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Biomedical subjects

R E Roberts

Publications and source records attributed to R E Roberts.

At least 91 records · Page 5Linked to original sources
PubMed1985

Atypical findings in 16 cases of canine ehrlichiosis.

Sixteen cases of clinically and serologically diagnosed canine ehrlichiosis were studied retrospectively. Findings not previously reported included diffuse, pulmonary interstitial radiopacities; weak-positive results for blastomycosis, using agar gel immunodiffusion; normal platelet counts; hemorrhage despite platelet counts greater than 100,000/mm3, and positive results for platelet factor 3 and antinuclear antibody assays. These atypical findings showed that the differential diagnosis of canine ehrlichiosis, blastomycosis, immune-mediated thrombocytopenia, and primary nasal lesions may be confusing, warranting careful assessment. The increased release of platelet factor 3 and the finding of antinuclear antibodies supported an immune mechanism in the pathogenesis of canine ehrlichiosis, as suggested by previous experimental studies.

Animals↗
PubMed1985

The fumarase genes of Escherichia coli: location of the fumB gene and discovery of a new gene (fumC).

The fumB gene of Escherichia coli, which complements the fumarase deficiency of a fumA mutant when present in multiple copies, has been located at 93.5 min in the E. coli linkage map and its product has been identified as a polypeptide of 61 kDal. Four overlapping ColE1-fumB+ plasmids representing a continuous segment of 23.3 kb of bacterial DNA have been isolated from the Clarke-Carbon E. coli gene bank and the location of the fumB gene relative to the restriction map and the adjacent mel operon has been defined. Hybridization studies have shown that the fumB gene is homologous to the fumA gene, which complements the fumA1 mutation in single and multi-copy situations, and encodes an analogous 61 kDal product formerly regarded as the E. coli fumarase. The hybridization studies also showed that the Bacillus subtilis fumarase gene (citG) is homologous to an independent gene, fumC (formerly g48), which lies adjacent to the fumA gene at 35.5 min in the E. coli linkage map. The N-terminal sequences of the citG and fumC products exhibit a 51% identity over 88 residues. It is possible that the fumC and citG genes are fumarase structural genes of E. coli and B. subtilis, and that the fumA gene may encode a differentially-regulated fumarase or be a positive regulator gene which is essential for the expression of fumC (but not citG). If so, the fumB gene may encode a related enzyme or activator that can replace the fumA function when amplified.

Autoradiography↗
PubMed1984

Ethnic status and participation in longitudinal health surveys.

Ethnic differences in survey participation and their effects on self-reported physical and psychiatric health status measures were examined in a longitudinal health study in Alameda County, California, in 1978 following two time intervals. Blacks and Mexican-Americans were more likely than whites to refuse to participate in follow-up surveys and were more difficult to trace when the time interval between interviews was long. With the exception of age, demographic characteristics were not consistently associated with participation status either across ethnic groups or across time periods. Self-reported psychiatric and physical health status were not statistically associated with participation status in any ethnic group for either time period, despite differential participation by ethnicity.

Adult↗
PubMed1984

Cloning of the aspartase gene (aspA) of Escherichia coli.

The aspartase gene (aspA) of Escherichia coli has been isolated in two plasmids, pGS73 and pGS94, which contain segments of bacterial DNA (12.5 and 2.8 kb, respectively) inserted into the tet gene of the vector pBR322. The plasmids were constructed by sequential sub-cloning from a larger ColE1-frd+ hybrid plasmid. The location of the aspA gene confirmed predictions based on a correlation between the genetic and restriction maps of the corresponding region. The aspartase activities of plasmid-containing aspA mutants were amplified four- to sixfold relative to aspA+ parental strains. The aspA gene product was tentatively identified as a polypeptide of Mr 55 000, which is somewhat larger than previous estimates (Mr 45000 to 48000) for aspartase.

Ammonia-Lyases↗
PubMed1984

Changing patterns in mental health service coverage within health maintenance organizations.

