Examination of a first-in-class bis-dialkylnorspermidine-terphenyl antibiotic in topical formulation against mono and polymicrobial biofilms

Biofilm-impaired tissue is a significant factor in chronic wounds such as diabetic foot ulcers. Most, if not all, anti-biotics in clinical use have been optimized against planktonic phenotypes. In this study, an in vitro assessment was performed to determine the potential efficacy of a first-in-class series of antibiofilm antibiotics and compare outcomes to current clinical standards of care. The agent, CZ-01179, was formulated into a hydrogel and tested against mature biofilms of a clinical isolate of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa ATCC 27853 using two separate methods. In the first method, biofilms were grown on cellulose discs on an agar surface. Topical agents were spread on gauze and placed over the biofilms for 24 h. Biofilms were quantified and imaged with confocal and scanning electron microscopy. In the second method, biofilms were grown on bioabsorbable collagen coupons in a modified CDC biofilm reactor. Coupons were immersed in treatment for 24 h. The first method was limited in its ability to assess efficacy. Efficacy profiles against biofilms grown on collagen were more definitive, with CZ-01179 gel eradicating well-established biofilms to a greater degree compared to clinical standards. In conclusion, CZ-01179 may be a promising topical agent that targets the biofilm phenotype. Pre-clinical work is currently being performed to determine the translatable potential of CZ-01179 gel.

Adaptation of the adult Functional Mobility Assessment (FMA) into a FMA-Family Centred (FMA-FC) paediatric version

AIM

The aims of this study were to adapt an adult wheeled mobility outcome measure, the Functional Mobility Assessment, for use with children (FMA-Family Centred) and establish the new measure's content validity, test-retest reliability, and internal consistency.

BACKGROUND

Although several tools exist to measure a child's ability to operate and move a wheeled mobility device, none focus on the ability of the wheeled mobility device to support children and their families as they perform daily activities.

METHODS

After adapting the FMA items with examples relevant to children aged 3-21, parent/caregiver and therapist stakeholder groups recommended adaptations relevant for families with children who cannot respond for themselves.

RESULTS

Six of the initial FMA items were retained with child-appropriate examples, and 4 new items were developed.

CONCLUSION

The content validity of the FMA-Family Centred was strongly supported, and internal consistency and test-retest reliability met accepted psychometric standards.

The protein storage vacuole: a unique compound organelle

Storage proteins are deposited into protein storage vacuoles (PSVs) during plant seed development and maturation and stably accumulate to high levels; subsequently, during germination the storage proteins are rapidly degraded to provide nutrients for use by the embryo. Here, we show that a PSV has within it a membrane-bound compartment containing crystals of phytic acid and proteins that are characteristic of a lytic vacuole. This compound organization, a vacuole within a vacuole whereby storage functions are separated from lytic functions, has not been described previously for organelles within the secretory pathway of eukaryotic cells. The partitioning of storage and lytic functions within the same vacuole may reflect the need to keep the functions separate during seed development and maturation and yet provide a ready source of digestive enzymes to initiate degradative processes early in germination.

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.

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.

Sorting of proteins to vacuoles in plant cells

An individual plant cell may contain at least two functionally and structurally distinct types of vacuoles: protein storage vacuoles and lytic vacuoles. Presumably a cell that stores proteins in vacuoles must maintain these separate compartments to prevent exposure of the storage proteins to an acidified environment with active hydrolytic enzymes where they would be degraded. Thus, the organization of the secretory pathway in plant cells, which includes the vacuoles, has a fascinating complexity not anticipated from the extensive genetic and biochemical studies of the secretory pathway in yeast. Plant cells must generate the membranes to form two separate types of tonoplast, maintain them as separate organelles, and direct soluble proteins from the secretory flow specifically to one or the other via separate vesicular pathways. Individual soluble and membrane proteins must be recognized and sorted into one or the other pathway by distinct, specific mechanisms. Here we review the emerging picture of how separate plant vacuoles are organized structurally and how proteins are recognized and sorted to each type.

Chemical and biological studies of a new cigarette that primarily heats tobacco. Part 1. Chemical composition of mainstream smoke

A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition from a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics, elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active.

