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PubMedDate not supplied

Gender differences in symptoms associated with acute myocardial infarction: a review of the research.

Recognizing similarities and differences in symptom experiences of acute myocardial infarction (AMI) between men and women has implications for both health care providers and the general public. Rapid accurate diagnosis is necessary to implement timely lifesaving treatment. The purpose of this article is to critically review and evaluate studies that have compared symptoms of AMI between men and women. Research to date has demonstrated that during AMI, women are more likely than men to report shortness of breath, nausea, vomiting, back pain, jaw pain, neck pain, cough, and fatigue, but less likely than men to report chest pain and sweating. However, the findings were inconsistent across studies. These inconsistent findings could be attributable to methodological issues such as collecting data from medical records, small sample sizes, and controversial eligibility criteria for studies. More studies are needed to confirm gender differences in symptom experiences of AMI.

Biomedical Research↗

PubMed2004

Symptoms in acute coronary syndromes: does sex make a difference?

BACKGROUND: Coronary heart disease is a major problem in both men and women, but several studies have shown sex differences in symptoms of acute coronary syndromes (ACS). Some findings, however, have been disparate and inadequate, and thus a comprehensive overview of this literature would be of value. METHOD: Fifteen studies that identified symptoms of ACS for both women and men were examined through a review of the literature from 1989 to 2002. Terms used for the search included "myocardial infarction," "symptoms," "gender differences," and "acute coronary syndromes." RESULTS: Although chest pain was the most common symptom in both men and women, several differences were also noted. In all types of ACS, women had significantly more back and jaw pain, nausea and/or vomiting, dyspnea, indigestion, and palpitations. In a number of studies, which solely sampled patients with acute myocardial infarction, women demonstrated more back, jaw, and neck pain and nausea and/or vomiting, dyspnea, palpitations, indigestion, dizziness, fatigue, loss of appetite, and syncope. Men reported more chest pain and diaphoresis in the myocardial infarction sample. The designs and methodologies of the studies varied considerably. CONCLUSION: In addition to the typical symptom of chest pain in ACS, women experience other atypical symptoms more frequently than men. Thus, there may be sex differences in the symptoms of ACS, differences that have a bearing not only on clinical practice, but also on the interpretation of available clinical studies and the design of future investigations.

Angina, Unstable↗

PubMed2004

Discovery stage pharmacokinetics using dried blood spots.

Early in the discovery stage, the measurement of drug candidates in biological fluids as a function time provides important information used in decision making for lead optimization. The detection methodology primarily used is liquid chromatography coupled to triple quadrupole mass spectrometry (LC-MS). Sample preparation is an important aspect of these experiments and robotic-based automation is commonly used. The often overlooked aspect of these experiments is the sample collection itself. Typically, several hundred microliters of whole blood is collected and the plasma fraction separated for each time-point. The plasma is then transferred to an appropriate vessel for subsequent aliquoting and processing. We describe a method for performing discovery stage pharmacokinetic analysis using whole blood dried onto filter paper. The use of dried blood spots is a well established technique for neo-natal screening, and its application to early screening of drug candidates proves to be robust, reliable and reproducible.

Animals↗

PubMedDate not supplied

Life after a cardiac event: women's experience in healing.

OBJECTIVE: To describe the experience of women's recovery after an acute cardiac event. DESIGN: Grounded theory provided the methodologic basis for qualitative data generation and analysis. SAMPLE: Thirteen women who had experienced an acute cardiac event. The participants' ages ranged from 42 to 78 with a mean age of 58 years. Four participants attended the group sessions after experiencing an acute myocardial infarction; five had undergone coronary artery bypass grafting; and two had undergone percutaneous transluminal coronary angioplasty. Two participants had undergone exercise testing that indicated myocardial ischemia. The time after the cardiac event ranged from 8 weeks to 3 years at the initiation of the study, with a mean time after the cardiac event of 8 months. RESULTS: Healing, the basic social process identified from the data, explained women's struggle through the uncertainty surrounding the cardiac event as a way of creating new and positive health patterns. The process of healing consisted of three stages: surviving, originating, and patterning balance. These stages of healing illustrated determinants of individual motivation that guided the initiation and maintenance of risk factor modification efforts in women after the cardiac event. CONCLUSIONS: Results of this study provide a basis for the development and evaluation of comprehensive rehabilitative interventions designed to enhance individual recovery after a cardiac event.

