Framing interethnic ideology: effects of multicultural and color-blind perspectives on judgments of groups and individuals

In 3 experiments, White American college students received a message advocating either a color-blind or a multicultural ideological approach to improving interethnic relations and then made judgments about various ethnic groups and individuals. Relative to a color-blind perspective, the multicultural perspective led to stronger stereotypes, greater accuracy in these stereotypes, and greater use of category information in judgments of individuals. This increase in between-category differentiation occurred both for attributes that favored the in-group and for attributes that favored the out-group and was also paired in some cases with greater overall positivity toward the out-group. The findings lead us to question the implicit assumption driving the majority of social psychological efforts at prejudice reduction: that the categorization process leads to prejudice, and that the relevance of social categories must therefore be de-emphasized.

In vitro alteration of macrophage phenotype and function by serum lipids

Diabetes (type I and type II) affects approximately 13 million people in the United States. Delayed and incomplete healing of wounds can be a major problem for diabetic patients. Macrophages are an important cell in the complex process of wound repair representing the major source of cytokines throughout the wound-healing process. Cytokines mediate many of the cellular responses critical to timely wound repair. It has been suggested that diabetes impairs wound healing through disruption of local cytokine production. Our previous in vivo studies in rats demonstrated that diabetes-induced and diet-induced hyperlipidemia cause changes in macrophage phenotype and function (Iacopino 1995; Doxey et al. 1998), suggesting that alterations in macrophage cytokine profiles represent the cellular/molecular mechanism responsible for delayed wound healing. The purpose of this study was to investigate how monocyte maturation/differentiation and cytokine production were altered by serum lipids in an in vitro system using human cells. Commercially prepared purified human monocytes were cultured and exposed to serum lipids. Phenotypic analysis of differentiated macrophages was then performed by flow cytometry and fluorescent microscopy using surface antigens specific for various macrophage subsets. Selected cytokines in conditioned medium were assayed using commercial human enzyme-linked immunosorbent assay (ELISA) kits. We demonstrate that serum lipids cause an increase in monocytic differentiation leading to an inflammatory macrophage phenotype rather than a reparative/proliferative phenotype. We also show that serum lipids cause a generalized decrease in macrophage cytokine production using interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha), platelet-derived growth factor (PDGF), and transforming growth factor beta 1 (TGF-beta 1) as marker cytokines. Our present in vitro results using human cells confirm our previous in vivo studies in the rat and support the hypothesis that diabetes-induced hyperlipidemia alters the monocyte differentiation process resulting in changes of macrophage subsets and cytokine release at the wound site, ultimately impairing the wound-healing process.

Activation of the Lbc Rho exchange factor proto-oncogene by truncation of an extended C terminus that regulates transformation and targeting

The human lbc oncogene product is a guanine nucleotide exchange factor that specifically activates the Rho small GTP binding protein, thus resulting in biologically active, GTP-bound Rho, which in turn mediates actin cytoskeletal reorganization, gene transcription, and entry into the mitotic S phase. In order to elucidate the mechanism of onco-Lbc transformation, here we report that while proto- and onco-lbc cDNAs encode identical N-terminal dbl oncogene homology (DH) and pleckstrin homology (PH) domains, proto-Lbc encodes a novel C terminus absent in the oncoprotein that includes a predicted alpha-helical region homologous to cyto-matrix proteins, followed by a proline-rich region. The lbc proto-oncogene maps to chromosome 15, and onco-lbc represents a fusion of the lbc proto-oncogene N terminus with a short, unrelated C-terminal sequence from chromosome 7. Both onco- and proto-Lbc can promote formation of GTP-bound Rho in vivo. Proto-Lbc transforming activity is much reduced compared to that of onco-Lbc, and a significant increase in transforming activity requires truncation of both the alpha-helical and proline-rich regions in the proto-Lbc C terminus. Deletion of the chromosome 7-derived C terminus of onco-Lbc does not destroy transforming activity, demonstrating that it is loss of the proto-Lbc C terminus, rather than gain of an unrelated C-terminus by onco-Lbc, that confers transforming activity. Mutations of onco-Lbc DH and PH domains demonstrate that both domains are necessary for full transforming activity. The proto-Lbc product localizes to the particulate (membrane) fraction, while the majority of the onco-Lbc product is cytosolic, and mutations of the PH domain do not affect this localization. The proto-Lbc C-terminus alone localizes predominantly to the particulate fraction, indicating that the C terminus may play a major role in the correct subcellular localization of proto-Lbc, thus providing a mechanism for regulating Lbc oncogenic potential.

