Showing papers by "University of Pittsburgh published in 1986"

Development of criteria for the classification and reporting of osteoarthritis: Classification of osteoarthritis of the knee

Abstract: For the purposes of classification, it should be specified whether osteoarthritis (OA) of the knee is of unknown origin (idiopathic, primary) or is related to a known medical condition or event (secondary). Clinical criteria for the classification of idiopathic OA of the knee were developed through a multicenter study group. Comparison diagnoses included rheumatoid arthritis and other painful conditions of the knee, exclusive of referred or para-articular pain. Variables from the medical history, physical examination, laboratory tests, and radiographs were used to develop sets of criteria that serve different investigative purposes. In contrast to prior criteria, these proposed criteria utilize classification trees, or algorithms.

Strategic Brand Concept-Image Management:

Abstract: Conveying a brand image to a target market is a fundamental marketing activity. The authors present a normative framework, termed brand concept management (BCM), for selecting, implementing, and co...

Axiomatic foundation of the analytic hierarchy process

Abstract: This paper contains an axiomatic treatment of the Analytic Hierarchy Process AHP. The set of axioms corresponding to hierarchic structures are a special case of axioms for priority setting in systems with feedback which allow for a wide class of dependencies. The axioms highlight: 1 the reciprocal property that is basic in making paired comparisons; 2 homogeneity that is characteristic of people's ability for making comparisons among things that are not too dissimilar with respect to a common property and, hence, the need for arranging them within an order preserving hierarchy; 3 dependence of a lower level on the adjacent higher level; 4 the idea that an outcome can only reflect expectations when the latter are well represented in the hierarchy. The AHP neither assumes transitivity or the stronger condition of consistency nor does it include strong assumptions of the usual notions of rationality. A number of facts are derived from these axioms providing an operational basis for the AHP.

Voltage-sensitive dyes reveal a modular organization in monkey striate cortex.

Abstract: Voltage-sensitive dyes allow neuronal activity to be studied by non-invasive optical techniques. They provide an attractive means of investigating striate cortex, where important response properties are organized in two dimensions. In the present study, patterns of ocular dominance and orientation selectivity were obtained repeatedly from the same patch of cortex using the dye merocyanine oxazolone, together with current image-processing techniques. The patterns observed agree with most established features of monkey striate cortex and suggest a new unit of cortical organization; one that is modular in structure and which appears to link the organization of orientation selectivity with that of ocular dominance.

Inventing the University

Abstract: Every time a student sits down to write for us, he has to invent the university for the occasion — invent the university, that is, or a branch of it, like history or anthropology or economics or English. The student has to learn to speak our language, to speak as we do, to try on the peculiar ways of knowing, selecting, evaluating, reporting, concluding, and arguing that define the discourse of our community. Or perhaps I should say the various discourses of our community, since it is in the nature of a liberal arts education that a student, after the first year or two, must learn to try on a variety of voices and interpretive schemes — to write, for example, as a literary critic one day and as an experimental psychologist the next; to work within fields where the rules governing the presentation of examples or the development of an argument are both distinct and, even to a professional mysterious.

Pathologic findings from the National Surgical Adjuvant Breast Project (protocol 6). I. Intraductal carcinoma (DCIS).

Abstract: Seventy-eight examples of intraductal carcinoma (DCIS) were identified after pathologic review of 2072 specimens obtained from National Surgical Adjuvant Breast Project protocol 6. This randomized clinical trial compares the therapeutic merit of total mastectomy (TM) with lumpectomy (L), with (LX) and without (LO) postoperative irradiation. All patients were subjected to axillary lymph node dissection. Seven (14%) of the 51 patients with DCIS treated by L exhibited breast recurrence within or close to the site of the initial lesion 4 to 53 months (average, 16 months) after L. Only 2 (7%) of these events occurred in the 29 women treated by LX, as opposed to 23% in the LO group. No pathologic features were noticed that might have been considered predictive of local breast recurrence. The three DCIS recurrences and the four invasive forms noted are considered to represent overlooked or incompletely excised foci of cancer because of the multifocality (not multicentricity) of some breast cancers. The possibility that DCIS may represent a marker of risk for the development of cancer rather than a precursor lesion per se is suggested. Despite apparent difficulties in the pathologic diagnosis of DCIS as well as uncertainty concerning its natural history, no evidence was found to indicate that it represents a more ominous disease than invasive cancer. Indeed, treatment failure occurred in only one patient treated by LX and a similar number subjected to TM (4% versus 2%). Although these observations are short term (average follow-up, 39 months), estimates of the probability of local recurrence or survival suggest that they will not be significantly altered after longer periods of surveillance. Thus, there are no compelling reasons why DCIS may not be treated in a cosmetically acceptable manner by LX. A randomized clinical trial addressing this issue is now in progress.