Adaptation, Psychological↗

PubMed2004

Working memory and aging: a cross-sectional and longitudinal analysis using a self-ordered pointing task.

Age-related declines in working memory performance have been associated with deficits in inhibition, strategy use, processing speed, and monitoring. In the current study, cross-sectional and longitudinal methodologies were used to investigate the relative contribution of these components to age-related changes in working memory. In Experiment 1, a sample of 140 younger and 140 older adults completed an abstract design version of the Self-Ordered Pointing Task modeled after Shimamura and Jurica (1994). Experiment 1 revealed that only processing speed and monitoring explained age differences in SOPT performance. Participants in Experiment 2 were 53 older adults who returned 4 years after the initial testing and 53 young adults. A task that assessed the ability to generate and monitor an internal series of responses as compared to an externally imposed series of responses was also administered. Experiment 2 replicated the key findings from Experiment 1 and provided some further evidence for age-related internal monitoring difficulties. Furthermore, the exploratory longitudinal analysis revealed that older age and lower intellectual abilities tended to be associated with poorer performance on the SOPT at Time 2.

Adolescent↗

PubMed2002

Student characteristics and subculture trends in interpersonal skills workshops.

The aim of this study was to explore the experiences of student nurses when learning interpersonal skills and to examine the impact of small group work. A qualitative methodology was used. The sample comprised 50 student nurses who were undertaking the preregistration diploma course. In-depth interviews were employed to collect the data. The findings indicated that many students resisted learning owing to a range of personal characteristics that influenced the learning process. A student typology was constructed which highlighted four types of student characteristics that emerged from the data. Significant characteristics relating to each type of student behaviour are emphasized. This report also combines the student typology with the emergence of three distinct subcultures that frequently both interrupt and enhance learning. In presenting the subcultures the implications for group work are considered in conjunction with study limitations.

Culture↗

PubMed2004

The lived experience of home total parenteral nutrition: an online qualitative inquiry with adults, children, and mothers.

BACKGROUND: The purpose of this study was to access a sample of short-bowel patients receiving home total parenteral nutrition (HTPN) in their home environment and describe their HTPN experience using qualitative methodology. METHODS: Three semistructured, open-ended, in-depth interviews were conducted online over a 5-month period with 6 adults (aged 27 to 45 years) who received HTPN for 2 to 8 years, 3 children (aged 8 to 10 years) receiving HTPN since birth, and the children's mothers. The constant comparison method was used to code and categorize data, inductively develop themes, and create a taxonomy (flow chart) of themes from the data. Credibility of data analysis and themes was established by the prolonged engagement with subjects and subject review of themes identified. RESULTS: Six major themes emerged: affirmation of life, infusion-related complications, lifestyle adaptations, self-worth, isolation, and food intake. Within most themes, subjects described similar concerns and reactions. A clear difference occurred within the theme of food intake. Adults reported feeling constantly hungry and challenged with resisting temptation to eat restricted foods. They admitted to lack of consistency in following dietary restrictions and repeated attempts to consume contraindicated foods. Children expressed lack of desire for food and mothers complained of their children's refusal to eat. CONCLUSIONS: Using qualitative methods allowed insight into the HTPN experience and depiction of the daily challenges of being total parenteral nutrition-dependent from patients' and caregivers' perspectives. It provides insight into their reactions and behaviors. By gaining this type of awareness and understanding, clinical protocols and services can be planned that are more likely to derive successful outcomes.

Journal Article↗

PubMed2004

Using an interview study of transport use by people who have had a stroke to inform rehabilitation.

