Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Predictive testing”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources

In vitro predictive testing: the sulfonamide era.

Since initial reports of use of a human tumor cloning system to predict response or lack of response of a patient's tumor to chemotherapy, there have been approximately 2,166 clinical correlations attempted. Overall, the percent true positives has been 69% while the percent true negatives has been 92%. Despite the high reliability of this system to predict patient response or lack of response, the cloning assay has not been put into general clinical use. Reasons for this include the past inability to grow a majority of the patients' malignancies and lack of controlled trials demonstrating an advantage of a cloning assay choice over a clinician's choice. Both of these problems are being addressed with greatly improved abilities to grow patient malignancies (70%-80% of patients' tumors can now be grown in vitro) and the reporting of results of prospectively controlled randomized trials. It is likely that the most significant limitation for the human tumor cloning assay will be the lack of agents with in vitro activity. It is proposed that we are in the "sulfonamide era" of in vitro drug sensitivity testing of human tumors. It is unlikely any predictive assay will be of major utility until a more active spectrum of agents becomes available for in vitro testing and in vivo treatment.

Cells, Cultured↗

Does the gonadotropin-releasing hormone stimulation test predict clinical outcomes after microsurgical varicocelectomy?

OBJECTIVES: To examine the predictive value of the gonadotropin-releasing hormone (GnRH) stimulation test in a large cohort of infertile men undergoing varicocelectomy. METHODS: We examined the records of 144 consecutive infertile couples in whom the man underwent microsurgical varicocelectomy between September 1998 and December 2002. All men underwent a GnRH stimulation test before surgery. Data on the preoperative and postoperative semen parameters, pregnancy outcome, and follicle-stimulating hormone (FSH) and luteinizing hormone increase after GnRH stimulation were recorded. RESULTS: The mean (+/-SE) sperm concentration and motility 6 months after varicocelectomy were significantly greater than the preoperative values (25.3 +/- 2.4 versus 19.7 +/- 2.1 x 10(6)/mL and 29.2% +/- 1.4% versus 25.3% +/- 1.3%, respectively, P <0.05). Overall, 28% of the couples achieved a spontaneous pregnancy at a mean of 22 months of follow-up. The median elevation in the FSH and luteinizing hormone value 60 minutes after GnRH administration was 1.8 and 5.6 times the baseline level, respectively. No statistically significant relationship was found between the FSH or LH response to GnRH stimulation and improvement in the semen parameters or positive pregnancy outcome in our population. CONCLUSIONS: Our data showed that the FSH response to bolus GnRH stimulation does not predict improvement in semen parameters or unassisted pregnancy outcome in couples in whom the man undergoes varicocelectomy (for treatment of varicocele). The study was the largest of its type and sufficiently powered to validate these findings. The results indicate that the bolus GnRH stimulation test is of no clinical value in the treatment of infertile men with varicoceles.

Adult↗

The six-minute walk test predicts peak oxygen uptake and survival in patients with advanced heart failure.

BACKGROUND: The 6-min walk test (6'WT) is a simple measure of functional capacity and predicts survival in patients with moderate heart failure (HF). METHODS: To assess the role of the 6'WT in the evaluation of patients with advanced HF, 45 patients (age 49 +/- 8 years, mean +/- SD; New York Heart Association class 3.3 +/- 0.6; left ventricular ejection fraction 0.20 +/- 0.06; right ventricular ejection fraction 0.31 +/- 0.11) underwent symptom-limited cardiopulmonary exercise testing and the 6'WT during cardiac transplant evaluation. RESULTS: Mean 6'WT distance ambulated was 310 +/- 100 m and peak oxygen uptake (peak Vo2) was 12.2 +/- 4.5 mL/kg/min. There was a significant correlation between 6'WT distance ambulated and peak Vo2 (r = 0.64, p < 0.001). Multivariate analysis of patient characteristics, resting hemodynamics, and 6'WT results identified the distance ambulated during the 6'WT as the strongest predictor of peak Vo2 (p < 0.001). 6'WT distance ambulated less than 300 m predicted an increased likelihood of death or pretransplant hospital admission for continuous inotropic or mechanical support within 6 months (p = 0.04), but did not predict long-term overall or event-free survival with a mean follow-up of 62 weeks. Peak Vo2 was the best predictor of long-term overall and event-free survival. CONCLUSIONS: In patients with advanced HF evaluated for cardiac transplantation, distance ambulated during the 6'WT predicts (1) peak Vo2 and (2) short-term event-free survival.