Diabetes-induced impairment of macrophage cytokine release in a rat model: potential role of serum lipids

Diabetes (type I and type II) affects approximately 13 million people in the United States. Delayed and incomplete healing of wounds can be a major problem for diabetic patients. Macrophages are an important cell in the complex process of wound repair representing the major source of cytokines throughout the wound healing process. Cytokines mediate many of the cellular responses critical to timely wound repair. It has been suggested that diabetes impairs wound healing through disruption of local cytokine production. We previously demonstrated that platelet-derived growth factor B chain (PDGF-B) levels are deficient at the wound site of diabetic rats. In the present study, we measured the levels of several marker cytokines released from cultured peritoneal macrophages of diabetic, nondiabetic hyperlipidemic, and normal rats. The diabetic condition was associated with a generalized reduction of macrophage cytokine release. Nondiabetic hyperlipidemic animals demonstrated similar cytokine reduction supporting the hypothesis that elevated serum lipids are the primary determinants of diabetes-induced reductions in macrophage cytokine release. Thus, manipulation of serum lipids may be a therapeutically useful modality for controlling macrophage cytokine release in the inflammatory and/or wound environment.

Near-infrared reflectance analysis for predicting beef longissimus tenderness

Near-infrared reflectance spectra (1,100 to 2,498 nm) were collected on beef longissimus thoracis steaks for the purpose of establishing the feasibility of predicting meat tenderness by spectroscopy. Partial least squares (PLS) analysis (up to 20 factors) and multiple linear regression (MLR) were used to predict cooked longissimus Warner-Bratzler shear (WBS) force values from spectra of steaks from 119 beef carcasses. Modeling used the combination of log(1/R) and its second derivative. Overall, absorption was higher for extremely tough steaks than for tender steaks. This was particularly true at wavelengths between 1,100 and 1,350 nm. For PLS regression, optimal model conditions (R2 = .67; SEC = 1.2 kg) occurred with six PLS factors. When the PLS model was tested against the validation subset, similar performance was obtained (R2 = .63; SEP = 1.3 kg) and bias was small (<.3 kg). Among the 39 samples in the validation data set, 48.7, 87.7, and 97.4% of the samples were predicted within 1.0, 2.0, and 3.0 kg, respectively, of the observed Warner-Bratzler shear force value. The optimal PLS model was able to predict whether a steak would have a Warner-Bratzler shear force value < 6 kg with 75% accuracy. The R2 of MLR model was .67, and 89% of samples were correctly classified (< 6 vs > 6 kg) for Warner-Bratzler shear force. These data indicate that NIR is capable of predicting Warner-Bratzler shear force values of longissimus steaks. Refinement of this technique may allow nondestructive measurement of beef longissimus at the processing plant level.

Evidence for racial prejudice at the implicit level and its relationship with questionnaire measures

The content of spontaneously activated racial stereotypes among White Americans and the relation of this to more explicit measures of stereotyping and prejudice were investigated. Using a semantic priming paradigm, a prime was presented outside of conscious awareness (BLACK or WHITE), followed by a target stimulus requiring a word-nonword decision. The target stimuli included attributes that varied in valence and stereotypicality for Whites and African Americans. Results showed reliable stereotyping and prejudice effects: Black primes resulted in substantially stronger facilitation to negative than positive stereotypic attributes, whereas White primes facilitated positive more than negative stereotypic traits. The magnitude of this implicit prejudice effect correlated reliably with participants' scores on explicit racial attitude measures, indicating that people's spontaneous stereotypic associations are consistent with their more controlled responses.

Intensive care for people with serious mental illness

This article describes the development of a psychiatric 'intensive care' service for men and women with serious or enduring forms of psychotic disorder. The authors suggest that such a residential therapeutic service may be an essential part of the development of community care for the most vulnerable people served by mental health services.

