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Biomedical subjects

J Lynn

Publications and source records attributed to J Lynn.

At least 19 recordsLinked to original sources
PubMed2006

Simple sequence repeats reveal uneven distribution of genetic diversity in chloroplast genomes of Brassica oleracea L. and (n = 9) wild relatives.

Diversity in the chloroplast genome of 171 accessions representing the Brassica 'C' (n = 9) genome, including domesticated and wild B. oleracea and nine inter-fertile related wild species, was investigated using six chloroplast SSR (microsatellite) markers. The lack of diversity detected among 105 cultivated and wild accessions of B. oleracea contrasted starkly with that found within its wild relatives. The vast majority of B. oleracea accessions shared a single haplotype, whereas as many as six haplotypes were detected in two wild species, B. villosa Biv. and B. cretica Lam.. The SSRs proved to be highly polymorphic across haplotypes, with calculated genetic diversity values (H) of 0.23-0.87. In total, 23 different haplotypes were detected in C genome species, with an additional five haplotypes detected in B. rapa L. (A genome n = 10) and another in B. nigra L. (B genome, n = 8). The low chloroplast diversity of B. oleracea is not suggestive of multiple domestication events. The predominant B. oleracea haplotype was also common in B. incana Ten. and present in low frequencies in B. villosa, B. macrocarpa Guss, B. rupestris Raf. and B. cretica. The chloroplast SSRs reveal a wealth of diversity within wild Brassica species that will facilitate further evolutionary and phylogeographic studies of this important crop genus.

Brassica↗
PubMed2006

Ectopic parathyroid adenoma with Tc-99m MIBI washout: role of SPECT.

The authors present a case of a 71-year-old woman with clinical and biochemical features of primary hyperparathyroidism and a history of right pneumonectomy. An ultrasound scan did not demonstrate any abnormality. A planar Tc-99m methoxyisobutylisonitrile (Tc-99m MIBI) scan showed an area of minimally increased uptake within the right hemithorax. However, unlike most adenomas, this demonstrated washout similar to the thyroid at 90 minutes and 3 hours. Subsequent SPECT imaging clearly showed the lesion in the superior right hemithorax. A CT scan and angiogram confirmed the presence of this mass. After surgery, histology confirmed the diagnosis of a parathyroid adenoma. Postoperatively, the calcium and PTH levels returned to normal.

Adenoma↗
PubMed2004

When does quality improvement count as research? Human subject protection and theories of knowledge.

The publication of insights from a quality improvement project recently precipitated a ruling by the lead federal regulatory agency that regulations providing protection for human subjects of research should apply. The required research review process did not match the rapid changes, small samples, limited documentation, clinician management, and type of information commonly used in quality improvement. Yet quality improvement can risk harm to patients, so some review might be in order. The boundaries and processes are not clear. Efforts have been made to determine what constitutes "research", but this has proved difficult and often yields irrational guidance with regard to protection of patients. Society needs a workable way to separate activities that will improve care, on the one hand, and those that constitute research, on the other. Practitioners who lead both quality improvement and research projects claim that those which rapidly give feedback to the care system that generated the data, aiming to change practices within that system, are "quality improvement" no matter whether the findings are published, whether the project is grant funded, and whether contemporaneous controls do not have the intervention. This criterion has not previously been proposed as a possible demarcation. The quandaries of which projects to put through research review and how to ensure ethical implementation of quality improvement need to be resolved.

Human Experimentation↗
PubMed2004

Multiple sclerosis gender issues: clinical practices of women neurologists.

Substantially more women than men develop multiple sclerosis (MS), but information about the effects of MS and gender-specific issues such as pregnancy, breastfeeding, menstruation and hormone use is lacking. A survey study of neurologists' practice patterns was undertaken to elicit information about gender-specific topics and the use of disease-modifying MS therapies (DMT) including the interferons and glatiramer acetate (GA). A total of 147 surveys were returned. Half of respondents require patients to discontinue DMT during pregnancy, while 35% encourage discontinuation. Among those who allow patients to continue therapy, half consider GA to be safer during pregnancy than the interferons. Nearly 86% of respondents do not use DMT in patients who are breastfeeding. Among the 11% who actually prescribe during breastfeeding, most recommend GA. Neurologists generally leave the decision to breastfeed up to patients, and most refer patients to obstetrician/gynaecologists for counselling about contraception or hormone replacement therapy. The survey results described here provide insight into how neurologists manage reproductive health issues among women with MS.

Breast Feeding↗
PubMed2001

Perspectives on care at the close of life. Serving patients who may die soon and their families: the role of hospice and other services.

