The Keller Plan in Science Teaching: An individually paced, student-tutored, and mastery-oriented instructional method is evaluated.

A review of evaluative research on the Keller plan establishes the following points: 1) The Keller plan is an attractive teaching method to most students. In every published report, students rate the Keller plan much more favorably than teaching by lecture. 2) Self-pacing and interaction with tutors seem to be the features of the Keller courses most favored by students. 3) Several investigators report higher-than-average withdrawal rates for their Keller sections. The conditions that influence withdrawal and procrastination in Keller courses have been studied, and it seems possible to control procrastination and withdrawal through course design. 4) Content learning (as measured by final examinations) is adequate in Keller courses. In the published studies, final examination performance in Keller sections always equals, and usually exceeds, performance in lecture sessions. 5) Students almost invariably report that they learn more in PSI than in lecture courses, and also nearly always report putting more time and effort into the Keller courses.

Presence of t(14;18) positive cells in blood and bone marrow does not predict outcome in follicular lymphoma.

Follicular Lymphoma International Prognostic Index-FLIPI is an established clinical predictor for outcome in follicular lymphoma. The role of molecular abnormalities in blood and bone marrow of follicular lymphoma patients including t(14;18) is less clear. Seventy-five patients from a single institution diagnosed with follicular lymphoma between1999 and 2005 were included into the study. Diagnosis was based on lymph node biopsy in 62 cases (83%). Thirty-nine patients (52%) had G1 histological grade and 47 (63%) had entirely follicular growth pattern, as well as 9 patients (12%) had systemic symptoms and 33 (44%) were assigned to a good risk according to FLIPI. Median age of patients was 53 years. During a median observation time of 3 years 63 patients (84%) required initiating anti-lymphoma treatment. Seventy-five samples of peripheral blood and 65 samples of bone marrow were collected at the diagnosis. Bcl2 rearrangements including major breakpoint region and minor breakpoint cluster region were investigated using nested polymerase chain reaction technique. The primary end points of the study were time to first line lymphoma treatment and progression-free survival. Cells carrying t(14;18) were found in 31 cases (41%) including 29 samples of peripheral blood and 26 samples of bone marrow. Detection of t(14;18) in blood and bone marrow at diagnosis had no influence on clinical outcome. Age, follicular growth pattern systemic symptoms, and FLIPI score above 1 were predictive for initiation of the first lymphoma therapy. Follicular growth pattern, initial nodal involvement, serum LDH level, and FLIPI score above 1 were predictive for longer progression-free survival.

Molecular and biochemical testing in stage III melanoma: multimarker reverse transcriptase-polymerase chain reaction assay of lymph fluid after lymph node dissection and preoperative serum lactate dehydrogenase level.

BACKGROUND: There is a need for biomarkers to identify patients at risk for disease progression after resection of melanoma regional lymph node metastasis. OBJECTIVES: This study assessed the prognostic value of multimarker reverse transcriptase-polymerase chain reaction (RT-PCR) assay in lymphatic drainage (LY) after lymph node dissection (LND) and of preoperative serum lactate dehydrogenase (LDH) levels in American Joint Committee on Cancer (AJCC) stage III melanoma patients. METHODS: We collected 24-h LY from 255 stage III melanoma patients after radical LND [114, completion LND after positive sentinel node biopsy (CLND); 141, therapeutic LND for clinically/cytologically detected regional nodal metastases (TLND)]. For detection of melanoma cells, RT-PCR assays with primers specific for tyrosinase, MART1 (MelanA) and uMAGE mRNA were conducted. The LY sample was deemed positive if at least one marker was detected. In 244 patients, the preoperative serum LDH level was available. Median follow-up time was 25 months (range 5-60). RESULTS: The LY multimarker RT-PCR assay results were positive in 82 of 255 patients (32%). A significantly higher rate of melanoma recurrence was observed in patients with positive LY multimarker RT-PCR results (P = 0.01). Significant relationships were observed between positive LY multimarker RT-PCR results and shorter 3-year overall survival (OS) and disease-free survival (DFS), both in univariate and multivariate analyses (P = 0.007). Preoperative serum LDH level was increased in 79 of 244 patients (32%) [40.5% in TLND group and 23.0% in CLND group (P = 0.003)]. There were significant differences in OS between patients with normal and high preoperative LDH levels (P = 0.007), and these differences were seen mainly in patients in the TLND group. CONCLUSIONS: The multimarker RT-PCR assay detected melanoma cells in approximately 32% of LY after LND, which correlated significantly with early melanoma recurrence and shorter survival. Increased pre-LND serum LDH level had an additional negative impact on OS of melanoma patients with palpable nodal metastases after TLND.