Disease-Free Survival↗

Serial color-word test predicts outcome of pharmacological treatment for panic disorder.

A group of 50 outpatients with Panic Disorder were given the Serial Color-Word Test at the beginning of a standard pharmacological treatment (selective serotonin reuptake inhibitors and benzodiazepines). A single treating psychiatrist, blind to test results, judged therapy outcome at a 5-mo. follow-up. Among the main types of adaptation to conflict assessed by the test (Stabilized, Cumulative, Dissociative, and Cumulative-Dissociative), the Stabilized pattern predicted a good therapy outcome. Response to therapy among the patients with a Stabilized pattern was judged as more often good and less often moderate or poor, compared with the members of the other three adaptation classes (p=.004), and specifically with the patients resorting to a Cumulative strategy (p=.005).

Adaptation, Psychological↗

Can haematological tests predict cardiovascular risk? The 2005 Kettle Lecture.

The risk of venous or arterial thrombosis is routinely assessed by clinical variables (risk factors) supplemented by measurement of blood lipids and glucose for arterial thrombotic events. Haematological tests that might play a role in risk prediction include haemostatic variables, haematocrit and inflammatory markers (erythrocyte sedimentation rate, plasma viscosity, white cell count). Recent epidemiological studies of these phenotypes and related genotypes are reviewed. For the risk prediction of first venous thrombosis, screening for thrombophilias in 'high-risk' situations does not appear clinically effective or cost-effective; with the possible exception of women considering oral hormone replacement therapy. General screening after a first venous event to predict recurrence (or risk in asymptomatic relatives) does not appear effective; with the possible exception of d-dimer, which requires further study. For risk prediction of first arterial thrombosis, screening adds little to prediction by current clinical risk scores. Screening of persons after a first arterial event, or with atrial fibrillation (e.g. with D-dimer for stroke prediction), requires further study. In conclusion, haematological tests have very limited roles in the prediction of cardiovascular risk, and should only be used according to evidence-based guidelines. The need for management studies is highlighted.

Biomarkers↗

Effects of ICI 169,369, a selective serotonin2 antagonist, in electrophysiological tests predictive of antipsychotic activity.

Extracellular single unit recording techniques were used to compare the effects of ICI 169,369, a selective serotonin2 receptor antagonist, with the reference antipsychotic (AP) agents clozapine and haloperidol, in electrophysiological tests that may predict AP activity. ICI 169,369 was found to reverse the inhibitory actions of amphetamine on A9 and A10 dopamine (DA) neurons, a common property shared by other AP drugs, and was comparable in potency to clozapine. In cell population studies, acute treatment with ICI 169,369 (at a low dose only) and clozapine selectively increased the number of spontaneously active A10 DA cells, which was found to correlate with the ability of both these drugs to cause depolarization inactivation (DI) of A10 DA cells after chronic administration. Interestingly, chronic treatment with ICI 169,369 also caused a significant increase in the number of actively discharging A9 DA cells, an effect not predicted on the basis of the acute data. A similar effect was noted for clozapine, although the magnitude did not reach statistical significance. This profile of activity was unlike that of haloperidol, which acutely caused a nonselective increase in the number of active A9 and A10 DA cells, associated with the ability of this agent to cause DI of both A9 and A10 DA cells after chronic treatment. Inasmuch as DI of A10 DA cells may be correlated with AP efficacy whereas DI of A9 DA cells may predict the ability of an AP to cause extrapyramidal side effects, ICI 169,369, like clozapine, may be a potential AP with a reduced likelihood for producing extrapyramidal side effects.

Action Potentials↗

Does the 6-minute walk test predict the prognosis in patients with NYHA class II or III chronic heart failure?