Chemical and biological studies of a new cigarette that primarily heats tobacco. Part 1. Chemical composition of mainstream smoke

A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition from a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics, elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active.

Electrophysiological and biochemical evidence that DEG/ENaC cation channels are composed of nine subunits

Members of the DEG/ENaC protein family form ion channels with diverse functions. DEG/ENaC subunits associate as hetero- and homomultimers to generate channels; however the stoichiometry of these complexes is unknown. To determine the subunit stoichiometry of the human epithelial Na+ channel (hENaC), we expressed the three wild-type hENaC subunits (alpha, beta, and gamma) with subunits containing mutations that alter channel inhibition by methanethiosulfonates. The data indicate that hENaC contains three alpha, three beta, and three gamma subunits. Sucrose gradient sedimentation of alphahENaC translated in vitro, as well as alpha-, beta-, and gammahENaC coexpressed in cells, was consistent with complexes containing nine subunits. FaNaCh and BNC1, two related DEG/ENaC channels, produced complexes of similar mass. Our results suggest a novel nine-subunit stoichiometry for the DEG/ENaC family of ion channels.

Molecular cloning and further characterization of a probable plant vacuolar sorting receptor

BP-80 is a type I integral membrane protein abundant in pea (Pisum sativum) clathrin-coated vesicles (CCVs) that binds with high affinity to vacuole-targeting determinants containing asparagine-proline-isoleucine-arginine. Here we present results from cDNA cloning and studies of its intracellular localization. Its sequence and sequences of homologs from Arabidopsis, rice (Oryza sativa), and maize (Zea mays) define a novel family of proteins unique to plants that is highly conserved in both monocotyledons and dicotyledons. The BP-80 protein is present in dilated ends of Golgi cisternae and in "prevacuoles," which are small vacuoles separate from but capable of fusing with lytic vacuoles. Its cytoplasmic tail contains a Tyr-X-X-hydrophobic residue motif associated with transmembrane proteins incorporated into CCVs. When transiently expressed in tobacco (Nicotiana tabacum) suspension-culture protoplasts, a truncated form lacking transmembrane and cytoplasmic domains was secreted. These results, coupled with previous studies of ligand-binding specificity and pH dependence, strongly support our hypothesis that BP-80 is a vacuolar sorting receptor that trafficks in CCVs between Golgi and a newly described prevacuolar compartment.

Monoclonal antibodies to barley aleurain and homologs from other plants

Barley aleurain is contained within a specific type of vacuole characterized by acidic pH and the presence of other hydrolytic enzymes. The aleurain-containing vacuole is distinct from protein storage vacuoles, and anti-aleurain antibodies serve as markers for this organelle in barley cells. Aleurain is a unique type of cysteine protease, and other plant species have genes for homologs whose sequences are highly conserved, but little is known about these homologs at the protein level. Seven monoclonal antibodies to barley aleurain were isolated, which bind to and define aleurain homologues in Arabidopsis, Petunia, and tobacco cell extracts. Interestingly, in addition to 29-32 kDa aleurain homologs, Petunia extracts contain a protein of approximately 50 kDa and tobacco extracts a protein of approximately 40 kDa that are recognized by multiple different monoclonal antibodies, indicating an unexpected diversity to the aleurain protein family. Among the group of antibodies are some that efficiently immunoprecipitate metabolically labeled aleurain from barley cell extracts, and some that efficiently label aleurain in immunofluorescence assays using root tip cells. These antibodies should be useful for plant cell biologists who study vacuole biogenesis and function and sorting of proteins to specific vacuolar compartments, in barley as well as other plant species.

Evaluation of daily living tasks: the home care advantage

Occupational therapists working in home care have an advantage over those working in other settings because they can observe the influence of the naturalistic context on task performance. However, to use this advantage, therapists working in home care must use an evaluation approach that enables them to capture the client-task-context transaction. In this article, we discuss the ability of four "evaluation approaches"--norm-referenced, criterion-referenced, dynamic, informal--to provide information about the client-task-context transaction that therapists need in order to plan effective intervention. The potential of each approach for identifying clients' performance problems, suggesting etiologies, determining rehabilitation potential, and guiding intervention is analyzed, and the appropriateness of each approach for application in the home is appraised. This analysis highlights the utility of combining the criterion-referenced and dynamic assessment approaches for use in home care. A sequential process for integrating these two approaches is provided, and the proposed outcomes to be obtained from this process are identified.

