Biomedical subjects

D T Miller

Publications and source records attributed to D T Miller.

At least 37 records · Page 2Linked to original sources

PubMed1998

The disparity between the actual and assumed power of self-interest.

Five studies examined the hypothesis that people overestimate the influence of self-interest on attitudes and behaviors. The results strongly supported the hypothesis. In Study 1, participants overestimated the impact that financial reward exerted on their peers' willingness to donate blood. In 4 subsequent studies, participants overestimated the impact that group membership had on their peers' attitudes (Studies 2, 3, and 4) and behaviors (Study 5). The tendency to overestimate the impact of self-interest on others was largely unrelated to the impact that it had on participants' own attitudes and behaviors. Implications of the lay person's belief in the power of self-interest are discussed.

Blood Donors↗

PubMed1998

Iodine nutrition in the United States. Trends and public health implications: iodine excretion data from National Health and Nutrition Examination Surveys I and III (1971-1974 and 1988-1994)

Iodine deficiency in a population causes increased prevalence of goiter and, more importantly, may increase the risk for intellectual deficiency in that population. The National Health and Nutrition Examination Surveys [NHANES I (1971-1974) and (NHANES III (1988-1994)] measured urinary iodine (UI) concentrations. UI concentrations are an indicator of the adequacy of iodine intake for a population. The median UI concentrations in iodine-sufficient populations should be greater than 10 microg/dL, and no more than 20% of the population should have UI concentrations less than 5 microg/dL. Median UI concentrations from both NHANES I and NHANES III indicate adequate iodine intake for the overall U.S. population, but the median concentration decreased more than 50% between 1971-1974 (32.0+/-0.6 microg/dL) and 1988-1994 (14.5+/-0.3 microg/dL). Low UI concentrations (<5 microg/dL) were found in 11.7% of the 1988-1994 population, a 4.5-fold increase over the proportion in the 1971-1974 population. The percentage of people excreting low concentrations of iodine (UI, <5 microg/dL) increased in all age groups. In pregnant women, 6.7%, and in women of child-bearing age, 14.9% had UI concentrations below 5 microg/dL. The findings in 1988-1994, although not indicative of iodine deficiency in the overall U.S. population, define a trend that must be monitored.

Adolescent↗

PubMed1998

Local induction of patterning and programmed cell death in the developing Drosophila retina.

Local cell signaling can pattern the nervous system by directing cell fates, including programmed cell death. In the developing Drosophila retina, programmed cell death is used to remove excess cells between ommatidia. Cell ablation revealed the source and position of signals required for regulating the pattern of programmed cell death among these interommatidial cells. Two types of signals regulate this patterning event. Notch-mediated signals between interommatidial precursors result in removal of unneeded cells. Cone cells and primary pigment cells oppose this signal by supplying a 'life'-promoting activity; evidence is provided that this signal occurs through localized activation of the EGF Receptor/Ras pathway. Together, these signals refine the highly regular pattern observed in the adult retina.

Animals↗

PubMed1998

Regulation of EGF receptor signaling establishes pattern across the developing Drosophila retina.

Developing epithelia use a variety of patterning mechanisms to place individual cells into their correct positions. However, the means by which pattern elements are established are poorly understood. Here, we report evidence that regulation of Drosophila EGF receptor (DER) activity plays a central role in propagating the evenly spaced array of ommatidia across the developing Drosophila retina. DER activity is essential for establishing the first ommatidial cell fate, the R8 photoreceptor neuron. R8s in turn appear to signal through Rhomboid and Vein to create a patterned array of 'proneural clusters' which contain high levels of phosphorylated ERKA and the bHLH protein Atonal. Finally, secretion by the proneural clusters of Argos represses DER activity in less mature regions to create a new pattern of R8s. Propagation of this process anteriorly results in a retina with a precise array of maturing ommatidia.

Animals↗

PubMed1997

Failure to recognize the effect of implicit social influence on the presentation of self.

