Cultural malpractice. The growing obsolescence of psychology with the changing U.S. population.

With the changing demographics occurring in the United States, psychology must make substantive revisions in its curriculum, training, research, and practice. Without these revisions, psychology will risk professional, ethical, and economic problems because psychology will no longer be a viable professional resource to the majority of the U.S. population. In particular, this article discusses the need for psychology to address issues of ethnicity/culture, gender, and sexual orientation.

Multiple synchronous primaries of the gastrointestinal tract: a molecular case report.

Six synchronous gastrointestinal primaries were identified in a 70 year old male with no known cancer predisposition syndrome or recognized risk factors except alcohol abuse. These specimens appeared to be independent and unrelated by gross and histopathological examination. In order to further evaluate the six tumors, we analyzed selected DNA sequences for alterations in the K-ras oncogene and p53 tumor suppressor gene. In addition, three loci were analyzed to determine microsatellite instability. Using the polymerase chain reaction, single stranded conformational polymorphism, and DNA sequencing, we demonstrated that each primary manifests genetic characteristics typical of the tissue of origin. In addition, one primary, a moderately differentiated colon adenocarcinoma, exhibited mutations not detected in the other specimens. This study suggests that these synchronous primaries arose independently and progressed along different carcinogenic pathways.

The shifting gender composition of psychology. Trends and implications for the discipline.

Psychology, along with the majority of professions and scientific disciplines, has undergone dramatic shifts in gender composition over the past two decades. These changes have prompted concern that this increased participation by women may lead to erosion in the status of these occupations. This article describes the results of a case study of psychology conducted by a subcommittee of the American Psychological Association's (APA's) Task Force on the Changing Gender Composition of Psychology to examine the discipline's changing gender composition and the factors related to these shifts. Societal and disciplinary trends are examined, along with data on the patterns of men's and women's involvement in the educational pipeline and workplace. The results provide little support for the concern over the increasing representation of women and its impact on the prestige of the discipline. Rather, they suggest that changes in the nature and status of psychology per se may be at least partly responsible for the changes in male and female participation and that the nature, magnitude, and causes of these disciplinary changes require further examination. Specific recommendations for the APA prepared by another subcommittee of the Task Force are also presented in the Appendix.

K-ras mutation in a tubular adenoma originating at an ileostomy in a familial adenomatous polyposis patient.

Genetic alterations in a tubular adenoma with severe dysplasia arising in a Brooke ileostomy of a familial adenomatous polyposis patient were analyzed. Clinical and morphological characteristics suggest that ileal mucosa progressed to colonic metaplasia and then to dysplastic adenoma. Such changes at ileostomy sites are rare, and little is known about the associated genetic alterations. To determine whether metaplastic epithelium progression to adenoma in the ileum is subject to the same mutations identified in colon carcinogenesis, we evaluated somatic genetic alterations associated with sporadic colorectal cancer development. Sequences examined included mutation cluster regions of the p53 tumor suppressor gene and the k-ras oncogene. Using polymerase chain reaction and DNA sequencing, we identified a point mutation at codon 12 of the K-ras oncogene. To our knowledge, this is the first report of a ras mutation occurring in a tumor originating from ileal mucosa.

Inhibitors of farnesyltransferase and Ras processing peptidase.

Four analogs of the carboxy terminus of unprocessed p21Ras protein were evaluated as inhibitors of the p21Ras processing farnesyltransferase and peptidase. While three showed no crossover of inhibitory activity between the enzymes, the fourth (a naphthyl-substituted peptide) inhibited both farnesyltransferase and peptidase, with IC50s of 16 microM and 3 microM, respectively. Such inhibition of more than one step of Ras processing may complicate assessment of the mode of action for some inhibitors of Ras processing peptidase.

Molecular oncology and the surgeon.

The last 20 years have witnessed a flood of new developments and discoveries in the fields of molecular biology and oncology. Dozens of human genes associated with cancer predisposition syndromes and the malignant and metastatic process have been identified and characterized. These findings have led to a greater understanding of this complex disease and inaugurated a new era of investigations seeking more effective diagnostic protocols and therapies. This review summarizes a few of the many salient discoveries and discusses the clinical implications for the surgeon.