Longitudinal changes in consensus as a function of acquaintance and agreement in liking

By using a round-robin design, groups of freshmen reported their impressions of dormmates at 4 different times during the year. Consensus on W. T. Norman's Big Five (1963) did not increase over the year, even though reported acquaintance did increase. Agreement in liking predicted agreement in the trait ratings, such that groups that agreed in their evaluations of one another were more likely to agree in their trait impressions of one another, and vice versa. These patterns, obtained by using trait ratings, were replicated with open-ended descriptions of the targets. Correlations with self-judgments did not increase with acquaintance. The data suggest that increased acquaintance does not produce increased consensus. Instead, the role of agreement in evaluations is explored as a determining factor in the level of obtained consensus.

Longitudinal changes in consensus as a function of acquaintance and agreement in liking

By using a round-robin design, groups of freshmen reported their impressions of dormmates at 4 different times during the year. Consensus on W. T. Norman's Big Five (1963) did not increase over the year, even though reported acquaintance did increase. Agreement in liking predicted agreement in the trait ratings, such that groups that agreed in their evaluations of one another were more likely to agree in their trait impressions of one another, and vice versa. These patterns, obtained by using trait ratings, were replicated with open-ended descriptions of the targets. Correlations with self-judgments did not increase with acquaintance. The data suggest that increased acquaintance does not produce increased consensus. Instead, the role of agreement in evaluations is explored as a determining factor in the level of obtained consensus.

Evidence for racial prejudice at the implicit level and its relationship with questionnaire measures

The content of spontaneously activated racial stereotypes among White Americans and the relation of this to more explicit measures of stereotyping and prejudice were investigated. Using a semantic priming paradigm, a prime was presented outside of conscious awareness (BLACK or WHITE), followed by a target stimulus requiring a word-nonword decision. The target stimuli included attributes that varied in valence and stereotypicality for Whites and African Americans. Results showed reliable stereotyping and prejudice effects: Black primes resulted in substantially stronger facilitation to negative than positive stereotypic attributes, whereas White primes facilitated positive more than negative stereotypic traits. The magnitude of this implicit prejudice effect correlated reliably with participants' scores on explicit racial attitude measures, indicating that people's spontaneous stereotypic associations are consistent with their more controlled responses.

Enhanced surface hardness by boron implantation in Nitinol alloy

Boron implantation into Nitinol alloy has a potential for developing improved Nitinol root canal instruments with excellent cutting properties, without affecting their superelastic bulk-mechanical properties. The surface hardness of nickel-titanium (NiTi) alloy, also known as "Nitinol" (50 atm% nickel+50 atm% titanium), has been improved by ion-beam surface modification. With an implantation dose of 4.8 x 10(17) boron/cm2, a high concentration of boron (30 atm%) is incorporated into NiTi alloy by 110 keV boron ions at room temperature (25 degrees C). Boron-implanted and unimplanted (pure) Nitinol alloys show surface hardness of 7.6 +/- 0.2 and 3.2 +/- 0.2 GPa, respectively, at the nanoindentation depth of 0.05 micron. The ion-beam-modified NiTi alloy exceeds the surface hardness of stainless steel.

Energy functions that discriminate X-ray and near native folds from well-constructed decoys

This study generates ensembles of decoy or test structures for eight small proteins with a variety of different folds. Between 35,000 and 200,000 decoys were generated for each protein using our four-state off-lattice model together with a novel relaxation method. These give compact self-avoiding conformations each constrained to have native secondary structure. Ensembles of these decoy conformations were used to test the ability of several types of empirical contact, surface area and distance-dependent energy functions to distinguish between correct and incorrect conformations. These tests have shown that none of the functions is able to distinguish consistently either the X-ray conformation or the near-native conformations from others which are incorrect. Certain combinations of two of these energy functions were able, however, consistently to identify X-ray structures from amongst the decoy conformations. These same combinations are better also at identifying near-native conformations, consistently finding them with a hundred-fold higher frequency than chance. The fact that these combination energy functions perform better than generally accepted energy functions suggests their future use in folding simulations and perhaps threading predictions.

