The trichome pattern diversity of Cardamine shares genetic mechanisms with Arabidopsis but differs in environmental drivers

Natural variation in trichome pattern (amount and distribution) is prominent among populations of many angiosperms. However, the degree of parallelism in the genetic mechanisms underlying this diversity and its environmental drivers in different species remain unclear. To address these questions, we analyzed the genomic and environmental bases of leaf trichome pattern diversity in Cardamine hirsuta, a relative of Arabidopsis (Arabidopsis thaliana). We characterized 123 wild accessions for their genomic diversity, leaf trichome patterns at different temperatures, and environmental adjustments. Nucleotide diversities and biogeographical distribution models identified two major genetic lineages with distinct demographic and adaptive histories. Additionally, C. hirsuta showed substantial variation in trichome pattern and plasticity to temperature. Trichome amount in C. hirsuta correlated positively with spring precipitation but negatively with temperature, which is opposite to climatic patterns in A. thaliana. Contrastingly, genetic analysis of C. hirsuta glabrous accessions indicated that, like for A. thaliana, glabrousness is caused by null mutations in ChGLABRA1 (ChGL1). Phenotypic genome-wide association studies (GWAS) further identified a ChGL1 haplogroup associated with low trichome density and ChGL1 expression. Therefore, a ChGL1 series of null and partial loss-of-function alleles accounts for the parallel evolution of leaf trichome pattern in C. hirsuta and A. thaliana. Finally, GWAS also detected other candidate genes (e.g. ChETC3, ChCLE17) that might affect trichome pattern. Accordingly, the evolution of this trait in C. hirsuta and A. thaliana shows partially conserved genetic mechanisms but is likely involved in adaptation to different environments.

Interspersed expression of CUP-SHAPED COTYLEDON2 and REDUCED COMPLEXITY shapes Cardamine hirsuta complex leaf form

How genetically regulated growth shapes organ form is a key problem in developmental biology. Here, we investigate this problem using the leaflet-bearing complex leaves of Cardamine hirsuta as a model. Leaflet development requires the action of two growth-repressing transcription factors: REDUCED COMPLEXITY (RCO), a homeodomain protein, and CUP-SHAPED COTYLEDON2 (CUC2), a NAC-domain protein. However, how their respective growth-repressive actions are integrated in space and time to generate complex leaf forms remains unknown. By using live imaging, we show that CUC2 and RCO are expressed in an interspersed fashion along the leaf margin, creating a distinctive striped pattern. We find that this pattern is functionally important because forcing RCO expression in the CUC2 domain disrupts auxin-based marginal patterning and can abolish leaflet formation. By combining genetic perturbations with time-lapse imaging and cellular growth quantifications, we provide evidence that RCO-mediated growth repression occurs after auxin-based leaflet patterning and in association with the repression of cell proliferation. Additionally, through the use of genetic mosaics, we show that RCO is sufficient to repress both cellular growth and proliferation in a cell-autonomous manner. This mechanism of growth repression is different to that of CUC2, which occurs in proliferating cells. Our findings clarify how the two growth repressors RCO and CUC2 coordinate to subdivide developing leaf primordia into distinct leaflets and generate the complex leaf form. They also indicate different relationships between growth repression and cell proliferation in the patterning and post-patterning stages of organogenesis.

Pan-European study of genotypes and phenotypes in the Arabidopsis relative Cardamine hirsuta reveals how adaptation, demography, and development shape diversity patterns

We study natural DNA polymorphisms and associated phenotypes in the Arabidopsis relative Cardamine hirsuta. We observed strong genetic differentiation among several ancestry groups and broader distribution of Iberian relict strains in European C. hirsuta compared to Arabidopsis. We found synchronization between vegetative and reproductive development and a pervasive role for heterochronic pathways in shaping C. hirsuta natural variation. A single, fast-cycling ChFRIGIDA allele evolved adaptively allowing range expansion from glacial refugia, unlike Arabidopsis where multiple FRIGIDA haplotypes were involved. The Azores islands, where Arabidopsis is scarce, are a hotspot for C. hirsuta diversity. We identified a quantitative trait locus (QTL) in the heterochronic SPL9 transcription factor as a determinant of an Azorean morphotype. This QTL shows evidence for positive selection, and its distribution mirrors a climate gradient that broadly shaped the Azorean flora. Overall, we establish a framework to explore how the interplay of adaptation, demography, and development shaped diversity patterns of 2 related plant species.