Beauty is in the soul of the beholder: psychological implications of beauty and African American women.

The criteria for beauty in the United States are primarily based on Caucasian European American, middle-class standards. African American women tend to vary greatly from these criteria. Though very few studies have been conducted on the body image of Black women in the United States, historically, the physical images portrayed of African American women in the United States have not been positive. Mental health practitioners must understand how these negative images may affect the body image and self-esteem of African American women. Therapeutic and community interventions are discussed.

A radiometric assay for Ras-processing peptidase using an enzymatically radiolabeled peptide.

A simple and sensitive radiometric assay for the peptidase involved in the post-translational processing of p21ras proteins at the carboxy-terminal Cys-aliphatic-aliphatic--any amino acid (CAAX) motif is described. An isoprenylated tetrapeptide substrate, N-acetyl-S-[3H]farnesyl-Cys-Val-Ile-Ser-OH (22-27 Ci/mmol), was synthesized from N-acetyl-Cys-Val-Ile-Ser-OH and commercial [3H]farnesyl pyrophosphate via farnesyltransferase. The isoprenylated tetrapeptide was then used at a concentration (0.3 microM) well below Km (6 microM) in assays with a microsomal preparation of Ras-processing peptidase from bovine liver. Under assay conditions, the peptidase reaction followed first order kinetics with respect to the substrate, allowing the IC50 values for alternative substrates and inhibitors to approximate Km and Ki values, respectively. In a further simplification, substrate and N-acetyl-S-[3H]farnesyl-Cys-OH product were separated by thin-layer chromatography on silica gel plates using chloroform:acetic acid:methanol:acetone (60:5:10:20, v/v) as solvents. The assay does not require costly, specialized equipment and provides easy means for screening potential substrates and inhibitors of Ras-processing peptidase.

Comparison of the Tu elongation factors from Staphylococcus aureus and Escherichia coli: possible basis for elfamycin insensitivity.

In a previous study (C. C. Hall, J. D. Watkins, and N. H. Georgopapadakou, Antimicrob. Agents Chemother. 33:322-325, 1989), the elongation factor Tu (EF-Tu) from Staphylococcus aureus was found to be insensitive to a series of kirromycin analogs which were inhibitory to the EF-Tu from Escherichia coli. In the present study, the EF-Tu from S. aureus was partially purified and characterized. Its apparent molecular mass was approximately 41,000 Da, and the enzyme copurified with EF-Ts (molecular mass, 34,000 Da). S. aureus EF-Tu differed from its E. coli counterpart in that it bound negligible amounts of [3H]GDP, in addition to being insensitive to pulvomycin and aurodox (50% inhibitory concentrations, approximately 100 and 1,000 microM, respectively, versus 2 and 0.2 microM, respectively, for E. coli). The results are consistent with the formation of a stable EF-Tu.EF-Ts complex that affects the interaction of EF-Tu with guanine nucleotides and inhibitors.

Effects of elfamycins on elongation factor Tu from Escherichia coli and Staphylococcus aureus.

Six kirromycin analogs (elfamycins) were compared on the basis of their inhibition of Escherichia coli poly(U)-directed poly(Phe) synthesis and stimulation of elongation factor Tu (EF-Tu)-associated GTPase activity. The elfamycins tested were kirromycin, aurodox, efrotomycin, phenelfamycin A, unphenelfamycin, and L-681,217. The last three lack the pyridone ring present in the other elfamycins. All the elfamycins inhibited poly(U)-dependent poly(Phe) synthesis and stimulated EF-Tu-associated GTPase activity, suggesting that the pyridone ring is not essential for activity. The six elfamycins were also examined in a poly(U)-directed, poly(Phe)-synthesizing system derived from Staphylococcus aureus and had 50% inhibitory concentrations of greater than or equal to 1 mM. When S. aureus ribosomes and E. coli elongation factors were combined in a hybrid poly(Phe)-synthesizing system, aurodox produced essentially complete inhibition of poly(Phe) synthesis with a 50% inhibitory concentration of 0.13 microM. This suggests that the observed high MICs of kirromycin and its congeners in S. aureus reflect a kirromycin-resistant EF-Tu rather than permeability constraints.

