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Results for “Randomized Response Technic”

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PubMed1990

Colorectal metastases to the liver: present status of management.

The management of patients with hepatic metastases from colorectal carcinoma is controversial. While a "no treatment" attitude still persists, other patients undergo systemic chemotherapy with very limited results. Other possible options are hepatic resection and locoregional treatments. One hundred twenty-three patients with hepatic metastases from colorectal cancer were treated at the authors' institution over a period of 15 years. Thirty-nine patients underwent hepatic resection while 84 underwent various forms of locoregional treatment. Several patients in the latter group were registered in one national (RNSI) Phase 2 study and one international (EORTC) Phase 3 trial. The authors' experience confirms the opinion that hepatic resection can be performed with the aim of curing in patients with isolated metastases. A five-year survival rate can be achieved in 25 to 30 percent of the resectable patients. Patients with unresectable extrahepatic disease or multiple bilateral metastases are usually excluded from resection. In other cases, hepatic resection should be carried out when technically possible. The value of adjuvant chemotherapy to the remaining liver has to be tested in prospective randomized trials. Patients with diffuse metastases can benefit from locoregional infusion of chemotherapeutic agents. Symptoms improve in most patients; objective responses vary from 53 to 83 percent of the cases, which is a higher rate than that reported for systemic chemotherapy. Survival may be prolonged in respect to untreated patients but this has not been demonstrated yet by prospective randomized studies. Current trends are continuous infusion of chemotherapeutic agents and experimentation of new drugs or drug combinations. Future improvements may be achieved by adding hepatic arterial ischemia, hyperthermia, or radiation therapy. As these kinds of treatments are still experimental, they should be applied to the patients only in the context of prospective clinical trials.

Adult↗

PubMed2000

Evaluating the equivalence of health care ratings by whites and Hispanics.

PURPOSE: This study was designed to assess the equivalence of a health care ratings scale administered to non-Hispanic white and Hispanic survey respondents. METHODS: We sent 18,840 questionnaires to a random sample of patients receiving medical care from a physician group association concentrated in the western United States; 7,093 were returned (59% adjusted response rate). Approximately 90% of survey respondents self-identified as white/Caucasian (n = 5,508) or Hispanic/Latino (n = 713). Interpersonal and technical aspects of medical care were assessed with 9 items, all administered with a 7-point response format: the best, excellent, very good, good, fair, poor, and very poor, with a "not applicable" option. Item response theory procedures were used to test for differential item functioning between white and Hispanic respondents. RESULTS: Hispanics were found to be significantly more dissatisfied with care than whites (effect size=0.27; P <0.05). Of the 9 test items, 2 had statistically significant differential item functioning (P <0.05): reassurance and support offered by your doctors and staff and quality of examinations received. However, summative scale scores and test characteristic curves for whites and Hispanics were similar whether or not these items were included in the scale. CONCLUSIONS: Despite some differences in item functioning, valid satisfaction-with-care comparisons between whites and Hispanics are possible. Thus, disparities in satisfaction ratings between whites and Hispanics should not be ascribed to measurement bias but should be viewed as arising from actual differences in experiences with care.

Adult↗

PubMed1989

Effects of a developmental physical therapy program on oxygen saturation and heart rate in preterm infants.

To evaluate the physiologic responses of 14 preterm infants to physical therapy, pulse oximetry was used to measure the percentage of arterial oxygen saturation (SaO2) and heart rate during baseline, intervention, and recovery phases. Treatment consisted of six one-minute activities that were equally divided between the side-lying and supported-sitting positions. The order of position and activities was randomly varied. A one-way analysis of variance for repeated measures revealed no significant changes in mean SaO2 as a function of the position or duration of intervention. Mean heart rate increased significantly as a result of intervention (p less than .0001), but there was no significant difference between the baseline and recovery phases. Further analysis indicated that the change in heart rate was not a function of duration of intervention. The results indicate that the preterm infants were able to tolerate the intervention without desaturation. The return of heart rate to baseline values during the recovery phase suggested a normal physiologic response to exercise. Despite some technical limitations, pulse oximetry is recommended to monitor preterm infants during physical therapy.

