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C Hawes

Publications and source records attributed to C Hawes.

At least 37 records · Page 2Linked to original sources

Membrane trafficking in higher plant cells: GFP and antibodies, partners for probing the secretory pathway.

Eukaryotic cells are characterised by the organised distribution of membrane bounded compartments in their cytoplasm. The endoplasmic reticulum (ER) and the Golgi apparatus (GA) are part of this endomembrane machinery. They are involved in protein flow, and are in charge of specific functions such as the assembly, sorting and transport of newly synthesised proteins, glycoproteins or polysaccharides to their final destination, where the macromolecules are recognised either for action, storage, deposition or degradation. The structural and functional relationship between the ER and GA in higher plants is still a matter of debate. Therefore, it was essential to develop probes that would specifically label proteins or glycoproteins of the endomembrane system in situ. Here we compare two complementary approaches to probe plant endomembranes; immunocytochemistry on fixed cells, and in vivo studies using the expression of GFP tagged chimeric proteins. The structural relationship between ER and GA as based on pharmacological approaches using the two systems is explored.

Animals↗

Biosynthesis and immunolocalization of Lewis a-containing N-glycans in the plant cell.

We recently demonstrated the presence of a new asparagine-linked complex glycan on plant glycoproteins that harbors the Lewis a (Lea), or Galbeta(1-3)[Fucalpha(1-4)]GlcNAc, epitope, which in mammalian cells plays an important role in cell-to-cell recognition. Here we show that the monoclonal antibody JIM 84, which is widely used as a Golgi marker in light and electron microscopy of plant cells, is specific for the Lea antigen. This antigen is present on glycoproteins of a number of flowering and non-flowering plants, but is less apparent in the Cruciferae, the family that includes Arabidopsis. Lea-containing oligosaccharides are found in the Golgi apparatus, and our immunocytochemical experiments suggest that it is synthesized in the trans-most part of the Golgi apparatus. Lea epitopes are abundantly present on extracellular glycoproteins, either soluble or membrane bound, but are never observed on vacuolar glycoproteins. Double-labeling experiments suggest that vacuolar glycoproteins do not bypass the late Golgi compartments where Lea is built, and that the absence of the Lea epitope from vacuolar glycoproteins is probably the result of its degradation by glycosidases en route to or after arrival in the vacuole.

Animals↗

People who make a difference. Interview by Wendy L. Bonifazi.

In last year's 20th anniversary issue, Contemporary started an annual tradition of honoring people whose innovative business practices, research, advocacy, and other efforts have shaped long term care. This year's four honorees have created groundbreaking tools for care, campaigned to promote the healthy growth of a fledgling form of care, and championed a vision for improving quality of life for residents.

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A calcium pump at the higher plant nuclear envelope?

Evidence for a Ca2+-pump at the nuclear envelope (NE) in plant cells has been obtained using confocal and electron microscope immunocytochemistry and antibodies raised to a plant homologue of the mammalian SERCA pump. This is the first evidence suggesting an NE Ca2+-pump in plants. In addition to being localised with the NE in interphase, the antigen was localised to membrane derived from the NE and associated ER during mitosis, correlating with known Ca2+-pools. The work suggests that a SERCA pump is present at the NE of plant as well as animal cells.

Calcium-Transporting ATPases↗

Stacks on tracks: the plant Golgi apparatus traffics on an actin/ER network.

We have visualized the relationship between the endoplasmic reticulum (ER) and Golgi in leaf cells of Nicotiana clevelandii by expression of two Golgi proteins fused to green fluorescent protein (GFP). A fusion of the transmembrane domain (signal anchor sequence) of a rat sialyl transferase to GFP was targeted to the Golgi stacks. A second construct that expressed the Arabidopsis H/KDEL receptor homologue aERD2, fused to GFP, was targeted to both the Golgi apparatus and ER, allowing the relationship between these two organelles to be studied in living cells for the first time. The Golgi stacks were shown to move rapidly and extensively along the polygonal cortical ER network of leaf epidermal cells, without departing from the ER tubules. Co-localization of F-actin in the GFP-expressing cells revealed an underlying actin cytoskeleton that matched precisely the architecture of the ER network, while treatment of cells with the inhibitors cytochalasin D and N-ethylmaleimide revealed the dependency of Golgi movement on actin cables. These observations suggest that the leaf Golgi complex functions as a motile system of actin-directed stacks whose function is to pick up products from a relatively stationary ER system. Also, we demonstrate for the first time in vivo brefeldin A-induced retrograde transport of Golgi membrane protein to the ER.