[3H]-p-azidopuromycin photoaffinity labeling of Escherichia coli ribosomes: evidence for site-specific interaction at U-2504 and G-2502 in domain V of 23S ribosomal RNA.

Previously we (1) showed that [3H]-p-azidopuromycin was a functional puromycin analogue that, on photolysis in the presence of 70S ribosomes from Escherichia coli, photoincorporated site specifically into proteins L23, L18/22, and L15 [Nicholson, A.W., Hall, C.C., Strycharz, W.A., & Cooperman, B.S. (1982) Biochemistry 21, 3809-3817] and (2) used immunoelectron microscopy to localize the principal sites of p-azidopuromycin photoincorporation within the 50S subunit [Olson, H.M., Nicholson, A.W., Cooperman, B.S., & Glitz, D.G. (1985) J. Biol. Chem. 260, 10326-10331]. These studies are here continued by identification of the principal sites of [3H]-p-azidopuromycin photoincorporation into ribosomal RNA. The major portion of such photoincorporation, 72%, takes place into 23S rRNA. Analysis by hybridization of the photoaffinity-labeled rRNA to restriction enzyme fragments of plasmid pKK3535, which contains rrnB DNA, using a refinement of a recently developed methodology [Hall, C.C., Smith, J.E., & Cooperman, B.S. (1985) Biochemistry 24, 5702-5711], shows that the most prominent [3H]-p-azidopuromycin photoincorporation occurs within bases 2445-2668 in domain V [Noller, H.F. (1984) Annu. Rev. Biochem. 53, 119-162] of 23S rRNA. Photoincorporation into this region is site specific, as demonstrated by the decrease in photoincorporation of radioactivity when unlabeled puromycin is included in the photolysis solution. Significant site-specific photoincorporation also occurs within bases 489-681 in domain II of 23S RNA. Further localization, by the method of reverse transcriptase primer extension [Barta, A., Steiner, G., Brosius, J., Noller, H.F., & Kuechler, E. (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 3607-3611], provides evidence that U-2504 and G-2502 are the principal sites of p-azidopuromycin interaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Mapping labeled sites in Escherichia coli ribosomal RNA: distribution of methyl groups and identification of a photoaffinity-labeled RNA region putatively at the peptidyltransferase center.

We have developed a method for the rapid localization of sites of ribosomal RNA labeling to limited regions (approximately 200 bases). The method is based on the formation and polyacrylamide gel electrophoretic separation of hybrids between restriction fragments of rrnB DNA and isotopically labeled rRNA and the subsequent determination of radioactivity across the gel. Using [3H]adenine-labeled rRNA as a control sample, we optimized experimental conditions with respect to a number of variables, including rRNA:DNA stoichiometric ratio, temperature of the annealing step, and levels of nucleases. An important result is that different rRNA X DNA hybrid fragments are obtained in different yields. The method was then applied to analyses of C3H3-labeled rRNA, giving results in good accord with known and proposed sites of rRNA methylation, and of rRNA that has been photoaffinity-labeled with 5-azido-2-nitrobenzoyl-[3H]Phe-tRNAPhe, a probe directed toward the peptidyltransferase center. The latter study showed a single major site of RNA labeling, falling within bases 2445-2668 of 23S rRNA. The extent of labeling was shown to be dependent on light-induced formation of a reactive intermediate and to be decreased in the absence of poly(uridylic acid) or in the presence of puromycin. The location of this major site of labeling is consistent with recent results obtained with an analogous tRNA photoaffinity label [Barta, A., Steiner, G., Brosius, J., Noller, H. F., & Kuechler, E. (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 3607-3611] and with related genetic and biochemical studies of antibiotic interaction with ribosomes suggesting that the peptidyltransferase center falls within region V (bases 2043-2625) of 23S rRNA.