This 1982 national survey of all operational health maintenance organizations (HMOs) provides information on the current status of mental health services, benefits, costs, and utilization within HMOs, updating and augmenting a 1978 study. Approximately 94 per cent of the responding HMOs offered mental health service coverage; over one-half (54 per cent) offered alcohol and drug abuse service coverage. The present coverage benefits and utilization of mental health services within HMOs continue to reflect greater variability vis-a-vis other health services within HMOs. Over one-half (57 per cent) of the HMOs provided for 30 days of inpatient mental health coverage (per member per year). Three out of four (77 per cent) of the health plans provided for 20 ambulatory visits (per member per year). The mean mental health hospital utilization rate was 32 days (per 1,000 members per year). The mean mental health ambulatory utilization rate was 0.33 encounters (per member per year). Further studies should investigate the combined influence of organization characteristics, mental health service organization characteristics, and service benefits on the costs and utilization of HMO mental health services.

Adolescent↗
PubMed1983

The evaluation ranking scale: clarification of methodological and procedural issues.

Compared with CSQ-8, a typical questionnaire approach to assessing global patient satisfaction, the Evaluation Ranking Scale (ERS) had equally good patient acceptability, yielded more normally distributed satisfaction scores, and results allowed comparative information about patients' evaluation of specific service dimensions. The study also addressed key questions that have emerged about the ERS procedure. Patients apparently do not distinguish conceptually between "importance" of dimensions and "satisfaction" with dimensions in the first phase (ranking) of the ERS. Results did confirm that the ERS sequence of ranking and then rating the dimensions is essential to achieving optimal utility of results. The ranking task seems to have an organizing effect on patients' approach to the rating task. This effect does not work to dictate results in the rating phase but rather seems to familiarize patients with the dimensions to be rated thereby yielding greater potential discriminative capacity for the ERS. Finally, results indicate that the ERS can be administered in a flexible fashion that yields additional information about the absolute importance of the six dimensions without loss of desired operating characteristics for the measure.

Analysis of Variance↗
PubMed1983

Comparison of indirect and direct approaches to measuring patient satisfaction.

One indirect (PSQ) and two direct (CSQ-18B and ERS) measures of patient satisfaction were compared across a series of psychometric, acceptability, and concurrent validity criteria. None of the three measures was significantly related to health status or demographic characteristics. Each measure performed as expected from prior research on their psychometric properties. The scales contrasted, however, in regard to acceptability, with the PSQ being much less acceptable to patients than the other two. The PSQ also produced more missing data. The results on the PSQ reflected patient inconsistency on cross-check items and patients tended to be uncertain in their responses to many items. In multivariate analyses the three measures were used as predictors of patient-rated indices of global service satisfaction. The CSQ-18B and the ERS were significant predictors of patient-rated indices of global service satisfaction, whereas the PSQ was unrelated to these indices. It was concluded that the direct and indirect approaches measure different satisfaction domains. The PSQ likely assesses more generalized attitudes about health services while the CSQ-18B and the ERS efficiently reflect opinions about the specific setting in which they are administered.

Analysis of Variance↗
PubMed1983

Relationship of service satisfaction to life satisfaction and perceived well-being.

Two procedures for gaining patients' evaluations of health services were compared: (a) the Client Satisfaction Questionnaire (CSQ-18B), a direct approach assessing the setting and services actually encountered, and (b) the Patient Satisfaction Questionnaire (PSQ), an approach that indirectly assesses satisfaction with service by inquiring about general health care attitudes. Results from 148 public health patients indicated that the PSQ produced the most acceptability problems and was tapping aspects of life satisfaction other than service satisfaction. However, the PSQ produced significantly lower reports of satisfaction. Additional comparison and interpretation of typical responses generated from the two approaches suggested, on the whole, that the CSQ-18B data provided clearer, more efficient, and more useful information for program planning and evaluation. In this study, service satisfaction measured by the CSQ-18B did not have any significant relationship to global or multidimensional (LDQ-30) measures of life satisfaction and well-being. In contrast, over a third of the variance in PSQ scores was accounted for by measures of life satisfaction. It appears that the PSQ elicits attitudes toward the more generalized health care delivery system as well as aspects of life satisfaction rather than reactions to specific services actually received.

Analysis of Variance↗
PubMed1983

Assessing client satisfaction among Hispanics.

