Search PubMed⌕ Search

Biomedical subjects

G A Miller

Publications and source records attributed to G A Miller.

At least 37 records · Page 2Linked to original sources
PubMed2000

Guidelines for using human event-related potentials to study cognition: recording standards and publication criteria.

Event-related potentials (ERPs) recorded from the human scalp can provide important information about how the human brain normally processes information and about how this processing may go awry in neurological or psychiatric disorders. Scientists using or studying ERPs must strive to overcome the many technical problems that can occur in the recording and analysis of these potentials. The methods and the results of these ERP studies must be published in a way that allows other scientists to understand exactly what was done so that they can, if necessary, replicate the experiments. The data must then be analyzed and presented in a way that allows different studies to be compared readily. This paper presents guidelines for recording ERPs and criteria for publishing the results.

Cognition↗
PubMed2000

Neuropsychological differentiation of depression and anxiety.

The high comorbidity of depression and anxiety is well established empirically but not well understood conceptually, in terms of either psychological or biological mechanisms. A neuropsychological model of regional brain activity in emotion provides contrasting hypotheses for depression and anxiety, with depression associated with a relative decrease and anxiety with a relative increase in right-posterior activity. These hypotheses received support in a comparison of individuals diagnosed with depression and community controls, and also in a separate study of nonpatients administered a measure of perceptual asymmetry. Hierarchical regressions revealed that depression and anxiety were uniquely and jointly associated with perceptual asymmetry. In light of consistent empirical support for the model, implications for conceptualizations of the comorbidity of depression and anxiety are discussed.

Adult↗
PubMed2000

Immunohistochemical staining of the mismatch repair gene, hMSH2, and survival in patients with ovarian carcinoma.

OBJECTIVE: hMSH2 is a mismatch repair gene. The protein of this gene can be demonstrated by immunohistochemical methods. The authors wanted to analyze whether the percent of positive nuclear area staining of the hMSH2 protein correlated with survival in patients with ovarian carcinoma. METHODS: One hundred and two patients with epithelial ovarian carcinoma were studied. Slides were prepared from snap frozen tissue. Quantification of staining and DNA index were performed using image analysis. In addition to hMSH2, FIGO stage, grade, histology, and level of cytoreduction were analyzed as prognostic factors. RESULTS: Mean follow-up was 64 months and median was 59 months. Nineteen patients had stage I cancers, 4 stage II, 59 stage III, and 20 stage IV. Optimal cytoreduction was accomplished in 71% of patients. hMSH2 staining was significantly higher in better differentiated tumors (p=0.006), but there was no difference in staining among the FIGO stages (p=0.43). Cox regression analysis revealed FIGO stage (p=0.0005), level of cytoreduction (p=0.006) and hMSH2 staining (p=0.016) to be independent predictors of survival in patients with ovarian carcinoma. CONCLUSION: The hMSH2 protein can be demonstrated by immunohistochemical methods and quantified by image analysis. hMSH2 staining was shown to be an independent prognostic indicator of survival in patients with ovarian carcinoma.

Adult↗
PubMed1999

A study of heat shock protein 27 in endometrial carcinoma.

OBJECTIVE: Heat shock protein 27 (HSP27) is a relatively small protein produced in response to pathophysiologic stress. The purpose of this study was to determine prospectively whether HSP27 was associated with known prognostic factors in patients with endometrial carcinoma. METHODS: One hundred fifty-three consecutive patients with endometrial carcinoma were studied. Slides were prepared from fresh tissue. HSP27 was analyzed using a semiquantitative measurement. Patient records were examined for FIGO stage, grade, depth of myometrial invasion, histology, lymphovascular space invasion, time to recurrence, and survival. RESULTS: The mean follow-up was 53 months (median 56 months, range 30-68 months). Endometrioid tumors showed significantly higher HSP27 staining than nonendometrioid tumors (P = 0.005). Patients alive at the conclusion of this study had significantly higher mean HSP27 staining than patients who were deceased (P < 0.001). Logistic regression revealed HSP27 staining (P = 0.02), FIGO stage (P = 0. 014), and lymphovascular space invasion (P = 0.046) to be independently predictive of survival. CONCLUSION: HSP27 staining is significantly higher in endometrioid than nonendometrioid tumors. HSP27 staining is an independent prognostic indicator in patients with endometrial carcinoma, the most common gynecologic malignancy in the United States.