Reciprocal translocation 4;11 with both adjacent-1 segregants viable within a family

We describe a family carrying a balanced 4;11 translocation in which both adjacent-1 segregants are viable. The proband had an unbalanced karyotype: 46,XY,der(11)t(4;11)(q34.3;q23.1)mat. At 8.5 years of age he showed trigonocephaly, hypertelorism, epicanthal folds, down-slanting palpebral fissures, low-set ears, anteverted nares, down-turned carp-shaped mouth, and bilateral fifth finger clinodactyly. His maternal aunt was also dysmorphic with high-arched palate, short philtrum and mild developmental delay. Her karyotype was 46,XX,der(4)t(4;11)(q34.3;q23.1)pat. Other relatives who likely carried a chromosomally unbalanced segregant were identified from photographs and medical records. We compare the clinical findings in our family with descriptions of other similar karyotypic abnormalities from previous case reports.

Phosphorylation of S1505 in the cardiac Na+ channel inactivation gate is required for modulation by protein kinase C

Inactivation of both brain and cardiac Na+ channels is modulated by activation of protein kinase C (PKC) but in different ways. Previous experiments had shown that phosphorylation of serine 1506 in the highly conserved loop connecting homologous domains III and IV (LIII/IV) of the brain Na+ channel alpha subunit is necessary for all effects of PKC. Here we examine the importance of the analogous serine for the different modulation of the rH1 cardiac Na+ channel. Serine 1505 of rH1 was mutated to alanine to prevent its phosphorylation, and the resulting mutant channel was expressed in 1610 cells. Electrophysiological properties of these mutant channels were indistinguishable from those of wild-type (WT) rH1 channels. Activation of PKC with 1-oleoyl-2-acetyl-sn-glycerol (OAG) reduced WT Na+ current by 49.3 +/- 4.2% (P < 0.01) but S1505A mutant current was reduced by only 8.5 +/- 5.4% (P = 0.29) when the holding potential was -94 mV. PKC activation also caused a -17-mV shift in the voltage dependence of steady-state inactivation of the WT channel which was abolished in the mutant. Thus, phosphorylation of serine 1505 is required for both the negative shift in the inactivation curve and the reduction in Na+ current by PKC. Phosphorylation of S1505/1506 has common and divergent effects in brain and cardiac Na+ channels. In both brain and cardiac Na+ channels, phosphorylation of this site by PKC is required for reduction of peak Na+ current. However, phosphorylation of S1506 in brain Na+ channels slows and destabilizes inactivation of the open channel. Phosphorylation of S1505 in cardiac, but not S1506 in brain, Na+ channels causes a negative shift in the inactivation curve, indicating that it stabilizes inactivation from closed states. Since LIII/IV containing S1505/S1506 is completely conserved, interaction of the phosphorylated serine with other regions of the channel must differ in the two channel types.

Comparison of standard and alternative health assessment questionnaire scoring procedures for documenting functional outcomes in patients with rheumatoid arthritis

OBJECTIVE

To compare statistical properties of data from the Health Assessment Questionnaire (HAQ) with those from an alternative version (AHAQ) that used a different scoring system for the item categories and disability index. Comparisons included descriptive statistics, correlations, and inferential statistics to determine whether the AHAQ would be a more sensitive measure of change in functional status.

METHODS

The subjects were 107 adults diagnosed with rheumatoid arthritis and hospitalized for exacerbations in their arthritis or arthritis related joint surgery. Disability was assessed upon admission to hospital and at one year followup with the HAQ. AHAQ scores were generated for the item categories making up the disability index by taking the mean of the item scores in a category instead of the worst item score; the disability index was the mean of the alternative category scores.

RESULTS

The standard method of scoring the HAQ was found to generate greater variance on category scores, lower correlations between category scores and the total disability index, and lower correlations between first and 2nd administrations of the instrument, compared to the AHAQ. HAQ disability index scores also correlated slightly lower than those of AHAQ to scores from the HAQ pain scales, and to scores from 2 other measures of functional disability. In addition, the AHAQ was found to be more powerful in detecting functional changes at one year followup.