Cyclosporine A upregulates platelet-derived growth factor B chain in hyperplastic human gingiva

Cyclosporine A (CSA) is a widely used immunosuppressant for transplant patients and is also used for the treatment of a wide variety of systemic diseases with immunologic components. A prominent side effect of CSA administration is gingival overgrowth (hyperplasia). It has been postulated that CSA alters fibroblast activity through effects on various growth factors/cytokines. However, as yet, data concerning the molecular mechanisms involved in pathologic connective tissue proliferation are preliminary in nature. Our previous investigations concerning phenytoin-induced effects on platelet-derived growth factor B (PDGF-B) gene expression have demonstrated that other drugs which cause gingival overgrowth can upregulate macrophage PDGF-B gene expression in vitro and in vivo. The purpose of the present study was to evaluate PDGF-B gene expression in gingival tissues of patients receiving CSA therapy and exhibiting gingival overgrowth to determine if similar PDGF-B upregulation occurs in response to CSA and to identify PDGF-B producing cells in these tissues. Quantitative competitive reverse transcription polymerase chain reaction (QC-RTPCR) techniques were utilized to measure PDGF-B mRNA levels in CSA overgrowth patients and normal controls (N = 6/group). Results were expressed as mean +/- mRNA copy number and tested for significance using unpaired t-tests. Gingival samples were harvested (standardized for local inflammation at the sample site), total RNA was extracted, and QC-RTPCR was performed using specific PDGF-B primers and a corresponding competitive internal standard. CSA-treated patients exhibiting gingival overgrowth demonstrated approximately 48-fold increase in PDGF-B mRNA (7667.1 +/- 477.4 copies for CSA patients vs. 158.2 +/- 37.1 copies for controls; P < 0.001). Additionally, dual fluorescence immunohistochemistry for mature macrophage marker antigen (CD51) and intracellular PDGF-B was utilized to identify and localize PDGF-B producing cells were demonstrated to be macrophages distributed in a non-uniform manner throughout the papillary connective tissue. These results further support the hypothesis that the molecular mechanisms responsible for drug-induced gingival overgrowth may involve upregulation of PDGF-B macrophage gene expression. We continue to investigated specific CSA-induced alterations of macrophage PDGF-B gene expression in vitro and in vivo.

Stereotypes and ethnocentrism: diverging interethnic perceptions of African American and white American youth

Much recent work on stereotyping has dealt with groups that are either artificially created or that do not have an extensive history of conflict. The authors attempted to overcome this limitation by examining issues of perceived variability and ethnocentrism among samples of White American and African American youth. The goals were both to examine theoretical issues in stereotyping and to describe the current state of ethnic interrelations among young people. Four studies are reported. Throughout, the samples of African Americans demonstrate interethnic judgments that are consistent with existing work on stereotyping and ethnocentrism. White American students, however, reported judgements that replicate neither the out-group homogeneity effect nor ethnocentrism. Alternative explanations for this difference are considered, and the discussion focuses on differing views concerning the role of ethnic identity and diversity in our society.

Subtyping versus subgrouping processes in stereotype representation

Participants were instructed to organize information about group members either by distinguishing stereotype-consistent from stereotype-inconsistent individuals (subtyping instructions), by dividing the individuals into multiple groups on the basis of similarities and differences (subgrouping instructions), or with no explicit organizing instructions. Participants given the subtyping instructions showed greater perceived stereotypicality and homogeneity and perceived a greater difference in how typical the confirming versus disconfirming group members were, relative to subgroup participants. Study 2 demonstrated natural variation among participants in the perceived atypicality of the disconfirming relative to confirming individuals when learning about a gay activist group. Atypicality predicted perceptions of this group, even when prejudice and strength of stereotyping toward gays as a whole were statistically controlled.

Subtyping versus subgrouping processes in stereotype representation

Participants were instructed to organize information about group members either by distinguishing stereotype-consistent from stereotype-inconsistent individuals (subtyping instructions), by dividing the individuals into multiple groups on the basis of similarities and differences (subgrouping instructions), or with no explicit organizing instructions. Participants given the subtyping instructions showed greater perceived stereotypicality and homogeneity and perceived a greater difference in how typical the confirming versus disconfirming group members were, relative to subgroup participants. Study 2 demonstrated natural variation among participants in the perceived atypicality of the disconfirming relative to confirming individuals when learning about a gay activist group. Atypicality predicted perceptions of this group, even when prejudice and strength of stereotyping toward gays as a whole were statistically controlled.

