Task independence, safety, and adequacy among nondisabled and osteoarthritis-disabled older women

OBJECTIVE

To examine the constructs of task independence, safety, and adequacy.

METHOD

Fifty-seven nondisabled (ND) and 56 osteoarthritis-disabled (OAK) women were observed performing daily tasks.

RESULTS

Intercorrelations among the constructs of independence and adequacy were uniformly high, while the relationship of safety to these constructs was moderate and more variable, although stronger in the OAK group. Task performance of the OAK group was consistently less adequate and independent than that of the ND group; however, the groups were generally equivalent in safety. For individual tasks, adequacy best differentiated between the groups. In both groups, those who performed independently also performed safely, but fewer independent OAK participants also performed totally adequately.

CONCLUSION

The majority of older women who perform tasks independently also perform them safely and adequately; for a clinically significant minority, independence is not always synonymous with safe and adequate performance. Patients may be placed at risk if independence is the only construct used to determine disability.

Can first-year students master clinical skills?

Performances on a clinical skills OSCE of first- and second-year students were compared to measure the success of a new interviewing and physical examination component of the first-year curriculum.

The association of late-life depression and anxiety with physical disability: a review of the literature and prospectus for future research

Depression and anxiety disorders are associated with excess disability. The authors searched the recent geriatric literature for studies associating late-life depression or anxiety with physical disability. Studies showed depression in old age to be an independent risk factor for disability; similarly, disability was found to be a risk factor for depression. Anxiety in late life was also found to be a risk factor for disability, although not necessarily independently of depression. Increased disability due to depression is only partly explained by differences in socioeconomic measures, medical conditions, and cognition. Physical disability improves with treatment for depression; comparable studies have not been done for anxiety. The authors discuss how these findings inform current concepts of physical disability and discuss the implications for future intervention studies of late-life depression and anxiety disorders.

Does a reduction in family medicine clerkship time affect educational outcomes?

BACKGROUND AND OBJECTIVES

Little is known about the relationship between the length of a family medicine clerkship and its educational outcomes. After our family medicine clerkship time decreased from 6 weeks to 4 weeks in July 1997, we studied how this change in clerkship length affected educational outcomes.

METHODS

Educational outcomes for the 2-year periods before and after the change were examined and compared whenever possible. Outcome measurements included student ratings of different aspects of the clerkship and student performance on clerkship examinations.

RESULTS

Students' exposure to common clinical problems was unaffected by the change. For the 4-week clerkship, there was a slight increase in student ratings of the adequacy of number of patients seen, the opportunity to follow-up with patients, the ability to develop health promotion plans, and overall satisfaction. Because the combinations of examinations used differed each year, student performance on clerkship examinations could not be directly compared.

CONCLUSIONS

Educational outcomes of the 4-week clerkship were similar to the 6-week clerkship. A few key outcomes improved. Various curricular and structural changes instituted for the 4-week clerkship contributed to the stability in outcomes. Reports from other medical schools may give additional insight into understanding this relationship.

Control-relevant intervention in the treatment of minor and major depression in a long-term care facility

The authors assessed the effect of a control-relevant psychosocial intervention in 31 nursing home residents with either major depressive episode or minor depression. An initial group of 22 residents were randomized to either active treatment or waiting list. Four of 11 residents randomized to active treatment were deemed Responders, compared with 0 of 11 on the waiting list (P < 0.05). Of the total of 31 residents who participated in the intervention, 14 (45%) were deemed Responders during the intervention period. For these Responders, the Hamilton Rating Scale for Depression (Ham-D) and Geriatric Depression Scale scores improved significantly during the intervention. The improvement in the Ham-D was not sustained 2 months after intervention was terminated. These findings suggest that a psychosocial intervention enhancing socialization according to each resident's choice had a positive therapeutic impact on almost half of the nursing home residents with major or minor depression. However this effect could not be sustained by the residents without the support of the structured program.