CONCLUSION

Because of its statistical properties the AHAQ scoring method may be preferable to the HAQ method when the instrument is used for documenting change in functional outcomes.

Molecular determinants of high affinity binding of alpha-scorpion toxin and sea anemone toxin in the S3-S4 extracellular loop in domain IV of the Na+ channel alpha subunit

alpha-Scorpion toxins and sea anemone toxins bind to a common extracellular site on the Na+ channel and inhibit fast inactivation. Basic amino acids of the toxins and domains I and IV of the Na+ channel alpha subunit have been previously implicated in toxin binding. To identify acidic residues required for toxin binding, extracellular acidic amino acids in domains I and IV of the type IIa Na+ channel alpha subunit were converted to neutral or basic amino acids using site-directed mutagenesis, and altered channels were transiently expressed in tsA-201 cells and tested for 125I-alpha-scorpion toxin binding. Conversion of Glu1613 at the extracellular end of transmembrane segment IVS3 to Arg or His blocked measurable alpha-scorpion toxin binding, but did not affect the level of expression or saxitoxin binding affinity. Conversion of individual residues in the IVS3-S4 extracellular loop to differently charged residues or to Ala identified seven additional residues whose mutation caused significant effects on binding of alpha-scorpion toxin or sea anemone toxin. Moreover, chimeric Na+ channels in which amino acid residues at the extracellular end of segment IVS3 of the alpha subunit of cardiac Na+ channels were substituted into the type IIa channel sequence had reduced affinity for alpha-scorpion toxin characteristic of cardiac Na+ channels. Electrophysiological analysis showed that E1613R has 62- and 82-fold lower affinities for alpha-scorpion and sea anemone toxins, respectively. Dissociation of alpha-scorpion toxin is substantially accelerated at all potentials compared to wild-type channels. alpha-Scorpion toxin binding to wild type and E1613R had similar voltage dependence, which was slightly more positive and steeper than the voltage dependence of steady-state inactivation. These results indicate that nonidentical amino acids of the IVS3-S4 loop participate in alpha-scorpion toxin and sea anemone toxin binding to overlapping sites and that neighboring amino acid residues in the IVS3 segment contribute to the difference in alpha-scorpion toxin binding affinity between cardiac and neuronal Na+ channels. The results also support the hypothesis that this region of the Na+ channel is important for coupling channel activation to fast inactivation.

Plant cells contain two functionally distinct vacuolar compartments

The plant cell vacuole has multiple functions, including storage of proteins and maintenance of an acidic pH where proteases will have maximal activity. It has been assumed that these diverse functions occur in the same compartment. Here, we demonstrate that antibodies to two different tonoplast intrinsic proteins, alpha-TIP and TIP-Ma27, label vacuole membranes of two different compartments within the same cell. These compartments are functionally distinct, because barley lectin, a protein stored in root tips, is exclusively contained within the alpha-TIP compartment, while aleurain, a protease that serves as a marker for an acidified vacuolar environment, is exclusively contained within the TIP-Ma27 compartment. As cells develop large vacuoles, the two compartments merge; this may represent a process by which storage products in the alpha-TIP compartment are exposed to the acidic lytic TIP-Ma27 compartment for degradation.

Modulation of cardiac Na+ channel expression in Xenopus oocytes by beta 1 subunits

Voltage-gated Na+ channels consist of a large alpha subunit of 260 kDa associated with beta 1 and/or beta 2 subunits of 36 and 33 kDa, respectively. alpha subunits of rat cardiac Na+ channels (rH1) are functional when expressed alone in Xenopus oocytes or mammalian cells. beta 1 subunits are present in the heart, and localization of beta 1 subunit mRNA by in situ hybridization shows expression in the perinuclear cytoplasm of cardiac myocytes. Coexpression of beta 1 subunits with rH1 alpha subunits in Xenopus oocytes increases Na+ currents up to 6-fold in a concentration-dependent manner. However, no effects of beta 1 subunit coexpression on the kinetics or voltage dependence of the rH1 Na+ current were detected. Increased expression of Na+ currents is not observed when an equivalent mRNA encoding a nonfunctional mutant beta 1 subunit is coexpressed. Our results show that beta 1 subunits are expressed in cardiac muscle cells and that they interact with alpha subunits to increase the expression of cardiac Na+ channels in Xenopus oocytes, suggesting that beta 1 subunits are important determinants of the level of excitability of cardiac myocytes in vivo.

