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C Sarrazin

Publications and source records attributed to C Sarrazin.

At least 37 records · Page 2Linked to original sources
PubMed2001

Assessment, by transcription-mediated amplification, of virologic response in patients with chronic hepatitis C virus treated with peginterferon alpha-2a.

Transcription-mediated amplification (TMA) is an isothermal, autocatalytic target amplification method which has the potential to detect less than 50 hepatitis C virus (HCV) RNA copies/ml (10 IU/ml). The TMA assay was used to assess the presence of residual HCV RNA in plasma from patients treated with polyethylene glycol-modified interferon alpha-2a (peginterferon alpha-2a) who showed a virologic relapse after the end of therapy. Stored end-of-treatment and end-of-follow-up plasma samples from 177 of 267 patients treated with peginterferon alpha-2a (S. Zeuzem et al., N. Engl. J. Med. 343:1666--1672, 2000) were available for retesting by TMA. Plasma samples from patients in the same study who exhibited virologic relapse after treatment with standard interferon alpha-2a served as controls. Virologic response during the trial was defined as HCV RNA that was undetectable using a PCR-based test system with a sensitivity of 50 IU/mL (Cobas Amplicor HCV version 2.0) and was compared with TMA-based retesting results (VERSANT HCV RNA Qualitative Assay). Residual HCV RNA was detected in 4 of 60 cases (7%) by the TMA technology in end-of-treatment plasma samples from patients who relapsed after receiving peginterferon alpha-2a and in 6 of 18 patients (33%) following therapy with standard interferon alpha-2a. For peginterferon alpha-2a-treated patients with sustained virologic response, HCV RNA was detectable by TMA in end-of-treatment samples in 3 of 78 cases but in none of the end-of-follow-up samples. For all end-of-treatment and end-of-follow-up plasma samples of virologic nonresponders, a complete concordance between the PCR-based assay and TMA was observed. In conclusion, in patients with virologic relapse after the end of therapy, according to PCR, who were treated with peginterferon alpha-2a or standard interferon alpha-2a, residual HCV RNA was detectable in end-of-treatment samples by the TMA-based assay in 7 or 33% of cases, respectively. The lower rate of residual HCV RNA detection by TMA for patients treated with peginterferon alpha-2a than that for patients treated with standard interferon alpha-2a may be due to the maintained antiviral pressure of the long-acting peginterferon alpha-2a at the end-of-treatment visit.

Antiviral Agents↗
PubMed2000

Prospective follow-up of patients with GBV-C/HGV infection: specific mutational patterns, clinical outcome, and genetic diversity.

An association between a specific mutational pattern within the nonstructural (NS)3 region of GB virus-C/hepatitis G virus (GBV-C/HGV) genome and fulminant hepatic failure has been suggested recently. The mutational pattern consists of 3-6 nucleotide mutations of which one is leading to an amino acid exchange. In the present study, patients with GBV-C/HGV mono-infection (n = 24) or GBV-C/HGV and HCV co-infection (n = 20) were investigated prospectively. In 6/44 patients (14%) the mutational pattern within GBV-C/HGV NS3 previously associated with fulminant hepatic failure was identified by direct sequence analysis of the NS3 region. All 44 patients were asymptomatic clinically and had normal liver functions at initial presentation and after a median follow-up of 2.2 years. In 22/24 patients with GBV-C/HGV mono-infection and all patients with GBV-C/HGV and HCV co-infection GBV-C/HGV RNA remained detectable at the end of the study period, whereas two patients infected with GBV-C/HGV alone became negative for GBV-C/HGV RNA and developed GBV-C/HGV anti-E2 antibodies indicating recovery from GBV-C/HGV infection. Aminotransferase levels remained elevated or became normal independent of the persistence of serum GBV-C/HGV RNA. The median rate of nucleotide substitutions in GBV-C/HGV mono-infected and HCV co-infected patients was 3.4 x 10(-3) and 3.2 x 10(-3) per site per year, respectively. In conclusion, the prevalence of the mutational pattern within NS3 region of GBV-C/HGV associated previously with fulminant hepatic failure is about 14% and not associated specifically with severe liver disease. Over a median follow-up of 2.2 years less than 5% of patients cleared spontaneously GBV-C/HGV and no correlation between viraemia and elevated liver enzymes was observed.

Adult↗
PubMed2000

Hepatocellular proliferation in patients with chronic hepatitis C and persistently normal or abnormal aminotransferase levels.