INTRODUCTION: Many people who have had a stroke want to get out of their house more often. This study explored attitudes and barriers to the use of transport with the aim of informing rehabilitation. METHOD: Semi-structured interview study of 24 community-dwelling people who had had a stroke, purposively sampled to find people with a variety of recent experiences of transport. Interviews were taped and transcribed. Analysis was by constant-comparative methodology, to develop emerging themes and concepts. RESULTS: Interviewees wanted to travel for specific purposes but also for its own sake. Many could no longer use their car. This gave them less flexibility to travel and reduced their autonomy. Barriers to using alternative forms of transport were fear of injury or embarrassment from falling, an associated lack of confidence, inadequate information about transport services, perceptions about the cost of taxis and pavement vehicles (scooters) and environmental factors such as the weather. Those who could drive, or who lived with someone who did, gave the most positive descriptions of transport use. Those reliant on family or friends felt they could ask only for help getting to health-related appointments and those who used specialist transport services provided the most negative descriptions of transport. CONCLUSIONS: Many of the barriers to transport use after stroke may be amenable to intervention. An intervention package capable of re-enabling people to drive or be driven, to use a pavement scooter safely, to provide information about the alternatives and to encourage best use of public transport is worth developing.

Activities of Daily Living↗

PubMed2006

Monitoring progress toward achieving Maternal and Infant Healthy People 2010 objectives--19 states, Pregnancy Risk Assessment Monitoring System (PRAMS), 2000-2003.

