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PubMed2001

On a variant of Stroop's paradigm: which cognitions press your buttons?

The Stroop effect typically refers to the fact that the time to identify the color of a visually presented word is affected by the relationship between the word and the color When the (irrelevant) word is semantically related to the color (e.g., the word green, presented in red) response time is slower than if the word is neutral or unrelated. One question that has been posed concerns whether semantics plays a role only when the task requires an explicit verbal response, or whether it also plays a role when the response is manual. Sharma and McKenna (1998) have reported that semantics plays a role only when the response is vocal. A reanalysis of their data shows that semantics also plays a role when manual responses are made.

Cognition↗
PubMed1999

Realism of confidence in sensory discrimination.

Is there a common and general basis for confidence in human judgment? Recently, we found that the properties of confidence judgments in the sensory domain mirror those previously established in the cognitive domain; notably, we found underconfidence on easy sensory judgments and overconfidence on hard sensory judgments. In contrast, data from the Uppsala laboratory in Sweden suggest that sensory judgments are unique; they found a pervasive underconfidence bias, with overconfidence being evident only on very hard sensory judgments. Olsson and Winman (1996) attempted to resolve the debate on the basis of methodological issues related to features of the stimulus display in a visual discrimination task. A reanalysis of the data reported in Baranski and Petrusic (1994), together with the findings of a new experiment that controlled stimulus display characteristics, supports the position that the difference between the Canadian and the Swedish data is real and, thus, may reflect cross-national differences in confidence in sensory discrimination.

Adult↗
PubMed1992

Single-parameter power law psychophysics of auditory numerosity and the psychological moment hypothesis.

In the present study, numerosity estimation was investigated. A two-parameter Stevens power law analysis was performed on a total of 944 subjects in six experiments. Two pulse ranges (2-17 or 17-253 pulses) and six pulse rates (either constant or randomly varied within trial blocks) were used, variously, in an unsuccessful attempt to find evidence for a psychological moment, under the supposition that the exponent (or, possibly, the measure constant) would become smaller as increasing numbers of pulses fell within the interval determined by each psychological moment. A single-parameter reanalysis of these six experiments under the initial value condition that a (standard) stimulus of one pulse be assigned a theoretical response (modulus) of one yielded single-parameter equations whose exponents were reliably less varied than those for conventional two-parameter equations in Experiments 1-4 (with randomly varying pulse rates from trial to trial) but not less varied in Experiments 5 and 6 (in which pulse rates were constant within trial blocks). It was concluded that the variable pulse rate condition, with its reduced exponent variability and presumed reduced temporal confounding, provides a more valid estimate of the single-parameter power law exponent for numerosity, which was found to be 0.80.

Adult↗
PubMed2000

Evaluating the importance of the convex hull in solving the Euclidean version of the traveling salesperson problem: reply to Lee and Vickers (2000).

Lee and Vickers (2000) suggest that the results of MacGregor and Ormerod (1996), showing that the response uncertainty to traveling salesperson problems (TSPs) increases with increasing numbers of nonboundary points, may have resulted as an artifact of constraints imposed in the construction of stimuli. The fact that similar patterns of results have been obtained for our "constrained" stimuli, for a stimulus constructed under different constraints, for 13 randomly generated stimuli, and for random and patterned 48-point problems provides empirical evidence that the results are not artifactual. Lee and Vickers further suggest that, even if not artifactual, the results are in principle limited to arrays of fewer than 50 points and that, beyond this, the total number of points and number of nonboundary points are "diagnostically equivalent." This claim seems to us incorrect, since arrays of any size can be constructed that will permit experimental tests of whether problem difficulty is influenced by the number of nonboundary points, or the total number of points, or both. We present a reanalysis of our original data using hierarchical regression analysis which indicates that both factors may influence problem complexity.

Attention↗
PubMed2005

Cognitive control and parsing: reexamining the role of Broca's area in sentence comprehension.