Heart Rate↗

PubMed2000

Adaptive beamforming at very low frequencies in spatially coherent, cluttered noise environments with low signal-to-noise ratio and finite-averaging times

Realistic simulations with spatially coherent noise have been run in order to compare the performance of adaptive beamforming (ABF), inverse beamforming (IBF), and conventional beamforming (CBF) for the case of finite-averaging times, where the actual spatial coherence of the acoustic field, or covariance matrix, is not known a priori, but must be estimated. These estimation errors cause large errors in the ABF estimate of the directionality of the acoustic field, partly because ABF is a highly nonlinear algorithm. In addition, it is shown that ABF is fundamentally limited in its suppression capability at very low frequency (VLF), based on the sidelobe level of the conventional beampattern in the direction of the noise interferer [G. L. Mohnkern, "Effects of Errors and Limitations on Interference Suppression," NOSC Technical Document 1478, Naval Ocean Systems Center (1989)]. The simulations include a low-level plane wave signal of interest, a stronger noise plane wave interferer, and spatially random background noise. Both IBF and ABF performed significantly better than CBF, and IBF's performance was slightly better than ABF's performance. The performances of IBF and the ABF algorithm, the minimum variance distortionless response (MVDR) [A. H. Nuttall and D. W. Hyde, "Unified Approach to Optimum and Suboptimum Processing for Arrays," USL Report Number 992, Naval Underwater Systems Center, New London, CT (22 April 1969)] were recently compared independently [J. S. D. Solomon, A. J. Knight, and M. V. Greening, "Sonar Array Signal Processing for Sparse Linear Arrays," Defense Science and Technology Organization (DSTO) Technical Report (June 1999)] using measured data, with the result that IBF outperformed MVDR. This result is significant because MVDR requires orders of magnitude more processing power than IBF or CBF.

Journal Article↗

PubMed2001

Prediction of node-negative breast cancer outcome by histologic grading and S-phase analysis by flow cytometry: an Eastern Cooperative Oncology Group Study (2192).

Histologic evaluation and reporting of invasive breast cancer has effectively used Nottingham combined histologic grade (NCHG). This approach to predict outcome in invasive breast cancer has not been tested in multicenter cooperative trials. Histologic slides from selected breast cancer cases entered on node-negative Eastern Cooperative Oncology Group trials were assigned grades. Two pathologists evaluated cases for NCHG defined from differentiation, mitotic index, and nuclear grade. The study population consisted of separate samples from low- and high-risk strata, where low risk was estrogen receptor positive with a tumor size of less than 3 cm and high risk was estrogen receptor negative or tumor size greater than or equal to 3 cm. The rate of agreement was generally good, with 80% of cases classified the same for mitotic count and 76% of the cases classified the same for combined grade. There were no cases disagreeing from the lowest to the highest of the three categories. The median follow-up is 11.6 years, but for analysis of survival, this was truncated at 5 years. Mitotic index and combined grade as assessed by both pathologists showed significant associations with survival. High combined histologic grade was predictive for response to cyclophosphamide/methotrexate/5-fluorouracil (CMF) with survival differences at 5 years of 30% in the treated high-grade patients over the untreated patients. Overall, it is clear that pathologists can have close agreement in assignment of combined histologic grades, with highly significant prediction in univariate and borderline significance in multivariate analysis in prognostication of time to recurrence as well as survival. Thus, stratification used in these trials was highly prognostic as hoped, leaving a role for histologic grading in these relatively large tumors, more powerful than S-phase analysis in this series. In the subgroups of high-risk patients randomized between CMF and observation, there was a suggestion that the high-combined-grade group was predictive of treatment efficacy. We conclude that a combined histologic grade with defined criteria may be reliably assigned by practiced pathologists using readily available criteria, and that the measure may be of use in prognostication and prediction of therapeutic responsiveness when done in a technically ideal fashion.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2004

Role of FDG-PET in the diagnosis and management of lung cancer.