Postnatal expression in hyaline cartilage of constitutively active human collagenase-3 (MMP-13) induces osteoarthritis in mice.

It has been suggested that increased collagenase-3 (MMP-13) activity plays a pivotal role in the pathogenesis of osteoarthritis (OA). We have used tetracycline-regulated transcription in conjunction with a cartilage-specific promoter to target a constitutively active human MMP-13 to the hyaline cartilages and joints of transgenic mice. Postnatal expression of this transgene resulted in pathological changes in articular cartilage of the mouse joints similar to those observed in human OA. These included characteristic erosion of the articular cartilage associated with loss of proteoglycan and excessive cleavage of type II collagen by collagenase, as well as synovial hyperplasia. These results demonstrate that excessive MMP-13 activity can result in articular cartilage degradation and joint pathology of the kind observed in OA, suggesting that excessive activity of this proteinase can lead to this disease.

The presence of Microlobius foetidus cause changes in the antioxidant defense of Urochloa decumbens?

Urochloa decumbens (Stapf) R. D. Webster (Poaceae) is an exotic species with has spread rapidly through the Cerrado area of Pantanal, Mato Grosso do Sul, Brazil. It has covered the soil aggressively turning it into cultivated pastures. Thus, it has become a challenge to protect native areas due its capacity of exclusion of native species. It has been observed that Microlobius foetidus (Jacq.) M.Sousa & G.Andrade species (Fabaceae) shows a dominant pattern over the development of U. decumbens. This work shows that M. foetidus interfere on the natural growth of U. decumbens within 10 m ratio. Between 15 and 20 m, it was observed an increase of Importance Value index (IVI) and Relative cover (RC) values. It was also observed a variation on the antioxidant defense system of U. decumbens within 10m ratio from M. foetidus. The enzymes superoxide dismutase, catalase and peroxidase present higher levels of activity then those found for glutathione reductase. This data indicates that M. foetidus may have an effect on U. decumbens, increase the activity of antioxidant enzymes. This effect probably happens as means to neutralize the toxic effects of the oxygen generated due to the presence of allelochemicals, which increases oxidative stress.

Respiratory illness in nonsmokers chronically exposed to tobacco smoke in the work place.

We evaluated CO levels as an index of cigarette smoke in the work place and analyzed diary entries on respiratory symptoms, eye irritation, chest colds and lost days from work due to respiratory illness in 40 passive smokers (nonsmokers chronically exposed to tobacco smoke in the work place) and 40 control subjects (nonsmokers not exposed to tobacco smoke in the work place) matched for age and gender. Passive smokers experienced greater CO levels during the workday. Also they reported significantly more cough, greater phlegm production, more shortness of breath, greater eye irritation, more chest colds and more days lost from work due to chest colds than control subjects. Nonsmoking workers and their employers are likely to incur significant financial loss because of missed workdays due to illnesses resulting from exposure to second-hand tobacco smoke.

Modified GFAP promoter auto-regulates tet-activator expression for increased transactivation and reduced tTA-associated toxicity.

Transactivator tTA is a necessary component of the tetracycline-regulated inducible gene system. While several transgenic animals have been described that express tTA in the central nervous system (CNS), their tTA levels are often limited, presumably due to toxic effects. We evaluated methods for auto-regulating tTA levels in astrocytes by modifying the transgenic promoter human GFAP (hGFAP). The hGFAP promoter carrying a single copy of the tet-operon in place of a native enhancer element (GFAPtetO1) drove expression of tTA at low levels during un-stimulated, basal condition. However the same promoter auto-induced expression of tTA to significant levels after tetracycline withdrawal. Glial cell-specificity of the promoter remained uncompromised during both basal and induced conditions. Transgenic rats were developed using the auto-inducible GFAPtetO1 promoter that expressed tTA mRNA to high levels in the brain. Expression was widespread within the CNS but enriched in astrocyte-rich regions including the cerebellum. Primary cerebellar astrocytes from GFAPtetO1 rats transfected with 07LacZ produced substantially greater inducibility of reporter gene compared to GFAP-tTA transgenic rats. Finally, GFAPtetO1 rats exhibited severe motor/gait deficit when bred to homozygosity. This phenotype was attributable to developmental abnormalities of the cerebellum and was completely abrogated by doxycycline administration. These results suggest that developmental toxicity resulting from tTA expression can be circumvented and tTA transgenics with high transactivation potential can be developed using the auto-activation strategy. Promoter modification presented here may be useful in developing highly inducible transgenic strategies without loss in tissue-specificity.

