Reporting contingencies of reinforcement in concurrent schedules.
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Journal Article↗
Biomedical subjects
B Jones
Publications and source records attributed to B Jones.
Performance On Concurrent Variable-interval Extinction Schedules.
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Journal Article↗
Use of the NAL-AB wordlists as a South African English speech discrimination test.
South Africa still lacks a South African English specific speech discrimination test. As an alternative, this study investigated the use of the Australian English, National Acoustic Laboratories Arthur Boothroyd (NAL-AB) wordlists to assess the speech discrimination of South African English speakers. Thirty South African English speakers were tested at 0, 5, 10, 20 and 25 dBHL (audiometer dial reading) and their performance-intensity functions were compared qualitatively to the NAL-AB wordlist normative data. Results showed three general patterns; similar performance for both groups; poorer performance by the South African English speakers at the low to mid presentation intensities only; and poorer performance by the South African English speakers across most presentation intensities. Use of the NAL-AB wordlists at threshold levels or for site of lesion assessment was therefore concluded to be unwise. Use of these wordlists at supra-threshold levels, however, would provide a valid and reliable option for the speech discrimination assessment of South African English speakers.
Adolescent↗
Calcium alginate as haemostatic swabs in hip fracture surgery.
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Alginates↗
Two low-dose OKT3 induction regimens following renal transplantation--clinical experience at a single center.
Experience with quadruple-drug induction therapy with two regimens of low-dose OKT3 in renal transplant patients was evaluated. Group I received 5.0 mg OKT3 in the operating room and on day 1, followed by 2.5 mg/d for a total dose and duration of 40 mg and 14 d, respectively, and group II received 14 d of OKT3 2.5 mg/d (a total dose of 35 mg). Rejection episodes developed in 21% of patients: 29% of group I vs. 17% of group II. In groups I and II, the mean number of days until first rejection was 134 and 119 d, respectively, and delayed graft function was observed in 24 vs. 13% of patients, respectively. Cytokine release syndrome was noted in 95% of group I patients and in 78% of group II patients. The overall incidence of infections did not differ significantly between the two groups; however, the incidence of oral candidiasis was higher in group II (30 vs. 11% in group I, p = 0.021) and the incidence of herpes simplex virus infection was higher in group I (13 vs. 1% in group II, p = 0.015). The average length of hospital stay was 6.7 d in group I and 6.2 d in group II. The current pharmacy charge for a 2.5-mg vial of OKT3 is 28% lower for a 5.0-mg vial. Our study suggests that by using either low-dose OKT3 regimen renal transplant patients can be safely treated with shortened hospital stays, lower pharmacy costs, and without increased incidence of graft loss or patient morbidity.
Adult↗
A tribute to our reviewers
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Journal Article↗
Breast leiomyoma.
Smooth muscle neoplasms exist as a spectrum of pathologic processes ranging from benign leiomyoma to anaplastic leiomyosarcoma. Although these tumors typically occur in regions where there is an abundance of smooth muscle, they may also be derived from the muscularis of the gastrointestinal tract or the media of blood vessels. The majority of breast leiomyomas are contiguous with the muscular components of the nipple areolar complex. Strong, in 1913, is credited with the early descriptions of leiomyoma of the mammary gland. There have been relatively few reports of this entity since Strong's initial description. Smooth muscle neoplasms of the breast present unique clinical challenges for which therapeutic decisions are based on criteria extrapolated from the management of similar tumors at other sites. This report high-lights key clinical and pathologic findings in a postmenopausal woman with a discrete breast mass of benign smooth muscle histology.
Breast Neoplasms↗
The effect of a video character's smoking status on young females' perceptions of social characteristics.
Despite public warnings of the health risks associated with cigarette smoking, as well as advertising bans and educational programs in schools, the percentage of young females who smoke is on the rise. This study examined the effect of a video character's smoking status on young females' perceptions of social characteristics. University students were shown a video of a young woman in a socially oriented role-play. The video portrayed a smoker for the experimental group and a nonsmoker for the control group; in all other respects the video presentations were identical. Both groups answered a questionnaire pertaining to social characteristics they believed she possessed. The experimental group rated the character as more outgoing, more sophisticated, not as easy to manipulate, and less emotional about breaking up with her boyfriend than did the control group. There were no significant differences in ratings of her uncertainty in a crowd, her degree of unpopularity, her ability to be intimidated, the degree others admire her, and her attractiveness. The results are discussed in the light of previous studies, and implications for future research are explored.