The cellular basis for synergy between RCO and KNOX1 homeobox genes in leaf shape diversity

Leaves of seed plants provide an attractive system to study the development and evolution of form. Leaves show varying degrees of margin complexity ranging from simple, as in Arabidopsis thaliana, to fully dissected into leaflets in the closely related species Cardamine hirsuta. Leaflet formation requires actions of Class I KNOTTED1-LIKE HOMEOBOX (KNOX1) and REDUCED COMPLEXITY (RCO) homeobox genes, which are expressed in the leaves of C. hirsuta but not A. thaliana. Evolutionary studies indicate that diversification of KNOX1 and RCO genes was repeatedly associated with increased leaf complexity. However, whether this gene combination represents a developmentally favored avenue for leaflet formation remains unknown, and the cell-level events through which the combined action of these genes drives leaflet formation are also poorly understood. Here we show, through a genetic screen, that when a C. hirsuta RCO transgene is expressed in A. thaliana, then ectopic KNOX1 expression in leaves represents a preferred developmental path for leaflet formation. Using time-lapse growth analysis, we demonstrate that KNOX1 expression in the basal domain of leaves leads to prolonged and anisotropic cell growth. This KNOX1 action, in synergy with local growth repression by RCO, is instrumental in generating rachises and petiolules, the linear geometrical elements, that bear leaflets in complex leaves. Our results show how the combination of cell-level growth analyses and genetics can help us understand how evolutionary modifications in expression of developmentally important genes are translated into diverse leaf shapes.

Complete Evaluation of Dementia: PET and MRI Correlation and Diagnosis for the Neuroradiologist

This article will familiarize neuroradiologists with the pathophysiology, clinical findings, and standard MR imaging and PET imaging features of multiple forms of dementia as well as new emerging techniques. Cases were compiled from multiple institutions with the goal of improved diagnostic accuracy and improved patient care as well as information about biomarkers on the horizon. Dementia topics addressed include the following: Alzheimer disease, frontotemporal dementia, cerebral amyloid angiopathy, Lewy body dementia, Parkinson disease and Parkinson disease variants, amyotrophic lateral sclerosis, multisystem atrophy, Huntington disease vascular dementia, and Creutzfeldt-Jakob disease.

The role of APETALA1 in petal number robustness

Invariant floral forms are important for reproductive success and robust to natural perturbations. Petal number, for example, is invariant in Arabidopsis thaliana flowers. However, petal number varies in the closely related species Cardamine hirsuta, and the genetic basis for this difference between species is unknown. Here we show that divergence in the pleiotropic floral regulator APETALA1 (AP1) can account for the species-specific difference in petal number robustness. This large effect of AP1 is explained by epistatic interactions: A. thaliana AP1 confers robustness by masking the phenotypic expression of quantitative trait loci controlling petal number in C. hirsuta. We show that C. hirsuta AP1 fails to complement this function of A. thaliana AP1, conferring variable petal number, and that upstream regulatory regions of AP1 contribute to this divergence. Moreover, variable petal number is maintained in C. hirsuta despite sufficient standing genetic variation in natural accessions to produce plants with four-petalled flowers.

Seasonal Regulation of Petal Number

Four petals characterize the flowers of most species in the Brassicaceae family, and this phenotype is generally robust to genetic and environmental variation. A variable petal number distinguishes the flowers of Cardamine hirsuta from those of its close relative Arabidopsis (Arabidopsis thaliana), and allelic variation at many loci contribute to this trait. However, it is less clear whether C. hirsuta petal number varies in response to seasonal changes in environment. To address this question, we assessed whether petal number responds to a suite of environmental and endogenous cues that regulate flowering time in C. hirsuta We found that petal number showed seasonal variation in C. hirsuta, such that spring flowering plants developed more petals than those flowering in summer. Conditions associated with spring flowering, including cool ambient temperature, short photoperiod, and vernalization, all increased petal number in C. hirsuta Cool temperature caused the strongest increase in petal number and lengthened the time interval over which floral meristems matured. We performed live imaging of early flower development and showed that floral buds developed more slowly at 15°C versus 20°C. This extended phase of floral meristem formation, coupled with slower growth of sepals at 15°C, produced larger intersepal regions with more space available for petal initiation. In summary, the growth and maturation of floral buds is associated with variable petal number in C. hirsuta and responds to seasonal changes in ambient temperature.

The Cardamine hirsuta genome offers insight into the evolution of morphological diversity

Finding causal relationships between genotypic and phenotypic variation is a key focus of evolutionary biology, human genetics and plant breeding. To identify genome-wide patterns underlying trait diversity, we assembled a high-quality reference genome of Cardamine hirsuta, a close relative of the model plant Arabidopsis thaliana. We combined comparative genome and transcriptome analyses with the experimental tools available in C. hirsuta to investigate gene function and phenotypic diversification. Our findings highlight the prevalent role of transcription factors and tandem gene duplications in morphological evolution. We identified a specific role for the transcriptional regulators PLETHORA5/7 in shaping leaf diversity and link tandem gene duplication with differential gene expression in the explosive seed pod of C. hirsuta. Our work highlights the value of comparative approaches in genetically tractable species to understand the genetic basis for evolutionary change.

Stochastic variation in Cardamine hirsuta petal number

BACKGROUND AND AIMS

Floral development is remarkably robust in terms of the identity and number of floral organs in each whorl, whereas vegetative development can be quite plastic. This canalization of flower development prevents the phenotypic expression of cryptic genetic variation, even in fluctuating environments. A cruciform perianth with four petals is a hallmark of the Brassicaceae family, typified in the model species Arabidopsis thaliana However, variable petal loss is found in Cardamine hirsuta, a genetically tractable relative of A. thaliana Cardamine hirsuta petal number varies in response to stochastic, genetic and environmental perturbations, which makes it an interesting model to study mechanisms of decanalization and the expression of cryptic variation.