Adult↗
PubMed1999

p53 expression as a prognostic indicator of 5-year survival in endometrial cancer.

BACKGROUND: One of the most common genetic alterations to occur in human cancers is an alteration of the p53 tumor suppressor gene. The purpose of this article was to build upon the authors' previous work with p53 and determine whether p53 was a prognostic indicator of 5-year survival. METHODS: One hundred thirty-seven consecutively surgically treated patients with endometrial cancer had their p53 expression studied by immunoperoxidase staining and quantified by image analysis. All patients were evaluable for 5-year survival. RESULTS: One hundred three patients had endometrioid adenocarcinoma; 6, adenosquamous carcinoma; 14, papillary serous carcinoma; 10, clear cell carcinoma; and 4, undifferentiated carcinoma. p53 expression ranged from 0.0 to 58.2% positive nuclear area with a mean of 11.5% (median 2.6%) for the cohort. For the patients with endometrioid carcinoma, the mean p53 expression was 7.1% while for the nonendometrioid tumors it was 24.6% (P<0.001). Fifty-nine of the 103 endometrioid tumors (57.3%) stained positive for p53 while 32 of the 34 nonendometrioid (94.1%) tumors stained positive (P<0.001). Increasing histologic grade correlated with an increasing p53 expression (P = 0.003). The percentage of tumors expressing p53 was found to be higher in FIGO stage II, III, and IV than in FIGO stage I cancer (P = 0.003). However, mean p53 expression did not differ between early (stage I) and advanced (stage II, III, and IV) cancers (P = 0.088). Utilizing 5-year survival as the endpoint for multivariate analysis, FIGO stage (P = 0.0028) and p53 expression (P<0.001) were the only independent prognostic indicators found. CONCLUSION: p53 expression is more commonly found in nonendometrioid than in endometrioid adenocarcinoma of the endometrium. It, along with FIGO stage, is an independent prognostic indicator of 5-year survival.

Adult↗
PubMed1999

MIB-1 in endometrial carcinoma: prognostic significance with 5-year follow-up.

OBJECTIVE: MIB-1, a monoclonal antibody to the Ki-67 antigen, has presumptively been shown to be predictive of recurrent disease in patients with endometrial cancer. In order to more conclusively establish whether MIB-1 staining can be used as a prognostic indicator of recurrent disease or survival, a larger group of patients with a minimum follow-up of 5 years was analyzed. METHODS: The tumors from 147 consecutive patients receiving primary surgical therapy for endometrial carcinoma were evaluated with the MIB-1 monoclonal antibody. Proliferation index was quantified by image analysis. Patients were followed for a minimum of 60 months. In addition to MIB-1 staining, histologic type, stage, grade, depth of invasion, lymphovascular space invasion, and peritoneal cytology were evaluated as prognostic indicators. RESULTS: Twenty-five of 147 patients died during the study period. MIB-1 staining was not significantly elevated in advanced (stage II, III, and IV) as opposed to early (stage I) carcinomas (P = 0.38). In patients whose tumor MIB-1 staining was less than 33.0%, no deaths occurred. By multivariate analysis, only MIB-1 staining (P < 0.001), FIGO stage (P = 0.005), and LVI (P = 0.005) were shown to be independent prognostic indicators predictive of survival. CONCLUSION: In this series of 147 consecutive patients with endometrial carcinoma, the monoclonal antibody MIB-1 was shown to be an independent prognostic indicator of 5-year survival. This follow-up further validates the previous work regarding the significance and potential usefulness of MIB-1 as a prognostic indicator.