Health status, perceptions of risk, and prevention interest for health and nonhealth problems.

Healthy and acutely ill college students indicated their risk compared to their peers for 10 health and nonhealth problems. Participants as a whole showed clear evidence of optimistic bias. However, whereas healthy participants showed an equal tendency to be biased optimistically for health and nonhealth problems, ill participants felt significantly more vulnerable to future health relative to nonhealth problems. This was the case even though the future health problems were objectively unrelated to their current illnesses. Perceptions of the preventability of the health and nonhealth problems paralleled the comparative risk judgments. Finally, those who were ill expressed relatively little interest in receiving prevention information. Possible mechanisms and implications are discussed.

Health care involvement preferences and social-emotional recovery of male coronary-artery-bypass patients.

Examined how the preferences of male coronary-bypass patients either for information or behavioral involvement, respectively, predicted social and emotional recovery during the year following hospital release. Preferences for health care involvement were assessed prior to surgery. Outcome measures were collected at 1-, 4-, and 13-month follow-ups. Results indicated that patients who preoperatively had a high relative to a low desire for behavioral involvement experienced less ambulation dysfunction, fewer social interaction problems, and less emotional upset during the initial 4 months following hospital release. Also, patients who had a high relative to a low desire for information involvement experienced more social interaction and emotional problems during this period. At the final follow-up, these involvement-group differences for social interaction and emotional status had disappeared, and no differences in cardiac health were found. However, there were systematic differences in use of medical services. Results are discussed with reference to recent considerations about the potential benefits of more active patient involvement in the health care process. Possible mechanisms and clinical implications are also discussed.

Effects of preoperative roommate assignment on preoperative anxiety and recovery from coronary-bypass surgery.

This study examined the effect of preoperative roommate assignment on the preoperative anxiety and postoperative recovery of 27 male coronary-bypass patients. Patients were assigned preoperatively to a roommate who was either similar or dissimilar in his surgical status (preoperative vs. postoperative, respectively) and either similar or dissimilar in his type of operation (cardiac vs. noncardiac, respectively). The results indicated that the similarity/dissimilarity of a roommate's surgical status exerted important effects. Specifically, patients who before their operations had a postoperative roommate were less anxious preoperatively, were more ambulatory postoperatively, and were released more quickly from the hospital than patients who before their operations had a preoperative roommate. In contrast, the similarity/dissimilarity of the roommate's type of operation exerted no significant effects either separately or in interaction with the similarity of the roommate's surgical status. Theoretical implications, possible mechanisms, and practical implications for hospital policy are discussed.

Social support and recovery from surgery.

This study examined the relationship of naturally occurring social support from the spouse with the preoperative anxiety and postoperative recovery of 56 male coronary-bypass patients. Patients were divided into groups based on whether the overall quality of their marital relationship was perceived to be relatively good or bad at the time of surgery and on whether they received relatively high or low spouse support in the hospital (defined in terms of frequency of visits). A fifth group (n = 16), consisting of unmarried patients, enabled additional comparisons. The results indicated that, although groups were essentially equivalent in preoperative physical status, married patients who received higher hospital support took less pain medication and recovered more quickly than their low-support counterparts. In contrast, perceived quality of the marital relationship was a relatively insignificant factor. Speed of recovery for unmarried patients was generally slower than for married, high-support patients and faster than for married, low-support patients.

Stress and affiliation: hospital roommate effects on preoperative anxiety and social interaction.