METHODS

Multitrait quantitative trait locus (QTL) analysis in recombinant inbred lines (RILs) was used to identify whether the stochastic variation found in C. hirsuta petal number had a genetic basis.

KEY RESULTS

Stochastic variation (standard error of the average petal number) was found to be a heritable phenotype, and four QTL that influenced this trait were identified. The sensitivity to detect these QTL effects was increased by accounting for the effect of ageing on petal number variation. All QTL had significant effects on both average petal number and its standard error, indicating that these two traits share a common genetic basis. However, for some QTL, a degree of independence was found between the age of the flowers where allelic effects were significant for each trait.

CONCLUSIONS

Stochastic variation in C. hirsuta petal number has a genetic basis, and common QTL influence both average petal number and its standard error. Allelic variation at these QTL can, therefore, modify petal number in an age-specific manner via effects on the phenotypic mean and stochastic variation. These results are discussed in the context of trait evolution via a loss of robustness.

The genetic architecture of petal number in Cardamine hirsuta

Invariant petal number is a characteristic of most flowers and is generally robust to genetic and environmental variation. We took advantage of the natural variation found in Cardamine hirsuta petal number to investigate the genetic basis of this trait in a case where robustness was lost during evolution. We used quantitative trait locus (QTL) analysis to characterize the genetic architecture of petal number. Αverage petal number showed transgressive variation from zero to four petals in five C. hirsuta mapping populations, and this variation was highly heritable. We detected 15 QTL at which allelic variation affected petal number. The effects of these QTL were relatively small in comparison with alleles induced by mutagenesis, suggesting that natural selection may act to maintain petal number within its variable range below four. Petal number showed a temporal trend during plant ageing, as did sepal trichome number, and multi-trait QTL analysis revealed that these age-dependent traits share a common genetic basis. Our results demonstrate that petal number is determined by many genes of small effect, some of which are age-dependent, and suggests a mechanism of trait evolution via the release of cryptic variation.

Cardamine hirsuta: a versatile genetic system for comparative studies

A major goal in biology is to identify the genetic basis for phenotypic diversity. This goal underpins research in areas as diverse as evolutionary biology, plant breeding and human genetics. A limitation for this research is no longer the availability of sequence information but the development of functional genetic tools to understand the link between changes in sequence and phenotype. Here we describe Cardamine hirsuta, a close relative of the reference plant Arabidopsis thaliana, as an experimental system in which genetic and transgenic approaches can be deployed effectively for comparative studies. We present high-resolution genetic and cytogenetic maps for C. hirsuta and show that the genome structure of C. hirsuta closely resembles the eight chromosomes of the ancestral crucifer karyotype and provides a good reference point for comparative genome studies across the Brassicaceae. We compared morphological and physiological traits between C. hirsuta and A. thaliana and analysed natural variation in stamen number in which lateral stamen loss is a species characteristic of C. hirsuta. We constructed a set of recombinant inbred lines and detected eight quantitative trait loci that can explain stamen number variation in this population. We found clear phylogeographic structure to the genetic variation in C. hirsuta, thus providing a context within which to address questions about evolutionary changes that link genotype with phenotype and the environment.

Paths to selection on life history loci in different natural environments across the native range of Arabidopsis thaliana

Selection on quantitative trait loci (QTL) may vary among natural environments due to differences in the genetic architecture of traits, environment-specific allelic effects or changes in the direction and magnitude of selection on specific traits. To dissect the environmental differences in selection on life history QTL across climatic regions, we grew a panel of interconnected recombinant inbred lines (RILs) of Arabidopsis thaliana in four field sites across its native European range. For each environment, we mapped QTL for growth, reproductive timing and development. Several QTL were pleiotropic across environments, three colocalizing with known functional polymorphisms in flowering time genes (CRY2, FRI and MAF2-5), but major QTL differed across field sites, showing conditional neutrality. We used structural equation models to trace selection paths from QTL to lifetime fitness in each environment. Only three QTL directly affected fruit number, measuring fitness. Most QTL had an indirect effect on fitness through their effect on bolting time or leaf length. Influence of life history traits on fitness differed dramatically across sites, resulting in different patterns of selection on reproductive timing and underlying QTL. In two oceanic field sites with high prereproductive mortality, QTL alleles contributing to early reproduction resulted in greater fruit production, conferring selective advantage, whereas alleles contributing to later reproduction resulted in larger size and higher fitness in a continental site. This demonstrates how environmental variation leads to change in both QTL effect sizes and direction of selection on traits, justifying the persistence of allelic polymorphism at life history QTL across the species range.