PROBLEM/CONDITION: Certain modifiable maternal behaviors and experiences before, during, and after pregnancy are associated with adverse health outcomes for the mother and her infant (e.g., physical abuse, insufficient folic acid consumption, smoking during pregnancy, and improper infant sleep position). Information about these behaviors and experiences is needed to monitor trends in maternal and infant health, enhance understanding of the relation between maternal behaviors and infant health outcomes, plan and evaluate maternal and infant health programs, direct policy decisions, and monitor progress toward achieving the national Healthy People 2010 [HP 2010] objectives (US Department of Health and Human Services. Healthy people 2010. 2nd ed. With understanding and improving health and objectives for improving health [2 vols.]. Washington, DC: US Department of Health and Human Services; 2000). REPORTING PERIOD COVERED: 2000-2003. DESCRIPTION OF SYSTEM: The Pregnancy Risk Assessment Monitoring System (PRAMS) is an ongoing, state- and population-based surveillance system designed to monitor selected maternal behaviors and experiences that occur before, during, and after pregnancy among women who deliver live-born infants. PRAMS employs a mixed mode data-collection methodology; up to three self-administered surveys are mailed to a sample of mothers; nonresponders are followed up with telephone interviews. Self-reported survey data are linked to selected birth certificate data and weighted for sample design, nonresponse, and noncoverage to create annual PRAMS analysis data sets that can be used to produce statewide estimates of perinatal health behaviors and experiences among women delivering live infants. This report summarizes data for 2000-2003 from 19 states (Alabama, Alaska, Arkansas, Colorado, Florida, Hawaii, Illinois, Louisiana, Maine, Nebraska, New Mexico, New York, North Carolina, Ohio, Oklahoma, South Carolina, Utah, Washington, and West Virginia) that measured progress toward achieving HP 2010 objectives for eight perinatal indicators: 1) pregnancy intention, 2) multivitamin use, 3) physical abuse, 4) cigarette smoking during pregnancy, 5) cigarette smoking cessation, 6) drinking alcohol during pregnancy, 7) breastfeeding initiation, and 8) infant sleep position. RESULTS: In 2003, prevalence of intended pregnancy among women having a live birth ranged from 48.1% in Louisiana to 66.5% in Maine; during 2000-2003, no state experienced a statistically significant (p< or =0.05) increase in prevalence of intended pregnancy, and one state experienced a significant decrease. In 2003, prevalence of multivitamin use at least four times per week during the month before pregnancy ranged from 23.0% in Arkansas to 45.2% in Maine; during 2000-2003, multivitamin use increased significantly in three states (Illinois, North Carolina, and Utah). In 2003, prevalence of physical abuse by a husband or partner during the 12 months before pregnancy ranged from 2.2% in Maine to 7.6% in New Mexico; during 2000-2003, significant decreases were recorded in three states (Alaska, Hawaii, and Nebraska). In 2003, prevalence of abstinence from cigarette smoking during the last 3 months of pregnancy ranged from 72.5% in West Virginia to 96.1% in Utah; during 2000-2003, a significant increase was recorded in Utah. In 2003, prevalence of smoking cessation during pregnancy ranged from 30.2% in West Virginia to 65.8% in Utah; during 2000-2003, a significant increase was recorded in Utah. In 2003, prevalence of abstinence from alcohol during the last 3 months of pregnancy ranged from 91.3% in Colorado to 98.0% in Utah; during 2000-2003, abstinence increased significantly in Louisiana and Utah but decreased significantly in Florida and Nebraska. In 2003, prevalence of mothers who breastfed their babies in the early postpartum period ranged from 51.2% in Louisiana to 90.3% in Alaska; during 2000-2003, significant increases were recorded in six states (Arkansas, Illinois, Louisiana, Nebraska, North Carolina, and South Carolina). In 2003, prevalence of healthy full-term infants who were placed to sleep on their backs ranged from 50.0% in Arkansas to 78.7% in Washington; during 2000-2003, significant increases were recorded in eight states (Alaska, Colorado, Illinois, Louisiana, Maine, Nebraska, North Carolina, and West Virginia). In 2003, all 19 states achieved or exceeded the HP 2010 objective for smoking cessation during pregnancy, and 16 states achieved the HP 2010 objective for abstinence from alcohol during the last 3 months of pregnancy. In addition, nearly half of the states achieved the objectives for breastfeeding in the early postpartum period and infant back sleep position. However, no state achieved the HP 2010 objectives for intended pregnancy, multivitamin use before pregnancy, absence of physical abuse before pregnancy, or abstinence from smoking during pregnancy. INTERPRETATION: PRAMS data indicate variability among states regarding progress toward achieving HP 2010 objectives in the area of maternal and child health. More progress has been made in achieving objectives focused on the period during and after pregnancy (e.g., smoking cessation and proper infant sleep position); less progress has been made in achieving objectives related to behaviors and experiences in the preconception period (e.g., pregnancy intention and multivitamin use). PUBLIC HEALTH ACTION: State maternal and child health programs can use these state- and population-based data to monitor progress toward achieving HP 2010 objectives, identify indicators to target for intervention, and plan and evaluate programs that promote positive maternal and infant health behaviors, experiences, and outcomes. These data also can be used to guide policy decisions that could affect the health of mothers and infants.

Adult↗

PubMed2005

Nurses' experiences of distance education programmes.

AIM: This paper reports on a study exploring the experiences of nurses undertaking distance education (DE) programmes. BACKGROUND: While DE has many advantages in terms of the flexibility, autonomy and freedom that it affords to learners, the literature reports that students undertaking these programmes can also experience feelings of being disconnected and isolated. METHODS: A convenience sample of 15 participants was selected, and data were collected using in-depth interviews. Data were analysed using a qualitative design that drew most heavily on the methodological procedures of grounded theory. FINDINGS: Habermas' theory of communicative action was found to be relevant to the interpretation of data and four categories were constructed to explain participants' experiences in relation to DE, namely: lifeworld lamented; lifeworld experienced; lifeworld ceded and learning within a bounded system. These categories reflect the manner in which participants experienced the lifeworld component (the interactive and subjective dimensions) and the system component (objective and outcome oriented dimensions) of the educational realm. While data indicated diversity in how the boundedness of the programmes was experienced, overall such standardized, instrumental courses were viewed favourably by participants within the limitations of their own personal circumstances. CONCLUSION: Distance education as a means of disseminating nursing knowledge should be strengthened. The challenge for nurse educators is to develop DE programmes that minimize their limitations and maximize their potential.