BACKGROUND: We prospectively evaluated the potential of the 6-minute walk test compared with peak VO2 in predicting outcome of patients with New York Heart Association (NYHA) class II or III heart failure. METHODS AND RESULTS: Patients with a history of heart failure caused by systolic dysfunction were included. The combined final outcome (death or hospitalization for heart failure) was used as the judgment criterion. One hundred twenty-one patients (age 59+/-11 years; left ventricular ejection fraction 29.6%+/-13%) were included and followed for 1.53+/-0.98 years. Patients were separated into two groups according to outcome: group 1 (G1, 74 patients), without events, and group 2 (G2, 47 patients), who reached the combined end point. Peak VO2 was clearly different between G1 and G2 (18.5+/-4 vs. 13.9+/-4 ml/kg/min, p=0.0001) but not the distance walked (448+/-92 vs 410+/-126 m; p=0.084, not significant). Survival analysis showed that unlike peak VO2, the distance covered was barely distinguishable between the groups (p < 0.08). However, receiver operating characteristic curves revealed that the best performances for the 6-minute walk test were obtained for subjects walking < or =300 m. These patients had a worse prognosis than those walking farther (p=0.013). In this subset of patients, there was a significant correlation between distance covered and peak VO2 (r=0.65, p=0.011). Thus it appears that the more severely affected patients have a daily activity level relatively close to their maximal exercise capacity. Nevertheless, the 300 m threshold suggested by this study needs to be validated in an independent population. CONCLUSIONS: A distance walked in 6 minutes < or =300 m can predict outcome. Moreover, in these cases there is a significant correlation between the 6-minute walk test and peak VO2 demonstrating the potential of this simple procedure as a first-line screening test for this subset of patients.

Adolescent↗

A novel sodium overload test predicting ascites decompensation in rats with CCl4-induced cirrhosis.

BACKGROUND/AIMS: We aimed to develop a non-invasive test to identify the initial alterations of sodium homeostasis and prospectively predict decompensation in preascitic cirrhotic rats. METHODS: The sodium overload test (SOT) was performed in control (CT) and CCl4-induced cirrhotic rats (CH) by calculating the percentage of sodium excreted in the urine after NaCl oral administration (0.5 g/kg). Liver fibrosis was quantified by image cytometry. RESULTS: From the 8th week of CCl4 intoxication, while the daily sodium balance did not change in CH and CT, SOT became significantly lower in the former (62.1+/-13.2 vs 78.8+/-13.2%; P=0.035). At sacrifice, ascites was only present in one animal. The degree of liver fibrosis correlated with SOT. In subsequent experiments, 17 cirrhotic rats developed ascites between the 9th and 14th weeks. SOT remained stable up to 3 weeks before ascites appearance, while it fell significantly to 35+/-19 and 26+/-21% at 2 and 1 week before ascites diagnosis, respectively. Nearly all the rats (95%) with a SOT<60% developed ascites within 3 weeks. CONCLUSIONS: In preascitic cirrhotic rats, SOT unveils sodium metabolism abnormalities earlier than the daily sodium balance and prospectively predicts ascites appearance, identifying rats in a homogeneous stage of cirrhosis, which is essential in pathophysiological studies on sodium retention.

Animals↗

Evaluation of in vitro predictive tests for irritation and allergic sensitization.

Investigations of in vitro procedures to predict the potential of substances as skin irritants and as allergens inducing delayed hypersensitivity (contact dermatitis) are described, with indications of possible advances and known limitations. The examination of keratome slices of skin for release of enzymes, for changed histochemistry and for utilization of radioisotope-labelled amino acids will detect weak irritants but is of doubtful value for moderate irritants and will detect corrosive substances only through their inhibition of all cell activities. Fibroblast cultures, tested with Clostridium perfringens toxin and chemicals, show similar limitations in detecting moderate or severe irritants. Fibroblast cultures can be made more relevant to epidermal exposure by an overlying layer of agar containing keratin. In vitro tests to detect induction of sensitizing potential for delayed hypersensitivity have made little progress. The most promising approach is to treat antigen-presenting Langerhans cells with antigen and co-culture with lymphocytes. The lymphocytes may be examined for changes in receptor expression, for synthesis of interleukin 2, and possibly for responses to allergen if sufficient cells become specifically sensitized. There are several in vitro techniques to detect responses of in vivo- or in vitro-sensitized lymphocytes treated with antigen.

Allergens↗

Eosinophilia and positive skin tests predict cardiovascular mortality in a general population sample followed for 30 years.