Stereotypes and ethnocentrism: diverging interethnic perceptions of African American and white American youth

Much recent work on stereotyping has dealt with groups that are either artificially created or that do not have an extensive history of conflict. The authors attempted to overcome this limitation by examining issues of perceived variability and ethnocentrism among samples of White American and African American youth. The goals were both to examine theoretical issues in stereotyping and to describe the current state of ethnic interrelations among young people. Four studies are reported. Throughout, the samples of African Americans demonstrate interethnic judgments that are consistent with existing work on stereotyping and ethnocentrism. White American students, however, reported judgements that replicate neither the out-group homogeneity effect nor ethnocentrism. Alternative explanations for this difference are considered, and the discussion focuses on differing views concerning the role of ethnic identity and diversity in our society.

Evaluation of in vitro cytotoxicity of nonsteroidal anti-inflammatory drugs against canine tumor cells

Piroxicam and other nonsteroidal anti-inflammatory drugs (NSAID) have antitumor activity against naturally acquired cancer in dogs and human beings, and against experimentally induced tumors in rodents. We are investigating potential mechanisms of NSAID antitumor activity. The direct cytotoxicity of piroxicam indomethacin, and aspirin against 4 canine tumor cell lines (transitional cell carcinoma, squamous cell carcinoma, melanoma, and soft tissue sarcoma) was determined in short-term growth rate assays and in clonogenic assays. Piroxicam was evaluated alone and in combination with the lipoxygenase inhibitor zileuton, and in combination with the chemotherapeutic agents cisplatin and carboplatin. The 50% inhibitory concentrations (IC50) against melanoma cells in short-term growth rate assays were: 530 microM piroxicam, 180 microM indomethacin, and greater than 1 mM aspirin. These IC50 values were over 10 times greater than serum concentrations of these drugs that could safely be achieved in vivo. The IC50 of zileuton combined with piroxicam (280 microM) was not different from the IC50 of zileuton alone (230 microM; ANOVA P = 0.47) in melanoma cells. Similarly, addition of piroxicam did not alter the IC50 of either cisplatin (1.6 microM) or carboplatin (6.1 microM). These results suggest that NSAID, at serum concentrations achievable in vivo, do not have direct cytotoxicity against canine tumor cells tested. It is unlikely that the in vivo antitumor activity of NSAID is attributable to a direct cytotoxic effect.

Low density lipoprotein receptors in rat adipose cells: subcellular localization and regulation by insulin

The distribution of LDL receptors within subcellular compartments of isolated rat adipose cells and the effects of insulin on their expression have been assessed. By immunoblotting with specific anti-rat LDL receptor antibodies, LDL receptors were 2.3- and 4.5-fold enriched in endoplasmic reticulum-rich high-density microsomes (HDM) and Golgi complex-rich low-density microsomes (LDM), respectively, compared to plasma membranes (PM). This distribution was similar in cultured cells in which total receptors were increased 2.5-fold compared to freshly isolated cells. After correction for enzyme recoveries, LDL receptors were distributed approximately 4% in HDM, approximately 73% in LDM, and approximately 23% in PM. Insulin decreased total LDL receptors in adipose cells approximately 44%, with a 48% and 49% decrease in HDM and LDM, respectively, without any changes in PM. In contrast, insulin caused an increase of glucose transporters in PM while also decreasing glucose transporters in LDM. When adipose cells were depleted of potassium to inhibit receptor-mediated endocytosis, insulin again caused a decrease of LDL receptors in LDM but now increased LDL receptors in PM. Insulin increased the rate of LDL receptor synthesis approximately 24%, but decreased their half life approximately 40%. Thus, in isolated adipose cells the majority of LDL receptors appear to be located in an intracellular compartment that co-sediments with the Golgi complex rather than located in the PM. The LDL receptors localized in intracellular compartments seem to be functionally regulated as insulin acutely diminishes the number of receptors by apparently accelerating their rate of degradation through, as yet, incompletely determined mechanisms.