Adult↗

PubMed2004

Surveillance for disparities in maternal health-related behaviors--selected states, Pregnancy Risk Assessment Monitoring System (PRAMS), 2000-2001.

PROBLEM/CONDITION: Disparities in maternal and infant health have been observed among members of different racial and ethnic populations and persons of differing socioeconomic status. For the Healthy People 2010 objectives for maternal and child health to be achieved (US Department of Health and Human Services. Healthy People 2010. 2nd ed. With understanding and improving health and objectives for improving health [2 vols.]. Washington DC: US Department of Health and Human Services, 2000), the nature and extent of disparities in maternal behaviors that affect maternal or infant health should be understood. Identifying these disparities can assist public health authorities in developing policies and programs targeting persons at greatest risk for adverse health outcomes. REPORTING PERIOD COVERED: 2000-2001. DESCRIPTION OF THE SYSTEM: The Pregnancy Risk Assessment Monitoring System (PRAMS) is an ongoing state- and population-based surveillance system designed to monitor selected maternal behaviors and experiences that occur before, during, and after pregnancy among women who deliver live-born infants. PRAMS employs a mixed mode data-collection methodology; up to three self-administered surveys are mailed to a sample of mothers, and nonresponders are followed up with telephone interviews. Self-reported survey data are linked to selected birth certificate data and weighted for sample design, nonresponse, and noncoverage to create annual PRAMS analysis data sets that can be used to produce statewide estimates of different perinatal health behaviors and experiences among women delivering live infants in 31 states and New York City. This report summarizes data for 2000-2001 from eight states (Alabama, Colorado, Florida, Hawaii, Illinois, Maine, Nebraska, and North Carolina) on four behaviors (smoking during pregnancy, alcohol use during pregnancy, breastfeeding initiation, and use of the infant back sleep position) for which substantial health disparities have been identified previously. RESULTS: Although the prevalence of each behavior varied by state, consistent patterns were observed among the eight states by age, race, ethnicity, education, and income level. Overall, the prevalence of smoking during pregnancy ranged from 9.0% to 17.4%. Younger (aged <25 years) women, white women, American Indian women, non-Hispanic women (except in Hawaii), women with a high school education or less, and women with low incomes consistently reported the highest rates of smoking. Overall, the prevalence of alcohol use during pregnancy ranged from 3.4% to 9.9%. In seven states, women aged >35 years, non-Hispanic women, women with more than a high school education, and women with higher incomes reported the highest prevalence of alcohol use during pregnancy. Overall, the prevalence of breastfeeding initiation ranged from 54.8% to 89.6%. Younger women, black women, women with a high school education or less, and women with low incomes reported the lowest rates of breastfeeding initiation. The size of the black-white disparity in breastfeeding varied among states. Overall, use of the back sleep position for infants ranged from 49.7% to 74.8%. Use of the back sleep position was lowest among younger women, black women, women with lower levels of education, and women with low incomes. Ethnic differences in sleep position varied substantially by state. INTERPRETATION: PRAMS data can be used to identify racial, ethnic, and socioeconomic disparities in critical maternal health-related behaviors. Although similar general patterns by age, education, and income were observed in at least seven states, certain racial and ethnic disparities varied by state. Prevalence of the four behaviors among each population often varied by state, indicating the potential impact of state-specific policies and programs. PUBLIC HEALTH ACTION: States can use PRAMS data to identify populations at greatest risk for maternal behaviors that have negative consequences for maternal and infant health and to develop policies and plan programs that target populations at high risk.sk. Although prevalence data cannot be used to identify causes or interventions to improve health outcomes, they do indicate the magnitude of disparities and identify populations that should be targeted for intervention. This report indicates a need for wider targeting than is often done. The results from this report can aid state and national agencies in creating more effective public health policies and programs. The data described in this report should serve as a baseline that states can use to measure the impact of policies and programs on eliminating these health disparities.

