PubMed1999

Strategies for improving health plan member retention.

Member retention is an increasingly important issue for health plans to address. It costs health plans $75 to $200 to acquire a commercial member and $400 to $800 to acquire a Medicare member. If members leave the plan within the first year or so, up to half of this investment is lost. Health plans should implement several strategies, therefore, to improve member retention. They should communicate the value of retention throughout the organization, use a cross-functional team approach to retention, analyze who is disenrolling and why, improve access to referral providers, and extend the retention effort until a relationship exists, evaluate and strengthen member orientation efforts. Other ways to enhance member retention are to improve access to health and service information, improve provider-staff interaction and communication skills, implement relationship-enhancing communication campaigns, manage expectations about treatment, and create personal relationships at the plan-purchaser level.

Economic Competition↗
PubMed1998

Scilla campanulata agglutinin crystallized in complex with the trimannoside alpha-D-man-(1-->6)-[alpha-D-man-(1-->3)]-alpha-D-Man.

The monocot mannose-specific lectin, Scilla campanulata agglutinin (SCA), from bluebell bulbs has a strong affinity for alpha1,3- and alpha1,6-linked mannosyl residues. SCA has been co-crystallized with the trisaccharide alpha-D-mannopyranosyl-(1-->6)-alpha-D-mannopyranosyl-(1-->3)-alpha-D -mannopyranoside ¿alpha-D-Man-(1-->6)-[alpha-D-Man-(1-->3)]-alpha-D-Man¿, the core structure of biantennary N-linked oligosaccharides. Crystals of the complex were obtained by the hanging-drop vapour-diffusion technique. A complete data set to 2.5 A resolution has been collected at 100 K, using a MAR image-plate system at a synchrotron source, from crystals which belong to the space group C2 with unit-cell dimensions a = 99.38, b = 119.86, c = 77.10 A and beta = 105.56 degrees. Use of a CCD detector with cryo-cooled crystals improved the resolution to 2.3 A. A molecular replacement solution, with the 2.5 A data set, using the native SCA as a search model was obtained, with six subunits per asymmetric unit.

Agglutinins↗
PubMed1998

Crystallization and preliminary structural studies of Scilla campanulata lectin complexed with alpha1-6 mannobiose.

Recent work has shown that Scilla campanulata agglutinin from bluebell bulbs has a strong affinity for alpha(1,3)- and alpha(1,6)-linked mannosyl residues and possesses moderate antiretroviral activity. This lectin has been crystallized by the hanging-drop method of vapour diffusion complexed with the disaccharide mannose-alpha1,6-D-mannose. The crystals are in the space group P21212 with unit-cell dimensions a = 70.63, b = 92.79 and c = 47.25 A, and with a dimer in the asymmetric unit. The crystals diffract X-rays to beyond 1.5 A resolution at 277 K and are stable in an X-ray beam. Data to 1.6 A resolution have been collected using a MAR image-plate system at a synchrotron source and the structure of the complex has been solved by the molecular replacement method.

Crystallization↗
PubMed1998

A comparison of expectations for selected physician and managed health care services between Medicare-eligible and the next Medicare-eligible generation.

The year 1998 marks the beginning of a major turning point in the composition of the Medicare-eligible population, making the next few years a significant watershed for those concerned with the provision of health care to seniors. For approximately the next 12 years, those seniors entering the Medicare-eligible health care market, the so-called Swing generation, will have different characteristics and expectations from those generations that precede or follow it. Through standard survey methods, this study explores and compares the differences in selected health services expectations between the current generation of Medicare-eligible seniors and the next Medicare-eligible generation. Significant differences were found between the two groups on variables related to wait time, medical preparedness, communication, and expectations of managed care coverage. The authors discuss the implications of the findings for health care service providers and managed care organizations.

Aged↗
PubMed1996

Using research for successful Medicare and Medicaid risk marketing.