A century of investigation into the role of the human frontal lobes in complex cognition, including language processing, has revealed several interesting but apparently contradictory findings. In particular, the results of numerous studies suggest that left inferior frontal gyrus (LIFG), which includes Broca's area, plays a direct role in sentence-level syntactic processing. In contrast, other brain-imaging and neuropsychological data indicate that LIFG is crucial for cognitive control--specifically, for overriding highly regularized, automatic processes, even when a task involves syntactically undemanding material (e.g., single words, a list of letters). We provide a unifying account of these findings, which emphasizes the importance of general cognitive control mechanisms for the syntactic processing of sentences. On the basis of a review of the neurocognitive and sentence-processing literatures, we defend the following three hypotheses: (1) LIFG is part of a network of frontal lobe subsystems that are generally responsible for the detection and resolution of incompatible stimulus representations; (2) the role of LIFG in sentence comprehension is to implement reanalysis in the face of misinterpretation; and (3) individual differences in cognitive control abilities in nonsyntactic tasks predict correlated variation in sentence-processing abilities pertaining to the recovery from misinterpretation.

Aphasia, Broca↗
PubMed2004

HER2 amplification ratios by fluorescence in situ hybridization and correlation with immunohistochemistry in a cohort of 6556 breast cancer tissues.

To analyze HER2 amplification in a large cohort of diagnostic breast cancer specimens, fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) were performed on the same specimens with use of Food and Drug Administration&approved products. Procedures were standardized following the manufacturers' recommendations. Of 116,736 IHC specimens, 20% were positive for HER2. In 16,092 FISH specimens, 22.7% showed HER2 amplification. In the subset of 6556 tissues analyzed with IHC and FISH, however, 59% were positive on IHC and 23.6% were amplified on FISH. The increased frequency of positive test results is skewed by more frequent reflex FISH testing. In general, expression and amplification trended together, with the least amplification (4.1%) seen in IHC-negative cases, 7.4% amplification seen in IHC 1+ cases, 23.3% amplification seen in IHC 2+ cases, and 91.7% amplification seen in IHC 3+ cases. When FISH amplification ratios were stratified, the low FISH ratios (2.0-2.2) were most frequently seen in specimens with negative IHC results, high ratios (>5.0) were seen in IHC 3+ specimens, and intermediate levels of amplification were similar for all levels of IHC. The effect of changing the cutoff point was analyzed: removing cases with a ratio of exactly 2.0 decreased the FISH positivity rate to 22.2% in the combined IHC and FISH cohort. Sequentially moving the cutoff point to 2.2 and 2.5 affected cases at all IHC expression levels. Each change removed approximately 2% from the apparent positivity. This large database provides the distribution frequency of HER2 protein expression and gene amplification in invasive ductal and lobular breast cancer. The relationship between level of HER2 amplification and clinical outcome will require reanalysis of pivotal trial data.

Breast↗
PubMed1996

Angiotropic large cell lymphoma (intravascular lymphomatosis) occurring after follicular small cleaved cell lymphoma.

Angiotropic large cell lymphoma is a rare, aggressive type of malignant lymphoma that primarily involves intravascular spaces and most often has clinical manifestations in the skin and central nervous system. Virtually any organ can be affected, however, including the lymph nodes and spleen. Peripheral blood involvement is usually not detectable morphologically. Conventional lymphoma in association with this entity has also been described. Herein we present a case of angiotropic lymphoma of B-cell lineage that affected the liver and skin. Reanalysis of a lymph node specimen that had been excised 3 years previously demonstrated a follicular small cleaved cell lymphoma. To our knowledge, this is the first reported case of possible evolution of follicular lymphoma to large cell lymphoma of angiotropic type.

Diagnosis, Differential↗
PubMed2005

Spurious hypocalcemia after gadodiamide administration.

Severe hypocalcemia may require prompt intervention to avoid life-threatening consequences. We report a case in which a 78-year-old man had a critically low serum calcium level measured with use of standard colorimetric assay after gadodiamide administration during magnetic resonance angiography. Reanalysis of the same serum specimen using absorption spectroscopy revealed normal calcium values, confirming the diagnosis of spurious hypocalcemia. The increasing use of gadolinium chelates during magnetic resonance imaging and anglography will lead to a marked increase in reports of critically low serum calcium values. Increasing physicians' awareness of gadodiamide-induced spurious hypocalcemia may prevent unnecessary and potentially inappropriate therapeutic interventions.

Aged↗
PubMed2002

Carbamazepine augmentation for schizophrenia: how good is the evidence?