Positron emission tomography (PET) using [(18)F]-2-deoxy-2-fluoro-d-glucose (FDG) has emerged as a valuable diagnostic modality in patients with non-small cell lung cancer (NSCLC). Data in the literature show that the addition of FDG-PET definitely alters clinical management in patients with potentially resectable NSCLC by adequately staging the mediastinum and detecting previously unknown distant metastases. Thus, the number of noncurative thoracotomies and unnecessary mediastinoscopies is reduced. Furthermore, there is increasing evidence that FDG-PET will change radiation treatment planning by defining a biologic treatment volume, incorporating unsuspected additional locoregional disease, and avoiding overtreatment by identifying computerized tomography abnormalities as benign. For follow-up during systemic therapy, early FDG-PET appears to be predictive for the response to therapy. However, before FDG-PET-induced changes in patient management can be incorporated into clinical practice both for radiation treatment planning and chemotherapy, technical issues must be resolved, validation studies should be performed and, most importantly, randomized trials are necessary to evaluate the effect of FDG-PET on patient outcome parameters.

Carcinoma, Non-Small-Cell Lung↗

PubMedDate not supplied

[Unintentional gunshot during police intervention].

33 cases of unintentional handgun use by police officers during operation since 1983 in Northern Germany have been evaluated. These cases have been selected from our own investigations and from prosecutors' and police departments' files and records. It was intended to find out criteria for forensic expertise. The unintended use of a handgun was always influenced in a decisive and causal manner by the behaviour of the delinquents (resistance, assault, escape). The confrontation of the police officer with the violence of aggressive offenders was of immediate importance for triggering the shot in various kinds of police operation. Sensorically caused, reflex muscle contractions as a consequence of a great effort, a loss of balance or fright when simultaneously protecting oneself with weapon in hand can be made responsible for the unvoluntary shot. In 10 cases (30%) persons were injured, 2 times lethally. As a whole, the consequences were of random nature, they could be explained by the series of actions in each case. The type and technical state of the weapons in use have not influenced the unintentional use. A behaviour of the police officers offending against the legally required care was stated in two of the investigated cases. Considering our investigations and the many policemen killed in duty we state that securing oneself in time with a weapon at the ready in critical phases of operations cannot be successfully replaced by any other method of self defense.

Accidents↗

PubMed2000

[Physiopathologic knowledge and clinical practice. A case of high dose chemotherapy in breast cancer].

Breast cancer is the major cause of death from cancer in women. This causes a great activity in oncological investigation in this field. During the 80s preclinical data and retrospective analysis suggested a dose-response relationship both for adjuvant treatment and metastatic disease. Technical advances in collection and administration of peripheral stem cells and the development of hematological growth factors permitted the use, in this and other diseases, of high dose chemotherapy, usually with hematological support. All these things produced the widespread use of this technique with the only scientific support of phase II studies usually performed in only one center and with highly selected patients. Most of the randomized trials performed afterwards did not show a clinically important relationship between dose and response. This makes us think that this technique should not be used as routinary treatment. From a methodological point of view it would be interesting to investigate the evolution of this modality of treatment and why, its use has been so generalized without good quality scientifically support. This could be due to predetermined ideas in relation to what is the evolution and treatment of this disease, the neglect in the use of scientific methodology and the pressures coming from different directions trying to adopt new (and presumably better, treatments). It is evident that if most of the patients who have received high dose treatment for breast cancer had participated in randomized trials the question would probably have already been answered.

Adult↗

PubMed2005

Computational modeling of the immune response to tumor antigens.

Vaccination protocols designed to elicit anti-cancer immune responses have, many times, failed in producing tumor eradication and in prolonging patient survival. Usually in cancer vaccination, epitopes from one organism are included in the genome or linked with some protein of another in the hope that the immunogenic properties of the latter will boost an immune response to the former. However, recent results have demonstrated that injections of two different vectors encoding the same recombinant antigen generate high levels of specific immunity. Systematic comparison of the efficacy of different vaccination protocols has been hampered by technical limitations, and clear evidence that the use of multiple vectors has advantages over single carrier injections is lacking. We used a computational model to investigate the dynamics of the immune response to different anti-cancer vaccines based on randomly generated antigen/carrier compounds. The computer model was adapted for simulations to this new area in immunology research and carefully validated to the purpose. As a matter of fact, it reproduces a relevant number of experimental observations. The model shows that when priming and boosting with the same construct, competition rather than cooperation develops amongst T cell clones of different specificities. Moreover, from the simulations, it appears that the sequential use of multiple carriers may generate more robust anti-tumor immune responses and may lead to effective tumor eradication in a higher percentage of cases. Our results provide a rational background for the design of novel strategies for the achievement of immune control of cancer.