Photoaffinity labeling of the ouabain binding site in Na, K-ATPase in developing brine shrimp.

Analysis of purified Na,K-ATPase from brine shrimp nauplii by sodium dodecyl sulfate-polyacrylamide gel electrophoresis reveals two large (alpha) subunits [G.L. Peterson, R.D. Ewing, S.R. Hootman, and F.P. Conte (1978) J. Biol. Chem. 253:4762]. The band with lower mobility in a neutral or alkaline gel is designated alpha 1 and the band with higher mobility alpha 2. Ouabain prevents dephosphorylation of both alpha 1 and alpha 2 as documented by gel analysis, but a higher concentration of ouabain is required to prevent dephosphorylation of alpha 2. The photoaffinity label, [3H]4'(2-ethyldiazomalonyl) digitoxigenin monodigitoxiside, specifically labels alpha in a ouabain-protectable manner without labeling other contaminating proteins in the preparation. Greater than 93% of the total ouabain-protectable labeling of the alpha subunits is associated with alpha 1. The photoaffinity label, [3H]4"' (2-ethyldiazomalonyl) digitoxin, specifically labels alpha 1 and beta in a ouabain-protectable manner without labeling other contaminating proteins. These data show that in the brine shrimp the third digitoxose residue of digitoxin binds in a region in which the alpha 1 and beta chains are in close proximity. Less than 5% of the specific ouabain-protectable labeling of total alpha is associated with alpha 2. These studies indicate that cardioactive steroids have higher affinity for the alpha 1 subunit.

Use of photolabels to probe the Na,K-ATPase and the beta-adrenergic receptor.

Radioactive photoaffinity labels have been used to probe the cardiac glycoside-binding site of Na,K-ATPase and the catecholamine-binding site of the beta-adrenergic receptor. For the Na,K-ATPase, a systematic positioning of the photoactive group on the first, second, and third digitoxoses of digitoxin showed that the specific radioactivity in the alpha subunit decreased 5- to 20-fold as the photoactive group was extended further away from the steroid nucleus, whereas the beta subunit is positioned very close to the alpha subunit in the region of the cardiac glycoside-binding site. For the beta-adrenergic receptor, a new class of orthoiodophenylazide derivatives of pindolol was prepared with carrier-free 125I. Photolysis of the beta-adrenergic receptor of duck, turkey, pigeon, and frog erythrocyte membrane with one of these compounds (iodoazidobenzylpindolol) allowed identification of the receptor polypeptides. It was found that the size of the polypeptides and the number of polypeptides varied.

Photoaffinity labeling of Escherichia coli ribosomes by an aryl azide analogue of puromycin. Evidence for the functional site specificity of labeling.

The photoincorporation of p-azido[3H]puromycin [6-(dimethylamino)-9-[3'-deoxy-3'-[(p-azido-L-phenylalanyl)amino]-beta-D-ribofuranosyl]purine] into specific ribosomal proteins and ribosomal RNA [Nicholson, A. W., Hall, C. C., Strycharz, W. A., & Cooperman, B. S. (1982) Biochemistry (preceding paper in this issue)] is decreased in the presence of puromycin, thus demonstrating that labeling is site specific. The magnitudes of the decreases in incorporation into the major labeled 50S proteins found on addition of different potential ribosome ligands parallel the abilities of these same ligands to inhibit peptidyltransferase. This result provides evidence that p-azidopuromycin photoincorporation into these proteins occurs at the peptidyltransferase center of the 50S subunit, a conclusion supported by other studies of ribosome structure and function. A striking new finding of this work is that puromycin aminonucleoside is a competitive inhibitor of puromycin in peptidyltransferase. The photoincorporation of p-azidopuromycin is accompanied by loss of ribosomal function, but photoincorporated p-azidopuromycin is not a competent peptidyl acceptor. The significance of these results is discussed. Photolabeling of 30S proteins by p-azidopuromycin apparently takes place from sites of lower puromycin affinity than that of the 50S site. The possible relationship of the major proteins labeled, S18, S7, and S14, to tRNA binding is considered.