QTL analysis of cadmium and zinc accumulation in the heavy metal hyperaccumulator Thlaspi caerulescens

Thlaspi caerulescens (Tc; 2n = 14) is a natural Zn, Cd and Ni hyperaccumulator species belonging to the Brassicaceae family. It shares 88% DNA identity in the coding regions with Arabidopsis thaliana (At) (Rigola et al. 2006). Although the physiology of heavy metal (hyper)accumulation has been intensively studied, the molecular genetics are still largely unexplored. We address this topic by constructing a genetic map based on AFLP markers and expressed sequence tags (ESTs). To establish a genetic map, an F(2) population of 129 individuals was generated from a cross between a plant from a Pb/Cd/Zn-contaminated site near La Calamine, Belgium, and a plant from a comparable site near Ganges (GA), France. These two accessions show different degrees of Zn and, particularly, Cd accumulation. We analyzed 181 AFLP markers (of which 4 co-dominant) and 13 co-dominant EST sequences-based markers and mapped them to seven linkage groups (LGs), presumably corresponding to the seven chromosomes of T. caerulescens. The total length of the genetic map is 496 cM with an average density of one marker every 2.5 cM. This map was used for Quantitative Trait Locus (QTL) mapping in the F(2). For Zn as well as Cd concentration in root we mapped two QTLs. Three QTLs and one QTL were mapped for Zn and Cd concentration in shoot, respectively. These QTLs explain 23.8-60.4% of the total variance of the traits measured. We found only one common locus (LG6) for Zn and Cd (concentration in root) and one common locus for shoot and root concentrations of Zn (LG1) and of Cd (LG3). For all QTLs, the GA allele increased the trait value except for two QTLs for Zn accumulation in shoot (LG1 and LG4) and one for Zn concentration in root (LG1).

Construction of a genetic linkage map of Thlaspi caerulescens and quantitative trait loci analysis of zinc accumulation

Zinc (Zn) hyperaccumulation seems to be a constitutive species-level trait in Thlaspi caerulescens. When compared under conditions of equal Zn availability, considerable variation in the degree of hyperaccumulation is observed among accessions originating from different soil types. This variation offers an excellent opportunity for further dissection of the genetics of this trait. A T. caerulescens intraspecific cross was made between a plant from a nonmetallicolous accession [Lellingen (LE)], characterized by relatively high Zn accumulation, and a plant from a calamine accession [La Calamine (LC)], characterized by relatively low Zn accumulation. Zinc accumulation in roots and shoots segregated in the F3 population. This population was used to construct an LE/LC amplified fragment length polymorphism (AFLP)-based genetic linkage map and to map quantitative trait loci (QTL) for Zn accumulation. Two QTL were identified for root Zn accumulation, with the trait-enhancing alleles being derived from each of the parents, and explaining 21.7 and 16.6% of the phenotypic variation observed in the mapping population. Future development of more markers, based on Arabidopsis orthologous genes localized in the QTL regions, will allow fine-mapping and map-based cloning of the genes underlying the QTL.

Influence of Nutrition Level on Digestibility in High Yielding Cows and Effects on Energy Evaluation Systems

The objective of the study was to determine the effect of nutrition level (NL, multiples of maintenance energy requirement) on the digestibility of nutrients for dairy cows regarding the energy supply of the animal. The digestion of nutrients and energy was investigated in two trials using lactating dairy cows. The NL varied from 2.7 to 5.0 using diets similar composition. In addition, sheep were given the same feed with a NL of 1.4. Digestibility of dry matter (DM) and all specific measures of dietary components declined significantly as NL increased. Digestibility of energy decreased by 4.1% for each increase in NL. The metabolizable energy, the ability to metabolize energy (metabolizable energy/gross energy), and the content of net energy for lactation (NE(L)) per kilogram of DM intake were calculated for NL from 1 to 6 on the basis of these relationships and as well as the gross energy, methane energy, and urine energy. Accordingly the NEL content declined by 0.11 MJ/kg of DM intake or 1.6% as the NL increased by one unit. It means that the NE(L) requirement above the maintenance requirement increased by 0.07 MJ of NE(L) per kilogram of fat-corrected milk, if the NL increased by one unit.

Chronic venous insufficiency in persons with a history of injection drug use

Persons with a history of injection drug use have many risk factors for the development of chronic venous insufficiency (CVI), yet this phenomenon has not been studied systematically in this population. Persons (N = 204) with a history of injection drug use who were in enrolled in a treatment center were examined for clinical manifestations of CVI. The CVI clinical classification was graded on a 7-point scale for each leg. Most participants (n = 179, 87.7%) exhibited clinical evidence of CVI. Significant predictors of CVI clinical manifestations were leg infections/cellulitis (rho =.53); years injection in the veins of the groin, legs, and feet (rho =.47); deep vein thrombosis (rho =.37); and total years injection heroin (rho =.27). There was a linear functional relationship between years of injection drug use and the CVI clinical classification, but only when the injections were in the veins of the groin, legs, or feet; otherwise, the specific mechanisms of this relationship were not evident. The findings indicate that CVI is a common occurrence in persons who have injected drugs.

Health maintenance in a primary care clinic for urban, indigent adults

OBJECTIVE

The objective was to examine the delivery of preventive health care services in an urban clinic for indigent adults and the impact of advanced practice nursing on these practices.

DESIGN

The study design was a descriptive chart review.