Animals↗

PubMed1999

Role of relationship context in influencing college students' responsiveness to HIV prevention videos.

This research examined the effectiveness of different HIV prevention videos for students as a function of whether they were in a dating relationship. Two hundred two college students completed pretest measures and were randomly assigned to watch one of three 42-min videos (communication skills, technical skills, combined skills). Posttest and 3-month follow-up data indicated that receiving the technical skills video was associated with greater self-efficacy for condom use across several different dimensions. However, students who received the combined skills video and were not currently in a dating relationship had the greatest proportion of protected acts of intercourse. These findings suggest that video-based interventions can be an effective way of decreasing risky sexual behavior, and that HIV prevention messages that focus on both technical and communication skills are the most successful in leading to behavioral change.

Acquired Immunodeficiency Syndrome↗

PubMed2006

Biventricular vs. left univentricular pacing in heart failure: rationale, design, and endpoints of the B-LEFT HF study.

AIMS: Cardiac resynchronization therapy (CRT) confers sustained therapeutic benefits to patients suffering from congestive heart failure (CHF) due to systolic dysfunction associated with ventricular dyssynchrony. Biventricular (BiV) pacing has, thus far, been the preferred method, as it corrects both electrical and mechanical dyssynchrony. Left ventricular (LV) only pacing, which has conferred similar benefits in pilot studies, may be an alternative treatment method. 'Biventricular vs. left univentricular pacing with ICD back-up in heart failure patients' (B-LEFT HF) is an international, prospective, randomized, parallel-design, double-blind, clinical trial to examine whether LV only pacing is as safe and effective as BiV pacing in patients suffering from CHF. METHODS AND RESULTS: The trial will randomly assign 172 patients to either LV only or BiV pacing. The study has prospectively defined efficacy endpoints to be evaluated at 6 months, which are (i) changes in functional capacity and degree of reverse remodelling (primary) and (ii) changes in the heart failure clinical composite response (secondary). CONCLUSION: Because LV only pacing in CRT is likely to be technically less challenging and costly than BiV, a specifically designed study is needed to compare the safety and effectiveness of the two configurations. B-LEFT HF has been designed to settle this critical issue.

Adult↗

PubMed2004

Percutaneous cholecystostomy versus gallbladder aspiration for acute cholecystitis: a prospective randomized controlled trial.

OBJECTIVE: This study was performed to determine and compare the effectiveness and incidence of complications of percutaneous cholecystostomy and gallbladder aspiration in cases of severe acute cholecystitis. SUBJECTS AND METHODS. Fifty-eight patients with severe acute cholecystitis who did not improve after antibiotic treatment were included in this study. The patients were randomized into either the percutaneous cholecystostomy group (n = 30) or the gallbladder aspiration group (n = 28). Under sonographic guidance, percutaneous cholecystostomy was performed in the usual manner using a 6.5- or 7-French catheter. Gallbladder aspiration was carried out with a 21-gauge needle under sonographic guidance. The technical success, clinical response, and complications in each group were evaluated. RESULTS: Percutaneous cholecystostomy and gallbladder aspiration were technically successful in 30 patients (100%) and 23 patients (82%), respectively (not statistically significant). In five patients (18%) of the gallbladder aspiration group, aspiration was unsuccessful because of replacement of bile with dense biliary sludge or pus. Good clinical response was obtained in 27 patients (90%) of the percutaneous cholecystostomy group and in 14 patients (61%) of the gallbladder aspiration group (p < 0.05). As for complications, dislodgment of the catheter occurred in one patient of the percutaneous cholecystostomy group and minor bleeding in one patient after gallbladder aspiration. No major complications or procedure-related deaths occurred in either group. CONCLUSION: For severe acute cholecystitis, percutaneous cholecystostomy was superior to gallbladder aspiration in terms of clinical effectiveness and had the same complication rate as gallbladder aspiration.

Acute Disease↗

PubMed1999

Improving informed consent in clinical trials: a duty to experiment.

