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Biomedical subjects

J C Rogers

Publications and source records attributed to J C Rogers.

At least 55 records · Page 3Linked to original sources
PubMed1996

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.

Aged↗
PubMed1995

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.

Animals↗
PubMed1995

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.

5-Methylcytosine↗
PubMed1994

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.

Amino Acid Sequence↗
PubMed1994

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.

Anxiety↗
PubMed1994

What did the doctor do? When physicians and patients disagree.

OBJECTIVE: A serendipitous finding in a study of routine clinical encounters was that physicians and patients frequently gave discrepant reports of what had happened during a clinic visit. This report examines the conditions under which these discrepant perceptions occurred. DESIGN: Five experienced physicians and 189 patients completed postencounter questionnaires immediately following visits to an academic family practice clinic. After each encounter, the physician and patient estimated the duration of the visit and reported whether each of seven clinical events had occurred. RESULTS: The most common disagreements concerned whether the physician had provided counseling or performed a treatment procedure. Multiple regression analyses suggest that patient characteristics contributed to specific forms of physician-patient disagreement but that overall discrepancy was greatest in cases in which the physician minimized the importance of psychosocial issues and/or felt relatively confident about understanding the patient's problem. CONCLUSIONS: Although correlation need not imply causality, the results raise the possibility that physicians can promote shared physician-patient understanding by paying more attention to psychosocial factors and being more circumspect in drawing conclusions about patients' problems.

Academic Medical Centers↗
PubMed1994

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.

Aflatoxin B1↗
PubMed1994

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.

Affective Symptoms↗
PubMed1994

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.

Amino Acid Sequence↗
PubMed1994

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.

Activities of Daily Living↗
PubMed1993

Evaluation of physician decision making with the use of prior probabilities and a decision-analysis model.

OBJECTIVES: To determine whether treatment decisions could be influenced by supplying probabilities and whether these decisions would be consistent with a decision-analysis model. DESIGN: Survey with case scenarios and a computerized decision-analysis model. SETTING: Family practice residency program. PARTICIPANTS: Forty family practice residents and faculty in the experimental group and six controls. INTERVENTIONS: Twelve cases scenarios of patients with hypertension and coexisting diseases were developed. Family practice physicians were asked to rank their drugs of choice for each case. In the second phase, six case scenarios included probabilities for efficacy and adverse reactions of step 1 antihypertensives. These drug selections were compared with a computerized decision-analysis model. MAIN OUTCOME MEASURES: Frequencies of matches between the drug selections of physicians and the computer model. RESULTS: The frequency of matches before probabilities were provided to physicians was low (45.6%) and there was a significant increase when probabilities were supplied (71.3%). Regardless of experience level, physicians increased their consistency with the computer model after probabilities were supplied. CONCLUSIONS: This study demonstrated that physician decision making for antihypertensive therapy can be influenced by patient-specific probability estimates. Probability data can help less experienced residents make decisions that are comparable to those of attending physicians. This study was conducted in one residency program and the generalizability to the practicing physician is unknown. These findings would suggest that educational efforts in residency programs, health maintenance organizations, or group practices may benefit from patient-specific probabilities that assist with decisions for drug therapy interventions.

Adult↗
PubMed1992

The importance of DNA methylation for stability of foreign DNA in barley.

We developed a system using 'passive' reporter genes driven by aleurone tissue-specific promoters to test the effect of methylation of foreign DNA on its stability after introduction into barley plants. The foreign DNA was introduced into barley cells and was able to persist through at least two plant generations. Transformation of barley cells was defined by showing initiation of transcription at the proper site on the barley promoter for the chimeric gene in aleurone tissue from both a primary transformant and its progeny, and by tissue-specific expression (aleurone greater than leaf) in the progeny. This persistence through many multiples of cell division is formally equivalent to transformation, regardless of whether the DNA was chromosomally integrated or carried as an episome, but did not necessarily represent stable integration into the genome since the foreign DNA was frequently rearranged or lost. The foreign DNA was most stable when plasmid DNA used in transformation lacked dA methylation but had complete methylation of dC residues in the CG dinucleotide at Hpa II sites; dA methylation alone was associated with marked foreign DNA instability. Our results are consistent with the presence of a previously undefined system in barley that identifies DNA lacking the proper methylation pattern and causes its loss from actively dividing cells. These results may be important when applied to different strategies using selectable markers for cereal transformation.