Comparison of the effects of N6-methyldeoxyadenosine and N5-methyldeoxycytosine on transcription from nuclear gene promoters in barley

Methylation of deoxycytosine residues in plant nuclear DNA at CpG dinucleotides is generally assumed to suppress transcription, while deoxyadenosine methylation on recombinant reporter gene constructs transiently introduced into plant cells increases expression by uncharacterized mechanisms. A particle bombardment transient expression system was used in intact barley aleurone layers to quantitate the effects of CpG and A methylation on transcription from well-characterized hormone-regulated alpha-amylase promoters. Methylation of C in all CpG pairs had little effect on transcription. In contrast, the presence of methylated A residues in the sequence GATC scattered in the reporter plasmid outside of the promoter increased transcription two- to fivefold, regardless of the strength of the promoter, and proper hormonal regulation of transcription was maintained. The methyl-dA effect was similar when the amount of reporter construct DNA used was varied over a 20-fold range, beginning with an amount that gave only a small increment of expression above background. Similar enhancing effects for methyl-dA were seen with the CaMV 35S, maize Adh1, and maize ubiquitin promoters, though the magnitude varied for each individual promoter. Methyl-dA did not detectably affect plasmid DNA stability in aleurone cells in transient expression experiments because the enhancing effect of methyl-dA on expression was the same regardless of whether the assay was performed at 12 h or 40 h. Several proteins in wheat germ nuclear extracts bound preferentially to methylated DNA as assessed by gel retardation assays; one showed preferential binding to methyl-dA rather than methyl-CpG residues. The data indicate that the presence of methyl-dA in the vicinity of active promoters enhances transcription of nuclear genes in barley in a manner independent of the strength of the promoter. This effect may be mediated by a methyl-dA-binding protein.

Can physicians use family genogram information to identify patients at risk of anxiety or depression?

Advocates of family-oriented care assert that physicians' use of family genograms can improve clinical practice, such as in the recognition of patients' emotional problems. The purpose of this article is to investigate whether physicians could use family genogram information to identify their patients at high risk of the two most common mental disorders, anxiety and depression. Physicians' use of family genograms to stratify their patients' risk raises two questions about the information recorded on the genograms: is family information reliable and valid, and is family information associated with anxiety and depression? A review of the published epidemiological literature revealed that some basic family information recorded on genograms is useful for risk stratification.

Stability and change in functional assessment of patients with geropsychiatric disorders

OBJECTIVES

Functional assessments of patients with geropsychiatric disorders accomplished by self-rating, informant rating, and performance test were compared.

METHOD

Fifty-eight inpatients with major depression or progressive dementia were evaluated on three occasions over 6 months with informant and patient versions of the Activities of Daily Living Scale of the Older Americans Resources and Services Multidimensional Functional Assessment (OARS-ADL) and with the Performance Assessment of Self-Care Skills (PASS).

RESULTS

Patients' scores became significantly worse (p < .01) on the informant version of the OARS-ADL and the PASS. Self-ratings with the OARS-ADL did not worsen significantly (p > .05).

CONCLUSION

Agreement between informant rating and performance test concerning functional status of patients with dementia was good. Elderly patients with depression may experience subtle deterioration that only becomes apparent on performance tests.

Inhibitory activity of cigarette-smoke condensate on the mutagenicity of heterocyclic amines