Antibodies, Monoclonal↗
PubMed1999

Converging evidence for a cognitive anomaly in early psychopathology.

Subcomponents of the N200 component of the event-related brain potential believed to be differentially sensitive to involuntary and voluntary cognitive processes were examined. Nonpatients (N = 131) identified initially by the Chapman and Depue research scales and classified later on the basis of diagnostic symptom clusters and family psychiatric history provided converging evidence for an intact mismatch negativity subcomponent. In contrast, the N2b subcomponent distinguished several groups of subjects. Results suggested abnormal voluntary cognitive processing, perhaps reflecting compensatory efforts in subjects at risk for or manifesting psychopathology, particularly those showing negative symptoms.

Adolescent↗
PubMed1999

Instrumentation for the genome project.

Much of the recent rapid progress in large-scale genomic sequencing has been driven by the dramatic improvements both in the area of biological protocols and in the availability of improved laboratory instrumentation and automation platforms. We discuss recent developments in the area of bioinstrumentation that are contributing to the current revolution in genetic analysis. Examples of systems for laboratory automation are described together with specific single-purpose instruments. Emphasis is placed on those tools that are contributing significantly to the scale-up of genomic mapping and sequencing efforts. In addition, we present a selection of more advanced measurement techniques and instrumentation developments that are likely to contribute significantly to future advances in sequencing and genome analysis.

Automation↗
PubMed1999

On knowing a word.

A person who knows a word knows much more than its meaning and pronunciation. The contexts in which a word can be used to express a particular meaning are a critical component of word knowledge. The ability to exploit context in order to determine meaning and resolve potential ambiguities is not a uniquely linguistic ability, but it is dramatically illustrated in the ease with which native speakers are able to identify the intended meanings of common polysemous words.

Journal Article↗
PubMed1999

Contrasting patterns of brain activity in anxious apprehension and anxious arousal.

Evidence suggests that a distinction between anxious apprehension (worry) and anxious arousal (somatic anxiety) might account for some discrepancies in the literature examining brain activity in anxiety. In the current study, we compared the regional brain activity of groups of anxious apprehension and anxious arousal participants, selected on the basis of self-report measures previously shown to be psychometrically distinct from each other and from a specific measure of depression. Patterns of hemispheric asymmetry in electroencephalogram alpha distinguished the two types of anxiety, with the anxious arousal group showing more right than left activity. No significant asymmetry was found for the anxious apprehension group. The results provide further support for contrasting patterns of brain activity in distinct types of anxiety. Research is needed to specify further the topography and functional significance of this distinction.

Adolescent↗
PubMed1998

Transient clouds in Titan's lower atmosphere.

The 1980 encounter by the Voyager 1 spacecraft with Titan, Saturn's largest moon, revealed the presence of a thick atmosphere containing nitrogen and methane (1.4 and approximately 0.05 bar, respectively). Methane was found to be nearly saturated at Titan's tropopause, which, with other considerations, led to the hypothesis that Titan might experience a methane analogue of Earth's vigorous hydrological cycle, with clouds, rain and seas. Yet recent analyses of Voyager data indicate large areas of super-saturated methane, more indicative of dry and stagnant conditions. A resolution to this apparent contradiction requires observations of Titan's lower atmosphere, which was hidden from the Voyager cameras by the photochemical haze (or smog) in Titan's stratosphere. Here we report near-infrared spectroscopic observations of Titan within four narrow spectral windows where the moon's atmosphere is ostensibly transparent. We detect pronounced flux enhancements that indicate the presence of reflective methane condensation clouds in the troposphere. These clouds occur at a relatively low altitude (15+/-10 km), at low latitudes, and appear to cover approximately 9 per cent of Titan's disk.