Female↗

PubMed2004

Detecting differential gene expression with a semiparametric hierarchical mixture method.

Mixture modeling provides an effective approach to the differential expression problem in microarray data analysis. Methods based on fully parametric mixture models are available, but lack of fit in some examples indicates that more flexible models may be beneficial. Existing, more flexible, mixture models work at the level of one-dimensional gene-specific summary statistics, and so when there are relatively few measurements per gene these methods may not provide sensitive detectors of differential expression. We propose a hierarchical mixture model to provide methodology that is both sensitive in detecting differential expression and sufficiently flexible to account for the complex variability of normalized microarray data. EM-based algorithms are used to fit both parametric and semiparametric versions of the model. We restrict attention to the two-sample comparison problem; an experiment involving Affymetrix microarrays and yeast translation provides the motivating case study. Gene-specific posterior probabilities of differential expression form the basis of statistical inference; they define short gene lists and false discovery rates. Compared to several competing methodologies, the proposed methodology exhibits good operating characteristics in a simulation study, on the analysis of spike-in data, and in a cross-validation calculation.

Algorithms↗

PubMed1998

Growing up with congenital heart disease: the dilemmas of adolescents and young adults [see comment].

Advances in diagnosis, medical management and surgical intervention have improved the longevity and quality of life for children with congenital heart disease. Despite this, research studies specifically examining the psychosocial concerns of adolescents and young adults with congenital heart disease are few. To explore the subjective experiences and dilemmas of this population during the transition from adolescence to young adulthood, we interviewed, using a semi-structured protocol, a convenience sample of nine adolescents and young adults. Using analytic procedures inherent in Grounded Theory methodology, seven themes were identified: the dilemma of normality; dilemmas in disclosure; dilemmas in strategies for management of illness; the challenge of social integration versus social isolation; the challenge of dependence versus independence; the challenge of uncertainty; and strategies for coping. An understanding of these experiences by health professionals can be beneficial in helping this clinical population as they grow up and face the challenges of an uncertain, yet promising, future.

Adaptation, Psychological↗

PubMed1992

Associations between sexual experiences and fantasies in a nonpatient population: a preliminary study.

We have been interested in devising some methodology short of psychoanalytic therapy to study the relationship of conscious fantasy to personality trends and behavior. Presented here is a pilot study, utilizing the questionnaire technique, the sample consisting of 193 students enrolled at one prestigious urban university, that reports on the prevalence and content of conscious sexual fantasies in a normal (nonpatient) population and their relationship to sexual behaviors. Factor analysis suggested four experience and four fantasy clusters. Those individuals who score high on one experience factor are apt to score high on all other experience factors as well. The same is true of the fantasy factors. Our findings indicate that low sexual activity and low levels of sexual fantasy go together, whereas more sexual experience is connected to a greater range of sexual fantasy. Consequently, erotic fantasies cannot be viewed as compensation for lack of sexual outlet. Instead, there is a positive correlation between the two domains of sexual fantasies and sexual behaviors. Our overall results lead us to conclude that by and large, people are sexual generalists not specialists.

Adult↗

PubMed2000

[Statistical insight to improve reliability of pharmacological studies].

When pharmaceutical scientists describe characteristics of a drug or when they decide whether it is appropriate to initiate clinical trials to determine the drug's effects in humans, their inferences are frequently grounded in information drawn from non-clinical studies. Therefore, certain and highly objective information is required. By introducing the concept of design of experiments to control some nuisance factors and performing confirmatory studies based on sample size estimation, trustworthy information can be efficiently obtained. This paper does not demand that researchers conduct an additional confirmatory study in a series of studies conducted so far. This is a reconsideration how a series of studies should be carried forward. Statistics ought to contribute much more not only to estimation or hypothetical tests after data are collected, but also to methodology of preliminary experiments and planning of studies. Cooperation with statisticians from an early stage of the studies is all the more helpful in non-clinical studies, in which, in a sense, "perfect" experiments can be conducted more than in clinical studies.