BACKGROUND: Augmentation strategies in schizophrenia treatment remain an important issue because despite the introduction of several new antipsychotics, many patients remain treatment resistant. The aim of this study was to undertake a systematic review and meta-analysis of the safety and efficacy of one frequently used adjunctive compound: carbamazepine. DATA SOURCES AND STUDY SELECTION: Randomized controlled trials comparing carbamazepine (as a sole or as an adjunctive compound) with placebo or no intervention in participants with schizophrenia or schizoaffective disorder were searched for by accessing 7 electronic databases, cross-referencing publications cited in pertinent studies, and contacting drug companies that manufacture carbamazepine. METHOD: The identified studies were independently inspected and their quality assessed by 2 reviewers. Because the study results were generally incompletely reported, original patient data were requested from the authors; data were received for 8 of the 10 randomized controlled trials included in the present analysis, allowing for a reanalysis of the primary data. Dichotomous variables were analyzed using the Mantel-Haenszel odds ratio and continuous data were analyzed using standardized mean differences, both specified with 95% confidence intervals. RESULTS: Ten studies (total N = 283 subjects) were included. Carbamazepine was not effective in preventing relapse in the only randomized controlled trial that compared carbamazepine monotherapy with placebo. Carbamazepine tended to be less effective than perphenazine in the only trial comparing carbamazepine with an antipsychotic. Although there was a trend indicating a benefit from carbamazepine as an adjunct to antipsychotics, this trend did not reach statistical significance. CONCLUSION: At present, this augmentation strategy cannot be recommended for routine use. The most promising targets for future trials are patients with excitement, aggression, and schizoaffective disorder bipolar type.

Anticonvulsants↗
PubMed2006

Using data mining to explore complex clinical decisions: A study of hospitalization after a suicide attempt.

BACKGROUND: Medical education is moving toward developing guidelines using the evidence-based approach; however, controlled data are missing for answering complex treatment decisions such as those made during suicide attempts. A new set of statistical techniques called data mining (or machine learning) is being used by different industries to explore complex databases and can be used to explore large clinical databases. METHOD: The study goal was to reanalyze, using data mining techniques, a published study of which variables predicted psychiatrists' decisions to hospitalize in 509 suicide attempters over the age of 18 years who were assessed in the emergency department. Patients were recruited for the study between 1996 and 1998. Traditional multivariate statistics were compared with data mining techniques to determine variables predicting hospitalization. RESULTS: Five analyses done by psychiatric researchers using traditional statistical techniques classified 72% to 88% of patients correctly. The model developed by researchers with no psychiatric knowledge and employing data mining techniques used 5 variables (drug consumption during the attempt, relief that the attempt was not effective, lack of family support, being a housewife, and family history of suicide attempts) and classified 99% of patients correctly (99% sensitivity and 100% specificity). CONCLUSIONS: This reanalysis of a published study fundamentally tries to make the point that these new multivariate techniques, called data mining, can be used to study large clinical databases in psychiatry. Data mining techniques may be used to explore important treatment questions and outcomes in large clinical databases and to help develop guidelines for problems where controlled data are difficult to obtain. New opportunities for good clinical research may be developed by using data mining analyses.

Adult↗
PubMedDate not supplied

Intravenous insulin infusion therapy: indications, methods, and transition to subcutaneous insulin therapy.

OBJECTIVE: To describe indications for intravenous (IV) insulin infusion therapy and glycemic thresholds, discuss methods and protocols, and promote use of and access to IV insulin infusion therapy for all appropriate patients in the hospital setting. RESULTS: Randomized, prospectively designed trials support the use of IV insulin infusion therapy for patients in the surgical intensive-care unit, including postoperative cardiac patients and patients having myocardial infarction. Among patients in the surgical intensive-care unit, reanalysis of the data suggested no threshold at which benefit occurred above the blood glucose level of 110 mg/dL. In another study, retrospective analysis of data among critically ill medical and surgical patients suggested a target blood glucose level of 145 mg/dL or less. In other populations, the threshold or ideal target blood glucose range has not been determined. Three protocols for IV insulin infusion are described that maintain blood glucose levels safely below the upper limit of their respective target ranges without substantial risk of hypoglycemia. CONCLUSION: The threshold for initiation of IV insulin infusion is 110 mg/dL for critically ill surgical patients, 140 mg/dL for other medical or surgical patients, 180 mg/dL for patients in whom subcutaneous insulin regimens fail, and 100 mg/dL for pregnant women. The blood glucose target range is 80 to 110 mg/dL for selected critically ill surgical patients, 70 to 100 mg/dL for pregnant women, and 90 to 140 mg/dL for all other patients. Hospitals should develop procedures to make IV insulin infusion therapy available to all appropriate patients.

