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Adverse effects of large artery stiffening are well established in the systemic circulation; stiffening of the proximal pulmonary artery (PPA) and its sequelae are poorly understood. We combined in vivo (n = 6) with ex vivo data from cadavers (n = 8) and organ donors (n = 13), ages 18 to 89, to assess whether aging of the PPA associates with changes in distensibility, biaxial wall strain, wall thickness, vessel diameter, and wall composition. Aging exhibited significant negative associations with distensibility and cyclic biaxial strain of the PPA (p ≤ 0.05), with decreasing circumferential and axial strains of 20% and 7%, respectively, for every 10 years after 50. Distensibility associated directly with diffusion capacity of the lung (R2 = 0.71, p = 0.03). Axial strain associated with right ventricular ejection fraction (R2 = 0.76, p = 0.02). Aging positively associated with length of the PPA (p = 0.004) and increased luminal caliber (p = 0.05) but showed no significant association with mean wall thickness (1.19 mm, p = 0.61) and no significant differences in the proportions of mural elastin and collagen (p = 0.19) between younger (<50 years) and older (>50) ex vivo samples. We conclude that age‐related stiffening of the PPA differs from that of the aorta; microstructural remodeling, rather than changes in overall geometry, may explain age‐related stiffening. [ABSTRACT FROM AUTHOR]

Medical students are expected to perform common procedures such as suturing on patients during their third-year clerkships. However, these experiences are often viewed by medical students as stressors rather than opportunities for learning. The source of this stress is the lack of instruction on common procedures prior to being asked to observe or perform the procedure on a patient. First-time exposures to procedures in stressful environments may result in decreased confidence in medical students and decrease the frequency with which they perform these procedures in the future. The authors sought to change this paradigm by: (1) introducing a suturing module to first-year medical students in the context of the anatomy dissection laboratory and (2) measuring its effects on student attitudes and behavior over the course of their third-year clerkships when they encounter patients. The authors found that early and prolonged introduction to suturing was associated with increased student confidence relative to suturing a patient. Participation in the suturing module was associated with increased student confidence in identifying suturing instruments (P < 0.001) and suturing patients (P = 0.013). Further it positively affected their behavior as demonstrated by increased performance of suturing events from students exposed to the suturing module. (P < 0.001) This study demonstrates that early and prolonged opportunities to practice a procedural skill in a low-stress environment increases student confidence during patient interactions and alters student behavior.

Objective To verify the articular branch contributions in the human knee, delineate their anatomical variance, and outline the limitations of currently applied procedure protocols for denervation of the knee joint. Design A detailed anatomical dissection. Setting Cadavers in residence at the Albert Einstein College of Medicine. Subjects In total, 24 lower extremity specimens from 14 embalmed cadavers. Methods Human cadaveric dissections were performed on 24 lower extremities from 14 embalmed cadavers. Results This cadaveric study has demonstrated that the anterior knee receives sensory innervations from SMGN, SLGN, LRN, NVI, NVL, RFN, and IMGN. The courses of SMGN, SLGN, RFN, and IMGN are similar to recent anatomical studies. However, discrepancies exist in their relative anatomy to bony and radiographic landmarks. Conclusions Genicular denervation using classical anatomical landmarks may not be sufficient to treat the anterior knee joint pain. Our findings illustrate more accurate anatomic landmarks for the three-target paradigm and support additional targets for more complete genicular denervation. This cadaveric study provides robust anatomical findings that can provide a foundation for new anatomical landmarks and targets to improve genicular denervation outcomes. [ABSTRACT FROM AUTHOR]