Cigarette-smoke condensate (CSC) is a complex mixture containing over 3800 identified chemicals including nicotine, water, mutagens, antimutagens, cytotoxins and inert chemicals. Although CSC is mutagenic in the Ames test, its effect on the activity of other mutagens has not been characterized. Using the Ames Salmonella bacterial mutagenesis assay, we found CSC exerts a significant inhibitory effect on mutagens requiring bioactivation. Those studied included heterocyclic amines (Glu-P-1, Glu-P-2, IQ, MeIQ, Trp-P-1 and Trp-P-2), benzo[a]pyrene (B[a]P) and aflatoxin B1. However, CSC had no effect on the activity of direct-acting mutagens (2-nitrofluorene, sodium azide, 4-nitro-1,2-phenylenediamine, 4-nitroquinoline N-oxide and methyl methanesulfonate). With indirect-acting mutagens, the reduced number of revertants observed in the presence of CSC was not attributable to cytotoxicity. CSC exhibited a potent inhibitory effect on the cytochrome P-450 dependent monooxygenases, ethoxyresorufin O-deethylase and B[a]P hydroxylase. This suggests inhibition of the cytochrome P-450 isozymes as one possible mechanism for the antimutagenicity of CSC. Fractionation studies of CSC revealed that the neutral, weakly acidic (phenolic) and basic fractions are all effective as antimutagens against Glu-P-1, a representative heterocyclic amine. This indicates that several classes of chemicals contribute to the inhibitory effect of CSC on the mutagenicity of the heterocyclic amines.

Systemic thinking: how do we know it when we see it?

One discussion within the field of family-oriented care concerns the distinction between those who practise a family approach and those who think in family system terms. This paper presents a comprehensive model of systemic thinking that may be useful for both family systems teachers and researchers. The conceptual model includes: (i) clinicians' experiences with and attitudes towards family aspects of health problems, and the context of clinicians' judgements about these problems; (ii) the way clinicians organize their knowledge about family factors and health problems in order for that knowledge to be readily available for decision making; and (iii) the interview sequences and hypothesis-generating or testing strategies used by clinicians in encounters with patients. The extent to which clinicians exhibit systemic thinking can be determined through interviews, questionnaires and case materials such as encounter transcripts. A method that assesses systemic thinking allows rigorous evaluations of family-oriented teaching efforts and clinical interventions.

The cis-acting gibberellin response complex in high pI alpha-amylase gene promoters. Requirement of a coupling element for high-level transcription

In cereal alpha-amylase gene promoters the cis-acting gibberellin response element (GARE) is required for increased transcription in the presence of gibberellin. In low-isoelectric point (pI) alpha-amylase gene promoters a second type of cis element, termed a coupling element, must also be present in a specific position near the GARE; otherwise, the level of transcription in the presence of gibberellin is only a few percent of maximum. The coupling element may help determine where and when in development high-level, hormonally regulated transcription will occur. Such coupling elements have not yet been shown to be necessary for high-level transcription from high-pI alpha-amylase gene promoters. Here we use quantitative transient expression assays to show that a high-pI promoter truncated to -300 is a weak promoter due to the absence of a functional coupling element in the vicinity of the GARE. Gibberellin-induced transcription increases substantially when coupling element function is provided, either by appending upstream regions normally attached to the promoter or by inserting a defined coupling element from a low-pI promoter. Thus, in a second type of gibberellin-regulated promoter coupling element function was found to be crucial for hormone regulation to result in high-level transcription.

Purification and initial characterization of a potential plant vacuolar targeting receptor

Clathrin-coated vesicles are known to be involved in the transport of proteins from the Golgi to the vacuole in plant cells. The mechanisms by which proteins are directed into this pathway are not known. Here we identify an integral membrane protein of approximately 80 kDa, extracted from clathrin-coated vesicles of developing pea (Pisum sativum L.) cotyledons, that bound at neutral pH to an affinity column prepared with the N-terminal targeting determinant of the vacuolar thiol protease, proaleurain, and eluted when the pH was lowered to 4. The protein was not retained on a control column prepared with the N-terminal sequence of a homologous, secreted thiol protease, endopeptidase B. The 80-kDa protein also accumulated in a membrane fraction that is less dense than clathrin-coated vesicles. In vitro studies demonstrated a binding constant of 37 nM between the approximately 80 kDa protein and the proaleurain targeting determinant. A peptide with a vacuolar targeting determinant from prosporamin weakly competed for binding to the approximately-80 kDa protein, while a peptide carrying a single amino acid substitution known to abolish prosporamin vacuolar targeting had no measurable binding affinity for the protein. The binding protein is a glycoprotein with a transmembrane orientation in which the C terminus is exposed to the cytoplasm. The binding domain is located in the N-terminal luminal portion of the protein. These properties of the binding protein are consistent with the function of a receptor that would select proteins in the trans-Golgi for sorting to clathrin-coated vesicles and delivery to the vacuole.