Caleosins: Ca2+-binding proteins associated with lipid bodies

We have previously identified a rice gene encoding a 27 kDa protein with a single Ca2+-binding EF-hand and a putative membrane anchor. We report here similar genes termed caleosins, CLO, in other plants and fungi; they comprise a multigene family of at least five members in Arabidopsis (AtClo1-5). Northern hybridization demonstrated that AtClo2-4 mRNAs levels were low in various tissues, while AtClo1 mRNA levels were high in developing embryos and mature seeds. Analysis of transgenic Arabidopsis plants expressing the GUS reporter under control of the AtClo1 promoter showed strong levels of expression in developing embryos and also in root tip cells. Antibodies raised against AtCLO1 were used to detect caleosin in cellular fractions of Arabidopsis and rapeseed. This indicated that caleosins are a novel class of lipid body proteins, which may also be associated with an ER subdomain.

Biogenesis of the protein storage vacuole crystalloid

We identify new organelles associated with the vacuolar system in plant cells. These organelles are defined biochemically by their internal content of three integral membrane proteins: a chimeric reporter protein that moves there directly from the ER; a specific tonoplast intrinsic protein; and a novel receptor-like RING-H2 protein that traffics through the Golgi apparatus. Highly conserved homologues of the latter are expressed in animal cells. In a developmentally regulated manner, the organelles are taken up into vacuoles where, in seed protein storage vacuoles, they form a membrane-containing crystalloid. The uptake and preservation of the contents of these organelles in vacuoles represents a unique mechanism for compartmentalization of protein and lipid for storage.

Excess disability during morning care in nursing home residents with dementia

Excess disability was examined in 17 nursing home residents with dementia by comparing their performance of morning care tasks under two activities of daily living (ADL) caregiving approaches-a dependence-supportive one under usual care and an independence-supportive one under functional rehabilitation. The results suggest that excess disability in severely cognitively impaired and functionally disabled residents can be reduced by increasing opportunities for independent activity, and substituting nondirective and directive verbal assists for physical assists. Further, the findings indicate that increased independence in ADL can be achieved without increasing disruptive behaviors and can foster appropriate requests for task-related help during caregiving. Functional rehabilitation, however, requires more time than usual care.

Structural requirements for ligand binding by a probable plant vacuolar sorting receptor

How sorting receptors recognize amino acid determinants on polypeptide ligands and respond to pH changes for ligand binding or release is unknown. The plant vacuolar sorting receptor BP-80 binds polypeptide ligands with a central Asn-Pro-Ile-Arg (NPIR) motif. tBP-80, a soluble form of the receptor lacking transmembrane and cytoplasmic sequences, binds the peptide SSSFADSNPIRPVTDRAASTYC as a monomer with a specificity indistinguishable from that of BP-80. tBP-80 contains an N-terminal region homologous to ReMembR-H2 (RMR) protein lumenal domains, a unique central region, and three C-terminal epidermal growth factor (EGF) repeats. By protease digestion of purified secreted tBP-80, and from ligand binding studies with a secreted protein lacking the EGF repeats, we defined three protease-resistant structural domains: an N-terminal/RMR homology domain connected to a central domain, which together determine the NPIR-specific ligand binding site, and a C-terminal EGF repeat domain that alters the conformation of the other two domains to enhance ligand binding. A fragment representing the central domain plus the C-terminal domain could bind ligand but was not specific for NPIR. These results indicate that two tBP-80 binding sites recognize two separate ligand determinants: a non-NPIR site defined by the central domain-EGF repeat domain structure and an NPIR-specific site contributed by the interaction of the N-terminal/RMR homology domain and the central domain.

Humanism: is its evaluation captured in commonly used performance measures?

BACKGROUND

There is an increased awareness of the importance of humanistic behavior and its education in the medical school curriculum. Relatively little is known about correlations between humanism and other performance measures.

PURPOSES

To determine the correlation between humanism and other commonly used performance measures, and to determine if more humanistic students perform better, the same, or worse than less humanistic students.

METHODS

During the Family Medicine clerkship, standardized patients (SPs) used the Physician Humanism Scale to assess 428 students for humanism. Clinical preceptors, SPs, written assignments, and a national knowledge examination also assessed student performance. The humanism scores were correlated with the SP and non-SP performance measures.