Aggregating social behavior into person models: perceiver-induced consistency

Two experiments explored the role of perceivers (judges) in aggregating social behavior into impressions. In Experiment 1, it was predicted and found that judges influence impressions (i.e., eye-of-the-beholder effects) not only because they disagree on how to interpret single acts but because they aggregate multiple acts in unique ways to arrive at idiosyncratic impressions. Using D. A. Kenny's (1991) general model of accuracy and consensus, it was found that judges perceived much greater consistency in the behavior of targets across situations when they were asked to aggregate the behavior than when they were not. Differential interpretation of single acts did not change as a function of aggregating behavior. This aggregation process was characterized as the construction of models of persons. In Experiment 2, the concept of person models was explored further, and it was argued that perceivers develop these models on the basis of what is viewed as the central concept of a target. For any given target, a limited number of models can be identified, and different perceivers develop different models. The particular model formed has implications for the perceiver's underlying memory representation and the perceived personality profile of the target.

Aggregating social behavior into person models: perceiver-induced consistency

Two experiments explored the role of perceivers (judges) in aggregating social behavior into impressions. In Experiment 1, it was predicted and found that judges influence impressions (i.e., eye-of-the-beholder effects) not only because they disagree on how to interpret single acts but because they aggregate multiple acts in unique ways to arrive at idiosyncratic impressions. Using D. A. Kenny's (1991) general model of accuracy and consensus, it was found that judges perceived much greater consistency in the behavior of targets across situations when they were asked to aggregate the behavior than when they were not. Differential interpretation of single acts did not change as a function of aggregating behavior. This aggregation process was characterized as the construction of models of persons. In Experiment 2, the concept of person models was explored further, and it was argued that perceivers develop these models on the basis of what is viewed as the central concept of a target. For any given target, a limited number of models can be identified, and different perceivers develop different models. The particular model formed has implications for the perceiver's underlying memory representation and the perceived personality profile of the target.

Measuring intramuscular fat in beef with ultrasonic frequency analysis

Frequency analysis of Fourier spectra from ultrasonic signals was used for predicting intramuscular fat content of beef tissue. The most significant parameter in the frequency domain for predicting intramuscular fat concentration in beef was the number of local maxima. It represents the discontinuity of the Fourier spectrum caused by inhomogeneous fat concentrations in the longissimus muscle, which had the correlation coefficient .89 (P < .05) when a 2.25-MHz shear probe was used. The optimum frequency for predicting the amount of intramuscular fat content in the longissimus muscle was found to be 1.92 MHz. A multivariate regression model was developed using parameters in the frequency domain as follows: percentage of fat concentration = 1.790 - 2.373x (lower frequency) + .049x (bandwidth) + 1.178x (local maxima) (R2 = .82). Validation demonstrated that the multivariate model in the frequency domain was capable of predicting intramuscular fat concentration with an average of 1.17 percentage of fat error (P < .05). The multivariate model was most appropriate for predicting intramuscular fat below 4%. The mean accuracy of the model in the frequency domain was approximately 79%.

Predicting intramuscular fat in beef longissimus muscle from speed of sound

The ultrasonic A-mode method was investigated for intramuscular fat measurement of beef. Cubes of meat samples that had different marbling scores were used as specimens. Ultrasonic speed decreased with increasing fat concentration. The correlation coefficient was -.82 (P < .05). Conversely, the correlation coefficient between visual marbling score and fat concentration was .70 (P < .05). Quantitatively, from the first derivative of a nonlinear function, it was concluded that the speed decreased at a rate of 2.69 m/(s-% fat) as a function of intramuscular fat. A nonlinear regression model to predict intramuscular fat content in beef was developed as follows: percentage of fat concentration = 7132.1574-9.1222 x (speed) + 2.91803 x 10(-3) x (speed)2 (R2 = .81). The nonlinear model was capable of predicting intramuscular fat concentration with 90% accuracy (> 8% fat) and 76.4% accuracy (< 8% fat), respectively (P < .001).