Adolescent↗
Simple models for repeated ordinal responses with an application to a seasonal rhinitis clinical trial.
In contrast to other models for ordinal data, the continuation ratio model can be fitted with standard statistical software. This makes it particularly appropriate for large clinical trials with ordinal response variables. In addition, when the trials are longitudinal, this model can be applied to individual responses instead of frequencies in contingency tables. Dependence can be incorporated by conditioning on the previous response, yielding a form of Markov chain. This approach is applied to the analysis of a large seasonal rhinitis trial, where patients were observed over 28 days and six symptoms recorded as ordinal responses.
Humans↗
Conformational integrity and ligand binding properties of a single chain T-cell receptor expressed in Escherichia coli.
We recently showed that a soluble, heterodimeric murine D10 T-cell receptor (TCR) (Valpha2Calpha, Vbeta8.2Cbeta) expressed in insect cells binds both Vbeta8.2-specific bacterial superantigen staphylococcal enterotoxin C2 (SEC2) and a soluble, heterodimeric major histocompatibility complex class II I-Ak.conalbumin peptide complex with a low micromolar affinity. To define further the structural requirements for the TCR/ligand interactions, we have produced in Escherichia coli a soluble, functional D10 single chain (sc) TCR molecule in which the Valpha and Vbeta domains are connected by a flexible peptide linker. Purified and refolded D10 scTCR bound to SEC2 and murine major histocompatibility complex class II I-Ak.conalbumin peptide complex with thermodynamic and kinetic binding constants similar to those measured for the baculovirus-derived heterodimeric D10 TCR suggesting that neither the TCR constant domains nor potential N- or O-linked carbohydrate moieties are necessary for ligand recognition and for expression and proper folding of the D10 scTCR. Purified D10 scTCR remained soluble at concentrations up to 1 mM. Circular dichroism and NMR spectroscopy indicated that D10 scTCR is stabilized predominantly by beta-sheet secondary structure, consistent with its native-like conformation. Because of its limited size, high solubility, and structural integrity, purified D10 scTCR appears to be suitable for structural studies by multidimensional NMR spectroscopy.
Amino Acid Sequence↗
Maternal immunization with a soluble TCR-Ig chimeric protein: long term, V beta-8 family-specific suppression of T cells by maternally transferred antibodies.
Maternal transfer of TCR clonotypic Ab protected young NOD mice against the adoptive transfer of diabetes by the BDC 2.5 T cell clone. The effect of maternal anti-TCR Vbeta-8 Ab on T cell development and function has now been investigated. SJL/J mice, which lack TCR Vbeta-8, were immunized with soluble, chimeric D10 TCR-IgG1 containing Vbeta-8.2. The (SJL/J x AKR/J) F1 offspring of immunized female SJL/J mice were severely depleted of peripheral T cells bearing Vbeta-8 until 11 to 17 wk of age. The loss of Vbeta-8 expression did not appear to be due to modulation of cell surface TCR. Since the Vbeta-8+ T cell population was unperturbed in the (AKR/J x SJL/J) F1 offspring of D10 TCR-IgG1-immunized AKR/J mothers making D10 clonotypic Ab, the effect was immunologically specific. The deletion of Vbeta-8+ T cells had functional consequences. In the in vitro response to the superantigen, staphylococcal enterotoxin B, the usually observed participation of Vbeta-8.2+ T cells was largely suppressed, whereas the recruitment of Vbeta-3+ T cells remained unaltered. In control mice, T cell responses to the 134- to 146-residue peptide of conalbumin (pCA(134-146)) were biased toward use of Valpha-2/Vbeta-8.2 TCR. In D10 TCR-IgG1 maternally immunized (SJL x AKR/J) F1 mice, the T cell responses to pCA(134-146) were suppressed, and T cell lines derived from these in vitro were devoid of Vbeta-8.2 expression. With an increased understanding of TCR V gene usage in autoimmune diseases, similar strategies for the depletion of autoreactive T cells may become feasible in humans.
Animals↗
Treatment-patient interactions for diagnostics of cross-over trials.