The case story of a 47-year-old man with advanced rectal carcinoma illustrates the professional services and care system strategies available to help clinicians serve patients coming to the end of life. For this patient, who understands his prognosis, primary care physician services include (1) prevention and relief of symptoms, (2) assessment of each treatment before and during implementation, (3) ensuring that the patient designates a surrogate decision-maker and makes advance plans, and (4) preparation of patient and family for the time near death. Good care may entail enduring unavoidably difficult times with patients and their families. Enrollment in a hospice program requires that decision-makers confront the prognosis and their uncertainties about it, consider the desirability of other services, recognize variations among available hospice programs, address financial issues, and weigh the distress of patients and loved ones at being labeled as "dying." Hospice provides competent, continuous, and reasonably comprehensive care, but it has some constraints. Function and symptoms for those living with serious chronic illness at the end of life generally follow 1 of 3 trajectories: (a) a short period of obvious decline at the end, which is typical of cancer; (b) long-term disability, with periodic exacerbations, and unpredictable timing of death, which characterizes dying with chronic organ system failures; or (c) self-care deficits and a slowly dwindling course to death, which usually results from frailty or dementia. Effective and reliable care for persons coming to the end of life will require changes in the organization and financing of care to match these trajectories, as well as compassionate and skillful clinicians.

Advance Care Planning↗
PubMed2001

"Serious and complex illness" in quality improvement and policy reform for end-of-life care.

Americans are living longer - a mark of success in public health and medical care - but more will live the last few years with progressive illness and disability. The dominant conception of care delivery separates "aggressive" or life-extending care from "palliative" or death-accepting care, with an assumed "transition" between them. The physiology and the experience of this population are mismatched in this model. Here, we propose a more useful category for public policy and clinical quality improvement: persons who will die as a result of "serious and complex illness." Delivery system changes could ensure reliable, continuous, and competent care to this population.

Chronic Disease↗
PubMed2001

Are aggressive treatment strategies less cost-effective for older patients? The case of ventilator support and aggressive care for patients with acute respiratory failure.

OBJECTIVES: A common assumption is that life-sustaining treatments are much less cost-effective for older patients than for younger patients. We estimated the incremental cost-effectiveness of providing mechanical ventilation and intensive care for patients of various ages who had acute respiratory failure. DESIGN: Retrospective analysis of data on acute respiratory failure from Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT). SETTING: Acute hospital. PARTICIPANTS: 1,005 with acute respiratory failure; 963 received ventilator support and 42 had ventilator support withheld. MEASUREMENTS: We studied 1,005 patients enrolled in a five-center study of seriously ill patients (SUPPORT) with acute respiratory failure (pneumonia or acute respiratory distress syndrome and an Acute Physiology Score > or = 10) requiring ventilator support. For cost-effectiveness analyses, we estimated life expectancy based on long-term follow-up of SUPPORT patients and estimated utilities (quality-of-life weights) using time-tradeoff questions. We used hospital fiscal data and Medicare data to estimate healthcare costs. We divided patients into three age groups (< 65, 65-74, and > or = 75 years); for each age group, we performed separate analyses for patients with a < or = 50% probability of surviving at least 2 months (high-risk group) and those with a > 50% probability of surviving at least 2 months (low-risk group). RESULTS: Of the 963 patients who received ventilator support, 44% were female; 48% survived 6 months; and the median (25th, 75th percentile) age was 63 (46, 75) years. For the 42 patients for whom ventilator support was withheld, the median survival was 3 days. For low-risk patients (> 50% estimated 2-month survival), the incremental cost (1998 dollars) per quality-adjusted life-year (QALY) saved by providing ventilator support and aggressive care increased across the three age groups ($32,000 for patients age < 65, $44,000 for those age 65-74, and $46,000 for those age > or = 75). For high-risk patients, the incremental cost-effectiveness was much less favorable and was least favorable for younger patients ($130,000 for patients age < 65, $100,000 for those age 65-74, and $96,000 for those age > or = 75). When we varied our assumptions from 50% to 200% of our baseline estimates in sensitivity analyses, results were most sensitive to the costs of the index hospitalization. CONCLUSIONS: For patients with relatively good short-term prognoses, we found that ventilator support and aggressive care were economically worthwhile, even for patients 75 years and older. For patients with poor short-term prognoses, ventilator support and aggressive care were much less cost-effective for adults of all ages.

Acute Disease↗
PubMed2001

Patients with eventually fatal chronic illness: their importance within a national research agenda on improving patient safety and reducing medical errors.

In September 2000, the Quality Interagency Coordination (QuIC) Task Force invited the RAND Center to Improve Care of the Dying and Americans for Better Care of the Dying to testify at its National Summit on Medical Errors and Patient Safety Research. In their testimony, the organizations urged the QuIC to consider the special vulnerability and needs of individuals at the end of life in crafting their research agenda. Patients at the end of life are particularly vulnerable to medical errors and other lapses in patient safety for three reasons: (1) substantially increased exposure to medical errors; (2) more serious effects from errors because they cannot protect themselves from risks and have less reserve with which to overcome the effects; and (3) pervasive patterns of care that run counter to well-substantiated evidence-based practices. A national research agenda on preventing medical errors and increasing patient safety must include a focus on how to improve shortcomings affecting these vulnerable patients. The QuIC's preliminary research agenda, released in October 2000, included patients coming to the end of life. The Agency for Healthcare Research and Quality, the lead federal agency for researching patient safety and medical errors, released between November 2000 and April 2001 six Requests for Applications for research into medical errors.