The formation of cartilage elements in the developing vertebrate limb, where they serve as primordia for the appendicular skeleton, is preceded by the appearance of discrete cellular condensations. Control of the size and spacing of these condensations is a key aspect of skeletal pattern formation. Limb bud cell cultures grown in the absence of ectoderm formed continuous sheet-like masses of cartilage. With the inclusion of ectoderm, these cultures produced one or more cartilage nodules surrounded by zones of noncartilaginous mesenchyme. Ectodermal fibroblast growth factors (FGF2 and FGF8), but not a mesodermal FGF (FGF7), substituted for ectoderm in inhibiting chondrogenic gene expression, with some combinations of the two ectodermal factors leading to well-spaced cartilage nodules of relatively uniform size. Treatment of cultures with SU5402, an inhibitor FGF receptor tyrosine kinase activity, rendered FGFs ineffective in inducing perinodular inhibition. Inhibition of production of FGF receptor 2 (FGFR2) by transfection of wing and leg cell cultures with antisense oligodeoxynucleotides blocked appearance of ectoderm- or FGF-induced zones of perinodular inhibition of chondrogenesis and, when introduced into the limb buds of developing embryos, led to shorter, thicker, and fused cartilage elements. Because FGFR2 is expressed mainly at sites of precartilage condensation during limb development in vivo and in vitro, these results suggest that activation of FGFR2 by FGFs during development elicits a lateral inhibitor of chondrogenesis that limits the expansion of developing skeletal elements. Key Words: limb development; pattern formation; fibroblast growth factor; FGF receptor; lateral inhibition.

Fibronectin expression and spatiotemporal distribution were examined in relation to the distinctive patterns of mesenchymal condensation and chondrogenesis seen in high-density serum-free cultures of chicken wing and leg bud precartilage cells. More fibronectin protein was produced on a per cell basis by leg than by wing mesenchyme, both in freshly isolated tissue and during the prechondrogenic condensation period in culture, where the difference was twofold. The quantitative difference in fibronectin expression in freshly isolated wing and leg mesenchyme was also seen at the level of total and poly[(A).sup.+] RNA. During the condensation phase, fibronectin was distributed in the wing and leg mesenchymal cultures in a way that prefigured the eventual distribution of cartilage in these cultures: in wing cultures condensations were broad and flat, and rich in diffusely organized fibronectin; in leg cultures, condensations were compact and spheroidal, and contained abundant deposits of fibronectin. In addition, the leg condensations were connected by long fibronectin-rich fibers. Transient treatment with TGF-[beta] early during the culture period led to increase in fibronectin production and expansion of condensations in both wing and leg cultures. Leg mesenchyme was more responsive to transforming growth factor-[beta] than wing mesenchyme with respect to fibronectin production, and this was reflected in a greater enhancement of cartilage formation in later cultures. Treatment of cultures with monoclonal antibody 304 directed against the aminoterminal heparin-binding domain of fibronectin inhibited condensation formation and reduced chondrogenesis in wing mesenchyme, but, left these two processes unchanged in leg mesenchyme, despite disruption by the antibody of the leg-specific specific fibronectin fibers. These studies indicate that for both wing and leg mesenchyme the morphology, extent, and spatiotemporal regulation of precartilage condensation and subsequent chondrogenesis closely parallels the deposition of fibronectin. But whereas the interaction between cells and fibronectin in wing bud mesenchyme is mediated in part by the protein's amino-terminal domain, this domain does not appear to be involved in analogous interactions in leg bud mesenchyme.

Morphogenetic differences between fore and hind limb cartilage mesenchymal cells obtained from stages 21-26 chicken embryos have been studied using a serum-free culture system. The quantity and spatial assembly of cartilage generated varied for wing and leg cultures in all stages. Differences were evident in relative cohesivity.

Objectives: The goal of the study was to explore the perceptions of physiatry-faculty, physiatry- residents and rehabilitation patients regarding humanism in physiatry, and whether humanistic principles can be incorporated in a physiatry residency teaching curriculum. Design: Quantitative and qualitative studies utilizing structured questionnaires and interviews were used to interview residents, faculty-physiatrists, and patients. 40 resident physicians, 30 faculty physicians and 20 patients participated in the study. Results: Faculty, residents and patients unanimously agreed that humanism is relevant to the practice of physiatry. A majority of participants were in agreement that it could be taught in a structured curriculum. Questionnaires were transcribed, and authors read them separately to identify themes among responses. The main themes were decided by consensus. Comments were assigned under identified themes and subthemes. All participants gave suggestions how to incorporate humanism teaching in the resident curriculum. Conclusions: Humanism is an important attribute in a physiatrist that most study participants agreed could be taught in a phsyiatry training curriculum. Ideas on how to incorporate humanism in the teaching curriculum as well as possible barriers were identified. This study also provided an unique patient perspective on humanism that has been lacking in prior studies. Patient responses indicated agreement with broad themes such as empathy, respect and compassion as seen with the two clinician groups. [ABSTRACT FROM AUTHOR]