RESULTS

Humanism scores were significantly and positively correlated to all of the performance measures, but the correlation coefficients were low, ranging from .12 to .31. Students in the lowest quartile for humanism consistently scored lower for all of the performance measures, including both local and national exams (two-tailed significance < .018). Students with very low humanism scores still passed other performance evaluations.

CONCLUSIONS

The correlation between humanism and other performance measures is quite low, indicating that a separate measure for humanism provides different and additional information that current performance measures do not include. More humanistic students perform better than their less humanistic peers, but current performance measures do not identify students with the lowest scores on humanistic behavior. This study supports the inclusion of humanism as an additional, independent performance measure.

Functional roles of the extracellular segments of the sodium channel alpha subunit in voltage-dependent gating and modulation by beta1 subunits

Voltage-gated sodium channels consist of a pore-forming alpha subunit associated with beta1 subunits and, for brain sodium channels, beta2 subunits. Although much is known about the structure and function of the alpha subunit, there is little information on the functional role of the 16 extracellular loops. To search for potential functional activities of these extracellular segments, chimeras were studied in which an individual extracellular loop of the rat heart (rH1) alpha subunit was substituted for the corresponding segment of the rat brain type IIA (rIIA) alpha subunit. In comparison with rH1, wild-type rIIA alpha subunits are characterized by more positive voltage-dependent activation and inactivation, a more prominent slow gating mode, and a more substantial shift to the fast gating mode upon coexpression of beta1 subunits in Xenopus oocytes. When alpha subunits were expressed alone, chimeras with substitutions from rH1 in five extracellular loops (IIS5-SS1, IISS2-S6, IIIS1-S2, IIISS2-S6, and IVS3-S4) had negatively shifted activation, and chimeras with substitutions in three of these (IISS2-S6, IIIS1-S2, and IVS3-S4) also had negatively shifted steady-state inactivation. rIIA alpha subunit chimeras with substitutions from rH1 in five extracellular loops (IS5-SS1, ISS2-S6, IISS2-S6, IIIS1-S2, and IVS3-S4) favored the fast gating mode. Like wild-type rIIA alpha subunits, all of the chimeric rIIA alpha subunits except chimera IVSS2-S6 were shifted almost entirely to the fast gating mode when coexpressed with beta1 subunits. In contrast, substitution of extracellular loop IVSS2-S6 substantially reduced the effectiveness of beta1 subunits in shifting rIIA alpha subunits to the fast gating mode. Our results show that multiple extracellular loops influence voltage-dependent activation and inactivation and gating mode of sodium channels, whereas segment IVSS2-S6 plays a dominant role in modulation of gating by beta1 subunits. Evidently, several extracellular loops are important determinants of sodium channel gating and modulation.

Tonoplast intrinsic protein isoforms as markers for vacuolar functions

Plant cell vacuoles may have storage or lytic functions, but biochemical markers specific for the tonoplasts of functionally distinct vacuoles are poorly defined. Here, we use antipeptide antibodies specific for the tonoplast intrinsic proteins alpha-TIP, gamma-TIP, and delta-TIP in confocal immunofluorescence experiments to test the hypothesis that different TIP isoforms may define different vacuole functions. Organelles labeled with these antibodies were also labeled with antipyrophosphatase antibodies, demonstrating that regardless of their size, they had the expected characteristics of vacuoles. Our results demonstrate that the storage vacuole tonoplast contains delta-TIP, protein storage vacuoles containing seed-type storage proteins are marked by alpha- and delta- or alpha- and delta- plus gamma-TIP, whereas vacuoles storing vegetative storage proteins and pigments are marked by delta-TIP alone or delta- plus gamma-TIP. In contrast, those marked by gamma-TIP alone have characteristics of lytic vacuoles, and results from other researchers indicate that alpha-TIP alone is a marker for autophagic vacuoles. In root tips, relatively undifferentiated cells that contain vacuoles labeled separately for each of the three TIPs have been identified. These results argue that plant cells have the ability to generate and maintain three separate vacuole organelles, with each being marked by a different TIP, and that the functional diversity of the vacuolar system may be generated from different combinations of the three basic types.