SETTING AND SUBJECTS

Data were collected in an urban outpatient clinic. Seven hundred sixty-five records were examined prospectively for health maintenance. Of these records, 523 were randomly selected and reviewed retrospectively for completion of health maintenance. The mean age of participants was 45.15 years (SD = 9.87); 92% were African American, and 48.9% were male.

INSTRUMENTS

The Health Maintenance Form was used to record data about demographics, health history, care provider, and completion of 10 health maintenance items.

METHODS

Records were reviewed prospectively prior to the patient's clinic visit. A form summarizing the patient's health maintenance status was placed at the front of the record. At least 4 weeks later, the record was reviewed a second time for completion of health maintenance items. This second review was the data collection phase.

RESULTS

Completion of health maintenance items was found to be low. The most up-to-date areas were serum cholesterol (83.9%) and mammography (70.1%). The lowest levels were rectal examination (34.5%), pneumococcal vaccination (35%), and fecal occult blood test (37.1%). Patients followed up by a nurse practitioner had significantly more health maintenance areas up-to-date than did patients followed-up by the nurse practitioner-physician team, which in turn had significantly more areas up-to-date than did patients followed up by a physician alone.

CONCLUSIONS

Health maintenance was accomplished at a low level, indicating that preventive health practices need to be re-evaluated. The nurse practitioner had the greatest impact on a patient's health maintenance being up-to-date.

Psychosocial adjustment, coping, and quality of life in persons with venous ulcers and a history of intravenous drug use

OBJECTIVE/PURPOSE

Psychosocial adjustment, coping, and quality of life for persons with a venous ulcer and a history of intravenous drug use were examined.

DESIGN

A cross-sectional design was used.

SETTING AND SUBJECTS

Data were collected in an urban outpatient clinic. All eligible persons were asked to participate. Thirty-two patients agreed to participate, providing an 89% response rate. The mean age of participants was 44.6 years (SD = 4.3); 91% were African American, and 72% were male.

INSTRUMENTS

Subjects responded to questions about their health and substance abuse history and completed the Quality of Life With a Leg Ulcer Questionnaire, Psychosocial Adjustment to Illness Scale (PAIS), Ways of Coping Instrument, and Pain Questionnaire. Leg ulcer tracings were measured with the SigmaScan computer program.

METHODS

Questionnaires were read to participants. Leg ulcers were traced at their borders onto plastic.

RESULTS

Wound area correlated significantly with the domestic environment (r = .43) and the psychosocial distress (r = .38) scores of the PAIS. Wound area was negatively correlated to Quality of Life With a Leg Ulcer Questionnaire score (r = -.52). Pain interference was significantly related to the self-controlling coping score (r = .40), domestic environment score of the PAIS (r = .51), and Quality of Life With a Leg Ulcer Questionnaire score (r = -.65). Cox and Wermuth's multiple regression modeling approach was used to summarize the study's variables.

CONCLUSIONS

A larger wound area was associated with greater illness-induced difficulties in the home environment, greater psychological distress, and poor quality of life. Pain Interference was associated with a greater effort to regulate one's feelings and actions, difficulties in the home, and poor quality of life.

Prevalence and types of wounds among children receiving care in the home

The purpose of this study was to determine the number of children with wounds receiving home care, determine the types of wounds among these children, and identify wound care products used in the treatment of children. This study was a multi-site, descriptive, cross-sectional, collaborative, study involving 13 home healthcare agencies and a university. Nurses (n = 281) were systematically selected to collect data for patients receiving home care visits during a 1-week period. The nurses recorded data on 77 children who ranged in age from less than 1 year to 18 years (mean = 3.1 years, SD = 4.72). The children included 47 males and 30 females, most of whom were African-American (n = 59). Among the 77 children, 16.9% had wounds. Children with wounds were significantly older and had more reasons for the home healthcare visit than children without wounds. The presence of a wound was not significantly related to the length of the visit, gender, or race. The most common wound was a surgical incision. The wound care treatments used most were tap water and gauze. In conclusion, wound care is frequently part of the care for a child in the home. Therefore, nurses need to be aware of wound assessment and wound care protocols that match a child's growth and development and family needs.

HIV/AIDS: impact on healing

Human immunodeficiency virus and acquired immune deficiency syndrome (HIV/AIDS) are leading chronic illnesses in many major cities worldwide. Frequently, people with HIV infection require surgery or develop chronic wounds. This paper summarizes the impact of HIV infection on body organs and systems and the effect of antiretroviral therapy as a basis for potential complications with wound care and healing. The authors also present research on wound healing in HIV-positive people undergoing operative procedures. Besides the physical effect of HIV infection on the person, clinicians must also realize psychosocial and economic effects of the disease when considering wound care. This paper also addresses care considerations for patients with HIV/AIDS in the inpatient, outpatient, and home care settings.

Project RATEMA--one year's experience

The RATEMA project is an international cooperation between the University of Ulm in Germany and the Urals Research Centre for Radiation Medicine in Chelyabinsk, Russia. For one year we conducted weekly conferences between the two sites, based on a satellite link with a 384 kbit/s connection. During the videoconferences the physicians on both sides--experts in radiation medicine--discussed the health status of Russian patients who had been chronically exposed to ionizing radiation in the South Urals region. The German partners presented patients with comparable haematological and oncological diseases. The project has shown the advantages and difficulties of working in an international and interdisciplinary environment. The experience gained has been very valuable for planning new projects with similar tasks. The results and the contents of the RATEMA database are the basis for education and research for physicians involved in the management of radiation victims.