Actins↗

The C-terminal HDEL sequence is sufficient for retention of secretory proteins in the endoplasmic reticulum (ER) but promotes vacuolar targeting of proteins that escape the ER.

Proteins are co-translationally transferred into the endoplasmic reticulum (ER) and then either retained or transported to different intracellular compartments or to the extracellular space. Various molecular signals necessary for retention in the ER or targeting to different compartments have been identified. In particular, the HDEL and KDEL signals used for retention of proteins in yeast and animal ER have also been described at the C-terminal end of soluble ER processing enzymes in plants. The fusion of a KDEL extension to vacuolar proteins is sufficient for their retention in the ER of transgenic plant cells. However, recent results obtained using the same strategy indicate that HDEL does not contain sufficient information for full retention of phaseolin expressed in tobacco. In the present study, an HDEL C-terminal extension was fused to the vacuolar or extracellular (delta pro) forms of sporamin. The resulting SpoHDEL or delta proHDEL, as well as Spo and delta pro, were expressed at high levels in transgenic tobacco cells (Nicotiana tabacum cv BY2). The intracellular location of these different forms of recombinant sporamin was studied by subcellular fractionation. The results clearly indicate that addition of an HDEL extension to either Spo or delta pro induces accumulation of these sporamin forms in a compartment that co-purifies with the ER markers NADH cytochrome C reductase, binding protein (BiP) and calnexin. In addition, a significant SpoHDEL or delta proHDEL fraction that escapes the ER retention machinery is transported to the vacuole. From these results, it may be proposed that, in addition to its function as an ER retention signal, HDEL could also act in quality control by targeting chaperones or chaperone-bound proteins that escape the ER to the plant lysosomal compartment for degradation.

Biological Transport↗

N-glycans harboring the Lewis a epitope are expressed at the surface of plant cells.

In plants, N-linked glycans are processed in the Golgi apparatus to complex-type N-glycans of limited size containing a beta(1,2)-xylose and/or an alpha(1,3)-fucose residue. Larger mono- and bi-antennary N-linked complex glycans have not often been described. This study has re-examined the structure of such plant N-linked glycans, and, through both immunological and structural data, it is shown that the antennae are composed of Lewis a (Le(a)) antigens, comprising the carbohydrate sequence Gal beta 1-3[Fuc alpha 1-4]GlcNAc. Furthermore, a fucosyltransferase activity involved in the biosynthesis of this antigen was detected in sycamore cells. This is the first characterization in plants of a Lewis antigen that is usually found on cell-surface glycoconjugates in mammals and involved in recognition and adhesion processes. Le(a)-containing N-linked glycans are widely distributed in plants and highly expressed at the cell surface, which may suggest a putative function in cell/cell communication.

Carbohydrate Sequence↗

Approaching cross-national comparisons of nursing home residents.

METHOD: since the 1990 implementation of the US nursing home Resident Assessment Instrument (RAI), researchers in other nations have begun to use the RAI to assess institutionalized elders for payment, research, or planning purposes. We report comparative statistics representing institutionalized residents in seven nations, describing from several hundred to hundreds of thousands of residents. RESULTS: significant differences are seen in age and length of stay, and in summary measures of physical and cognitive functioning and case-mix. Countries also differ in their homogeneity across nursing homes. CONCLUSION: these differences strengthen the position that 'nursing home' does not provide a sound basis for cross-national comparisons, and should be replaced with resident-specific descriptors. This also suggests that cross-national comparisons need to adjust at the level of the individual resident for differences in resident populations.