The authors investigated whether two objective allergy markers, peripheral blood eosinophilia and skin tests for common aeroallergens, were associated with cardiovascular death. Of 5,382 subjects in the Vlagtwedde-Vlaardingen Study (the Netherlands) with data on allergy markers in 1965-1972, 507 subjects died from cardiovascular disease during 30 years of follow-up. Subjects with eosinophilia had an increased risk of cardiovascular death (relative risk (RR) = 1.7; 95% confidence interval (CI): 1.4, 2.2), including ischemic heart disease death (RR = 1.6; 95% CI: 1.2, 2.2) and cerebrovascular death (RR = 2.3; 95% CI: 1.4, 3.8), independent of major risk factors. This association was limited to subjects with a percentage of the predicted forced expiratory volume in 1 second (FEV1 % predicted) of <100%. Positive skin tests were associated with a significantly reduced cardiovascular mortality in subjects with normal lung function and weight who did not smoke (RR = 0.15; 95% CI: 0.05, 0.46). Conversely, when subjects with positive skin tests had a body mass index of > or =25 kg/m2, had an FEV1 % predicted of <80%, or smoked, they had an increased risk for cardiovascular mortality. These results were not restricted to asthmatics. Our data suggest a possible link between eosinophilia and positive skin tests and cardiovascular mortality, especially in combination with other risk factors associated with its mortality.

Asthma↗

Phenotypic drug susceptibility testing predicts long-term virologic suppression better than treatment history in patients with human immunodeficiency virus infection.

To assess the value of phenotypic drug susceptibility testing as a predictor of antiretroviral treatment response in human immunodeficiency virus (HIV)-infected people, drug susceptibility testing was performed retrospectively on plasma samples collected at baseline in a cohort of 86 antiretroviral-experienced, HIV-infected people experiencing treatment failure and initiating a new antiretroviral treatment regimen. Two separate criteria for reduced drug susceptibility were evaluated. In multivariate analyses, phenotypic susceptibility was an independent predictor of time to treatment failure (adjusted hazards ratio [HR], 0.70; 95% confidence interval [CI], 0.55-0.90; and adjusted HR, 0.76; 95% CI, 0.61-0.95, with reduced drug susceptibility cutoffs defined as 4.0-fold and 2.5-fold higher than reference virus IC(50) values, respectively). Previous protease inhibitor experience was also a significant independent predictor. Notably, drug susceptibility predicted on the basis of treatment history alone was not predictive of time to treatment failure. In this cohort, phenotypic testing results enhanced the ability to predict sustained long-term suppression of virus load.

Adult↗

Intravenous octreotide test predicts the long term outcome of treatment with octreotide-long-acting repeatable in active acromegaly.

OBJECTIVE: Depot formulations of somatostatin analogues are increasingly used in the treatment of active acromegaly. A priori knowledge of the efficacy of these drugs in controlling GH excess is clinically relevant, because only approximately 60% of the patients respond with adequate control of GH (GH levels < 5 mU/L) and/or IGF-1 levels upon this treatment. Therefore, we assessed the acute responses of serum GH levels to a new octreotide test (intravenous administration of 50 microg) in 98 consecutive patients with active acromegaly and we measured the predictive value of this test for the efficacy of chronic octreotide-long acting repeatable (octreotide-LAR) treatment in 18 patients. DESIGN: Serum GH concentrations were measured before and at 20, 30, 45, 60, 90, 120, 150 and 180 min following 50 microg i.v. octreotide. The minimal achieved GH was used for analysis. Octreotide-LAR was individually titrated aiming at a normal serum IGF-I for age and a serum GH < 5 mU/L. The mean of 3-6 monthly serum GH and IGF-I measurements after individual dose adjustment was used for evaluating the efficacy of chronic therapy. RESULTS: Octreotide decreased GH levels to values below 5 mU/L in only 49% of unselected consecutive patients and the response was inversely related to basal GH levels. In patients with baseline GH above 50 mU/L, 50 microg i.v. octreotide reduced GH to < 5 mU/L in only 15% of cases (n = 41), whereas in patients with baseline GH levels below 50 mU/L this goal was achieved in 77% of cases. The fractional decrease in GH levels upon octreotide injection was similar in microadenomas and macroadenomas. The minimally achieved serum GH concentration during the intravenous octreotide test was a good predictor for the GH concentrations during long-term octreotide-LAR treatment as assessed in 18 patients. The intravenous octreotide test, using a minimal GH level of < 5 mU/L, had a sensitivity, positive and negative predictive value of 100% for prediction of GH suppression to below 5 mU/L during long term octreotide-LAR treatment. For predicting the response of IGF-I during long-term treatment, the test performed with a sensitivity of 73% and a positive predictive value of 73%. CONCLUSION: Intravenous octreotide reduces GH to concentrations < 5 mU/L in approximately 50% of consecutive patients with active acromegaly, which predicts a good response to chronic octreotide-LAR treatment.