Wound prevalence, types, and treatments in home care

OBJECTIVE

To ascertain the number of home care patients with wounds, determine the types of wounds being treated in the community, and identify wound care treatments used at home.

DESIGN

Descriptive, multisite, collaborative project.

SETTING

13 home care agencies located throughout lower Michigan that had voluntarily formed a research consortium. The location of patients visited was 43% urban, 39% suburban, 16% rural, and 2% unaccounted.

PATIENTS

Systematic sampling was used to select nurses in each agency to collect data. Nurses (n = 281) recorded information about adult patients visited during the 1 week of the study. Data were recorded about 2847 patients, M age = 72.5 years. They included 1793 women and 1040 men (gender was not recorded for 14 patients); most patients in the sample (72%) were white. MAIN PLANNED OUTCOMES: A significant number of home visits would include wound care and that wound care would be primarily done with tap water and gauze.

RESULTS

Wounds were present in 36.3% of patients. Of the patients with wounds, 58.3% had 1 wound and 41.7% had multiple wounds. Wound types included surgical (62.4%), pressure ulcers (24.9%), and vascular leg ulcers (22.2%). Tap water and gauze were the most-used wound care treatments. Patients with wounds had significantly longer home care visits than patients without wounds.

CONCLUSIONS

Patients with wounds are commonly found in home care. There is a low utilization of specialty dressings and commercial irrigation solutions across all wound types. Nurses who follow patients with wounds may need additional time to provide the care.

Pain associated with venous ulcers in injecting drug users

Pain is a concern among people with venous ulcers. Although the prevalence is unknown, venous ulcers occur in those who have a history of illicit injecting drug use. The purpose of this study was to (a) examine the relationship between venous ulcer characteristics and pain severity, (b) ascertain factors that cause pain, (c) determine methods to alleviate pain, and (d) explore beliefs about pain medications among people with a history of injection drug use. Thirty-two patients answered pain and demographic questionnaires and had their venous ulcers traced onto plastic to identify wound area. Greater current pain, worse pain in 24 hours, and higher levels of pain relief from medications were significantly related to larger wound areas. Ibuprofen, compression dressing Unna's boot, and heroin ranked highest in decreasing pain. The most painful activities were working, walking outside, standing, and stair climbing. Many patients (41%) did not like to bother others with their complaints of pain. Participants were generally satisfied with pain treatments and the response of care providers to their pain. People who have used injected drugs and have venous ulcers do have pain. Therefore, research must continue to evaluate this pain as well as the best ways to treat it.

Reasons for nonattendance for the treatment of venous ulcers in an inner-city clinic

PURPOSE

This study examined the reasons that people attending an inner-city wound clinic gave for missing appointments and compared these reasons with those of people who did not have chronic wounds.

METHODS

Thirty-six patients with venous ulcers and 115 people without leg ulcers responded to a survey that queried the reasons for missing clinic appointments. Consecutive sampling was used to obtain participants. The Clinic Attendance Questionnaire was developed for the study and consisted of a demographic section and the Reasons for Nonattendance Questionnaire, which has 45 Yes/No items. Items in the Reasons for Nonattendance Questionnaire were sorted by the investigators into 5 subscores (Personal, Clinic Problem, Illness, Mental Health, and Social). Questionnaires were read to participants. Data were not collected from patients who kept all appointments or from new patients.

RESULTS

The primary reasons that patients seeking wound care gave for missing appointments were no ride, no money, out of town, forgot, and in too much pain. People with leg ulcers had significantly more Social, Illness, Personal, and Total reasons, but fewer Clinic Problem reasons, for missing appointments than did the people without leg ulcers. The two groups did not differ in their rating of health, importance of health, or age. Most of the people with leg ulcers had a history of illicit drug abuse.

CONCLUSIONS

Nonattendance for clinic appointments may delay healing of venous ulcers and decrease the efficiency of the clinic. Reasons for missing wound clinic appointments are numerous and may vary with the patient's condition and background.

Altered bleeding time associated with ibuprofen and zidovudine use

The purpose of this article is to describe a patient who was HIV-positive, had a massive venous ulcer, and developed a prolonged bleeding time with marked blood loss from the ulcer. The patient underwent a workup to rule out possible causes for this prolonged bleeding time; all studies were negative. A review of his history identified that he was self-medicating with ibuprofen while taking zidovudine. A potentiated effect of these two medications on the bleeding time has been reported in the literature. This case illustrates the importance of revisiting a patient's history while working up an acute problem as well as clinically monitoring for blood loss if a person takes ibuprofen and zidovudine.