BACKGROUND/AIMS: Some patients chronically infected with the hepatitis C virus (HCV) have persistently normal alanine aminotransferase (ALT) levels while progressive liver damage is observed histologically. In the present study, we compared the rate of proliferation, apoptosis, and necrosis in liver biopsy specimens of patients with persistently normal or elevated ALT levels. METHODS: Fourteen patients with persistently normal and 14 age- and sex-matched patients with elevated ALT levels were enrolled. Proliferation was detected using anti-Ki 67 in 10-microm liver biopsy specimens of the patients. Apoptosis was measured by TUNEL-assay and by monoclonal anti-M30 directed against caspase-cleaved cytokeratin 18 filaments. RESULTS: The mean number of anti-Ki 67 positive hepatocytes was lower in patients with persistently normal aminotransferases (3.1 +/- 2.8/10(3) vs 10.8 +/- 8.8/10(3) hepatocytes, p<0.0011) and was correlated with serum ALT (r=0.86, p<0.01) and aspartate aminotransferase levels (r=0.83, p<0.01). The rate of apoptosis detected by TUNEL assay was low and not different between patients with persistently normal and elevated aminotransferases. Staining with anti-M30 revealed a granular staining pattern and showed a trend towards higher cell death rates in patients with elevated aminotransferase levels (apoptotic hepatocytes with >75% staining: 3.97 +/- 6.24/10(3) hepatocytes vs 13.65 +/- 19.41/10(3) hepatocytes; p=0.08). CONCLUSIONS: Patients with chronic hepatitis C and normal aminotransferases have significantly lower hepatocyte proliferation rates and show a trend towards lower apoptosis rates compared with patients with elevated aminotransferases.

Adult↗
PubMed2000

Detection of residual hepatitis C virus RNA by transcription-mediated amplification in patients with complete virologic response according to polymerase chain reaction-based assays.

A considerable proportion of patients with chronic hepatitis C who achieve a virologic end-of-treatment response relapse after discontinuation of therapy. It is conceivable that polymerase chain reaction (PCR)-based assays with a lower detection limit of 100 to 1, 000 hepatitic C virus (HCV) RNA copies/mL are still too insensitive to detect residual viremia. End-of-treatment serum samples of 47 patients with a virologic relapse according to results of qualitative PCR assays (Amplicor HCV; Roche Molecular Systems, Mannheim, Germany) were tested by transcription-mediated amplification (TMA), an isothermal, autocatalytic target amplification method that has the potential to detect less than 50 HCV RNA copies/mL. Virologic sustained responders (n = 59) and nonresponders (n = 49) served as controls. In end-of-treatment serum samples of virologic sustained responders and nonresponders an almost complete concordance between PCR and TMA results was observed (98%). However, HCV RNA was detectable by TMA in end-of-treatment serum samples from 16 of 25 relapse patients (64%) who were HCV-RNA-negative according to Amplicor HCV version 1.0 (lower detection limit 1,000 copies/mL) and in 8 of 22 patients (36%) who were HCV-RNA-negative according to Amplicor HCV version 2.0 (lower detection limit 100 copies/mL). End-of-treatment alanine transaminase (ALT) levels of sustained virologic responders and TMA-negative relapsers were similar, whereas a trend toward higher ALT values was observed in TMA-positive relapsers compared with sustained virologic responders (P = 0.09). In conclusion, HCV RNA can be detected at the end of treatment by TMA in a considerable proportion of patients who were classified as virologic end-of-treatment responders with a subsequent virologic relapse according to PCR-based methods.

Adult↗
PubMed2000

Mutations within the E2 and NS5A protein in patients infected with hepatitis C virus type 3a and correlation with treatment response.