In cross-over trials, various types of responses may be recorded, not all of which can be appropriately modelled by a Normal distribution. Widening the class of models to the generalized linear model family has a number of advantages. An important one is that certain interactions, especially that between patients and treatments, can easily be fitted for frequency and count data. These can be used as diagnostics for the fit of the model used. One handicap has been the frequentist difficulty of comparing the fit of different non-nested models in this family. This can be overcome by the use of a model selection criterion such as the Akaike or Bayesian information criterion. This approach to modelling and diagnostics for cross-over trials is applied to two studies involving small counts of anginal attacks, previously analysed in the literature using classical Normal techniques.
Clinical Trials as Topic↗
Constraints on the nucleus and dust properties from mid-infrared imaging of comet Hyakutake.
We use Mie scattering theory to determine the expected thermal emission from dust grains in cometary comae and apply these results to mid-infrared images of comet Hyakutake (C/1996 B2) obtained preperihelion in 1996 March. Calculations were performed for dust grains in the size range from 0.1 to 10 micrometers for two different compositions: amorphous olivine (a silicate glass) and an organic residue mixture. The resulting emission efficiencies are complicated functions of wavelength and particle size and are significantly different for the two materials in question. The Hyakutake data set consists of three nights of high-resolution imaging (100-150 km pixel-1 at the comet) of the inner coma at 8.7, 11.7, 12.5, and 19.7 micrometers. Attempts to fit the observed colors (ratios of fluxes at different wavelengths) using a single grain composition failed. However, fits to the data were achieved for all three nights using a mixture of approximately 1 micrometer olivine grains and approximately 7 micrometers organic grains. The resulting olivine mass fraction was between 8% and 16% of the total dust mass-loss rate. We also estimate the radius of the nucleus to be r = 2.1 +/- 0.4 km.
Astronomy↗
Predictions of hospital mortality rates: a comparison of data sources.
BACKGROUND: Comparing hospital mortality rates requires accurate adjustment for patients' intrinsic differences. Commercial severity systems require either administrative data that omit vital clinical facts about patients' conditions at hospital admission or costly, time-consuming abstraction of medical records. The validity of supplementing administrative data with laboratory data has not been assessed. OBJECTIVE: To compare risk-adjusted mortality predictions using administrative data alone; administrative data plus laboratory values; and the combination of administrative, laboratory, and clinical data. DESIGN: Retrospective cohort study. SETTING: 30 acute care hospitals. PATIENTS: 46,769 patients hospitalized with acute myocardial infarction, cerebrovascular accident, congestive heart failure, or pneumonia. MEASUREMENTS: Each patient's probability of dying was estimated by using administrative data only (unrestricted administrative models), administrative data restricted to secondary diagnoses that are unlikely to be hospital-acquired complications (restricted administrative models), restricted administrative data plus laboratory data (laboratory models), and restricted administrative data plus laboratory and abstracted clinical data (clinical models). RESULTS: The unrestricted administrative models predicted death better than the restricted administrative models (average areas under the receiver-operating characteristic [ROC] curves, 0.87 and 0.75, respectively) and as well as the laboratory models and the clinical models (average areas under the ROC curves, 0.86 and 0.87, respectively). The good mortality predictions obtained by using the unrestricted administrative models result from inclusion of hospital-acquired complications that commonly precede death. The laboratory models ranked 93% of patients and 95% of hospitals in a manner similar to the clinical models; in comparison, rankings provided by the laboratory models were similar to those provided for 75% of patients and 69% of hospitals by the unrestricted administrative models and for 72% of patients and 77% of hospitals by the restricted administrative models. CONCLUSIONS: Adding laboratory data (often available electronically) to restricted administrative data sets can provide accurate predictions of inpatient death from acute myocardial infarction, cerebrovascular accident, congestive heart failure, or pneumonia. This alternative avoids the cost of data abstraction and the serious errors associated with using administrative data alone.
Adult↗
Surveillance for silicosis, 1993--Illinois, Michigan, New Jersey, North Carolina, Ohio, Texas, and Wisconsin.