Developing collaborative multisite research in home care

This article present the collaborative process for conducting research among a state home care foundation, its associated membership, and a university. Research collaboration allowed the merging of talents and resources from persons, home care agencies, and a university. The history and development of the project, sampling procedure, and data collection and analysis are discussed. The project increased the appreciation for research, allowed an opportunity for scholarly exchange, and accented the positive use of resources in all settings.

Drinking water fluoridation: bone mineral density and hip fracture incidence

The role of drinking water fluoride content for prevention of osteoporosis remains controversial. Therefore, we analyzed the influence of drinking water fluoridation on the incidence of osteoporotic hip fractures and bone mineral density (BMD) in two different communities in eastern Germany: in Chemnitz, drinking water was fluoridated (1 mg/L) over a period of 30 years; in Halle, the water was not fluoridated. BMD was measured in healthy hospital employees aged 20-60 years (Halle: 214 women, 98 men; Chemnitz: 201 women, 43 men, respectively) using dual-energy X-ray absorptiometry. Hip fractures in patients > or = 35 years admitted to the local hospitals in the years 1987-1989 were collected from the clinic registers. There was no difference in age, anthropometric, hormonal, or lifestyle variables between the two groups. Mean fluoride exposure in Chemnitz was 25.2 +/- 7.3 years. No correlation was found between fluoride exposure and age-adjusted BMD. We found no significant difference in spinal or femoral BMD between subjects living in Halle and Chemnitz [lumbar spine: 0.997 +/- 0.129 (g/cm2) vs. 1.045 + 0.171 (g/cm2), p = 0.08, for men; 1.055 +/- 0.112 (g/cm2) vs. 1.046 +/- 0.117 (g/cm2), p = 0.47, for women]. The fracture incidence showed an exponential increase with aging in men and women with an incidence about 3.5 times higher for women. In Chemnitz, we calculated an age-adjusted annual incidence of 142.2 per 100,000 for women and 72.5 per 100,000 for men, respectively. In Halle, the incidences were 178.5 per 100,000 for women and 89.2 per 100,000 for men. There was a lower hip fracture incidence after the age of 85 in women in Chemnitz (1391 per 100,000 in Chemnitz vs. 1957 per 100,000) in Halle, p = 0.006). Using the age-adjusted incidences, significantly fewer hip fractures occurred in Chemnitz in both men and women. In conclusion, our study suggests that optimal drinking water fluoridation (1 mg/L), which is advocated for prevention of dental caries, does not influence peak bone density but may reduce the incidence of osteoporotic hip fractures in the very old.

Risk factors, prevention methods, and wound care for patients with pressure ulcers

The purposes of this study about patients with pressure ulcers were to: (a) examine demographic characteristics, laboratory values, Braden Scale scores, and presence of pressure ulcer prevention methods and (b) examine pressure ulcers in terms of classification, stage, wound care, and documentation. The investigation was a prospective, descriptive study; the methods used were patient observations and data recordings from the medical record. Of the patients followed (n = 694), 71 had pressure ulcers. Patients with pressure ulcers were significantly older, with longer lengths of stay, more comorbid conditions, lower blood hemoglobin, lower serum albumin, higher white blood cell counts, and lower Braden Scale scores than patients without pressure ulcers. The presence of pressure ulcer prevention methods was greatly lacking. Nosocomial pressure ulcers tended to be a lower stage compared with pressure ulcers present on admission. Dressings used for wound care were generally gauze or a hydrocolloid. Nurses' charting about pressure ulcers was complete for only 35% of notations. The results of this study indicate that advanced practice nurses have a critical role in caring for patients with pressure ulcers and educating care providers.

Pressure ulcer prevention within 72 hours of admission in a rehabilitation setting

This prospective study followed 91 patients in an acute rehabilitation facility from admission until discharge. Of these patients, 35 patients were initially assessed at-risk for pressure ulcers. Demographics, risk status, and pressure ulcer prevention strategies were examined and assessed for at-risk and not at-risk patients. At-risk patients had significantly more medical diagnoses and longer hospitalizations than not at-risk patients, but did not differ by sex, race or age. The following pressure ulcer prevention strategies were considered for both at-risk and not at-risk patients within the first three days of admission: pressure-reducing bed surface, pillows for positioning, lift sheet, heel protection, posted turning schedule, pressure ulcer prevention care plan, pressure ulcer prevention charted, and pressure ulcer prevention educational materials at the bedside. Only the use of pillows for positioning was significant between the two groups; all other preventive strategies were comparable between both groups. For at-risk patients, it is necessary to implement pressure ulcer prevention strategies as early as possible after admission since pressure ulcers may quickly develop.

Presence of pressure ulcer prevention methods used among patients considered at risk versus those considered not at risk

PURPOSE

This study examined pressure ulcer-prevention strategies available for patients considered at risk versus those considered not at risk.

DESIGN

The study used a prospective, longitudinal design.

SETTING AND SUBJECTS

Six hundred ninety-four patients from units of five acute care hospitals, a rehabilitation facility, and two nurses' home care caseloads participated in the investigation.

INSTRUMENTS

Data-collection instruments included the Braden Scale for risk assessment, demographic information, and the Pressure Ulcer-Prevention Strategies tool, which assessed for the presence of 16 pressure ulcer-prevention strategies.