Improving morning care routines of nursing home residents with dementia

OBJECTIVES

This study examined the effectiveness of a behavioral rehabilitation intervention for improving the performance of morning care activities of daily living (ADL) of nursing home residents with dementia.

DESIGN

Participants and their caregivers were observed for 5 days each under conditions of Usual Care (naturalistic) and Skill Elicitation (intervention), and for 15 days under Habit Training (intervention follow-up). Observations involved the ADL categories of DRESSING, OTHER ADL, and NO ADL. A 3 x 3 design (condition x ADL category) was used.

SETTING

Observations occurred in five proprietary nursing homes in Pittsburgh, Pennsylvania.

PARTICIPANTS

The participants were 58 women and 26 men, mean age 82 years (range = 64-97, SD = 6.3), with Probable Alzheimer 's disease (AD) (n = 19) and Possible AD (n = 65), with a mean MMSE score of 6.07.

INTERVENTION

Condition 1, Usual Care, was the naturalistic caregiving condition. Condition 2, Skill Elicitation, consisted of an individualized behavioral rehabilitation intervention designed to identify and elicit retained ADL skills. Under Condition 3, Habit Training, the behavioral rehabilitation intervention was continued to reinforce and solidify retained skills and to facilitate further functional gains.

MEASUREMENTS

A computer-assisted data collection system was used to document in real-time the assists used by caregivers, the participants' ADL performance, and the participants' responses to caregiving, including disruptive behavior.

RESULTS

Compared with Usual Care, during Skill Elicitation participants increased the proportion of time engaged in nonassisted and assisted dressing significantly and increased their overall participation in ADL, with a concomitant significant decrease in disruptive behavior. These functional gains were demonstrated within 5 days of initiating the behavioral rehabilitation intervention and were maintained for 3 weeks during Habit Training. Physical assists were provided for significantly smaller proportions of a morning care session during Skill Elicitation and Habit Training compared with Usual Care.

CONCLUSIONS

Even very severely cognitively impaired and functionally disabled nursing home residents can respond to a systematically implemented behavioral rehabilitation intervention. Their rapid response to this intervention suggests that it is alleviating excess disabilities brought on by care patterns rather than retraining ADL task performance. Residents with dementia benefit from behavioral rehabilitation by becoming more appropriately involved in their care and being less disruptive. However, behavioral rehabilitative care takes considerably more time than usual care.

Processes and outcomes of care for patients with community-acquired pneumonia: results from the Pneumonia Patient Outcomes Research Team (PORT) cohort study

BACKGROUND

Although understanding the processes of care and medical outcomes for patients with community-acquired pneumonia is instrumental to improving the quality and cost-effectiveness of care for this illness, limited information is available on how physicians manage patients with this illness or on medical outcomes other than short-term mortality.

OBJECTIVES

To describe the processes of care and to assess a broad range of medical outcomes for ambulatory and hospitalized patients with community-acquired pneumonia.

METHODS

This prospective, observational study was conducted at 4 hospitals and 1 health maintenance organization in Pittsburgh, Pa, Boston, Mass, and Halifax, Nova Scotia. Data were collected via patient interviews and reviews of medical records for 944 outpatients and 1343 inpatients with clinical and radiographic evidence of community-acquired pneumonia. Processes of care and medical outcomes were assessed 30 days after presentation.

RESULTS

Only 29.7% of outpatients had 1 or more microbiologic tests performed, and only 5.7% had an assigned microbiologic cause. Although 95.7% of inpatients had 1 or more microbiologic tests performed, a cause was established in only 29.6%. Six outpatients (0.6%) died, and 3 of these deaths were pneumonia related. Of surviving outpatients, 8.0% had 1 or more medical complications. At 30 days, 88.9% (nonemployed) to 95.6% (employed) of the surviving outpatients had returned to usual activities, yet 76.0% of outpatients had 1 or more persisting pneumonia-related symptoms. Overall, 107 inpatients (8.0%) died, and 81 of these deaths were pneumonia related. Most surviving inpatients (69.0%) had 1 or more medical complications. At 30 days, 57.3% (non-employed) to 82.0% (employed) of surviving inpatients had returned to usual activities, and 86.1% had 1 or more persisting pneumonia-related symptoms.