Low-density lipoprotein receptors in rat adipocytes: regulation with fasting

Adipose tissue metabolism is exquisitely sensitive to caloric intake. With increasing adiposity more triglyceride and cholesterol are stored within increasingly large adipocytes, whereas less triglyceride and cholesterol are stored as the size of the fat cell decreases. A portion of the uptake of cholesterol by adipocytes is mediated by low-density lipoprotein (LDL) receptors. The present studies addressed whether LDL receptors are differentially regulated in adipose tissue and the liver during fasting in the rat. Two days of fasting caused a reduction in body weight with an approximately 40% decrease in the epididymal fat depot and fat cell size. No changes in serum cholesterol were noted, but serum triglycerides fell approximately 55% with fasting. LDL receptors detected by immunoblotting decreased progressively with fasting to levels that were 95% below controls in adipocytes isolated from epididymal fat pads by 2-3 days. In contrast, hepatic LDL receptor expression was unaltered by fasting. After 2 days of fasting, the rate of synthesis of LDL receptors in isolated adipose cells was decreased approximately 35%, whereas levels of LDL receptor mRNA were diminished approximately 55%. It is concluded that the expression of LDL receptors in rat adipocytes is markedly downregulated during fasting through transcriptional and posttranscriptional mechanisms. Furthermore, LDL receptor expression is differentially regulated in adipose tissue and liver during fasting in the rat.

Definition and assessment of accuracy in social stereotypes

A perennial issue in the study of social stereotypes concerns their accuracy. Yet, there is no clear concept of the various ways in which stereotypes may be accurate or inaccurate and how one would assess their accuracy. This article is designed to rectify this situation. Three forms of stereotype inaccuracy are identified: stereotypic inaccuracy, valence inaccuracy, and dispersion inaccuracy. The implications of each form are discussed, along with how each can be assessed using a full-accuracy design. Past research that has attempted to examine stereotype accuracy is reviewed, and new data on the issue are presented. Although of perennial interest, the theoretical and methodological difficulties of assessing stereotype accuracy are substantial. The goal in this article is to alert the researcher to these difficulties and point toward their solution.

Principles of ultrasound and measurement of intramuscular fat

A review of basic engineering concepts of ultrasound is presented for the layperson with implications toward the use of ultrasound on beef animals. The use of ultrasound for determining quality traits such as percentage of intramuscular fat is discussed in detail. Results of both A-mode and B-mode preliminary investigations are presented. Preliminary results show that intramuscular fat may be predicted using an A-mode transducer coupled with frequency analysis.

Role of meaningful subgroups in explaining differences in perceived variability for in-groups and out-groups

Five aspects of the complexity of the knowledge representation of business and engineering majors were examined to see whether these differed by group membership and whether these differences were related to differences in perceived variability. Significantly more subgroups were generated when describing the in-group than the out-group; this difference predicted the relative tendency to see the in-group as more variable, and when controlled for statistically, out-group homogeneity effects were eliminated. Familiarity, redundancy, number of attributes used to describe the group, and the deviance of the subgroups from the larger group generally showed differences for in-group and out-group but did not show consistent evidence of mediation. In a 2nd study, Ss who were asked to sort group members into meaningful subgroups perceived greater variability relative to those who did not perform the sorting task.

Accuracy in the judgment of in-group and out-group variability

The accuracy of in-group and out-group variability judgments was examined by comparing those judgments with the variability of self-ratings provided by random samples of group members. Following Park and Judd (1990), perceptions of both group dispersion and group stereotypicality were examined. Accuracy was examined both by within-subject sensitivity correlations and by simple discrepancies between perceived and actual variability estimates. In-group-out-group differences in sensitivity were shown, particularly for judgments of stereotypicality. These differences were related to differences in the degree to which out-group variability is underestimated relative to in-group variability (i.e., the out-group homogeneity effect). Out-group stereotypicality judgments were overestimated, supporting the view that out-group stereotypes are overgeneralizations. Whether dispersion judgments were over- or underestimated depended on their measurement.

Accuracy in the judgment of in-group and out-group variability

The accuracy of in-group and out-group variability judgments was examined by comparing those judgments with the variability of self-ratings provided by random samples of group members. Following Park and Judd (1990), perceptions of both group dispersion and group stereotypicality were examined. Accuracy was examined both by within-subject sensitivity correlations and by simple discrepancies between perceived and actual variability estimates. In-group-out-group differences in sensitivity were shown, particularly for judgments of stereotypicality. These differences were related to differences in the degree to which out-group variability is underestimated relative to in-group variability (i.e., the out-group homogeneity effect). Out-group stereotypicality judgments were overestimated, supporting the view that out-group stereotypes are overgeneralizations. Whether dispersion judgments were over- or underestimated depended on their measurement.