Two studies demonstrated that individuals can fail to detect changes in their actions that are induced by implicit social influence. In both studies, observers' impressions indicated that actors matched the positivity of their remarks about themselves to the positivity of another person's self-description. However, actors' own judgments of the types of impressions they conveyed revealed that they did not perceive the effect of the other's self-description on their self-presentation. Study 1 suggested that actors' relatively poor access to their own nonverbal behavior could not fully account for their failure to perceive how they were influenced. Study 2 indicated that actors' metaperceptions were connected to actors' general beliefs about themselves, whereas observers' impressions were not. The "blindness" effect was driven primarily by actors low in self-esteem. Implications for self-presentation and other social phenomena are discussed.

Adult↗

PubMed1997

Blastic natural killer cell leukemia/lymphoma: a clinicopathologic study.

The classification of natural killer (NK)-cell and NK-like T-cell malignancies has undergone significant evolution in recent years. Although examples of NK-cell tumors resembling acute leukemia have been described anecdotally as blastic, blastoid, or monomorphic NK-cell leukemia/lymphoma (NKL/L), the clinical and pathologic features of these tumors have not been systematically defined. We report four patients with blastic NKL/L and describe the clinical, pathologic, and immunophenotypic findings in these cases. All patients were elderly (58-82 years) and presented with cutaneous plaques. Two patients also had adenopathy, and three patients had marrow involvement at presentation. Biopsy of cutaneous lesions showed atypical superficial and deep dermal lymphoid infiltrates. Involved lymph nodes were architecturally effaced by an interfollicular infiltrate with blastic cytologic features. In Wright-Giemsa-stained blood or marrow smears, tumor cells had finely distributed nuclear chromatin, many with nucleoli, and variable amounts of cytoplasm. In contrast to many NK and NK-like T-cell disorders, azurophilic cytoplasmic granules were absent or inconspicuous. The tumor cells were immunophenotypically distinctive. They expressed intermediate density CD45, as is characteristic of blasts; in addition, the cells were positive for HLA-DR, CD2, CD4, and the NK-associated antigen CD56. Surface CD3, cytoplasmic CD3, and CD5 were negative in all cases tested, whereas CD7 was expressed in two cases. In formalin-fixed tissue, tumor cells marked with antibodies to CD43, but not with other T- or B-lineage-related antibodies. All three cases studied for Epstein-Barr viral RNA by in situ hybridization were negative. Although treatments varied, all three patients with clinical follow-up died within months of the diagnosis. The clinical course in two patients culminated in an overtly leukemic phase. These findings suggest that blastic NKL/L represents a distinct clinicopathologic entity, characterized by cutaneous, nodal, and marrow involvement by blastic cells with immunophenotypic characteristics of true NK cells. The disease afflicts elderly patients, pursues an aggressive course, and may culminate in overt leukemia.

Aged↗

PubMed1997

Supernormal vision and high-resolution retinal imaging through adaptive optics.

Even when corrected with the best spectacles or contact lenses, normal human eyes still suffer from monochromatic aberrations that blur vision when the pupil is large. We have successfully corrected these aberrations using adaptive optics, providing normal eyes with supernormal optical quality. Contrast sensitivity to fine spatial patterns was increased when observers viewed stimuli through adaptive optics. The eye's aberrations also limit the resolution of images of the retina, a limit that has existed since the invention of the ophthalmoscope. We have constructed a fundus camera equipped with adaptive optics that provides unprecedented resolution, allowing the imaging of microscopic structures the size of single cells in the living human retina.

Contrast Sensitivity↗

PubMed1996

Images of cone photoreceptors in the living human eye.

Though the photoreceptor mosaic has been imaged through the intact optics of the eyes of several species, it has not been clear whether individual photoreceptors can be resolved in the living human eye. We have constructed a high-resolution fundus camera and have resolved cones with a spacing as small as 3.5 microns in single images of the fundus. The high contrast of these images implies that almost all the light returning from the retina at this wavelength (555 nm) has passed through the apertures of foveal cones. The average power spectra of our retinal images show that it is possible to recover spatial frequencies as high as 150 c/deg in eyes with normal optical quality, a conclusion that was confirmed with estimates of the optical quality of these eyes obtained with a Hartmann-Shack wavefront sensor. These results emphasize the superiority of the eye's optics over the spatial sampling limits of the retina when the eye's optical quality is optimized. They also show that it would be possible to routinely resolve retinal structures as small as photoreceptors in the normal living eye if its aberrations could be corrected.