CONCLUSIONS

In this study, conducted primarily at hospital sites with affiliated medical education training programs, virtually all outpatients and most inpatients had pneumonia of unknown cause. Although outpatients had an excellent prognosis, pneumonia-related symptoms often persisted at 30 days. Inpatients had substantial mortality, morbidity, and pneumonia-related symptoms at 30 days.

Cloning and characterization of a gibberellin-induced RNase expressed in barley aleurone cells

We cloned a cDNA for a gibberellin-induced ribonuclease (RNase) expressed in barley (Hordeum vulgare) aleurone and the gene for a second barley RNase expressed in leaf tissue. The protein encoded by the cDNA is unique among RNases described to date in that it contains a novel 23-amino acid insert between the C2 and C3 conserved sequences. Expression of the recombinant protein in tobacco (Nicotiana tabacum) suspension-cultured protoplasts gave an active RNase of the expected size, confirming the enzymatic activity of the protein. Analyses of hormone regulation of expression of mRNA for the aleurone RNase revealed that, like the pattern for alpha-amylase, mRNA levels increased in the presence of gibberellic acid, and its antagonist abscisic acid prevented this effect. Quantitative studies at early times demonstrated that cycloheximide treatment of aleurone layers increased mRNA levels 4-fold, whereas a combination of gibberellin plus cycloheximide treatment was required to increase alpha-amylase mRNA levels to the same extent. These results are consistent with loss of repression as an initial effect of gibberellic acid on transcription of those genes, although the regulatory pathways for the two genes may differ.

Functional analysis of a Golgi-localized Kex2p-like protease in tobacco suspension culture cells

Kex2p is the prototype of a Golgi-resident protease responsible for the processing of prohormones in yeast and mammalian cells. A Kex2p-like pathway was shown to be responsible for processing the fungal KP6 protoxin in transgenic tobacco plants. We previously described a chimeric integral membrane reporter protein that traffics through Golgi to the lytic prevacuole where it was proteolytically processed. As a first step to isolate and clone the Kex2p-like protease in plant cells, we designed and used a similar chimeric reporter protein containing Kex2 cleavage sites to assay the Kex2p-like activity and to determine its substrate specificity in tobacco cells. Here we demonstrate that the Kex2 cleavage sites of the reporter were specifically processed by a protease activity with a substrate specificity characteristic of yeast Kex2p. This Kex2p-like protease in tobacco cells is also a Golgi-resident enzyme. Thus, the reporter protein provides a biochemical marker for studying protein traffic through the Golgi in plant cells. These results additionally should allow the design of synthetic substrates for use in biochemical purification of the plant enzyme.

Observational data collection using computer and manual methods: which informs best?

Computer and manual systems were used simultaneously to record observations of nursing home residents with dementia during a study designed to improve their dressing performance. This article differentiates the overlapping and unique features of the two data collection systems and discusses the clinical and research utility of each system. Although the computer system was more suited to clinical research and the manual system to clinical practice, when used in tandem each system provided data about the residents' performance that could be used for both clinical research and clinical practice, and complemented or expanded upon data generated by the other system.

Integral membrane protein sorting to vacuoles in plant cells: evidence for two pathways

Plant cells may contain two functionally distinct vacuolar compartments. Membranes of protein storage vacuoles (PSV) are marked by the presence of alpha-tonoplast intrinsic protein (TIP), whereas lytic vacuoles (LV) are marked by the presence of gamma-TIP. Mechanisms for sorting integral membrane proteins to the different vacuoles have not been elucidated. Here we study a chimeric integral membrane reporter protein expressed in tobacco suspension culture protoplasts whose traffic was assessed biochemically by following acquisition of complex Asn-linked glycan modifications and proteolytic processing, and whose intracellular localization was determined with confocal immunofluorescence. We show that the transmembrane domain of the plant vacuolar sorting receptor BP-80 directs the reporter protein via the Golgi to the LV prevacuolar compartment, and attaching the cytoplasmic tail (CT) of gamma-TIP did not alter this traffic. In contrast, the alpha-TIP CT prevented traffic of the reporter protein through the Golgi and caused it to be localized in organelles separate from ER and from Golgi and LV prevacuolar compartment markers. These organelles had a buoyant density consistent with vacuoles, and alpha-TIP protein colocalized in them with the alpha-TIP CT reporter protein when the two were expressed together in protoplasts. These results are consistent with two separate pathways to vacuoles for membrane proteins: a direct ER to PSV pathway, and a separate pathway via the Golgi to the LV.