Activities of Daily Living↗

Development of the nursing home Resident Assessment Instrument in the USA.

BACKGROUND: the nursing home Resident Assessment Instrument (RAI) includes a set of core assessment items, known as the Minimum Data Set (MDS), for assessment and care screening and more detailed Resident Assessment Protocols in 18 areas that represent common problem areas or risk factors for nursing home residents. Its primary use is clinical, to assess residents on admission to the nursing home, at least annually thereafter and on any significant change in status and to develop individualized, restorative plans of care. AIM: to describe the content and development of the RAI, including US testing for MDS item reliability and validity of the RAI, and the results of a 4-year evaluation of the effects of its clinical use. CONCLUSIONS: the evaluation found that implementation of the RAI was associated with significant improvements in a variety of measures of process quality, resident functional outcomes and reduced hospitalization. Other uses of the RAI data in the USA-including payment using resident classification systems and, with RAI-based outcome-oriented quality indicators, quality assurance activities-and the status of RAI use in other countries are also summarized.

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Nursing homes in 10 nations: a comparison between countries and settings.

AIM: to illustrate demographic differences and recent trends in the provision and structure of long-term care systems in the 10 countries participating in the Resident Assessment Instrument studies (Denmark, France, Iceland, Italy, Japan, The Netherlands, Sweden, Switzerland, the UK and the USA). METHOD: data were assembled from government documents, statistical yearbooks and articles from journals; supplemental data on long-term care and nursing homes were solicited from colleagues. RESULTS: All 10 countries are developed nations with high life-expectancies. Sweden has the oldest and Iceland the youngest population in this study, with Japan showing the highest ageing rates over the next three decades. Between 2 and 5% of elderly people reside in nursing homes. Interestingly, Iceland, as the 'youngest country' in this study, has the highest rate of institutionalization (living in residential or nursing homes), while the 'oldest country' (Sweden) has a low rate of institutionalization. In all countries the support ratio (number of elderly people per 100 younger adults) is high and increasing rapidly. CONCLUSIONS: no relation appears to exist between the ageing status of a country and the number of nursing home beds. Institutionalization rates among the nations studied differ even more, due at least in part to differences in the organization and financing of long-term care services, in the amount of responsibility assumed in the care for disabled elderly people by each sector and the availability of long-term care beds. Facing a rapid ageing of their population, many countries are in the process of health and social care reforms.

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Changes in advance care planning in nursing homes before and after the patient Self-Determination Act: report of a 10-state survey.

OBJECTIVE: The Patient Self-Determination Act (PSDA) implemented in 1991 has focused national attention on the right of patients to be involved in decision-making and on the use of written advance directives. We report changes in advance care planning with the PSDA and other historical events in nursing homes in 10 states. DESIGN: Pre- and Post-observational cohort study. PATIENTS: Nursing home residents, residing in 270 long-term care facilities in 10 states, stratified to ensure representation of urban and rural facilities in each state. In 1990, 2175 patients were sampled, and 2088 different patients from the same facilities were sampled in 1993. Six-month follow-up was obtained at both time periods. MAIN OUTCOME MEASURES: Advance care planning was defined as the documentation in the medical record of a living will, a durable power of attorney, a "Do Not Resuscitate" (DNR) order, a "Do Not Hospitalize" (DNH) order, or an order to forgo artificial nutrition or hospitalization. RESULTS: The rate of chart documentation of living wills increased from 4.2% in 1990 to 13.3% in 1993, and DNR orders increased dramatically from 31.1% to 51.5%. The rates of DNH and orders to forgo artificial hydration and nutrition remained less than 8% in both years. We found striking variations in advance care planing among the 10 states. In 1990, having a DNR order varied from 10.1% to 69.2% across the 10 states. With the exception of Oregon, where 69.2% of patients already had a DNR order, the states saw a 1.5 to 3.1 times increase in the rate of DNR orders in 1993 compared with 1990. CONCLUSION: With the implementation of the PSDA, there was modest increase in documentation of living wills, but DNH and orders to forgo artificial hydration and nutrition remained the same. There was a substantial increase in DNR orders that began before the PSDA implementation. This increase was associated both with the implementation of the PSDA and the increased debate about the appropriateness of CPR for nursing home residents. This increase varied considerably among geographic areas from the 10 states. Future research is needed to understand this geographic variation.