Fifty-three preoperative men were studied who were assigned to a hospital roommate who varied in terms of the similarity of the roommate's health problem and surgical status. The similarity of a roommate's particular type of health problem to that of the patient exerted little detectable influence. However, patients assigned to a preoperative roommate were more anxious compared with those assigned a postoperative or nonsurgical roommate. Affiliation was also significantly greater with fellow preoperative roommates compared with postoperative roommates. The possibility that the obtained roommate effects on anxiety are mediated directly by affiliation is explored. Additional mechanisms and theoretical implications for basic research involving social comparison, stress, and affiliation relationships are discussed. Practical considerations for hospital policy also are considered.

The ability of DNA polymerase beta to synthesize DNA beyond the gap with displacement of the non-replicated strand.

Study was made of the ability of calf thymus DNA polymerases alpha and beta to replicate templates containing a small gap. It was found that during extensive replication of activated DNA or synthetic template.primers or specially prepared circular DNA containing a small gap, catalyzed by DNA polymerase alpha, the levels of incorporated nucleotides corresponded to the amounts of the single-stranded fraction of these templates. In contrast, in the reaction catalyzed by DNA polymerase beta the amounts of products were several times greater. The ability to synthesize the product in a great excess was a specific feature of the latter enzyme. An analysis of the gap-filling products by sucrose gradient centrifugation, gel electrophoresis and Southern hybridization showed that, contrary to DNA polymerase alpha, DNA polymerase beta exhibited the ability to synthesize DNA not only within but also beyond the gap. The "net" DNA product is complementary to the template strand. It is suggested that DNA was synthesized beyond the gap by displacement of the non-replicated strand.

Detection of circulating melanoma cells in peripheral blood by a two-marker RT-PCR assay.

The aim of this study was to develop a highly sensitive two-marker assay for the detection of circulating melanoma cells in patients' blood using a reverse transcriptase-polymerase chain reaction (RT-PCR). We analysed the usefulness of two different sets of markers: tyrosinase and MUC-18 (TYR/MUC-18), and tyrosinase and MART 1 (TYR/MART 1). Total cellular RNA was isolated from 337 blood samples from 80 melanoma patients at different stages of the disease. All patients had undergone primary surgery. Assay sensitivity and specificity were confirmed using three different melanoma cell lines and two different fibroblast lines. In addition, blood from 47 healthy subjects and 10 patients with non-melanoma cancer was used as a negative control. We found that two-marker analysis is more accurate than the single tyrosinase assay. The frequency of melanoma cell detection in patients' blood was about 10% higher when the TYR/MART 1 two-marker assay was used. Using this assay we did not find any statistical correlation between the molecular markers and the UICC stage of disease or the Breslow thickness or Clark level of the primary melanoma. The frequency of melanoma cell detection with the TYR/MUC-18 two-marker assay was even higher than the TYR/MART 1 assay, but unfortunately the MUC-18 transcript was also present in about 20% of healthy subjects. Therefore we do not recommend the use of MUC-18 as a standard value marker.

Stress, affiliation, and emotional contagion.

Female participants were exposed to high or low threat in the presence of another person believed to be facing either the same or a different situation. In Study 1, each dyad consisted of 2 actual participants, whereas in Study 2, each dyad consisted of 1 participant and 1 confederate, trained to convey either a calm or a nervous reaction to the situation. Affiliation patterns in both studies, defined in terms of the amount of time spent looking at the affiliate, were consistent with S. Schachter's (1959) "emotional similarity hypothesis"; threat increased affiliation and did so particularly with affiliates believed to be facing the same situation. The authors also found evidence of behavioral mimicry, in terms of facial expressions, and emotional contagion, in terms of self-reported anxiety. The behavioral mimicry and emotional contagion results are considered from both primitive emotional contagion and social comparison theory perspectives.

Social comparison and affiliation under threat: going beyond the affiliate-choice paradigm.

This study examined the emotional similarity hypothesis--a derivation from social comparison theory, which predicts that increasing fear should lead to greater affiliation with someone who is awaiting the same threat (and who therefore is of relatively similar emotional status) relative to someone who has already experienced the threat (and who therefore is of relatively dissimilar emotional status). The results failed to support the emotional similarity hypothesis and in so doing challenged the importance of emotional comparison as a determinant of verbal affiliation under threat. Cognitive clarity concerns instead seemed to account better for the observed effects on verbal affiliation. Supplementary analyses of nonverbal affiliation (facial glances) likewise ran counter to an emotional similarity prediction. Effects of affiliation on anxiety were also examined. Previous conclusions regarding the pattern and causes of affiliation under threat that have relied on the affiliate-choice paradigm are considered.