Atmosphere↗
PubMed1998

Heat shock protein 27: an independent prognostic indicator of survival in patients with epithelial ovarian carcinoma.

OBJECTIVE: Heat shock protein 27 (HSP27) is produced in response to pathophysiologic stress in animal cells. The purpose of this study was to determine prospectively whether HSP27 was associated with known prognostic factors as well as survival in patients with epithelial ovarian carcinoma. METHODS: Ninety-nine patients with epithelial ovarian carcinoma were studied. Slides were prepared from fresh tissue. Patient records were examined for FIGO stage, grade, histology, level of cytoreduction, and survival. RESULTS: Immunohistochemical staining for HSP27 was not related to histologic grade, level of cytoreduction or histologic subtype. A statistically significant difference in HSP27 staining was found in relation to FIGO stage (P = 0.013). HSP27 staining was found to be an independent predictor of 2-year survival in these patients (P = 0.041). CONCLUSION: The level of HSP27 significantly decreases as the FIGO stage increases and is an independent prognostic indicator of survival in patients with epithelial ovarian carcinoma.

Adult↗
PubMed1998

Lack of bcl-2 persistence: an independent prognostic indicator of poor prognosis in endometrial carcinoma.

OBJECTIVE: bcl-2 is a protein which prohibits programmed cell death. The purpose of this study was to determine whether bcl-2 staining was related to traditional prognostic factors and/or recurrence in patients with endometrial carcinoma. METHODS: One hundred twenty consecutively surgically treated patients with endometrial carcinoma had their tumors studied immunohistochemically for bcl-2 staining. RESULTS: The mean follow-up of the patients was 53 months with a median of 56 months (range 30 to 68 months). bcl-2 staining was positive in 44.0% of patients with endometrioid carcinomas and in 23. 1% of patients with nonendometrioid carcinomas (P < 0.001). Increasing depth of invasion (P = 0.014), grade (P = 0.011), and FIGO stage (P = 0.018) were each correlated with decreasing bcl-2 staining. bcl-2 staining was positive in 44.1% of patients whose tumors showed no lymphovascular space invasion and in 11.1% of patients with lymphovascular space invasion (P < 0.001). Only 1 of 26 patients with recurrent disease had persistence of bcl-2 staining. Multivariate analysis revealed FIGO stage (P = 0.0051), histologic grade (P = 0.050), and lack of staining for bcl-2 (P = 0.012) to be independent predictors of recurrence. CONCLUSION: bcl-2 persistence is more common in endometrioid than in nonendometrioid adenocarcinomas of the endometrium. It appears to be inversely correlated with the universally recognized prognostic factors of depth of invasion, histologic grade, and FIGO stage. Lack of bcl-2 persistence was an independent predictor of recurrence of disease. This group of patients continues to be followed to determine the role of bcl-2 persistence or lack of persistence as a predictor of 5-year survival of patients with endometrial carcinoma.

Endometrial Neoplasms↗
PubMed1998

Cytokine production by cryopreserved human peripheral blood mononuclear cells in response to periodontal pathogens.

Freezing techniques provide a way of repeating and extending immunological assays by using frozen portions of an individual's peripheral blood mononuclear cell fraction. Earlier work shows that the lymphocytes that are stored frozen retain their ability to respond to polyclonal B-cell activators, mitogens, superantigens and bacterial extracts of oral interest. These studies extend previous findings by determining cytokine production by lymphocytes following frozen storage for up to 24 weeks. Production of interleukin (IL)-1beta, IL-2, IL-6, and tumour necrosis factor (TNF)-beta by stimulated lymphocytes after cyropreservation was not significantly different from those responses before storage, with one exception: IL-6 production was negligible after 24 weeks' frozen storage when thawed cells were cocultured with pokeweed mitogen. After stimulation with extracts from Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans, the proliferative capacity of the frozen cells was maintained as well as the production of IL-1beta, IL-2, and IL-6. TNF-beta was not produced in response to bacterial antigen stimulation. The ability of peripheral blood mononuclear cells to retain functional activity after frozen storage should permit more effective monitoring during longitudinal clinical studies and a better evaluation of changes in cytokine production in patients with advanced periodontitis both during and after treatment.