Advance Care Planning↗

The OBRA-87 nursing home regulations and implementation of the Resident Assessment Instrument: effects on process quality.

OBJECTIVE: To characterize changes in key aspects of process quality received by nursing home residents before and after the implementation of the national nursing home Resident Assessment Instrument (RAI) and other aspects of the Omnibus Budget Reconciliation Act (OBRA) nursing home reforms. DESIGN: A quasi-experimental study using a complex, multistage probability-based sample design, with data collected before (1990) and after (1993) implementation of the RAI and other OBRA provisions. SETTING AND PARTICIPANTS: Two independent cohorts (n > 2000) of residents in a random sample of 254 nursing facilities located in metropolitan statistical areas in 10 states. INTERVENTION: OBRA-87 enhanced the regulation of nursing homes and included new requirements on quality of care, resident assessment, care planning, and the use of neuroleptic drugs and physical restraints. One of the key provisions, used to help implement the OBRA requirements in daily nursing home practice, was the mandatory use of a standardized, comprehensive system, known as the RAI, to assist in assessment and care planning. OBRA provisions went into effect in federal law on October 1, 1990, although delays issuing the regulations led to actual implementation of the RAI during the Spring of 1991. MEASUREMENTS AND ANALYSES: Research nurses spent an average of 4 days per facility in each data collection round, assessing a sample of residents, collecting data through interviews with and observations of residents, interviews with multiple shifts of direct staff caregivers for the sampled residents, and review of medical records, including physician's orders, treatment and care plans, nursing progress notes, and medication records. The RNs collected data on the characteristics of the sampled residents, on the care they received, and on facility practices. The effect of being a member of the 1990 pre-OBRA or the 1993 post-OBRA cohort was assessed on the accuracy of information in the residents' medical records, the comprehensiveness of care plans, and on other key aspects of process quality while controlling for any changes in resident case-mix. The data were analyzed using contingency tables and logistic regression and a special statistical software (SUDAAN) to assure proper variance estimation. RESULTS: Overall, the process of care in nursing homes improved in several important areas. The accuracy of information in residents' medical records increased substantially, as did the comprehensiveness of care plans. In addition, several problematic care practices declined during this period, including use of physical restraints (37.4 to 28.1% (P < .001)) and indwelling urinary catheters (9.8 to 7% (P < .001)). There were also increases in good care practices, such as the presence of advanced directives, participation in activities, and use of toileting programs for residents with bowel incontinence. These results were sustained after controlling for differences in the resident characteristics between 1990 and 1993. Other practices, such as use of antipsychotic drugs, behavior management programs, preventive skin care, and provision of therapies were unaffected, or the differences were not statistically significant, after adjusting for changes in resident case-mix. CONCLUSION: The OBRA reforms and introduction of the RAI constituted an unprecedented implementation of comprehensive geriatric assessment in Medicare- and Medicaid-certified nursing homes. The evaluation of the effects of these interventions demonstrates significant improvements in the quality of care provided to residents. At the same time, these findings suggest that more needs to be done to improve process quality. The results suggest the RAI is one tool that facility staff, therapists, pharmacy consultants, and physicians can use to support their continuing efforts to provide high quality of care and life to the nation's 1.7 million nursing home residents.

Advance Directives↗

Association of the Resident Assessment Instrument (RAI) with changes in function, cognition, and psychosocial status.