Practitioners of clinical trials have a responsibility to ensure that patients' participation in research be informed and voluntary. This responsibility implies that we should strive continuously to improve the effectiveness of methods for informing prospective research volunteers about experimental studies, thereby enhancing the protection of their interests. We should test innovations in informed consent in realistic contexts (i.e., in clinical trials) and with randomization, when it is appropriate, at the first opportunity. In this study, we develop a preliminary proposal to improve the quality of informed consent, based on experimentation with informed consent in ongoing clinical trials. We discuss the conceptual, ethical, organizational, and technical bases for such an effort.

Choice Behavior↗

PubMed2003

Estimating efficiency a priori: a comparison of blocked and randomized designs.

This technical note deals with a priori estimation of efficiency of functional magnetic resonance imaging (fMRI) designs. The efficiency of an estimator is a measure of how reliable it is and depends on error variance (the variance not modeled by explanatory variables in the design matrix) and the design variance (a function of the explanatory variables and the contrast tested). Changes in the experimental design can induce changes in the variance of estimated responses. This translates into changes in the standard error of the response estimate or equivalently into changes in efficiency. One consequence is that statistics, testing for the same activation in different contexts (i.e., experimental designs), can change substantially even if the activation and error variance are exactly the same. We demonstrate this effect using an event-related fMRI study of single word reading during blocked and randomized trial presentations. Furthermore, we show that the error variance can change with the experimental design. This highlights a problem with a priori comparison of efficiency for two or more experimental designs, which usually assumes identical error variance.

Adult↗

PubMed2003

Effects of cis-nonachlor, trans-nonachlor and chlordane on the immune system of Sprague-Dawley rats following a 28-day oral (gavage) treatment.

The immunotoxicity of cis- and trans-nonachlor and chlordane were investigated in adult male and female Sprague-Dawley rats following a 28-day oral (gavage) treatment. Rats were randomly assigned to six experimental groups: cis-nonachlor, females; trans-nonachlor, females; technical chlordane females; cis-nonachlor, males; trans-nonachlor, males; technical chlordane, males. The immunologic endpoints included: quantification of the total serum immunoglobulin (Ig) levels and subclasses and flow cytometric analysis of peripheral blood leukocytes and T-lymphocyte subsets, evaluation of the lymphoproliferative activity of splenocytes in response to concanavalin A (Con A) and Salmonella typhimurium (STM) mitogens, and natural killer (NK) cell activity of splenocytes. Satellite experiments to examine the delayed-type hypersensitivity (DTH) response to oxazolone, and resistance to Listeria monocytogenes were set up for female rats treated with cis- or trans-nonachlor. Statistically significant (P<0.05) effects included: increased serum immunoglobulin M (IgM) levels in the chlordane-treated females at the 25 mg/kg dose (pairwise comparison); increased serum IgG(1) and IgG(2c) in the cis-nonachlor-treated males at the 2.5 and 25 mg/kg doses and increased serum IgG(2a) levels at all doses; increased serum IgG(2b) at the 25 mg/kg dose and decreased (dose-related) serum IgM levels in the cis-nonachlor-treated male rats; increased (linear trend) IgG(1) and IgG(2a) in the cis-nonachlor-treated females with effects on IgG(2a) significant at the 25 mg/kg dose compared with control; increased serum IgG(2a) in the trans-nonachlor-treated male and female rats at the 2.5 mg/kg dose; increased absolute numbers (linear trend) of peripheral white blood cells, B lymphocytes, natural killer (NK) cells, T-suppressor/cytotoxic lymphocytes, and the double positive (T-helper/inducer, T-suppressor/cytotoxic) cells in the trans-nonachlor-treated females; increased (non-linear trend) lymphoproliferative activity in the Con A-stimulated splenocytes and decreased (linear trend) activity in the S. typhimurium mitogen-stimulated splenocytes of the cis-nonachlor-treated females; reduced resistance to L. monocytogenes in the cis-nonachlor (day 3, P=0.034)- and trans-nonachlor (day 2, P=0.0001)-treated females, and reduced (linear trend) NK cell activity in the cis-nonachlor-treated males. The present data indicated that the chlordane compounds tested in this study had significant effects on a number of immunologic endpoints. In comparison to technical chlordane, cis- and trans-nonachlors were more immunotoxic. Therefore, an evaluation of the risk these chlorinated compounds may pose to human health should consider the potential effects different chlordane compounds may have on the immune system.