Meniscal tears: The effect of meniscectomy and of repair on intraarticular contact areas and stress in the human knee A preliminary report

Abstract: The role of the meniscus in load transmission across the knee has long been a subject of debate. In this study, we examined the biomechanical consequences of the operative treatments for bucket-handle and peripheral meniscal tears. Contact areas and instantaneous intraarticular pressure distributions were measured in two groups of human cadaver knees. In Group I, consisting of four knees, we created a bucket-handle tear involving the inner one-third of the meniscus, followed by partial, and then total meniscectomy. Knees were tested in an Instron testing machine after each procedure, using a 400 pound load at 0 degrees or 30 degrees flexion. Contact areas and local stresses were measured using Prescale, a pressure-sensitive film. After partial meniscectomy, contact areas decreased approximately 10%, and peak local contact stresses (PLCS) increased approximately 65%. After total meniscectomy, contact areas decreased approximately 75%, and PLCS increased approximately 235%. In Group II, consisting of three additional knees, we created a 2 cm peripheral tear of the posterior meniscal horn, followed by open repair, arthroscopic repair, segmental, and then total meniscectomy. Repair of the tear was accomplished with either vertically placed sutures by an open technique or horizontally placed sutures by an arthroscopic technique. Knees were tested in the neutral position in the Instron machine and contact areas and local stresses measured using Prescale. PLCSs and contact areas were found to be the same using either repair technique. There was, however, a 110% increase in PLCS after segmental meniscectomy of that portion of the meniscus involved in the peripheral tear.(ABSTRACT TRUNCATED AT 250 WORDS)

An analysis of a phase field model of a free boundary

Abstract: A mathematical analysis of a new approach to solidification problems is presented. A free boundary arising from a phase transition is assumed to have finite thickness. The physics leads to a system of nonlinear parabolic differential equations. Existence and regularity of solutions are proved. Invariant regions of the solution space lead to physical interpretations of the interface. A rigorous asymptotic analysis leads to the Gibbs-Thompson condition which relates the temperature at the interface to the surface tension and curvature.

Conduct disorders in childhood and adolescence

Abstract: The prevalence of conduct disorder in children constitutes a severe and persistent social problem. Conduct disorder - which encompasses antisocial behaviours such as aggressive acts, theft, vandalism, arson, running away, truancy and defying authority - is a common reason for referring children and adolescents for psychological and psychiatric treatment. The newly revised edition of this volume describes the nature of conduct disorder, incorporating the most important findings since the publication of the original. The author draws on current research and clinical work from a variety of fields to explore such topics as: psychiatric diagnosis; child-rearing practices; parent psychopathology; sex differences in development; interactions of heredity and environment; risk and protective factors; and treatment and prevention.

Construct Measurement in Organizational Strategy Research: A Critique and Proposal

Abstract: Strategic management researchers have emphasized concept development but generally have ignored construct measurement issues. Because a strong linkage between concepts and their measures enhances theory development, it is necessary to validate strategy measures systematically. In this vein, this paper (a) critically reviews the state of construct measurement in organizational strategy research; (b) develops a set of key criteria specifically for strategy measurement; and (c) proposes some recommendations for integrating strategy concepts with their measures.

The organization of the pudendal nerve in the male and female rat.

Abstract: Mature male and female Sprague-Dawley rats were used in this study to compare the organization of the pudendal nerve in the two sexes. Experiments included incubating the cut pudendal nerve in diamidino-2-phenylindole HCl (DAPI), fast blue (FB), or horseradish peroxidase (HRP) and injecting individual perineal muscles with these substances. In both sexes, incubation of the pudendal nerve labelled two motoneuron nuclei in the L5-L6 segments of the spinal cord. These nuclei are the dorsomedial (DM) and dorsolateral (DL) cell columns described by Schroder (J. Comp. Neurol. 192:567-587, 1980). In agreement with previous studies, there were significantly more neurons in both nuclei in the male than in the female and the neurons were larger in the male. In both sexes, the DL and DM nuclei were characterized by a longitudinal dendritic structure. The DM nucleus also had numerous dendritic bundles extending across the midline, linking the DM nuclei bilaterally. Pudendal nerve afferent neurons were located in the L6 and S1 dorsal root ganglia. In the male, the afferent neurons were larger and more numerous. In both sexes, labelled pudendal afferent fibers in the spinal cord were located in the dorsal columns, the medial half of Lissauer's tract, the extreme medial edge of the dorsal horn, both ipsilaterally and contralaterally, and in a large terminal field in the dorsal gray commissure. No labelled afferents were seen in the intermediate or ventral gray. Perineal muscle injections established that there was no difference between males and females in the number of motoneurons innervating the external anal or urethral sphincters. In the female, urethral sphincter motoneurons accounted for almost all the DL motoneurons, and anal sphincter motoneurons accounted for almost all the DM motoneurons. The ischiocavernosus and bulbospongiosus muscles are vestigial in the female rat. In the male, neurons innervating the anal sphincter and bulbospongiosus muscles were intermingled in the DM nucleus. In contrast, in the DL nucleus, the urethral sphincter neurons were located in the lateral portion of the nucleus and the ischiocavernosus neurons were located in the medial portion.