OBJECTIVE: To evaluate the impact of the Resident Assessment Instrument (RAI) on changes in nursing home residents' functional status, cognitive status, and psychosocial well-being. DESIGN: A quasi-experiment involving the collection of longitudinal data on two cohorts of nursing home residents. One cohort was assessed before the implementation of the RAI, and the other was assessed after the implementation of the new assessment process. SETTING AND PARTICIPANTS: Over 2000 nursing home residents in 267 nursing homes located in 10 geographic areas were assessed during the pre-RAI period. In the post-RAI period, 2000 new residents in 254 of the same facilities were assessed. INTERVENTION: RAI implementation began in October 1990 and continued until October 1991. The RAI includes a structured, multidimensional resident assessment and problem identification system designed to form the basis for residents' care plans. MEASUREMENTS: All residents were assessed at baseline and at 6 months using the Minimum Data Set for Nursing Home Resident Assessment and Care Screening (MDS) and its protocols. All data were collected by research nurses employed and trained by the research team. RESULTS: Implementation of the RAI significantly reduced the rate of decline in seven of the nine outcomes under consideration. Reductions in improvement were also observed in all outcomes. In activities of daily living, social engagement, and cognitive function, the reduced decline far outweighed any reductions in improvement. In mood problems, problem behaviors, and understanding others, however, reductions in improvement were greater than any reductions in decline. Changes in the rates of decline and improvement were not uniform across all residents. CONCLUSION: The RAI may have improved the quality of care of nursing home residents by reducing overall rates of decline in important areas of resident function. However, this innovation may have generated trade-offs in that it may have reduced improvement rates in some areas of function. The system's implementation also seems to have focused staff's attention on the needs and strengths of specific subpopulations of residents. Revisions of the RAI must assist staff in generalizing their efforts to all residents and to increasing improvement rates, especially in areas related to mood and behavior.

Activities of Daily Living↗

Effect of the National Resident Assessment Instrument on selected health conditions and problems.

OBJECTIVE: To evaluate the effect of the implementation of the National Resident Assessment Instrument (RAI) system on selected conditions representing outcomes for nursing home residents. DESIGN: Quasi-experimental, pre-/post-design, with assessments at baseline and 6-month follow-up. SAMPLE: Two thousand one hundred twenty-eight residents from 268 nursing homes in 10 states before RAI implementation, and 2,088 from 254 of the same nursing homes after implementation. MEASURES: From the full RAI Minimum Data Set, measures of dehydration, falls, decubitus, vision problems, stasis ulcer, pain, dental status (poor teeth), and malnutrition were examined at baseline and 6 months later. Poor nutrition was evaluated using a body mass index score below 20 and vision using a 4-level scale; other conditions were represented by their presence or absence. Decline and improvement were computed as the changes in level between baseline and follow-up, limiting the sample to those who could manifest each such change. MAIN RESULTS: Of eight health conditions representing poorer health status, dehydration and stasis ulcer had significantly lower prevalence after the implementation of the RAI (1993) compared with 1990. At the same time, there was an increase in the prevalence of daily pain. Fewer residents declined over 6 months in nutrition and vision after implementation. Although for these two conditions there were also significantly reduced rates of improvement, the net was an overall reduction in the 6-month rate of decline for all residents. Pain also demonstrated a decline in the postimplementation rate of improvement. The combined eight conditions showed reductions in the rates of both decline and improvement. CONCLUSIONS: Several outcomes for nursing home residents improved after implementation of the RAI. Of the four conditions for which there are significant declines in prevalence or outcome changes, three are specifically addressed in the care planning guidelines incorporated the RAI system (all except stasis ulcer, although there is a RAP for decubitus ulcer). Pain, the only other condition with a significant result --an increase in baseline prevalence--also has no RAP. Although the changes might be ascribed otherwise, they support the premise that the RAI has directly contributed to improved outcomes for nursing home residents.

Accidental Falls↗

Changes in hospitalization associated with introducing the Resident Assessment Instrument.