Serum antibodies to cow's milk proteins in pediatric inflammatory bowel disease. Crohn's disease versus ulcerative colitis

Serum antibodies to five cow's milk proteins (alpha-casein, bovine serum albumin, beta-lactoglobulin A and B, and alpha-lactalbumin) were investigated in young patients with inflammatory bowel disease (56 Crohn's disease, 24 ulcerative colitis). IgG antibodies against bovine serum albumin, beta-lactoglobulin A and beta-lactoglobulin B were higher in Crohn's disease patients than in those with ulcerative colitis or the controls. IgG anti-bovine serum albumin antibodies were higher in those Crohn's disease patients who had higher scores of disease activity. Finally, IgA antibodies to alpha-casein were higher in patients with Crohn's disease and ulcerative colitis when compared to controls. These findings may be due to increased uptake of dietary antigens or enhanced immunological response occurring in Crohn's disease patients.

Serum antibodies to cow's milk proteins in pediatric inflammatory bowel disease: Crohn's disease vs. ulcerative colitis

Serum antibodies to five cow's milk proteins, alpha-casein, bovine serum albumin (BSA), beta-lactoglobulin A and B (BLG-a, BLG-b) and alpha-lactalbumin (ALA) were investigated in young patients with inflammatory bowel disease, 56 with Crohn's disease (CD), 24 with ulcerative colitis (UC). IgG antibodies against BSA and BLG-a and -b were higher in Crohn's disease patients as compared to those with ulcerative colitis and controls. The IgG anti-BSA were higher in the group of CD patients with higher score of disease activity. Additionally, IgA antibodies to alpha-casein were higher in CD and UC compared to control. These findings may be due to increased uptake of dietary antigens or enhanced immunological response occurring in CD patients.

Immunological aspects in patients with chronic active hepatitis--cellular immune responses

We studied host immune parameters which might be related to the activity and the pathogenetic mechanism of chronic active hepatitis. The subjects consisted of 45 cases with hepatitis B virus surface antigen (HBsAg)-positive chronic active hepatitis (CAH), 44 HBsAg-negative CAH, 22 with inactive chronic hepatitis, and 45 cases of normal persons, hepatitis B virus (HBV) carriers, or the patients with acute myocardial infarction. The in vitro assay for the in vivo activated lymphocytes was performed by measuring spontaneous thymidine uptake (SLT) of lymphocytes isolated from peripheral blood. SLT was significantly (p < 0.001) elevated in cases with HBsAg-positive (1227 +/- 806 cpm) and-negative CAH (1017 +/- 559 cpm) compared to the patients with inactive chronic hepatitis (347 +/- 79 cpm) and to the control group (320 +/- 106 cpm). SLT values observed in 7 cases with active disease (group I and II), in which remission and relapsing phase could be assessable, were elevated from 648 +/- 121 cpm in remission phase to 1548 +/- 606 cpm one to two weeks before the appearance of biochemical evidence (SGPT) of relapse. This pattern of SLT elevation, however, was not observed in patients with inactive hepatitis. Neither the abnormal distribution of T-cell subsets nor the presence of conventional HBV markers were related to the elevated SLT value. Our findings may therefore indicate that SLT might be useful in assessment of the disease activity in patients with CAH.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromosomes and causation of human cancer and leukemia. XLVIII. T-cell acute leukemia in ataxia telangiectasia

Cytogenetic and immunologic studies were performed on the cells of an 18-year-old female with ataxia telangiectasia (AT) associated with acute lymphocytic leukemia (ALL). At the onset of the leukemia 15.4% of peripheral blood cells stimulated with phytohemagglutinin (PHA) contained a tandem translocation of the long arm of chromosome #14, i.e., t(14;14). To ascertain if these karyotypically abnormal cells and the leukemic cells had a common lineage, chromosome analyses were performed on bone marrow cells. Examination of the marrow cells on the seven occasions when leukemic cells were present in the marrow, including times when they were predominant, showed only a normal karyotype without the presence of t(14;14). However, an abnormal clone, which had the karyotype 45,XX,-9,t(9;6)(q12;q13), was identified in the marrow cells on the last examination during the terminal phase of the leukemia. Immunologically, the ALL was classified as an atypical type which had characteristics in common with certain T-cell subsets. We suggest that the malignant cells did not originate from the preexisting cells with a tandem duplication of the 14q.