Base Composition↗
PubMed1992

Differences between patient and physician perceptions of predicted compliance.

One approach to improving patient compliance is for physicians to adapt their behaviour to fit patients' psychological characteristics. Previous university-based research has suggested that physician adaptation to patients' locus of control interferes with patient-physician congruence on expected compliance, but not with congruence on satisfaction with their relationship. This study was conducted in a community practice to clarify the relationship between the physician's adaptation to locus of control and likelihood of and commitment to compliance, and satisfaction with the doctor-patient match. One physician saw 148 patients with a variety of illnesses after they had completed the Health Locus of Control (HLC) questionnaire. The physician altered how he spoke with a patient based on whether the patient scored internally or externally on the HLC. After the encounter, both patient and physician rated the patient's likelihood of and commitment to complying with each of the three recommendations. The physician and each patient also rated their satisfaction with the match between them. Patients' ratings of commitment, likelihood, and satisfaction were significantly higher than those of the physician. Unlike earlier results, there were strong correlations between the patients' and physician's estimates of compliance (commitment and likelihood). Just as with the previous study, there was no correlation between the levels of physician and patient satisfaction with their match. This study indicates that physician adaptation to patients' locus of control does not interfere with compliance outcomes of doctor-patient encounters. Whether such adaptation will improve compliance outcomes is yet to be determined.

Adult↗
PubMed1992

Purification and characterization of aleurain : a plant thiol protease functionally homologous to Mammalian cathepsin h.

Barley (Hordeum vulgare L. cv Himilaya) aleurain is a vacuolar thiol protease originally isolated as a cDNA with 65% derived amino acid sequence identity with cathepsin H (JC Rogers, D Dean, GR Heck [1985] Proc Natl Acad Sci USA 82: 6512-6516). We purified aleurain from barley leaves to homogeneity (>1000-fold) and characterized its activity against a number of substrates. Aleurain is best described as an aminopeptidase; it hydrolyzes three different aminopeptidase substrates with similar catalytic efficiency but is less efficient at hydrolyzing an NH(2)-blocked substrate analog and azocasein. Our values for K(m) and k(cat) for three substrates (arginine 4-methyl-7-coumarylamide, l-arginine beta-naphthylamide, and N-alpha-benzoyl-l-arginine beta-naphthylamide) and specific activity with azocasein are all within a threefold range of those previously reported for human cathepsin H for these substrates (WN Schwartz, AJ Barrett [1980] Biochem J 191: 487-497). Aleurain also shows a number of other similarities to cathepsin H including heterogeneity of charge forms, position of the NH(2)-terminus of the mature protein, and pH-activity profile. The similar properties of aleurain and cathepsin H suggest that these enzymes have a similar function(s) that is required by both plant and animal cells. The availability of a plant system may permit functional ablation experiments in the future to clarify the role of this enzyme in higher eukaryotes.

Journal Article↗
PubMed1992

Definition and functional implications of gibberellin and abscisic acid cis-acting hormone response complexes.

The mechanisms by which cis-acting hormone response elements affect transcription is unclear. In this study, we demonstrated that a second "coupling element," identified as O2S, must be present to allow a single copy of either the gibberellin response element (GARE) or the abscisic acid response element (ABRE) to mediate their hormonal effects in the barley Amy32b alpha-amylase gene promoter. The interactive effects of the O2S and the GARE are constrained positionally and spatially; thus, together they form a gibberellin response complex (GARC). The absolute requirement of the O2S for function of the ABRE demonstrates that these together form an abscisic acid response complex (ABRC). A second copy of the GARE can substitute for the O2S in the GARC, but only in one orientation. By expressing the GARC-containing and ABRC-containing promoters in developing aleurone tissue, we showed that hormonal effects prevent alpha-amylase gene expression during the second half of grain development, but other mechanisms suppress expression earlier. Our results suggest that the specific sequence serving as a coupling element in a given gene promoter will greatly affect where and when the GARE or ABRE will be able to regulate transcription.

Abscisic Acid↗