Patterns of scientific growth. [Review of: Cohen, HF. The scientific revolution: a historiographical inquiry. Chicago: University of Chicago Press, 1994].
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The University of Chicago Hospitals has planned for every kind of crisis, including last January's snow-storm of the decade. Executives only used internal communication and situation updates to ensure the hospital was ready to cope with adequate staffing and supply demands.
The University of Chicago Pritzker School of Medicine has developed and evaluated an extensive teaching program in clinical ethics coordinated primarily through the Center for Clinical Medical Ethics. The program provides medical students with a foundation in medical ethics during the four years of medical school and augments the clinical ethics knowledge and teaching skills of the housestaff and clinical faculty at the University of Chicago. Together, medical student teaching and clinical faculty development have made clinical ethics an integral part of medical education at the University of Chicago. Through these efforts, the teaching program aims to incorporate clinical ethics considerations into medical decisions and in this way contribute to improving patient care. (A detailed overview of all clinical ethics instruction at the school is provided.)
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OBJECTIVES: To describe a longitudinal profile of resistance to beta-lactam antimicrobials among isolates of Staphylococcus aureus at a large university teaching hospital and to evaluate the impact of the methicillin resistance phenotype on resistance trends for non-beta-lactam antimicrobials. DESIGN: Retrospective evaluation of antimicrobial susceptibility data for all 17,287 S. aureus isolates obtained from January 1986 through December 2000. SETTING: The University of Chicago Hospitals, a family of tertiary-care, university-affiliated hospitals in Chicago, Illinois, consisting of 547 adult and pediatric beds. RESULTS: The annual rate of resistance to methicillin increased from 13% in 1986 to 28% in 2000 (P < .001) and has not plateaued. For each non-beta-lactam antimicrobial tested, the annual rates of resistance were far higher among methicillin-resistant S. aureus (MRSA) isolates than among methicillin-susceptible S. aureus (MSSA) isolates. The annual rates of resistance to the macrolide, lincosamide, and streptogramin (MLS) antimicrobials erythromycin and clindamycin increased among MSSA isolates (P < .01), but remained lower than 20%. Resistance to the MLS antimicrobials was higher among MRSA isolates (higher than 60%), but the annual rate decreased significantly during the study (P < .01). CONCLUSION: The prevalence of methicillin resistance among S. aureus isolates has continued to increase; resistance to non-beta-lactam antimicrobials is far more common among MRSA isolates. Recent decreases in the proportion of MRSA isolates resistant to non-beta-lactam antimicrobials suggest important changes in the epidemiology of this pathogen.
The current members of the faculty at the University of Chicago are acutely aware of the great historic tradition they have inherited. Like all academic medical centers, they are challenged by the current socioeconomic climate, but with the vast intellectual resources of the University of Chicago and its secure place in the community, both locally and nationally, we are confident of our ability to make a continuing contribution to the development of neurosurgery.
The 1994 University of Chicago "definitive" survey of adults estimated prevalence of homosexuality among males at 2.8% and among females at 1.4%. Corrected for the exclusion of those over the age of 59 years, the estimates should be 2.3% and 1.2%.
The identity and taxonomic distribution of paranasal sinuses among living platyrrhines has remained a contentious issue (e.g., Cave [1967] Am J Phys Anthropol 26:277-288 vs. Hershkovitz [1977] Chicago: University of Chicago Press) largely because the ontogenetic data required for their detection and identification (e.g., Cave [1967]; Maier [2000] Cambridge, UK: Cambridge University Press, 99-132.) were not attainable without sacrificing valuable juvenile and subadult specimens. Non-invasive computed tomography (CT) scanning of ontogenetic series of skulls for 10 platyrrhine genera demonstrates the presence of maxillary and ethmoid sinuses, as well as homologs of the human sphenoid and frontal sinuses. Differences in the latter two sinuses between platyrrhines and hominoids highlight the need for early developmental data in establishing sinus homology. In particular, the identification of homologous recesses in the cartilaginous nasal capsule, from which sinuses later develop, emerges as the critical step. This developmental approach also reveals that the anterior and posterior ethmoid sinuses are each sets of serial homologs, a point which reconciles previous difficulties in establishing sinus homologies across mammalian orders (e.g., Paulli [1900] Gegenbaurs Morphol Jahrb 28:147-178, 179-251, 483-564).
New taphonomic data on the Sterkfontein Member 4 (South Africa) fossil hominid assemblage are presented. The previous estimate of hominid individuals represented in the deposit (45) is increased to 87. New minimum numbers of hominid skeletal elements are provided, and incidences of bone surface damage inflicted by prehistoric biological agents are summarized. The hominid sample from Member 4 is composed predominately of gnathic remains and has a paucity of postcrania. This dearth of postcrania limits, to some extent, inferences about the formation of the Sterkfontein assemblage. However, carnivore tooth marks on some fossil specimens and an overall broad similarity in patterns of skeletal part representation between Sterkfontein and primate bone assemblages created by extant carnivores suggest that carnivores did have some involvement in the accumulation of the fossil hominid assemblage. Thus, this study provides support for the "carnivore-collecting hypothesis" of Brain (Brain [1981] The Hunters or the Hunted? Chicago: University of Chicago Press), which implicates large carnivores as prominent collecting agents of hominid body parts in Sterkfontein Member 4. Evidence of bone surface damage is, however, too scant to make confident inferences about specific carnivore taxon/taxa involved in hominid bone collection at the site.