Consumer Response to Television Commercials: The Impact of Involvement and Background Music on Brand Attitude Formation:

Abstract: Past research has examined the effect of level of involvement (high vs. low) on subjects’ reactions to persuasive communications. The authors suggest that high involvement can be differentiated int...

Parent-child agreement on child psychiatric symptoms assessed via structured interview.

Abstract: Correlations between scores derived from structured interviews with 299 disturbed children aged 6-18 and their parents indicated low-to-moderate levels of agreement regarding the presence and severity of child psychiatric symptoms. Agreement was higher on behavior and conduct problems than on anxiety, fears, obsessions-compulsions, psychotic symptoms and affective disturbances. Parents reported more child behavior and conduct problems than children, whereas children reported more affective and neurotic symptoms than parents. Parent-child agreement also increased sharply with age.

Clinical Pharmacokinetics of Cyclosporin

Abstract: Cyclosporin (cyclosporin A) is a unique immunosuppressant used to prevent the rejection of transplanted organs and to treat diseases of autoimmune origin. Therapeutic drug monitoring of cyclosporin is essential for several reasons: (a) wide variability in cyclosporin pharmacokinetics has been observed after the oral or intravenous administration of the drug. The variability in the kinetics of cyclosporin is related to a patient’s disease state, the type of organ transplant, the age of the patient and therapy with other drugs that interact with cyclosporin; (b) maintaining a blood concentration of cyclosporin required to prevent rejection of the transplanted organ; (c) minimising drug toxicity by maintaining trough concentrations below that which toxicity is most likely to occur; and (d) monitoring for compliance since patient non-compliance with drug regimens is a significant reason for graft loss after 60 days. Clinical monitoring and pharmacokinetic studies of cyclosporin can be performed using different biological fluids (plasma, serum or whole blood) and different analytical techniques (radioimmunoassay or high pressure liquid chromatography). The available analytical methods provide different results when using blood, plasma, or serum. Comparison of therapeutic ranges and pharmacokinetic parameters should be made with careful attention given to the method of cyclosporin analysis.

Structure of the DNA-Eco RI endonuclease recognition complex at 3 A resolution.

Abstract: The crystal structure of the complex between Eco RI endonuclease and the cognate oligonucleotide TCGCGAATTCGCG provides a detailed example of the structural basis of sequence-specific DNA-protein interactions. The structure was determined, to 3 A resolution, by the ISIR (iterative single isomorphous replacement) method with a platinum isomorphous derivative. The complex has twofold symmetry. Each subunit of the endonuclease is organized into an alpha/beta domain consisting a five-stranded beta sheet, alpha helices, and an extension, called the "arm," which wraps around the DNA. The large beta sheet consists of antiparallel and parallel motifs that form the foundations for the loops and alpha helices responsible for DNA strand scission and sequence-specific recognition, respectively. The DNA cleavage site is located in a cleft that binds the DNA backbone in the vicinity of the scissile bond. Sequence specificity is mediated by 12 hydrogen bonds originating from alpha helical recognition modules. Arg200 forms two hydrogen bonds with guanine while Glu144 and Arg145 form four hydrogen bonds to adjacent adenine residues. These interactions discriminate the Eco RI hexanucleotide GAATTC from all other hexanucleotides because any base substitution would require rupture of at least one of these hydrogen bonds.