Defined regions of hepatitis C virus (HCV) envelope 2 (E2), PePHD, and nonstructural 5A (NS5A) protein (PKR-binding domain) have been shown to interact with interferon alfa (IFN-alpha)-inducible double-stranded RNA-activated protein kinase (PKR) in vitro, suggesting a possible mechanism of HCV to evade antiviral effects of IFN-alpha. The clinical correlation between amino acid mutations within the E2 PePHD or the NS5A PKR-binding domain and response to antiviral treatment in HCV-3a-infected patients is unknown. Thirty-three patients infected with HCV-3a isolates were treated with IFN-alpha with or without ribavirin. The carboxyterminal half of E2 and of the NS5A gene were sequenced. Sixteen patients achieved a sustained virological response (SR), 6 patients an end-of-treatment response with relapse thereafter (ETR), and 11 patients were nonresponders (NR). Within the PePHD of the E2 protein 0.5 (range, 0-2) mutations were observed in SR patients, whereas the number of mutations in ETR or NR patients was 0.2 (0-1). Quasispecies analyses showed almost no heterogeneity. The mean number of mutations within the PKR-binding domain of the NS5A protein was 1.6 (range, 0-4) in SR patients, 1 (0-2) in ETR patients, and 1.6 (0-3) in NR patients. Patients with higher numbers of mutations within the E2 or NS5A region showed a trend towards lower pretreatment viremia. Phylogenetic and conformational analyses of E2 or NS5A sequences allowed no differentiation between sensitive and resistant isolates. However, mutations within the E2 PePHD in SR patients were frequent, and hydrophobic mutations within the hydrophilic area of PePHD at codon 668 and 669 were exclusively observed in sustained virological responders.

Adult↗
PubMed2000

Mutations in the protein kinase-binding domain of the NS5A protein in patients infected with hepatitis C virus type 1a are associated with treatment response.

An interaction of the hepatitis C virus (HCV) NS5A protein with the interferon (IFN)-alpha-inducible double-stranded RNA-activated protein kinase (PKR) was demonstrated in vitro. The clinical correlation between amino acid mutations within the HCV NS5A region and response to antiviral treatment is controversial. Thirty-two patients chronically infected with HCV-1a, who were treated with IFN-alpha with or without ribavirin, were studied. The carboxy-terminal half of HCV NS5A was sequenced and was investigated by phylogenetic and conformational analyses. Eight patients achieved a sustained virologic response. An end-of-treatment response but relapse thereafter was observed among 8 patients, whereas 16 patients were nonresponders. The median number of mutations within the PKR-binding domain but not within the previously described IFN sensitivity-determining region was significantly higher for patients with sustained (3 mutations [range, 1-5]) or end-of-treatment (4 mutations [range, 1-5]) virologic response than for nonresponders (2 mutations [range, 0-3]) (P=.0087). Phylogenetic and conformational analyses of NS5A sequences allowed no differentiation between sensitive and resistant strains.

Adult↗
PubMed1999

Improved correlation between multiple mutations within the NS5A region and virological response in European patients chronically infected with hepatitis C virus type 1b undergoing combination therapy.

BACKGROUND/AIMS: Studies from Japan showed that HCV-1b isolates with at least four amino acid changes within NS5A2209-2248 compared with the prototype sequence HCV-J are more sensitive to interferon than isolates with a prototype sequence. However, the data were not unequivocally confirmed in studies from other geographical areas. These discrepancies may be explained by differences in the prevalence of multiple mutations within the NS5A2209-2248 and/or the treatment efficacy. METHODS: In the present study, we therefore investigated the correlation between NS5A2209-2248 sequences of HCV-1b isolates and sustained virological response in 72 European patients treated with 3x6 MU interferon-a per week with (n = 26) and without (n = 46) ribavirin (1000-1200 mg/day). Serum HCV RNA was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and the NS5A2209-2248 region was analyzed by sequencing of PCR products or individual clones. RESULTS: Compared with HCV-1b prototype sequences, 19 patients (26%) had no amino acid changes (prototype), 47 patients (65%) had 1-3 mutations (intermediate type) and six patients (8%) had at least 4 mutations in the NS5A2209-2248 region (mutant type). Nine of the 12 patients with sustained virological response were infected with an intermediate type HCV-1b, the remaining three patients revealed a mutant type HCV-1b. A sustained virological response was achieved in three of four patients with a mutant type HCV-1b treated with interferon-alpha and ribavirin, but in none of the mutant type HCV-1b infected patients treated with interferon-a alone. Quasispecies analysis of HCV in the NS5A2209-2248 region showed only minor heterogeneity of the amino acid sequence. CONCLUSIONS: The prevalence of mutant type HCV-1b isolates in European patients is low. In patients treated with combination therapy interferon-a and ribavirin, a correlation between mutant type HCV-1b isolates and sustained virological response was observed. The discrepancies between previous studies appear to be related to the efficacy of antiviral treatment and to the low prevalence of mutant type HCV-1b isolates in Western countries.

Adult↗
PubMed1999

Peri-hepatic lymphadenopathy in primary biliary cirrhosis reflects progression of the disease.