Data from two studies using community health center clients are analyzed to assess how a measure of client satisfaction operates when used with different ethnic populations. The eight-item version of the Client Satisfaction Questionnaire (CSQ-8) is a measure of general satisfaction with services that was developed to provide a brief, standard assessment procedure suitable for use in a wide variety of service settings. Based on the results of this survey, the CSQ-8 seems to operate about the same, whether administered to Anglos, blacks, persons of Mexican descent, or persons of other Hispanic origin, or whether in English or Spanish. There were essentially no differences among the various ethnic groups across statistical criteria of internal consistency reliability, central tendency, dispersion, item intercorrelation, or missing values. These results suggest that the CSQ-8 is a measure of general satisfaction with services suitable for use with a variety of client populations, including Hispanics.

Analysis of Variance↗
PubMed1983

Hybrid plasmids containing the pyruvate dehydrogenase complex genes and gene-DNA relationships in the 2 to 3 minute region of the Escherichia coli chromosome.

A sample of colonies from the Clarke-Carbon ColE1-Escherichia coli DNA plasmid gene bank was screened by conjugation for complementation of the lipoamide dehydrogenase lesion of a deletion strain lacking all components of the pyruvate dehydrogenase complex, delta (aroP aceE aceF lpd). Two ColE1-lpd+ hybrid plasmids were identified: pGS2 (ColE1-ace lpd+; 24 kb) and pGS5 (ColE1-lpd+; 14 kb). Enzymological studies confirmed that pGS2 expressed all the activities of the pyruvate dehydrogenase complex, whereas pGS5 expressed the lipoamide dehydrogenase and acetyltransferase activities (the latter from a ColE1 promoter). These and other plasmids were used to construct a 47-site (15 enzymes) restriction map for a 24.2 kb segment of bacterial DNA in the nadC-lpd region. A further 13 sites (six enzymes) were defined in a 5.4 kb sub-segment containing the lpd gene. lambda phage derivatives containing specific fragments were constructed and used in transduction studies which located the ace and lpd genes in a 7.78 kb sub-segment flanked by AccI and NruI sites.

Bacteriophage lambda↗
PubMed1983

Cloning, mapping, and expression of the fumarase gene of Escherichia coli K-12.

Two classes of fumarase-transducing phages, lambda fumA and lambda fumB, were isolated from populations of recombinant phages containing HindIII fragments of Escherichia coli DNA; they were isolated by virtue of their ability to complement the metabolic lesion of a fumarase-negative mutant. The strongly complementing lambda fumA phages contained a 6.2-kilobase HindIII fragment encoding: the fumA gene, located at 35.5 min in the E. coli linkage map and expressing the major fumarase activity; the mannosephosphate isomerase gene, manA; and an unidentified gene, g48. The three genes were located relative to the restriction map of the cloned fragment and the genetic linkage map (terC-g48-fumA-manA-uidAoR), their transcription polarities were defined as anticlockwise in the chromosome, and the molecular weights of the corresponding gene products were established: fumA, 61,500; manA, 42,000; g48, 48,000. Organisms containing the fumA gene sub-cloned in multicopy plasmids overproduced fumarase up to 50-fold. The weakly complementing class of transducing phages, lambda fumB, contained several genes in an 8.2-kilobase HindIII fragment, including one (fumB) that determines a minor fumarase activity. Complementation by fumB was only observed in high-copy situations such as transduction plaques and in strains containing a multicopy plasmid in which 40% of normal fumarase activity was detected. The basis for the complementation by fumB was not defined.

Bacteriophage lambda↗
PubMed1983

The Center for Epidemiologic Studies Depression Scale: its use in a community sample.

The authors gave the Center for Epidemiologic Studies Depression (CES-D) Scale, a self-report depression symptom scale, to 528 subjects drawn from a larger longitudinal community survey. Interviewers also assessed respondents using the Schedule for Affective Disorders and Schizophrenia (SADS), a structured clinical interview; on the basis of the SADS the subjects were then given diagnoses according to the Research Diagnostic Criteria. The results corroborated earlier findings of a modest relationship between self-reported symptoms of depression and the diagnosis of depression. The authors conclude that the CES-D Scale may be useful as an initial or first-stage screening test.