Adult↗

PubMed1994

Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. Eye Disease Case-Control Study Group.

OBJECTIVE--To evaluate the relationships between dietary intake of carotenoids and vitamins A, C, and E and the risk of neovascular age-related macular degeneration (AMD), the leading cause of irreversible blindness among adults. DESIGN--The multicenter Eye Disease Case-Control Study. SETTING--Five ophthalmology centers in the United States. PATIENTS--A total of 356 case subjects who were diagnosed with the advanced stage of AMD within 1 year prior to their enrollment, aged 55 to 80 years, and residing near a participating clinical center. The 520 control subjects were from the same geographic areas as case subjects, had other ocular diseases, and were frequency-matched to cases according to age and sex. MAIN OUTCOME MEASURES--The relative risk for AMD was estimated according to dietary indicators of antioxidant status, controlling for smoking and other risk factors, by using multiple logistic-regression analyses. RESULTS--A higher dietary intake of carotenoids was associated with a lower risk for AMD. Adjusting for other risk factors for AMD, we found that those in the highest quintile of carotenoid intake had a 43% lower risk for AMD compared with those in the lowest quintile (odds ratio, 0.57; 95% confidence interval, 0.35 to 0.92; P for trend = .02). Among the specific carotenoids, lutein and zeaxanthin, which are primarily obtained from dark green, leafy vegetables, were most strongly associated with a reduced risk for AMD (P for trend = .001). Several food items rich in carotenoids were inversely associated with AMD. In particular, a higher frequency of intake of spinach or collard greens was associated with a substantially lower risk for AMD (P for trend < .001). The intake of preformed vitamin A (retinol) was not appreciably related to AMD. Neither vitamin E nor total vitamin C consumption was associated with a statistically significant reduced risk for AMD, although a possibly lower risk for AMD was suggested among those with higher intake of vitamin C, particularly from foods. CONCLUSION--Increasing the consumption of foods rich in certain carotenoids, in particular dark green, leafy vegetables, may decrease the risk of developing advanced or exudative AMD, the most visually disabling form of macular degeneration among older people. These findings support the need for further studies of this relationship.

Aged↗

PubMed1994

Determination of polychlorinated biphenyl levels in the serum of residents and in the homogenates of seafood from the New Bedford, Massachusetts, area: a comparison of exposure sources through pattern recognition techniques.

We measured the residues of polychlorinated biphenyls (PCBs) in the serum of 23 residents of the New Bedford, Massachusetts, area and from two homogenates each of bluefish and lobsters from the same area. We used congener-specific and total Aroclor quantitative approaches, both of which involved gas chromatography with electron capture detection. Using gas chromatography mass spectrometry (electron ionization mode), we confirmed the presence of PCBs in the combined serum samples and in the aliquots of bluefish and lobsters. In measuring the PCB levels in serum, we found good agreement between the two electron capture detector approaches (r > or = 0.97) when the serum of specific congeners was compared to total Aroclor. We used univariate and multivariate quality control approaches to monitor these analyses. Analytical results for bluefish showed a better agreement between the two techniques than did those for lobsters; however, the small number of samples precluded any statistical comparison. We also measured levels of chlorinated pesticides in the serum samples of two groups of New Bedford residents, those with low PCB levels (< 15 ng/ml) and those with high PCB levels (> or = 15 ng/ml). We found that residents with high PCB levels also tended to have higher levels of hexachlorobenzene (HCB) and 1,1-dichloro-2,2-di-(p-chlorophenyl) ethylene (p,p'-DDE). The higher concentration of all three analytes appears to be influenced by employment in the capacitor industry, by seafood consumption, or both. Using Jaccard measures of similarity and principal component analysis we compared the gas chromatographic patterns of PCBs found in the serum of New Bedford area residents with high serum PCBs with the patterns found in homogenates of lobsters (inclusive of all edible portions except the roe), in homogenates of bluefish fillets taken from local waters, and in serum from goats fed selected technical Aroclors (e.g. Aroclors 1016, 1242, 1254, or 1260). The patterns found in human serum samples were similar to the patterns found in lobster homogenates. Both of these patterns closely resembled patterns found in the serum samples of the goat fed aroclor 1254, as demonstrated by both pattern recognition techniques. In addition, the chromatographic patterns of human serum and of lobsters and bluefish homogenates all indicated the presence of PCBs more characteristic of Aroclors 1016 or 1242.