OBJECTIVE: We prospectively investigated the peri-hepatic lymph node volume in patients with primary biliary cirrhosis (PBC) and healthy controls to evaluate the correlation with histology, biochemical and immunological features. MATERIALS AND METHODS: The total peri-hepatic lymph node volume in the liver hilus was evaluated by high-resolution ultrasound in 67 consecutive patients with PBC and in 43 healthy controls. Stages I-IV of PBC were biochemically, immunologically and histologically proven in all patients. RESULTS: Adequate visualization of the liver hilus was achieved in 59/67 patients (88%) with PBC and in 39/43 healthy controls (91%). Lymph nodes in the liver hilus were sonographically detected in all 59 patients with PBC and in 26/39 healthy controls (67%) with adequate visualization of the liver hilus. The mean peri-hepatic lymph node volumes were: stage I (n = 9): 0.8 +/- 0.5 ml; stage II (n = 28): 2.4 +/- 1.5 ml; stage III (n = 21): 4.2 +/- 2.3 ml; stage IV (n = 9): 3.2 +/- 1.0 ml. The peri-hepatic lymph node volume did not significantly correlate with cholestasis, liver function tests or the immunological status. CONCLUSIONS: Enlarged lymph nodes in the liver hilus are sonographically detectable in almost all patients with PBC. The total peri-hepatic lymph node volume in patients with PBC reflects histological stage, i.e. larger lymph nodes are observed in more advanced disease.

Adult↗
PubMed1998

Effect of ribavirin on virus load and quasispecies distribution in patients infected with hepatitis C virus.

BACKGROUND/AIMS: The combination of ribavirin and interferon alfa has potent synergistic effects in the treatment of chronic hepatitis C. The antiviral mechanism of ribavirin is unknown. We investigated whether a transient initial antiviral effect of ribavirin was sufficient to improve the response to interferon. METHODS: Fifteen HCV-infected patients (ten male, five female; mean age 45.4+/-11.0 years) treated with ribavirin (1000-1200 mg) and 17 untreated patients with chronic hepatitis C (11 male, six female; mean age 45.6+/-9.9 years) were investigated. All patients were either non-responders to (n=19) or relapsed after (n=13) previous interferon treatment. Serum HCV-RNA concentrations and HCV quasispecies distribution were serially measured over 4 weeks by quantitative reverse transcription-polymerase chain reaction and single-strand conformation polymorphism analysis, respectively. RESULTS: In six of the 15 patients treated with ribavirin, but in none of the controls, serum alanine aminotransferase levels declined by at least 30%. Pretreatment HCV-RNA levels ranged from 5.0x10(5)-5.0x10(7) copies/ml. After initiation of ribavirin treatment, minor (0.5-1.0 log) or no changes (<0.5 log) in total hepatitis C viremia were observed in ten and five patients, respectively. In HCV-infected patients without treatment 7/17 patients had minor and 10/17 no changes in viremia. Polymerase chain reaction amplification of the hypervariable region-1 of HCV was successful in 13/15 treated and in 17/17 untreated patients. Changes in HCV quasispecies according to the single-strand conformation polymorphism band pattern occurred in only one patient treated with ribavirin and in three of the untreated patients. CONCLUSIONS: Ribavirin monotherapy has no initial antiviral effect on total hepatitis C viremia nor on HCV quasispecies. Unlike the rapid emergence of antiviral drug-resistant strains in HIV-infected patients, no viral escape phenomena are observed in HCV-infected patients treated with ribavirin.

Adult↗
PubMed1998

Hepatic and portal vein flow pattern in correlation with intrahepatic fat deposition and liver histology in patients with chronic hepatitis C.

OBJECTIVE: The flow pattern in hepatic veins depends on cardiac physiology and liver histology. The aim of our study was to determine the dependence of the flow pattern of hepatic and portal veins in relation to histologic features in patients with chronic hepatitis C. SUBJECTS AND METHODS: In 135 patients with chronic hepatitis C, the Doppler sonography spectrum of the right hepatic vein was classified as triphasic, biphasic, or monophasic. The flow of the portal vein was characterized according to the undulation (velocity(max,min)). A liver biopsy was performed during sonography, and biopsy specimens were semiquantitatively evaluated on a histologic activity index and a score of the hepatic fat content. Multiple logistic regression analysis was used to identify the histologic features that might contribute to the type of flow pattern. RESULTS: The hepatocyte fat content was the only variable associated with an independent effect on the type of flow pattern (monophasic versus triphasic; odds ratio, 16.26; 95% confidence interval, 6.38-41.45; p < .0001). A pronounced undulation in the portal vein was associated with portal inflammation but not with other parameters of the histologic activity index or the intrahepatic fat deposition. CONCLUSION: On sonography, the normal flow pattern in the right hepatic vein is triphasic. The monophasic flow pattern in the right hepatic vein is mainly caused by intrahepatic fat deposition and occasionally by inflammatory or fibrotic changes. Conversely, the flow pattern of the portal vein is mainly influenced by portal inflammation.