California↗
PubMed1982

Use of the SADS-RDC in a tri-ethnic community survey.

The Schedule for Affective Disorders and Schizophrenia and the Research Diagnostic Criteria were used to ascertain community-based rates of affective and nonaffective psychiatric disorders. Both current-point and lifetime prevalence rates were reported for a sample of whites, blacks and Mexican-Americans. Rates for whites were compared with those reported for another community sample in which the same diagnostic criteria were applied. Comparison of lifetime rates from the two studies showed good concurrence for most of the affective disorders, particularly depression. This study also examined differences in rates by ethnic status.

Adult↗
PubMed1982

Depression in the community: prevalence and treatment.

Research Diagnostic Criteria were used to make psychiatric diagnoses in a study of the prevalence of depression and its treatment in Alameda County, California, in 1978. As in findings from a study in New Haven, Conn, the number of people with clinical depression (as well as those with other psychiatric disorders) who sought help from a mental health professional or from any other source was quite low (only one in five had seen a mental health professional). Men in particular were less likely to report having received treatment for their emotional problems. However, contrary to the New Haven study, in Alameda County those with depression diagnosed were not more likely than those with other psychiatric diagnoses to seek care for emotional problems from nonpsychiatric physicians or from other sources of care.

Adult↗
PubMed1982

Prevalence of treated and untreated psychiatric disorders in three ethnic groups.

The pattern and overlap of treated and untreated rates of psychiatric symptoms and disorders were examined in a sample of whites, blacks, and Mexican-Americans. In addition, we compared treatment sources for family or personal problems for the three groups. The results suggest caution in substituting treated for untreated rates and also in interchanging rates based on symptom scales with rates from clinical diagnostic instruments. Underutilization was assessed by linking psychiatric status with reports of help-seeking behavior. Comparisons indicated that all groups underuse services relative to need, but underutilization is greater for blacks and Mexican-Americans. With the exception of nonpsychiatric physicians, use of treatment sources was similar for all groups. Whites were much more likely than blacks or Mexican-Americans to use this source of care. Possible reasons for this difference are discussed in the context of the methodology employed in the study.

Black or African American↗
PubMed1982

Response tendencies, ethnicity, and depression scores.

The Center for Epidemiologic Studies Depression scale was given to a sample of whites, blacks, and Mexican-Americans residing in Alameda County, California, in 1978. Scores on the scale were analyzed to see whether or not a potentially important source of bias called response tendencies affected prevalence estimates and associations between symptom scores and demographic variables. Response tendencies were found to be differentially correlated with symptom scores by ethnic status; however, their effects were not of sufficient magnitude to alter most associations observed between symptom scores and demographic variables. The need for further methodological studies to clarify the definitions of concepts such as "depression" is discussed.

Adult↗
PubMed1982

Effect of aspirin on collateral blood flow after experimental thrombosis of the feline aorta.

In 11 cats, the caudal aorta was occluded with a thrombus to inhibit opening of collateral vessels to the hindlimbs. Five cats were not treated, and 6 cats were given aspirin (650 mg, orally) 1 hour before aortic occlusion. Before the aortas were occluded, platelet counts were measured in the 11 cats, and platelet aggregation by adenosine diphosphate was assessed in 4 cats scheduled for aspirin treatment. Cats were maintained for 3 hours after surgery, and the tests were repeated. In addition, serum salicylate concentrations were determined for all aspirin-treated cats. Collateral circulation was assessed as the time necessary for contrast media to appear in the iliac arteries caudal to the thrombus during aortography. Platelet counts were significantly (P less than or equal to 0.05) reduced in nontreated cats, but not in the aspirin-treated cats. Serum salicylate concentrations indicated that aspirin had reached therapeutic blood concentrations. Inhibition of adenosine diphosphate-induced platelet aggregation was observed in all postthrombosis aspirin-treated cats. Contrast media did not appear in the iliac arteries of nontreated cats until 7.5 +/- 0.5 s after injection. In all aspirin-treated cats, contrast media appeared in the iliac arteries within 2.3 +/- 0.3 s after injection. Platelet thromboxane A2 may be the factor promoting collateral inhibition after aortic thrombosis in cats.

Animals↗