delta-Tonoplast intrinsic protein defines unique plant vacuole functions

Plant cell vacuoles may have either storage or degradative functions. Vegetative storage proteins (VSPs) are synthesized in response to wounding and to developmental switches that affect carbon and nitrogen sinks. Here we show that VSPs are stored in a unique type of vacuole that is derived from degradative central vacuoles coincident with insertion of a new tonoplast intrinsic protein (TIP), delta-TIP, into their membranes. This finding demonstrates a tight coupling between the presence of delta-TIP and acquisition of a specialized storage function and indicates that TIP isoforms may determine vacuole identity.

Predictors of functional disability in patients with rheumatoid arthritis

OBJECTIVE

Using the World Health Organization's classification system of the consequences of disease, this study sought to examine the impact of physical and psychological impairment variables, beyond that contributed by social, demographic, and disease variables, on the functional disability of a rheumatoid arthritis (RA) sample. Data collected during an acute episode were used to predict concurrent and future disability status.

METHOD

A secondary data analysis of 85 adults hospitalized for exacerbations in arthritis was undertaken. Disability was assessed with the Health Assessment Questionnaire. Physical impairment was measured with the Keitel Function Test and Pain Analog Scales, and psychological impairment was measured with the Center for Epidemiologic Studies Depression Scale and the Perceived Self-Efficacy Scale for People with Arthritis.

RESULTS

Our findings indicated that physical impairment, demographic, and disease variables accounted for 64% of the explained variance in disability during the concurrent episode. Psychological impairment as well as demographic and disease variables accounted for 49% of the explained variance in future disability status.

CONCLUSION

The combined influence of demographic characteristics and the consequences of the pathology of RA experienced as physical and psychological impairments contributed differentially to disability during concurrent and future time periods.

Voltage sensor-trapping: enhanced activation of sodium channels by beta-scorpion toxin bound to the S3-S4 loop in domain II

Polypeptide neurotoxins alter ion channel gating by binding to extracellular receptor sites, even though the voltage sensors are in their S4 transmembrane segments. By analysis of sodium channel chimeras, a beta-scorpion toxin is shown here to negatively shift voltage dependence of activation and enhance closed state inactivation by binding to a receptor site that requires glycine 845 (Gly-845) in the S3-S4 loop at the extracellular end of the S4 segment in domain II of the alpha subunit. Toxin action requires prior depolarization to drive the S4 voltage sensors outward, but these effects are lost in the mutant G845N. The results reveal a voltage sensor-trapping model of toxin action in which the IIS4 voltage sensor is trapped in its outward, activated position by toxin binding.

HRT, a novel zinc finger, transcriptional repressor from barley

A barley gene encoding a novel DNA-binding protein (HRT) was identified by southwestern screening with baits containing a gibberellin phytohormone response element from an alpha-amylase promoter. The HRT gene contains two introns, the larger of which (5722 base pairs (bp)) contains a 3094-bp LINE-like element with homology to maize Colonist1. In vitro mutagenesis and zinc- and DNA-binding assays demonstrate that HRT contains three unusual zinc fingers with a CX8-9CX10CX2H consensus sequence. HRT is targeted to nuclei, and homologues are expressed in other plants. In vivo, functional tests in plant cells indicate that full-length HRT can repress expression from certain promoters including the Amy1/6-4 and Amy2/32 alpha-amylase promoters. In contrast, truncated forms of HRT containing DNA-binding domains can activate, or derepress, transcription from these promoters. Northern hybridizations indicate that HRT mRNA accumulates to low levels in various tissues. Roles for HRT in mediating developmental and phytohormone-responsive gene expression are discussed.