Adult↗
PubMed1998

[GB virus-C/hepatitis G virus--discovery, epidemiology, diagnosis and clinical relevance].

Recently, two isolates of a new virus, designated GB virus C (GBV-C) and hepatitis G virus (HGV) were identified. Genomic organization place them in the family Flaviviridae, which includes HCV. A classification of GBV-C/HGV strains into at least three genotypes (West Africa, Europe/North America, Asia) has been proposed. GBV-C/HGV has a positive-stranded, linear RNA genome possessing a large open reading frame that encodes a single large polyprotein. As a possible genomic defect no core protein has yet been identified in GBV-C/HGV isolates. Whether GBV-C/HGV can be classified as a hepatotropic virus with replication in the liver is under discussion. The prevalence in the general population is high (2%). GBV-C/HGV is transmitted parenterally e.g., by transfusion of blood and blood products. Furthermore, cases of vertical and horizontal transmission are reported. Detection of GBV-C/HGV infection is exclusively possible by reverse transcription polymerase chain reaction (RT PCR). E2-specific antibodies are associated with loss of detectable GBV-C/HGV RNA and appear to indicate recovery from GBV-C/HGV infection. An acute icteric state with transient elevation of aminotransferases in association with GBV-C/HGV infection may exist. These cases are rare and approximately only 0.3% of persons with acute viral hepatitis are infected with GBV-C/HGV alone. Whether GBV-C/HGV is a cause of fulminant hepatic failure has not yet been proven. Persistent viremia of the GBV-C/HGV infection is frequent but is not related to chronic liver disease. Since no other chronic diseases associated with GBV-C/HGV infection could yet be identified, chronic GBV-C/HGV infections appear to be without clinical significance. GBV-C/HGV and hepatitis B or C virus (HBV, HCV) coinfection seem not to interfere with the outcome of HBV-respective HCV-related liver disease. The cause of the majority of cases with non-A-E viral hepatitis remains unknown and other yet undiscovered hepatic viruses must exist.

Cross-Sectional Studies↗
PubMed1997

Prevalence and clinical and histological manifestation of hepatitis G/GBV-C infections in patients with elevated aminotransferases of unknown etiology.

BACKGROUND/AIMS: Hepatitis G virus (HGV) and hepatitis GB virus-C (GBV-C) are recently identified non-A-E hepatitis-associated viruses. The prevalence of HGV/GBV-C in the general population is high (1.0-1.7%), but data on the clinical and histological manifestations of the new viruses are sparse. In the present study we investigated the prevalence and clinical and histological manifestation of HGV/GBV-C infections in patients with elevated aminotransferase levels of unknown etiology. METHODS: In 52 of 630 consecutive patients referred for evaluation of elevated aminotransferases the underlying liver disease remained unknown. Serum samples of these 52 patients with elevated aminotransferase levels of unknown etiology were tested for HGV/GBV-C RNA by reverse transcription-polymerase chain reaction (RT-PCR) using primers deduced from nonstructural regions. Cloned PCR products were sequenced and compared by phylogenetic analysis. RESULTS: HGV/GBV-C RNA was consistently detected in 7 of the 52 patients (13%). Sequence and phylogenetic analysis revealed the presence of only one subtype, with nucleotide sequence homologies between 86 and 91%. All seven patients had persistent viremia for at least 9 months. In six patients liver function test results normalized, and alanine aminotransferase levels remained persistently elevated in only one patient. Four HGV/GBV-C positive and ten HGV/GBV-C negative patients consented to a liver biopsy, which revealed similar results with minimal to mild chronic hepatitis and mild portal fibrosis. CONCLUSIONS: The prevalence of HGV/GBV-C infections in patients with elevated aminotransferases of unknown etiology is low. Since clinical, biochemical and histomorphologic features of patients with elevated aminotransferases of unknown etiology with and without HGV/GBV-C infection are indistinguishable, the role of HGV/GBV-C in the pathogenesis of chronic liver disease appears insignificant.