Medicare/Medicaid risk marketing is a vital business challenge, one that countless managed care organizations are facing right now. Early entry into new markets and aggressive participation in existing markets are essential to meet competitive pressures. Health plans intent on success in government risk programs should conduct research to learn the medical needs, wants, and desires of older persons in the geographic area they serve. Original, market-specific research yields critical marketing and clinical data that can be used to improve care and member satisfaction along with customer loyalty and retention.

Aged↗
PubMed1991

Identification and treatment of retinopathy of prematurity: an update and review.

The risk of retinopathy of prematurity (ROP) is higher in infants with a birth weight less than 1501 g (3 lb 5 oz). Identification programs coupled with refined treatment procedures can reduce visual impairment in infants with ROP. Physicians providing in-hospital care to these infants should ensure that ophthalmologic referral has been established before hospital discharge. Physicians examining these infants for their 6-week checkups are also vital safeguards in the ROP screening and referral process.

Cryosurgery↗
PubMed1990

Two team synchronous esophagectomy.

A modification of the Lewis esophagectomy for carcinoma of the intrathoracic esophagus is described herein. With the patient in the semilateral position, two surgical teams operate simultaneously. The abdominal team mobilizes the stomach while the thoracic team removes the esophagus. Esophagogastric anastomosis is performed by stapling at the apex of the thorax. The procedure was performed upon 50 patients. There were two anastomotic leaks and one death occurred in the hospital. The two team synchronous approach avoids changes in the position of the patient, shortens operating time and may contribute to lower morbidity rates for patients undergoing esophagectomy.

Carcinoma, Squamous Cell↗
PubMed1987

Management styles and marketing strategies: an analysis of HMOs.

The results of a recently conducted national study indicate that a variety of strategic management styles are being pursued by HMOs, and that relationships exist between these styles and marketing strategies. The findings themselves have strategic relevance for HMOs and other health service providers.

Advertising↗
PubMed1986

The growth of alternative delivery systems and the implications for hospitals.

The blending of the health care service and insurance industries into health service plans is reflected in the rapid emergence of alternative delivery systems. Detailed here is the growth and potential future of HMOs and PPOs. Also explored is how this phenomenon will affect hospital operations.

Delivery of Health Care↗
PubMed1986

Longitudinal evaluation of pulmonary function in copper smelter workers exposed to sulfur dioxide.

From 1973 to 1974, a longitudinal study of pulmonary function in 113 Utah copper smelter workers reported significant declines in FVC and FEV1 related to sulfur dioxide exposure. In 1980, we performed a 7-yr follow-up study, finding significant increases in FVC and FEV1. The 66 follow-up participants were similar to those 47 lost to follow-up with regard to age and initial pulmonary function. Subgroups of smelter workers with initial higher exposures to sulfur dioxide and FEV1 less than 90% predicted did not show an accelerated rate of decline. To reconcile these differences between the 2 studies, we reevaluated the spirometry curves from 1973 and 1974. All had short expiratory times, with none 6 s or longer, whereas all of the curves from the spirograms obtained in 1980 exceeded 6 s. In addition, from 1980 to 1983, we performed a longitudinal study of 48 of the original workers, finding small annual mean declines for FVC of 6 ml and FEV1 of 5 ml. Personal exposures to sulfur dioxide were not significantly different in 1982 than in 1976; thus, we were unable to corroborate the findings of the initial longitudinal study.

Copper↗
PubMed1983

Sister chromatid exchange frequency in asbestos workers.

In vitro cytogenetic studies of amosite, chrysotile, and crocidolite asbestos have shown that these fibers may induce chromosome abnormalities and an elevated sister chromatid exchange (SCE) rate in mammalian cells. Twenty-five asbestos insulators (6 with radiographic asbestosis) were compared to 14 controls frequency matched for age and were found to have a marginally increased SCE rate in circulating lymphocytes with increasing years of exposure (P= 0.057). There was a significant association between SCE rate and smoking (P=0.002) after controlling for years of asbestos exposure and age. Smoking asbestos insulators had the highest SCE rate. Sister chromatid exchanges in chromosomes of group A, i.e., the group with the longest chromosomes, were significantly associated with asbestos exposure and cigarette smoking, with an interaction between the two.

Asbestos↗