Analysis of Variance↗

PubMed1994

Technical and scientific developments in exposure marker methodology.

Recent advances in techniques to measure markers of exposure to environmental toxicants in humans are changing the ways in which environmental scientists, epidemiologists, and policymakers characterize and interpret such exposure. In this article we review some major technical and scientific developments in exposure marker methodology for estimating internal dose, with special reference to studies conducted at the US Centers for Disease Control and Prevention. We consider important characteristics of laboratory methods, advances in laboratory technology, analytical standards, and quality assurance of laboratory measurements; comparisons with indirect methods for estimating exposures, such as exposure indices and questionnaires; human pharmacokinetic data; sampling problems; surveillance of human exposures to toxicants; and interpretation of measurements. With a view to increasing the reliability of exposure assessment, we make recommendations for obtaining more data on human exposure to toxicants.

Biomarkers↗

PubMed1993

Pluralistic ignorance and alcohol use on campus: some consequences of misperceiving the social norm.

Four studies examined the relation between college students' own attitudes toward alcohol use and their estimates of the attitudes of their peers. All studies found widespread evidence of pluralistic ignorance: Students believed that they were more uncomfortable with campus alcohol practices than was the average student. Study 2 demonstrated this perceived self-other difference also with respect to one's friends. Study 3 traced attitudes toward drinking over the course of a semester and found gender differences in response to perceived deviance: Male students shifted their attitudes over time in the direction of what they mistakenly believed to be the norm, whereas female students showed no such attitude change. Study 4 found that students' perceived deviance correlated with various measures of campus alienation, even though that deviance was illusory. The implications of these results for general issues of norm estimation and responses to perceived deviance are discussed.

Adult↗

PubMed1991

Problems associated with interferences in the analysis of serum for polychlorinated biphenyls.

During a recent survey to determine serum concentrations of polychlorinated biphenyls (PCBs) among people living around New Bedford, MA, U.S.A., an unidentified contaminant precluded the quantification of some early eluting Webb and McCall peaks. Loss of data is estimated to have reduced reported serum levels by 12%. Efforts to identify the contaminant by gas chromatography with an electron-capture detector, a Hall electrolytic condutivity detector, and mass spectrometer were not successful. Researchers ascertained, however, that the contaminant is not a PCB, it does not contain halogens, but it may contain phthalates. Vacutainer tubes and closures for serum storage bottles are suspected sources of contamination.

Chromatography, Gas↗

PubMed1991

Human exposure to polychlorinated biphenyls in Greater New Bedford, Massachusetts: a prevalence study.

A study was conducted in the community of Greater New Bedford, Massachusetts, from 1984 through 1987 to assess the prevalence of elevated levels of polychlorinated biphenyls (PCBs) in the serum of individuals aged 18 to 64 years who had resided in the area for at least 5 years. Eight hundred and forty subjects were interviewed, examined, and tested in a cross-sectional sample of the towns of Acushnet, Dartmouth, and Fairhaven and the city of New Bedford. Serum PCBs were measured to estimate the extent of human exposure. Because of documented environmental contamination by PCBs in the New Bedford area, and the practice of recreational fishing in the harbor for food, a significant number of persons with elevated serum PCB levels were expected to be identified. Instead, the prevalence of elevated serum PCBs in the sample was found to be typical of "unexposed" urban populations in the United States. Only 1.3% of the subjects had serum PCB levels greater than 30 ppb. The same percentage was observed among males (n = 391) and females (n = 449). The geometric means of PCB levels were 4.3 ppb among males (Range = 0.50-60.9) and 4.2 ppb among females (Range = 0.38-154). We conclude that the prevalence of elevated serum PCBs is low in the population of Greater New Bedford.

Adolescent↗

PubMed1991

Gender gaps: who needs to be explained?