Algorithms↗
PubMed2006

Studying the right cell in acute myelogenous leukemia: dynamic changes of apoptosis and signal transduction pathway protein expression in chemotherapy resistant ex-vivo selected "survivor cells".

We hypothesized that studying protein expression in cells surviving in vitro chemotherapy ("survivor cells", SV), could provide more important insight into the biology of drug-resistant AML cells than analysis of the bulk population of leukemic cells. Leukemia-enriched samples from 79 patients with new or relapsed AML were cultured for four days +/- cytarabine (5-10 microM). Early apoptotic cells were removed to yield purified SV. Expression of BCL2, bax, PKC alpha, ERK2 and pERK2 proteins was measured using laser scanning cytometry. The SV population was enriched for CD34+ stem cells. Protein expression patterns in SV differed considerably from those in controls; culture and reanalysis of protein expression revealed stability, reversion, or new patterns of change. Patterns of pairs or triads of proteins were nonrandomly distributed and appeared at statistically unlikely frequencies, suggesting preferential adoption of certain patterns. The patterns of change were highly predictive of remission attainment, relapse, and survival in univariate and multivariate analysis. We conclude that in vitro SV cells have protein expression patterns distinct from those of the bulk population of leukemic cells and that these patterns are predictive of outcome. Analysis of SV cells may be more informative than analysis of the bulk population of leukemia cells.

Adult↗
PubMed1992

Persistence of eggs and hepatic fibrosis after treatment of Schistosoma mansoni-infected mice.

In 1971 we estimated that Schistosoma mansoni eggs in the tissues of mice were destroyed with an approximate half-life of four weeks. Our present results of five experiments suggest that egg destruction is not as rapid, and no significant destruction of eggs was detected for up to 26 weeks after treatment. However, in these experiments, a mean of 60% of the eggs in intestinal tissues were found in the feces at the time of treatment. In previously reported experiments, only 15% of gut eggs were passed in the feces. We now believe that underestimation of the number of eggs passed in the feces led to an overestimation of the number of eggs destroyed in the tissues. We analyzed liver eggs separately because eggs lost from this site are unaffected by eggs passed in the feces. No significant decrease in liver eggs occurred in the present experiments, but reanalysis of previously published data showed significant egg destruction in the liver in several experiments, although at a much slower rate than previously estimated. However, inspection of the data in the previously published and present experiments does not show a convincing difference in the number of eggs in the liver after treatment. The persistence of egg shells is probably not important in the pathogenesis of disease, but is of concern in calculating worm fecundity. Hepatic collagen levels increased markedly two weeks after treatment and subsequently decreased significantly in some, but not all, experiments.

Analysis of Variance↗
PubMed2001

Screening bovine carcass sponge samples for Escherichia coli O157 using a short enrichment coupled with immunomagnetic separation and a polymerase chain reaction-based (BAX) detection stept.

A bovine carcass sponge sample screening protocol for detecting Escherichia coli O157:H7 was composed of a short selective enrichment followed by an immunomagnetic separation (IMS) and target detection using the BAX E. coli O157 polymerase chain reaction assay. This screening protocol was compared to a culture-based method for detection of the organism in carcass sponge samples. Enriched samples were subjected to IMS; the bead suspension was divided and plated on selected media or stored at -20 degrees C, then subjected to BAX analysis. The results showed a high degree of agreement between the plating method and the BAX system. Fifty-two of the 59 culture-positive samples were also positive using the BAX system (88.1% sensitivity). Of the 76 samples that appeared negative for the presence of E. coli O157:H7 by the culture method, 66 were determined as negative using the BAX system (86.8% specificity). Four of the 10 samples found negative by the initial culture method and positive by the BAX method were subsequently found to be culture positive upon reanalysis. Based on these data, the BAX system combined with a short, selective enrichment and IMS may be a rapid, reliable, and simple method to screen for E. coli O157:H7 in carcass sponge samples. Our data indicate that optimization and subsequent testing of this protocol for use as a carcass screening tool are warranted.

Animals↗
PubMed1993

Formaldehyde exposure and respiratory cancer--a meta-analysis of the epidemiologic evidence.