Administration, Oral↗

PubMed1976

Studies on the regulation of the neutrophil chemotactic response using a rapid and reliable method for measuring random migration and chemotaxis of neutrophil granulocytes.

An economic and sensitive test system for measuring random and directional migration of human neutrophils is described. The technique, based on a modified Boyden chamber equipped with a two-filter system, permits a substantial reduction of both incubation time and sample volume. The influence of various technical factors such as the neutrophil concentration in the cell suspension, the incubation time of the chambers, the test concentration of activated plasma or serum, the presence of heparin, and the procedure for separating neutrophils from human peripheral blood, was investigated. Standardized procedures for measuring and reporting neutrophil chemotaxis are proposed. The method has been used to study the significance of factors regulating neutrophil migration such as cytotaxin inactivators and neutrophil immobilizing factors (NIF). Activity of cytotaxin inactivators as assessed in undiluted serum or plasma at pH 7.4, 6.0 or 4.0 was very low. In contrast, potent neutrophil immobilizing activity was found in human serum or diluted plasma. These factors which inhibit migration were accordingly termed neutrophil immobilizing factors of plasma (NIF-P) and neutrophil immobilizing factor of serum (NIF-S). These factors are heat-stable, non-dialysable and of high molecular weight.

Antigen-Antibody Complex↗

PubMed1992

Need for and influence of feedback from the Finnish birth register to data providers.

Data for the Finnish medical birth register (established 1987) are collected by local hospital personnel as a part of their routine work. The purpose of this study was to study the need of personnel for feedback and the impact of feedback on later data quality. Furthermore, we studied whether such feedback tends to modify extreme cesarean section rates. Data on attitudes towards the birth register and on the need for feedback of data providers were collected through interviews and observations. In March 1988, an information package describing births, birth procedures and infant outcomes in each hospital compared with other hospitals was sent to a random stratified sample of 26 hospitals out of a total of 53. Opinions of the package were obtained by questionnaire from 104 physicians and nurses (82% response rate). Most hospital personnel, especially physicians, had negative attitudes towards the birth register. Comparison of the hospitals which had received feedback with other hospitals in terms of quality of data furnished in 1987 and 1988 suggested that feedback may improve the technical quality of data. There was no evidence, however, that feedback caused hospitals to change their practices in regard to cesarean sections.

Attitude of Health Personnel↗

PubMed2003

Multicenter randomized trial of the spiral Z-stent compared with the Wallstent for malignant biliary obstruction.

BACKGROUND: The industry standard since 1990 for self-expanding biliary metallic stents has been the Wallstent. In 1998 the Spiral Z-stent was released. This randomized trial compared the Z-stent with the Wallstent in the treatment of malignant biliary obstruction. METHODS: Patients with unresectable malignant biliary obstruction distal to the bile duct bifurcation were randomized to receive a 10-mm diameter Wallstent or a 10-mm diameter Z-stent. RESULTS: A total of 145 patients were randomized; 13 were excluded. Sixty-four patients who received a Z-stent and 68 who had a Wallstent are included in the analysis. Tumors responsible for bile duct obstruction were pancreatic cancer (108), cholangiocarcinoma (15), metastatic cancer (6), and papillary cancer (3). Metallic stents were successfully placed in all patients. Seven technical problems were encountered during placement of the Z-stent and 5 with the Wallstent. There were 21 occlusions requiring reintervention (8 Z-stent, 13 Wallstent; p = 0.30). Median time to reintervention was the following: Z-stent, 162 days; Wallstent, 150 days (p = 0.22). A total of 104 patients died of progressive disease or other cause; 7 patients remain alive with patent stents. The overall calculated median patency rates were: Z-stent, 152 days; Wallstent, 154 days (p = 0.90). CONCLUSIONS: The Spiral Z-stent is comparable with the Wallstent in terms of placement, occlusion rates, and overall patency. Occasional early occlusion of both stents suggests tumor characteristics instead of the size of the mesh openings in the stents as important factors.

Aged↗