The systematics of the Saguinus oedipus group within the bare-face tamarins remains open to question. Hershkovitz (Living New World Monkeys (Platyrrhini), Vol.1. Chicago: University of Chicago Press, 1977) places the cotton-top and rufus-naped tamarins as subspecies of Saguinus oedipus (S. o. oedipus and S. o. geoffroyi, respectively). In contrast, several other authors have argued that these two taxa should be considered separate species (S. oedipus and S. geoffroyi). Phylogenetic relationships within the group are also disputed. Resolving these different interpretations has been difficult in part because no study of this group has included an objective measure of expected levels of specific vs. subspecific variation. We used facial measurements from 179 adult crania to address the systematics of this group and included a related species that is known to include multiple subspecies. Our sample included three taxa from the S. oedipus group of the bare-face tamarins (S. oedipus, S. geoffroyi, and S. leucopus) and six subspecies from the related hairy-face tamarin species S. fuscicollis. Comparisons to S. leucopus provided a relative measure of species-level differences. Analyses that included S. fuscicollis provided a measure of subspecific variation. There was no evidence of facial sexual dimorphism in any of these taxa. A variety of multivariate statistical analyses including discriminant function and cluster analysis suggest that S. oedipus and S. geoffroyi differ morphologically at a level consistent with species-level distinctions. The extent of differences between these taxa is large. The differences in their facial morphology was on the order of differences between S. oedipus or S. geoffroyi and S. leucopus rather than the extent of variation among S. fuscicollis subspecies. Furthermore, a comparison of collecting localities revealed that the variation we observed among S. oedipus and S. geoffroyi was not clinical but presented a large morphological discontinuity at the boundary between taxa. Our analyses also suggested that S. leucopus is more similar to S. oedipus than is either to S. geoffroyi. Finally, it may be that there are some distinct species within the S. fuscicollis group. However, this hypothesis, along with other phylogenetic relationships suggested by this study, will require more data and further study.
As in all mammals studied to date, primate retina contains morphologically distinct classes of retinal ganglion cells (Polyak: The Retina. Chicago: University of Chicago Press, '41; Boycott and Dowling: Philos. Trans. R. Soc. Lond. [Biol.] 225:109-184, '69; Leventhal et al.: Science 213:1139-1142, '81; Perry et al.: Neuroscience 12:1101-1123, '84; Rodieck et al.: J. Comp. Neurol. 233:115-132, '85; Rodieck: In H.D. Steklis and J. Erwin (eds): Comparative Primate Biology, Volume 4: Neurosciences. New York: Alan R. Liss, Inc., pp. 203-278, '88). We have now studied the morphologies, central projections, and retinal distributions of the major morphological classes of ganglion cells in the normal adult monkey, the newborn monkey, and the adult monkey in which restricted regions of retina were depleted of ganglion cells at birth as a result of small lesions made around the perimeter of the optic disc. Both old-world (Macaca fascicularis) and new-world (Saimiri sciureus) monkeys were studied. Our results indicate that, at birth, the major morphological classes of monkey retinal ganglion cells are recognizable; cells in central regions are close to adult size whereas cells in peripheral regions are much smaller than in the adult. As in the adult (Stone et al.: J. Comp. Neurol. 150:333-348, '73), in newborn monkeys there is a very sharp division between ipsilaterally and contralaterally projecting retinal ganglion cells (nasotemporal division). Consistent with earlier work (Hendrickson and Kupfer: Invest. Ophthalmol. 15:746-756, '76) we find that the foveal pit in the neonate is immature and contains many more ganglion cells than in the adult. In the adult monkey in which the density of retinal ganglion cells in the central retina was reduced experimentally at birth, the fovea appeared immature, and an abnormally large number of retinal ganglion cells were distributed throughout the foveal pit. The cell bodies and dendritic fields of ganglion cells that developed within cell-poor regions of the central retina were nearly ten times larger than normal. In peripheral regions the effects were smaller. The dendrites of the abnormally toward the foveal pit. They did not extend preferentially into the cell-poor region as do the abnormally large cells on the borders of experimentally induced cell-poor regions of cat central retina (Leventhal et al.: J. Neurosci. 8:1485-1499, '88) or, as we found here, in paracentral regions of primate retina.(ABSTRACT TRUNCATED AT 400 WORDS)
Golgi-impregnated horizontal cells (HCs) as viewed in whole mount human retinas have been studied by light microscopic (LM) techniques. Impregnated HCs have been drawn by camera lucida and by the Eutectics neuron tracing method to provide quantitative data on dendritic tree sizes, dendritic tree shapes, and dendritic terminals for statistical treatment and cluster analysis. In addition, fractal analyses of HC dendritic branching patterns have been performed. Three significantly different HCs can be classified on both subjective and objective morphological criteria in central and peripheral human retina. In the fovea all HCs are so small that it is difficult to achieve a clear separation of the subtypes, although they can be distinguished by the experienced observer. HI types are the classic HCs of Polyak (The Retina, Chicago: University of Chicago Press, 1941) with distinct dendritic terminal clusters going to cones and a fan-shaped axon terminal consisting of large numbers of rod-destined terminals. HII cells have profusely branched, overlapping dendrites, with poorly defined terminals going to cones and a short curled axon bearing small terminals also going to cones. The HIII types exhibit larger diameter, more asymmetrically shaped dendritic trees and 30% more dendritic terminal clusters than HI cells at any location on the retina. Many HIII cells appear to emit a process from the cell body in the inner nuclear layer (INL) that descends into the outer strata of the inner plexiform layer (IPL). The axon of the HIII cell may end in a loosely organized, sprawling arborization. Fractal dimensions of the horizontal cells also show significant differences between the three groups. HII cells exhibit the highest fractal dimension followed by HI and HIII cells with lower and lowest fractal dimensions, respectively. The fractal dimension of HII cells of rhesus monkey, as determined from drawings by other authors in other publications, are the same as HII cells of human retina.