METHODS

All patients admitted to a participating unit during a 2-month period were followed up until discharge. Depending on the site, patients were assessed for the presence of pressure ulcer-prevention strategies one to three times per week.

RESULTS

Patients in the at-risk group versus those in the not-at-risk group were more likely (p < 0.01) to have the head of the bed in a low position, a pressure-reducing bed surface, pressure ulcer prevention charted, a positioning wedge, incontinence cleanser and ointment, heel protection, a prevention care plan, a trapeze, and a posted turning schedule. The at-risk group had significantly (p < 0.01) more prevention strategies present than did the not-at-risk group. However, the percentage of patients placed on a pressure ulcer-prevention program was low for both groups.

CONCLUSIONS

Pressure ulcer prevention was evident for the at-risk group, but at a low rate. Institutions must continue to explore this critical area affecting patient outcomes.

Occurrence of skin lesions/conditions in ill persons

The purpose of this study was to examine the occurrence of common skin lesions that potentially may be misdiagnosed as a pressure ulcer, and to examine the characteristics of ill persons who have these skin changes. This was a prospective, descriptive study which included five acute care hospitals, a rehabilitation hospital, and a home care agency. Results indicated that patients with skin lesions/conditions were significantly older and had longer lengths of stay, more diseases, lower Braden Scale scores, and lower serum albumin levels. Nurses must gain knowledge about identifying and treating skin conditions. Assessment of the patient's skin should occur throughout their length of stay.

Critical care nurses' knowledge of pressure ulcer prevention, staging and description

The purpose of this study was to ascertain critical care nurses' knowledge of pressure ulcer prevention, staging, and description in reference to the AHCPR guideline on pressure ulcer prediction and prevention. A cross-sectional survey design was used to collect data from 75 critical care nurses. The Pressure Ulcer Knowledge Test, used to assess nurses' knowledge, consisted of 47 true/false items and had a total alpha reliability of.91. Items were sorted into subscores of Prevention (33 items), Staging (7 items), and Wound (7 items). The percentage of items answered correctly on the test by critical care nurses ranged from 15 percent to 83 percent. Test scores were not affected by years of nursing experience, type of nursing education, or when the nurses had last read an article about pressure ulcers. Only the Wound subscore was significantly affected by the time since listening to a pressure ulcer lecture. Few critical care nurses had read the AHCPR guideline on pressure ulcer prevention. This study revealed a knowledge deficit about pressure ulcer prevention among critical care nurses. Since pressure ulcers have been identified as a national health concern, information about their prevention must be shared and implemented in patient care.

A comparison of two pressure-relieving devices on the prevention of heel pressure ulcers

The effectiveness of hospital pillows versus a commercial heel elevation device (the Foot Waffle [EHOB incorporated]) in preventing heel pressure ulcers was examined using an experimental balanced factorial design with repeated measures on 52 patients (ages 27 to 90) in randomized groups. Heel interface pressures were taken with patients in supine and right lateral tilt positions. Logistic regression demonstrated a statistically significant difference between interface pressures on left and right heels (p = .004) and a trend toward significance between the pillow and Foot Waffle (p = .069). The Generalized Estimating Equations (GEE) method revealed the Foot Waffle was four times more likely not to suspend the heel off the bed than the pillow, and the left heel was four-and-a-half times more likely to have higher interface pressures than the right. There was no significant difference between groups in incidence of lower-extremity pressure ulcers, but patients using the Foot Waffle developed pressure ulcers significantly sooner (10 days versus 13 days for the pillow). Heels require additional protection beyond the use of specially beds and mattress overlays. In order to provide continuous heel suspension, clinicians must consider proper fit, turning schedules, patient position, patient activity, and presence of additional equipment when selecting heel protection products. This study illustrates how difficult it is to control for all these factors when doing clinical research. Note: This study was done with a Foot Waffle model that has since been redesigned. No research is available on the new model.

A retrospective analysis of venous ulcer healing in current and former users of injected drugs

PURPOSE

This study examined persons with a history of heroin injection who sought wound care for lower extremity venous ulcers and explored factors that affected their wound healing.

METHODS

Descriptive, retrospective data were obtained by review of the medical records of an outpatient, urban clinic. An instrument was developed to record demographic, health, and illicit substance use information from the record.

SUBJECTS

One hundred forty men and 32 women, 160 of whom were black, 12 of whom were white, seen in a wound care clinic in an urban medical center were included in the study.

PRIMARY OUTCOME VARIABLES

Healing of venous ulcers present at the time care was sought, coexisting alcohol and tobacco use, and coexisting medical and mental health diagnoses.

RESULTS

Persons who sought care tended to be middle-aged men with multiple health problems and a long history of illicit drug use. Persons whose leg ulcers healed had significantly smaller leg ulcers than did persons currently in treatment or not available for follow-up.

CONCLUSIONS

Health care providers must be aware of the risk of venous insufficiency in current and former users of injected drugs and assess for venous insufficiency and venous ulcers. Users of injected drugs should be encouraged to seek professional wound care when ulcers are small, rather than attempting self-treatment.