PROBLEM/CONDITION: Silicosis is an occupational respiratory disease caused by the inhalation of respirable dust containing crystalline silica. Public health surveillance programs to identify workers at risk for silicosis and target workplace-specific and other prevention efforts are currently being field-tested in seven U.S. states. REPORTING PERIOD COVERED: Confirmed cases ascertained by state health departments during the period January 1, 1993, through December 31, 1993; the cases and associated workplaces were followed through December 1994. DESCRIPTION OF SYSTEMS: As part of the Sentinel Event Notification System for Occupational Risks (SENSOR) program initiated by CDC's National Institute for Occupational Safety and Health (NIOSH), development of state-based surveillance and intervention programs for silicosis was initiated in 1987 in Michigan, New Jersey, Ohio, and Wisconsin and in 1992 in Illinois, North Carolina, and Texas. RESULTS: From January 1, 1993, through December 2, 1994, the SENSOR silicosis programs in Illinois, Michigan, New Jersey, North Carolina, Ohio, Texas, and Wisconsin confirmed 256 cases of silicosis that were initially ascertained in 1993. Overall, 185 (72%) were initially identified through review of hospital discharge data or through hospital reports of silicosis diagnoses; 188 (73%) were associated with silica exposure in manufacturing industries (e.g., foundries; stone, clay, glass, and concrete manufacturers; and industrial and commercial machinery manufacture). Overall, 42 (16%) cases were associated with silica exposure from sandblasting operations. Among the 193 confirmed cases for which information was available about duration of employment in jobs with potential exposure to silica, 37 (19%) were employed < or = 10 years in such jobs and 156 (81%) were employed > or = 11 years. A total of 192 primary workplaces associated with potentially hazardous silica exposures were identified for the 256 confirmed silicosis cases. Of these, nine (5%) workplaces were inspected by state health department (SHD) industrial hygienists, 19 (10%) were referred to the Occupational Safety and Health Administration (OSHA) for follow-up, and seven (4%) were routinely monitored by the Mine Safety and Health Administration. Of the 157 (82%) remaining workplaces, follow-up activities determined that 82 were no longer in operation, eight were no longer using silica, 18 were assigned a lower priority for follow-up, six were associated with building trades and could not be inspected because of the transient nature of work in the construction industry, and 43 workplaces were not inspected for other reasons. Fourteen (7%) of the 192 workplaces were inspected. At 10 of the 14 workplaces, airborne levels of crystalline silica were measured; in nine, silica levels exceeded the NIOSH-recommended exposure level of 0.05 mg/m, and in six, airborne silica levels also exceeded federal permissible exposure limits. ACTIONS TAKEN: Employee-specific and other preventive interventions have been initiated in response to reported cases. In addition, special silicosis prevention projects have been initiated in Michigan, New Jersey, North Carolina, Ohio, Texas, and Wisconsin. To facilitate the implementation of silicosis surveillance by other states, efforts are ongoing to identify and standardize core data needed by surveillance programs to describe cases and the workplaces where exposure occurred. These core variables will be incorporated into a user-friendly software system that states can use for data collection and reporting.
Female↗
PCR typing of Enterococcus faecium. An evaluation.
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Bacterial Typing Techniques↗
Age, gender and the effectiveness of high-threat letters: an analysis of Oregon's driver improvement advisory letters.
The Oregon Driver Improvement Program monitors driver records and takes corrective action at each of four levels. The advisory letter is the first level. An automated quality control system randomly withholds actions from five percent of drivers, producing a control group. Records of 27,026 advisory letter recipients and 1453 control subjects were analyzed. Of the 27,026 letter recipients, 13,623 received a randomly assigned, experimental soft-sell letter and the rest a standard letter. Records were monitored for 24 subsequent months. Overall, those receiving either advisory letter had fewer traffic accidents than the control group, and the standard letter is significantly more effective than the soft-sell letter. However there are several apparent differences in effectiveness by age and by gender. The standard letter is clearly more effective for younger drivers but the soft-sell letter appears to be most effective for drivers over age 45. Considering gender, both letters reduce collisions but the standard letter is more effective for men. For women, the standard letter is more effective than the soft-sell letter, but not more effective than no letter. In fact, accident-free survival for women receiving no letter was nominally but not significantly higher than for women receiving either letter. There are no significant differences in moving violations. However, with regard to major traffic violations, those receiving letters had significantly higher violation free survival, although there were also notable differences in effectiveness, by age.
Accidents, Traffic↗