A recent meta-analysis by Blair and his co-workers stimulated the undertaking of a reanalysis of the epidemiologic evidence of an association between formaldehyde and respiratory cancer. Emphasis was placed on extracting the maximal amount of relevant data from the source studies. In close agreement with the original analysis, the aggregated evidence did not indicate an excess risk or an exposure-response gradient for lung cancer. An exposure-response gradient was seen for both sinonasal and nasopharyngeal cancers. The risk for substantial exposure was significantly elevated (odds ratio 1.7 for sinonasal and 2.7 for nasopharyngeal cancer). It is suggested that at least substantial levels of occupational exposure to formaldehyde are associated with a risk of these cancers. The excess risk would be of the order of 100% or more over background rates.

Epidemiologic Methods↗
PubMed1996

Brain tumor risk in offspring of men occupationally exposed to electric and magnetic fields.

OBJECTIVES: The purpose of the study was to address the possible associations between the occupational exposure of men to electromagnetic fields (EMF) and the risk of childhood brain tumors in offspring by reanalyzing case-referent interview data from a study of environmental factors and childhood brain tumors conducted by one of the authors and first reported in 1990. METHODS: Analyses of the case-referent data were limited to the 94 cases and 166 individually-matched referents for whom data on the biological fathers were available. Paternal exposure to occupational EMF was inferred from a list of job titles compiled for that purpose. Mantel-Haenszel odds ratios (OR) for individually matched cases and referents were estimated for different definitions of exposure. RESULTS: The findings suggested at best very small increases in risk for jobs associated with the occupational EMF exposure of fathers during the one-year period prior to conception, the OR values ranging from 1.12 to 1.31. Notably elevated OR values were, however, found in association with any paternal welding in the one-year preconception period (OR 3.8, 95% confidence interval 0.95-15.55). CONCLUSIONS: The results of reanalysis indicate that preconceptional paternal occupational exposure to EMF is at best only weakly associated with a risk of childhood brain tumors. However, the findings for paternal welding are somewhat intriguing since relatively strong EMF have been measured in association with welding. Further study of welding as a potential risk factor is required since welders may be exposed to a wide range of toxic agents in addition to EMF.

Adult↗
PubMed1995

Male-mediated risk of spontaneous abortion with reference to stainless steel welding.

OBJECTIVES: It was hypothesized that the welding of stainless steel involves a risk of male-mediated developmental toxicity because of exposure to mutagenic substances, including hexavalent chromium. The purpose of the present study was to corroborate or refute earlier findings that spouses of stainless steel welders have an increased risk of spontaneous abortion. METHODS: The occurrence of spontaneous abortion among 2520 pregnancies of spouses of 1715 married metal workers from 1977 through 1987 was examined. Occupational histories were collected with a postal questionnaire in a previous study. Information on children born live, spontaneous abortion, and induced abortion was obtained from national medical registers. RESULTS: The proportion of spontaneous abortions was not increased for pregnancies at risk from stainless steel welding when compared with pregnancies not at risk (odds ratio 0.78, 95% confidence interval 0.55-1.1). The risk estimate was robust to adjustment for potential confounding effects of maternal age and parity and male smoking and alcohol consumption. CONCLUSIONS: This study does not corroborate earlier findings that spouses of stainless steel welders have increased risk of spontaneous abortion. A reanalysis indicated that earlier findings were probably biased because the job exposure of male metal workers is apparently modified by the outcome of their partners' first pregnancy.

Abortion, Spontaneous↗
PubMed1989

Intakes and sources of a range of dietary sugars in various Australian populations.

Data from the Apparent Consumption of Foodstuffs publications of the Australian Bureau of Statistics have, until recently, been the major source of information in Australia about the consumption of refined sugars. This database, which relies on national figures for production, importation, export, storage and stocks, and on population statistics, had indicated that some 14% of the total energy that was available in Australia was derived from refined sugars. Similar figures have been derived for both the United States and United Kingdom by means of this kind of national food-availability database. However, a recent reanalysis of a large-scale dietary survey of individuals in the United States has indicated a much lower level of consumption of refined sugars. In recent years, several large-scale surveys of individuals' consumption patterns in the Australian population have been carried out by the Social Nutrition Program at the CSIRO Division of Human Nutrition. These surveys indicate that the mean level of consumption of refined sugars is not as high as that which previously was estimated from Apparent Consumption data. However, there was a wide range of intakes and a substantial proportion of individuals with intakes that were above recommended levels.

Adult↗