Pathologic findings from the national surgical adjuvant breast project (protocol 6). Relation of local breast recurrence to multicentricity

Abstract: One hundred ten local breast recurrences were observed in 1108 pathologically evaluable patients enrolled in NSABP protocol 6 who were treated by lumpectomy and followed for 5 to 95 months (average, 39 months). Eighty-six percent and 95% of all local breast recurrences were noted within 4 and 5 years, respectively, following lumpectomy. Life table analysis revealed their incidence to be 24% for those not and 6% for those receiving lumpectomy and breast irradiation. One hundred four (95%) of the breast recurrences involved the mammary parenchyma and the remaining 6 (5%) involved the skin and/or nipple only. Eleven (10%) of the former were noninvasive. The most common (86%) presentation of breast recurrence appeared to be a localized mass within or close to the quadrant of the index cancer. In 14% the recurrence not only involved the same quadrant, but was more diffuse within the breast extending to remote areas as well. This type was characterized pathologically by marked intralymphatic extension as well as involvement of the overlying skin and/or nipple after the fashion of so-called inflammatory or occult inflammatory breast cancer. The recurrences noted in the skin and/or nipple only were also pathologically characterized by intralymphatic involvement at these sites in the majority of instances. These two forms of breast recurrences appear to reflect the localized growth of highly aggressive invasive breast cancers. The concordance of histologic types and grades of the index and recurrent cancers implies that such events represent growth of overlooked tumor, a deficiency attendant with lumpectomy due to the extreme multifocal nature (not multicentricity) of some breast cancers and/or inadequacies in evaluating the lines of resection of lumpectomy specimens. Sources of error in regard to this latter are identified and guidelines for the examination of such specimens, as well as the assessment of margins, are presented. The observation that local breast recurrences noted following lumpectomy occurred within or close to the same quadrant as the index cancer, despite the presence of multicentric noninvasive cancers in 10% of the patients treated by total mastectomy, minimizes the biological and clinical significance of multicentric foci of cancer present in some breast cancers. Cancer measuring greater than or equal to 2.0 cm, having high histologic and nuclear grades, or intralymphatic extension, were found to have a statistically significant association with local breast recurrence in all patients following lumpectomy. A converse relationship was noted with tubular and scar cancers of types 1 and 4.(ABSTRACT TRUNCATED AT 400 WORDS)

Environments as Moderators of the Relationship Between Strategy and Performance

Abstract: Environments have been viewed as key contingency variables for relationships between strategy and performance. Yet, the nature of this contingency relationship has not been resolved; do environments moderate its form or its strength? Using moderated regression analysis and subgroup analysis, this study demonstrated that environments, as measured by characteristics of market structures, moderate the strength but not the form of relationships between strategy variables and performance.

Pulmonary hypertension in the CREST syndrome variant of systemic sclerosis.

Abstract: Pulmonary hypertension (PHT) occurred in 59 (9%) of 673 systemic sclerosis patients seen between 1963 and 1983 In 30 patients, all with the CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias), the pulmonary hypertension was isolated, ie, independent of other pulmonary or cardiac conditions In 20 patients, isolated PHT was demonstrated by cardiac catheterization All had normal or only mildly decreased lung volumes, and mild or no pulmonary interstitial fibrosis on chest roentgenogram In comparison with 287 CREST syndrome patients without PHT, these 20 patients had markedly reduced diffusing capacity for carbon monoxide (DLCO) (mean 39% of predicted normal) In 6 patients, the low DLCO antedated clinical evidence of PHT by 1-6 years At autopsy there was marked intimal fibrosis with hyalinization and smooth muscle hypertrophy in the small- and medium-sized arteries, without significant parenchymal fibrosis or inflammation Patients with isolated PHT did not respond favorably to vasodilators and had a very poor prognosis, with a 2-year cumulative survival rate of 40% A DLCO less than 45% of predicted in the absence of pulmonary interstitial fibrosis may be an important predictor of the subsequent development of isolated PHT

Face-to-face interactions of depressed mothers and their infants.

Abstract: Although some depressed mothers are withdrawn, others are highly engaged and intrusive. There are correspondences between the behavior of depressed mothers and their infants.

Oxytocin secretion in response to cholecystokinin and food: differentiation of nausea from satiety

Abstract: Administration of cholecystokinin (CCK) to rats caused a dose-dependent increase in plasma levels of the neurohypophyseal hormone oxytocin (OT). The OT secretion was comparable to that found in response to nausea-producing chemical agents that cause learned taste aversions. The effect of CCK on OT secretion was blunted after gastric vagotomy, as was the inhibition of food intake induced by CCK. Food ingestion also led to elevated plasma OT in rats, but CCK and aversive agents caused even greater OT stimulation. Thus, after administration of large doses of CCK, vagally mediated activation of central nausea pathways seems to be predominantly responsible for the subsequent decrease in food intake. Despite their dissimilar affective states, both nausea and satiety may activate a common hypothalamic oxytocinergic pathway that controls the inhibition of ingestion.