OBJECTIVE: To compare the rates of hospitalization among cohorts of nursing home residents assembled before and after the implementation of the federally mandated Resident Assessment Instrument (RAI). SAMPLE: Subjects were nursing home residents chosen from 268 facilities in major Metropolitan Statistics Areas in 10 states and representing more than 1500 facilities and 60,000 residents. Two resident cohorts (1990 and 1993) were sampled (8 to 16 residents per facility, depending upon facility size) as part of an evaluation of the impact of implementing the RAI. METHODS: Research nurses reviewed records, interviewed staff, observed patients, and completed an RAI at baseline and 6 months later. All transitions during this interval (hospital admissions, nursing home transfers, returns home, death, etc.) were tracked. Using polytomous logistic regression, we tested the effect of cohort on the probability of being hospitalized in light of the competing risks of dying or remaining in the home, controlling for demographic and casemix variables, and having a DNR order in the chart. RESULTS: A total of 4196 residents were studied, 2118 in 1990 (age 81.3, female 77.7%, LOS 6+ months 49.8%) and 2078 in 1993 (age 81.7, females 75.5%, LOS 6+ months 50.2%). The unadjusted probability of hospitalization dropped from .205 to .151. Multivariate analyses revealed a significant adjusted odds of hospitalization of .74 (95% CI .60-.91) and no cohort effect on home discharge or death. Among severely cognitively impaired residents, the adjusted odds of hospitalization in 1993 compared with the 1990 cohort was 0.74 (.53-1.03). Finally, among survivors in both cohorts who had a follow-up MDS performed, and whose ADL remained stable, 15.9% were hospitalized in 1990, whereas only 10.9% were hospitalized in 1993. On the other hand, ADL decliners were more likely to have been hospitalized in 1993 than in 1990 (40.6% vs 25.2%). CONCLUSIONS: Although other changes in the industry, clinical practice, and health care policy may have influenced hospitalization of nursing home residents, the substantial reductions observed among the cognitively impaired and those with stable ADL suggest superior and uniform assessment information in the form of the RAI contributed significantly to this decline.

Activities of Daily Living↗

A commitment to change: revision of HCFA's RAI.

OBJECTIVE: To describe the reliability of new assessment items and their clinical utility as judged by experienced nurse assessors, based on the results from the field test of Version 2.0 of the Resident Assessment Instrument (RAI). DESIGN: Independent dual assessment of residents of nursing facilities by staff nurses using a draft of Version 2.0 of the minimum data set (MDS). SETTING AND PARTICIPANTS: A total of 187 randomly selected residents from 21 nursing homes in seven states volunteered to test Version 2.0 of the MDS. MEASUREMENT: The full array of MDS assessment items included measures in the following areas: Background information, cognitive patterns, communication/hearing, vision, mood and behavior, psychosocial well-being, physical functioning and structural problems, continence, disease diagnoses, health condition, oral/nutritional status, dental status, skin condition, activity pursuit patterns, medications, special treatments and procedures, and discharge potential and overall status. RESULTS: Evaluative data address issues of MDS item utility and reliability. For new items, almost all achieved a reasonably high-weighted Kappa interrater reliability; revised items also surpassed earlier items, and with the updated training materials, even the non-changed items had higher average reliability levels. Based on the success of the field test and the positive response of the industry, Version 2.0 of the RAI has been adopted, and HCFA has initiated a more long-range process to update further the RAI when necessary. CONCLUSION: Findings support the reliability and clinical utility of the new and revised assessment items incorporated by HCFA in Version 2.0 of the MDS.

Activities of Daily Living↗

Inappropriate drug prescriptions for elderly residents of board and care facilities.

OBJECTIVES: Using 1993 data, this study examines the prevalence of presumptively inappropriate prescriptions among residents, aged 65 and older, of board and care homes. METHODS: Inappropriate drug prescriptions were identified through the use of established criteria developed for application to older nursing home residents and to community-dwelling elderly. This research used a sample of 2054 elderly residents from 410 facilities in 10 states. Weighted analyses were performed with SUDAAN, which accounted for the complex, multistage sampling design. RESULTS: Depending on the criterion applied, between 20% and 25% of residents had at least one inappropriate prescription. Propoxyphene, long-acting benzodiazepines, dipyridamole, and amitriptyline were prescribed most frequently. Residents with inappropriate drug prescriptions had more complex drug regimens prescribed on a routine basis. CONCLUSIONS: The results are a conservative estimate of the extent of inappropriate drug prescribing and utilization in board and care facilities. Increased involvement by pharmacists and physicians in systematic drug utilization review is warranted.

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