Social comparison and affiliation under threat: effects on recovery from major surgery.

This study extends stress and affiliation research by examining the effects of preoperative roommate assignments on the affiliation patterns, preoperative anxiety, and postoperative recovery of 84 male coronary-bypass patients. Patients were assigned preoperatively to a room alone or to a semiprivate room with a roommate who was either cardiac or noncardiac and either preoperative or postoperative. Patients assigned to a roommate who was postoperative rather than preoperative were less anxious, were more ambulatory postoperatively, and had shorter postoperative stays. Independently, patients were more ambulatory postoperatively and were discharged sooner if assigned to a roommate who was cardiac rather than noncardiac. No-roommate patients generally had the slowest recoveries. Affiliations reflecting cognitive clarity concerns, emotional comparison, and emotional support were examined. Theoretical implications for research involving social comparison and affiliation under threat are considered.

Preferences for health care involvement, perceived control and surgical recovery: a prospective study.

In a sample (N = 75) of coronary bypass patients, we examined the manner in which preoperative perceptions of personal control over recovery, desires for behavioral involvement in health care, and desires for information about health care predicted recovery in the hospital. Results indicated that preoperative control beliefs and desires for health care involvement predicted independently several important indices of recovery. Specifically, patients who prior to their surgery expressed a greater desire for information tended to experience less surgical pain and more negative psychological reactions. Greater preferences for behavioral involvement were associated with greater pain behavior, more ambulation, and shorter hospital stays. Finally, greater perceived personal control over recovery was associated with a shorter hospital stay.

Bioimpedance cardiac output measurements in patients with presumed congestive heart failure.

OBJECTIVE: To describe preliminary ED experience with thoracic electrical bioimpedance (TEB) for evaluation of patients with complaints suggestive of congestive heart failure (CHF). METHODS: A 6-month, prospective, observational study was performed using a convenience sample of patients with signs and symptoms consistent with CHF. Patients were excluded if they had received medication prior to arrival in the ED, if they were obese, and if they had unstable vital signs. They also were excluded if they were combative, refused to sign consent, or had invasive lines that did not allow for TEB lead placement. Patients also were excluded if the study could not be completed because the patient was taken from the department for a diagnostic test, or if there were no good follow-up records available 6-12 months after the patient's visit. The patient's physician was blinded to the output of the TEB monitor. Cardiac output (CO), stroke volume (SV), end-diastolic volume (EDV), thoracic fluid index (TFI), and acceleration index (ACI) were recorded at 5-minute intervals. Results were evaluated for the time intervals 0-5 minutes, 30-35 minutes, and 60-65 minutes. RESULTS: Seven patients were included in the study. The echocardiographic diagnoses were hypertrophic cardiomyopathy (2 cases), dilated cardiomyopathy (2 cases), ischemic cardiomyopathy (1 case), right ventricular hypertrophy (1 case), and pericardial effusion (1 case). Significant changes were seen in all cardiac parameters, with variance from individual to individual. CONCLUSIONS: Significant differences in TEB variables exist between patients who appear similar on initial examination in the ED. Changes noted on TEB may help to further elucidate physiologic differences. The clinical use of TEB-based hemodynamic measurements to guide presumed CHF patient management remains speculative.

The development and validation of three videos designed to psychologically prepare patients for coronary bypass surgery.

The purpose of this study was to demonstrate the validation of videotape interventions that were designed to prepare patients for coronary artery bypass graft (CABG) surgery. First, three videotapes were developed. Two of the tapes featured the experiences of three actual CABG patients and were constructed to present either an optimistic portrayal of the recovery period (mastery tape) or a portrayal designed to inoculate patients against potential problems (coping tape). The third videotape contained the more general nurse scenes and narration used in the other two tapes, but did not include the experiences of particular patients. We then conducted a study to establish the convergent and discriminant validity of the three tapes. That is, we sought to demonstrate both that the tapes did differ along the mastery-coping dimension, and that they did not differ in other respects (such as in the degree of information provided or the perceived credibility of the narrator). The validation study, conducted with 42 males who had previously undergone CABG, demonstrated that the intended equivalences and differences between the tapes were achieved. The importance of establishing the validity of health-related interventions is discussed.