The hypothesis that explanations for differences between prototypical and nonprototypical members of categories would focus more on attributes of the latter than on those of the former was examined. Explanations for alleged gender differences in the behavior of voters, elementary school teachers, and college professors were elicited. As predicted, explanations for gender differences within the 3 categories emphasized the qualities of the "deviant" member. Ss' explanations of alleged gender gaps in the behavior of voters and college professors focused more on qualities of women than on qualities of men. In contrast, Ss' explanations of an alleged gender gap in the behavior of elementary school teachers focused more on qualities of men than on qualities of women. The results are interpreted in terms of Kahneman and Miller's (1986) norm theory.

Adult↗

PubMed1991

Interlaboratory comparison of the measurement of albumin in urine.

Because of increased interest in the assay of albumin in urine and the sensitivity required to quantify concentrations associated with (a) increased risk of developing end-stage renal disease and cardiovascular disease among people with diabetes and (b) renal damage caused by exposure to nephrotoxic substances, we conducted a pilot study of the variation of these measurements within and among five laboratories that use various immunoassays. These assays included two different enzyme immunoassays, two different immunoturbidimetric assays, a fluorescent immunoassay, and a zone immunoelectrophoresis assay. The results indicate considerable variation both within and among laboratories for measurements at or near the normal range. Variability is equally attributable to the precision of individual immunoassays and to the variation of the mean values obtained by each laboratory. Individual laboratory CVs ranged from 5.8% to 18.2% for mid- and high-concentration samples treated with preservative and from 8.4% to 23.6% for mid- and high-concentration samples containing no preservative. The relative bias of individual laboratory means ranged from -56.4% to 20.5% for the two preserved materials and from -32.6% to 0.8% for the two materials containing no preservative. To reduce the chance of misdiagnosing the risk associated with above-normal albumin concentrations in urine, we need to address the problems contributing to imprecision and inaccuracy, particularly laboratory-to-laboratory variability.

Albuminuria↗

PubMed1990

Suspicion of ulterior motivation and the correspondence bias.

Three studies examined the hypothesis that when perceivers learn of the existence of multiple, plausibly rival motives for an actor's behavior, they are less likely to fall prey to the correspondence bias than when they learn of the existence of situational factors that may have constrained the actor's behavior. In the first 2 studies, Ss who learned that an actor was instructed to behave as he did drew inferences that corresponded to his behavior. In contrast, Ss who were led to suspect that an actor's behavior may have been motivated by a desire to ingratiate (Study 1), or by a desire to avoid an unwanted job (Study 2), resisted the correspondence bias. The 3rd study demonstrated that these differences were not due to a general unwillingness on the part of suspicious perceivers to make dispositional inferences. The implications that these results have for understanding attribution theory are discussed.

Adult↗

PubMed1990

Effect of platelet activation inhibitors on the loss of glycoprotein Ib during storage of platelet concentrates.

Platelet membrane glycoprotein Ib (GPIb) in stored platelet concentrates was analyzed by flow cytometry with three separate monoclonal antibodies (AN-51, 6D1, and SZ-2), by tritiated glycoprotein radiolabeling, and by ristocetin-induced agglutination. Flow cytometry showed that a population of surface GPIb-negative platelets was evident at 5 days and increased three- to fivefold by the tenth day. Tritium radiolabeling of surface GPIb showed a decrease over 10 days of 37% +/- 17%. The degree of loss of surface GPIb correlated well with other changes during storage: decreased ristocetin-induced agglutination, decreased responsiveness in the hypotonic shock test, lower plasma pH, and increased extracellular lactic dehydrogenase. Immunoblotting of total platelet GPIb with the SZ-2 antibody showed a decrease of 58% +/- 16% during the 10-day storage period. The effect of protease inhibitors or platelet activation inhibitors on the loss of GPIb during storage was studied in platelet concentrates paired with untreated controls. Only the platelet activation inhibitors prostaglandin E1 and theophylline retarded the loss of surface GPIb levels (93% +/- 5% GPIb remaining vs 65% +/- 16%). Total GPIb levels also decreased less in the presence of the activation inhibitors (45% +/- 22% lost vs 70% +/- 14% lost). These findings suggest that platelet activation, rather than plasma enzymatic activity, is responsible for the loss of platelet GPIb during storage of platelet concentrates.

Alprostadil↗