Acromegaly↗

An approach to predictive testing of contact sensitizers in vitro by monitoring their influence on endocytotic mechanisms.

Endocytotic activation of epidermal Langerhans cells (LC) by immunogenic haptens is an early event during development of allergic contact dermatitis. In this work a fast and objective flow-cytometric assay for predictive in vitro testing of contact sensitizers by monitoring their influence on endocytotic mechanisms in murine LC was developed. Epidermal cell suspensions were labelled with a monoclonal antibody directed to MHC class II molecules and pH-sensitive fluorochrome-coupled second-step reagents. For untreated LC a significant quenching of fluorescence intensity by internalization of the MHC-antibody complexes into acidic compartments was noticed. Similar results were obtained in the presence of irritants, the lectin concanavalin A and the phorbol ester phorbol 12-myristate 13-acetate. In contrast stimulation with several well-defined sensitizing compounds resulted in partial conservation of the fluorescence intensity due to the internalization of the labelled complexes into less acidic compartments. Monitoring this modulation of endocytosis is an effective in vitro method to test for properties typical for moderate and strong contact sensitizers. It will help to assess the risk of unknown chemicals to act as haptens and should be useful for restriction of animal experimentation in this field.

Animals↗

Antiarrhythmic drug efficacy at electrophysiology testing: predictive effectiveness of procainamide and flecainide.

In an effort to assess the ability of procainamide to predict effectiveness of antiarrhythmic agents at programmed electrical stimulation (PES) testing, we compared the result of procainamide at PES testing with that of all of the other agents studied. One hundred fifty-three patients underwent PES studies because of either sustained or nonsustained ventricular tachycardia (VT). Procainamide prevented VT induction in 79 of 153 patients. Seventy-four of the remaining 153 were inducible for VT on procainamide, with 55 of these being protected by another antiarrhythmic agent (p less than 0.001). If procainamide failed to prevent VT induction, other conventional and experimental agents were equally as likely to be effective in preventing VT induction. Analysis of flecainide acetate as a predictor of efficacy was also evaluated. Fifty-five patients received flecainide and 29 of these were protected at PES testing; 26 of these patients were also protected with another agent. When VT was inducible in patients who received flecainide, 15 of these 26 patients were protected by another agent, either conventional or experimental (p less than 0.01). Thus, if procainamide or flecainide prevented VT induction they accurately predicted effectiveness of other drugs; however, when they did not prevent VT induction, they served as a poor predictor of the possible effectiveness of other drugs. Serial drug testing at PES studies with multiple conventional and experimental drugs increases the likelihood of finding an effective antiarrhythmic agent.

Anti-Arrhythmia Agents↗

Absence of tachycardia during tilt test predicts failure of beta-blocker therapy in patients with neurocardiogenic syncope.

Not all patients with neurocardiogenic syncope respond to beta-blockers. To determine whether differences in heart rate response to head-up tilt test with and without isoproterenol may predict drug efficacy, we evaluated 32 consecutive patients with a history of syncope, who were treated with beta-blockers after a positive tilt test. During the tilt test 21 patients (group A) with a baseline heart rate of 72 +/- 15 beats/min had tachycardia (mean 131 +/- 15) during tilt, before syncope, whereas 11 patients (group B) with a baseline heart rate of 68 +/- 13 beats/min did not (mean 86 +/- 13; p < 0.001). There were no significant differences between groups with regard to demographic and clinical characteristics or mean heart rate and mean arterial pressure in the supine position and during syncope. However, the proportion of patients requiring isoproterenol for provocation of syncope was significantly higher in group A compared with group B (15 of 21 vs 1 of 11; p < 0.001). All patients were treated with beta-blockers (propranolol or metoprolol). During a follow-up period of 18 +/- 6 months only one patient in group A had syncope and a positive tilt test compared with six patients in group B (9% vs 54%; p < 0.01). Development of tachycardia was a better predictor of drug efficacy than an isoproterenol-induced positive tilt test. The six nonresponders from group B were subsequently treated with disopyramide. During a mean follow-up period of 9 +/- 3 months, only one patient had syncope and another had a positive response to tilt test.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