Animals↗

PubMed2003

Brief measure of expressed emotion: internal consistency and stability over time.

The study examined three methodological aspects of expressed emotion (EE) as assessed in the course of PACE (Psychosocial Assessment of Childhood Experiences) interviews with a parent. In a sample of 87 children, aged 6 13 years, enrolled in a prospective study examining the role of stress on the course of asthma, EE was assessed at three time points, 9 months apart. A high degree of agreement was found among the three concurrent measures of negative and positive EE (kappas from 0.74 to 0.97, and from 0.45 to 0.88, respectively; p < or = 0.0001 in all instances). The temporal stability of all measures was lower, although statistically significant in all but 2 instances (kappas from 0.19 to 0.59, and from 0.11 to 0.39, respectively). The temporal stability across measures, as well as across interviewers and over time, was broadly similar (kappas from 0.21 to 0.56 for negative EE, and from 0.09 to 0.38 for positive EE, with all but three of the 36 statistically significant). The findings provide support for the underlying assumptions of the PACE-EE and show the utility of measures based on just very brief periods of non-directive interviewing, making them practical in a wide range of studies with EE just one of a larger set of measures.

Adolescent↗

PubMed2002

Graphical models for multivariate time series from intensive care monitoring.

Nowadays physicians are confronted with high-dimensional data generated by clinical information systems. The proper extraction and interpretation of the information contained in such massive data sets, which are often observed with high sampling frequencies, can hardly be done by experience only. This yields new perspectives of data recording and also sets a new challenge for statistical methodology. Recently graphical models have been developed for analysing the partial correlations between the components of multivariate time series. We apply this technique to the haemodynamic system of critically ill patients monitored in intensive care. In this way we can appraise the practical value of the new procedure by re-identifying known associations within the haemodynamic system. From separate analyses for different pathophysiological states we can even conclude that distinct clinical states are characterized by distinct partial correlation structures. Hence, this technique seems useful for automatic statistical analysis of high-dimensional physiological time series and it can provide new insights into physiological mechanisms. Moreover, we can use it to achieve an adequate dimension reduction of the variables needed for online monitoring at the bedside.

Blood Pressure↗

PubMed2002

Immunofluorescent surface labelling, flow sorting and culturing of putative epidermal stem cells derived from small skin punch biopsies.

Basal keratinocytes of human epidermis strongly express the cell surface glycoprotein beta(1)-integrin, and putatively harbour epidermal stem cells. Selective sorting and culturing of keratinocyte stem cells forms the basis for studies on the role of these cells as targets for therapeutic intervention and gene therapy. Here we have studied variables which affect cell surface labelling for beta(1)-integrin, flow sorting and subsequent culturing of beta(1)-integrin-positive and beta(1)-integrin-negative keratinocytes. Keratinocytes were derived from small human skin punch biopsies (3 or 4 mm in diameter), and we tested a number of variables such as choice of proteolytic enzyme for cell isolation, cell concentration, fixation, storage of fixed cell suspensions and labelling conditions. In contrast to thermolysin treatment for cell isolation, trypsin treatment left most cell surface beta(1)-integrin molecules intact. Ethanol and paraformaldehyde fixation interfered with beta(1)-integrin detection, and unfixed cells gave the best results. Optimisation of all the individual steps resulted in a labelling protocol for reproducible staining and sorting of the cells. Sorted cells were seeded in 96-well plates (300 cells/well) and colonies were obtained in more than 50% of the wells with beta(1)-integrin-positive keratinocytes. In plates with beta(1)-integrin-negative cells, only 10% of the wells contained keratinocyte colonies. Flow sorted keratinocytes obtained by trypsin formed numerous colonies in cell culture experiments. In cell suspensions obtained with thermolysin, only sparse colonies were formed. We conclude that our methodology permits the use of small human tissue samples for cell labelling and sorting, while preserving the clonogenic potential.

3T3 Cells↗