Adult↗
PubMed1997

Heterosexual transmission of GB virus-C/hepatitis G virus infection.

GB virus-C (GBV-C) and hepatitis G virus (HGV) are recently identified non-A-E hepatitis-associated viruses belonging to the family Flaviviridae. The prevalence of GBV-C/HGV in the general population is high (1.2-3.0%), but data on possible transmission routes are sparse. In this report GBV-C/HGV RNA was detected in a couple by reverse transcription polymerase chain reaction (RT-PCR) using primers deduced from non-structural regions. Neither partner was coinfected with hepatitis B (HBV), hepatitis C (HCV) or human immunodeficiency virus (HIV). The child of the couple tested repeatedly negative for GBV-C/HGV by RT-PCR. The couple had lived in a stable monogamous relationship for 10 years and had never used barrier contraception. Other than sexual risk, factors for transmission were carefully excluded. GBV-C/HGV isolates obtained from the couple were sequenced and phylogenetically analysed together with control GBV-C/HGV isolates. The evolutionary distance between the sequences obtained from the couple (1%) was smaller than between any other GBV-C/HGV sequence. Taken together, the clinical and molecular data provide strong evidence for heterosexual but not vertical transmission of GBV-C/HGV in non-coinfected individuals.

Adult↗
PubMed1994

Topoisomerase I-inhibition enhances vitamin D-responsive expression of the receptor for lipopolysaccharide binding protein CD 14.

Pretreatment (4h) of human HL 60 leukemia cells with the topoisomerase I-inhibitor camptothecin (7-28 x 10(-9) Mol/l, single dose) enhanced vitamin D3-responsive CD 14 expression (10(-11)-10(-8) Mol/l vitamin D3) up to twofold, as measured by fluorescence activated flow cytometry after 1-3 days. Camptothecin by itself caused marginal effects. Hybridization of total RNA with oligonucleotides (bases 1358-1333 of CD 14 sequence) showed increased steady state levels of the 1.75 kb CD 14 mRNA after 24 h when normalized to beta-actin. The nuclear accumulation of [3H]-vitamin D3/receptor complexes (VDR) in a nuclear translocation assay was significantly enhanced (by 3 h) in the presence of camptothecin. We conclude that inhibition of topoisomerase I enhances vitamin D3-stimulated CD 14 expression. Topoisomerase I might either be a negatively active transcription factor itself or maintenance of DNA-bending, local supercoiling and accessibility of responsive elements might lead to reduction of VDR turnover and produce a stimulatory effect on vitamin D3-responsive transcription.

Acute-Phase Proteins↗
PubMed1990

Additive latency effects of selective and nonselective restricted priming types.

The purpose of this investigation was to examine further the contention of Alain et al. (1988) that a third priming type exists, called nonselective restricted (NSR) and controlled by response probability, which is distinct from those types influenced by foreperiod duration (nonselective general priming) and prediction probability (selective priming). In a four-choice reaction time (RT) task, prediction probability (.5, .7, & .9, indicating the likelihood of a particular response) and response probability (.5, .9, denoting the likelihood that a response would be needed at all) exerted significant but noninteractive effects on RTs for prepared responses (most probable), suggesting that each of these probabilities influence different priming types (Sternberg, 1969; selective and NSR, respectively). This was further indicated by the fact that prediction probability, but not response probability, significantly altered RTs for the unprepared (lesser probable) responses. Finally, the hypothesized nonselective character of NSR priming (i.e., all outputs controlled by response probability are equally affected by its value changes) was supported when responses were equiprobable, and, while the null effect of response probability just mentioned seemingly argued against this property when selective priming took place, the interpretation provided herein negated this opposition.

Adult↗
PubMed1990

Study of decision-making in squash competition: a computer simulation approach.

This paper describes how a computer simulation approach was used to specify some of the cognitive processes underlying decision-making in squash competition. The work presented in this article focused on the cognitive strategy of the defending player when choosing among three categories of preparation. (Total preparation for one particular event, partial preparation in favor of one event, and absence of biased preparation.) The defending player is viewed as in information processing system (IPS) placed in a problem-solving situation, the problem being what decision to reach. There are four steps inherent to the computer simulation approach: (a) obtaining the verbal protocol, (2) analyzing the protocol, (3) computer simulation, and (4) validation. This paper describes how each of those steps have been completed, with a special emphasis being placed on the first step of the procedure, that of obtaining the verbal protocol.

Cognition↗