Chronic Disease↗
PubMed2001

Stress in caregivers of hospitalized oldest-old patients.

BACKGROUND: Stress in caregivers of elderly patients is a well-recognized health care problem. However, little has been published about the stress in caregivers of the oldest-old patients, the most rapidly growing segment of our population. METHODS: A prospective cohort study was conducted in four teaching hospitals. Questionnaires were administered to patients 80 years of age and older and their surrogates (the person who would make decisions if the patient were unable to-usually a family member) who identified themselves as the primary caregivers for the patients. Data were abstracted from medical records. RESULTS: Caregivers tended to be female and 50 years of age or older. About one in five described her own health as fair or poor; nearly half of them lived with the patient. About one quarter spent at least 8 h/d caring for the patient, and they had few persons available to help them with care. Most of the caregivers reported mild-to-moderate levels of stress. After adjustment, higher stress scores were associated with female caregivers, poorer caregiver health, more hours per day spent caring for the patient, and the presence of patient depression and hearing impairment. CONCLUSION: Stress is common in caregivers of the hospitalized oldest-old patients. Women who are in poor health and spend 8 or more hours every day caring for relatives aged 80 and over are at high risk for caregiver stress. Treatment of patient depression and hearing impairment may ameliorate caregiver stress.

Aged↗
PubMed2001

Sleep disorders: a risk factor for pseudotumor cerebri?

OBJECTIVE: To determine whether sleep-related breathing disorders are common in patients with idiopathic intracranial hypertension. MATERIALS AND METHODS: Medical records of 53 patients with idiopathic intracranial hypertension from a tertiary center neuroophthalmology practice were reviewed. Thirty-seven patients were identified who had a history of snoring, difficulty sleeping, or daytime somnolence. The data from polysomnograms were tabulated to determine the frequency of apneas, hypopneas, and arousals. RESULTS: Fourteen of 37 patients with idiopathic intracranial hypertension and symptoms of sleep disturbance underwent polysomnography. There were two men and 12 women varying in age from 24 to 58 years (mean, 39.4 +/- 11.9). These patients were obese with body mass indexes varying from 33.0 to 63.2 (mean, 46.0 +/- 9.5). A diagnosis of sleep apnea was made in six and upper airway resistance syndrome in seven patients. CONCLUSIONS: Sleep-related breathing problems were common in our patients with idiopathic intracranial hypertension. Obesity was common in these patients and may be playing a causative role in sleep apnea and idiopathic intracranial hypertension. It is suggested that idiopathic intracranial hypertension patients who have symptoms of sleep disturbance should be further evaluated for the presence of sleep-related breathing problems.

Adult↗
PubMed2000

Outcomes and cost-effectiveness of ventilator support and aggressive care for patients with acute respiratory failure due to pneumonia or acute respiratory distress syndrome.

PURPOSE: Many patients with acute respiratory failure die despite prolonged and costly treatment. Our objective was to estimate the cost-effectiveness of providing rather than withholding mechanical ventilation and intensive care for patients with acute respiratory failure due to pneumonia or acute respiratory distress syndrome. SUBJECTS AND METHODS: We studied 1,005 patients enrolled in a five-center study of seriously ill patients (the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments [SUPPORT]) with acute respiratory failure (pneumonia or acute respiratory distress syndrome and an Acute Physiology Score > or =10) who required ventilator support. We estimated life expectancy based on long-term follow-up of SUPPORT patients. Utilities were estimated using time-tradeoff questions. Costs (in 1998 dollars) were based on hospital fiscal data and Medicare data. RESULTS: Of the 963 patients who received ventilator support, 48% survived for at least 6 months. At 6 months, survivors reported a median of 1 dependence in activities of daily living, and 72% rated their quality of life as good, very good, or excellent. Among the 42 patients in whom ventilator support was withheld, the median survival was 3 days. Among patients whose estimated probability of surviving at least 2 months from the time of ventilator support ("prognostic estimate") was 70% or more, the incremental cost per quality-adjusted life-year (QALY) saved by providing rather than withholding ventilator support and aggressive care was $29,000. For medium-risk patients (prognostic estimate 51% to 70%), the incremental cost-effectiveness was $44,000 per QALY, and for high-risk patients (prognostic estimate < or =50%), it was $110,000 per QALY. When assumptions were varied from 50% to 200% of baseline estimates, the results ranged from $19,000 to $48,000 for low-risk patients, from $29,000 to $76, 000 for medium-risk patients, and from $67,000 to $200,000 for high-risk patients. CONCLUSIONS: Ventilator support and intensive care for acute respiratory failure due to pneumonia or acute respiratory distress syndrome are relatively cost-effective for patients with >50% probability of surviving 2 months. However, for patients with an expected 2-month survival < or =50%, the cost per QALY is more than threefold greater at >$100,000.

APACHE↗