Aggregatibacter actinomycetemcomitans↗
PubMed1998

Interleukin-6 in neutrophils from peripheral blood and inflammatory periradicular tissues.

Periradicular tissue samples were recovered from patients undergoing endodontic surgery. Immunohistochemical procedures were used to identify interleukin-6 (IL-6) present in the neutrophils associated with these lesions. Using specific polyclonal antibody, 15 to 20% of the neutrophils associated with the periradicular tissue lesions were positive for IL-6. IL-6-positive plasma cells and histiocytes were also abundant. Cytokine production by neutrophils from the peripheral blood of nondiseased individuals was also evaluated. The cells were stimulated with lipopolysaccharides and bacterial extracts of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. Significant levels of IL-6 were produced by cells stimulated with Escherichia coli lipopolysaccharide B5 (933 pg/ml/10(7) neutrophils) and E. coli lipopolysaccharide B12 (791 pg/ml/10(7) neutrophils) when compared with unstimulated cells (39.31 pg/ml/10(7) cells). There was a dose-dependent increase in IL-6 production when cells were stimulated for 24 h with 6 and 12 micrograms/ml of A. actinomycetemcomitans extract. Less stimulation occurred with P. gingivalis, but it was also dose-dependent. Neutrophils resident in periradicular lesions may, therefore, provide a source of IL-6 in addition to that produced by tissue histiocytes and plasma cells.

Aggregatibacter actinomycetemcomitans↗
PubMed1998

Comparative genomic hybridization and its application to Wilms' tumorigenesis.

Eighty sporadic Wilms' tumor samples were analyzed by comparative genomic hybridization (CGH) to identify chromosomal regions involved in the etiology of the disease. Twenty percent of the samples showed chromosomal gains or losses. The majority of chromosomal gains and losses were similar to those identified through molecular and cytogenetic studies. Gains were observed on chromosomes 1q, 7q, 8, and 12, whereas losses were found on chromosomes 1p, 4p, 4q, 7p, 16q, 18q, 21q, and 22q. Other genetic aberrations identified in this study included deletions of chromosomes 5p and 15q, as well as gains of discrete loci on chromosomes 3p and 3q. These latter regions have not been previously implicated in Wilms' tumorigenesis and may contain novel genes relevant to the development and/or progression of this disease.

Chromosome Aberrations↗
PubMed1998

Efficacy of the Substance Abuse Subtle Screening Inventory-3 (SASSI-3) in identifying substance dependence disorders in clinical settings.

This article presents analyses on psychometric properties of a recent revision of the Substance Abuse Subtle Screening Inventory (SASSI-3). Participants were 772 individuals from a range of clinical settings who were independently diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev. [DSM-III-R]; American Psychiatric Association [APA], 1987) or DSM-IV (APA, 1994) criteria regarding the presence or absence of a substance-dependence disorder. A development sample (n = 391) was used to formulate SASSI-3 decision rules that yielded 95% agreement with clinical diagnoses of substance dependence. Correspondence with the criterion variable was shown to be 97% in a cross-validation sample (n = 381) from the same clinical settings. Convergent relations were demonstrated with a variety of other indexes of substance misuse, including clinical assessments of substance abuse history, alcohol and drug-related arrests, self-reported use of illicit drugs, and other instruments designed to screen for substance misuse. Further, logistic regression analyses indicated no significant differences in the overall accuracy of the SASSI-3 as a function of respondents' demographic characteristics or clinical ratings of respondents' level of adjustment and functioning (Global Assessment of Functioning ratings; APA, 1987, 1994).

Adult↗