Charcot neuroarthropathy versus osteomyelitis: a case series.

INTRODUCTION: Patients with diabetes and peripheral neuropathy have a 25% risk of developing a foot ulcer, and these can lead to soft tissue infections that worsen and result in osteomyelitis. While Charcot neuroarthropathy is not as common as osteomyelitis, it is often misdiagnosed as osteomyelitis. CASE REPORTS: Three patients presented with diabetes, neuropathy, and foot ulcers. They underwent prophylactic surgery but later developed swelling at the surgical sites. Radiographs showed fragmentations that caused concern about osteomyelitis. The authors maintained diagnoses of Charcot neuroarthropathy and treated the patients with immobilization and offloading. All patients resolved the fragmentations without antibiotics or surgery. CONCLUSION: While Charcot neuroarthropathy and osteomyelitis have similar signs and symptoms, understanding the similarities and differences between the conditions can aid providers in appropriate wound management.

Measurement of the helicity asymmetry E for the reaction γ p → π 0 p : The CBELSA/TAPS Collaboration.

A measurement of the double-polarization observable E for the reaction γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C 4 H 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from E γ = 600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.

Cournand's and Richards' Post-Nobel Challenge: "Do Anything on the Structure of the Lung That Is of Interest for Physiology".

In their Nobel Lectures of 1956, the two cardiopulmonary physiologists André Cournand and Dickinson Richards described the future projects that they considered important for rounding up their impressive scientific achievements. One of them called for work that brought together structure and function of the lung in a systematic way. They challenged a young anatomist to undertake this in their cardiopulmonary laboratory at Bellevue Hospital. The first steps established the need for quantitative information on the structures that form the pulmonary gas exchanger as well as the airway tree. This resulted in a new approach to lung anatomy: morphometry would provide the quantitative information for modeling structure-function relations in the lung, and eventually in the entire respiratory system, thus allowing a rational analysis of how structures affect or limit functions.

Lung morphometry: the link between structure and function.

The study of the structural basis of gas exchange function in the lung depends on the availability of quantitative information that concerns the structures establishing contact between the air in the alveoli and the blood in the alveolar capillaries, which can be entered into physiological equations for predicting oxygen uptake. This information is provided by morphometric studies involving stereological methods and allows estimates of the pulmonary diffusing capacity of the human lung that agree, in experimental studies, with the maximal oxygen consumption. The basis for this "machine lung" structure lies in the complex design of the cells building an extensive air-blood barrier with minimal cell mass.

Morphometric differences between central vs. surface acini in A/J mice using high-resolution micro-computed tomography.

Through interior tomography, high-resolution microcomputed tomography (µCT) systems provide the ability to nondestructively assess the pulmonary acinus at micron and submicron resolutions. With the application of systematic uniform random sampling (SURS) principles applied to in situ fixed, intact, ex vivo lungs, we have sought to characterize morphometric differences in central vs. surface acini to better understand how well surface acini reflect global acinar geometry. Lungs from six mice (A/J strain, 15-20 wk of age) were perfusion fixed in situ and imaged using a multiresolution µCT system (Micro XCT 400, Zeiss). With the use of lower-resolution whole lung images, SURS methods were used for identification of central and surface foci for high-resolution imaging. Acinar morphometric metrics included diameters, lengths, and branching angles for each alveolar duct and total path lengths from entrance of the acinus to the terminal alveolar sacs. In addition, acinar volume, alveolar surface area, and surface area/volume ratios were assessed. A generation-based analysis demonstrated that central acini have significantly smaller branch diameters at each generation with no significant increase in branch lengths. In addition to larger-diameter alveolar ducts, surface acini had significantly increased numbers of branches and terminal alveolar sacs. The total path lengths from the acinar entrance to the terminal nodes were found to be higher in the case of surface acini. Volumes and surface areas of surface acini are greater than central acini, but there were no differences in surface/volume ratios. In conclusion, there are significant structural differences between surface and central acini in the A/J mouse.

Lung Structure and the Intrinsic Challenges of Gas Exchange.

Structural and functional complexities of the mammalian lung evolved to meet a unique set of challenges, namely, the provision of efficient delivery of inspired air to all lung units within a confined thoracic space, to build a large gas exchange surface associated with minimal barrier thickness and a microvascular network to accommodate the entire right ventricular cardiac output while withstanding cyclic mechanical stresses that increase several folds from rest to exercise. Intricate regulatory mechanisms at every level ensure that the dynamic capacities of ventilation, perfusion, diffusion, and chemical binding to hemoglobin are commensurate with usual metabolic demands and periodic extreme needs for activity and survival. This article reviews the structural design of mammalian and human lung, its functional challenges, limitations, and potential for adaptation. We discuss (i) the evolutionary origin of alveolar lungs and its advantages and compromises, (ii) structural determinants of alveolar gas exchange, including architecture of conducting bronchovascular trees that converge in gas exchange units, (iii) the challenges of matching ventilation, perfusion, and diffusion and tissue-erythrocyte and thoracopulmonary interactions. The notion of erythrocytes as an integral component of the gas exchanger is emphasized. We further discuss the signals, sources, and limits of structural plasticity of the lung in alveolar hypoxia and following a loss of lung units, and the promise and caveats of interventions aimed at augmenting endogenous adaptive responses. Our objective is to understand how individual components are matched at multiple levels to optimize organ function in the face of physiological demands or pathological constraints.

Three-body nature of N(*) and Δ(*) resonances from sequential decay chains.

The Nπ^{0}π^{0} decays of positive-parity N^{*} and Δ^{*} resonances at about 2 GeV are studied at ELSA by photoproduction of two neutral pions off protons. The data reveal clear evidence for several intermediate resonances: Δ(1232), N(1520)3/2^{-}, and N(1680)5/2^{+}, with spin parities J^{P}=3/2^{+}, 3/2^{-}, and 5/2^{+}. The partial wave analysis (within the Bonn-Gatchina approach) identifies N(1440)1/2^{+} and the N(ππ)_{S wave} (abbreviated as Nσ here) as further isobars and assigns the final states to the formation of nucleon and Δ resonances and to nonresonant contributions. We observe the known Δ(1232)π decays of Δ(1910)1/2^{+}, Δ(1920)3/2^{+}, Δ(1905)5/2^{+}, Δ(1950)7/2^{+}, and of the corresponding spin-parity series in the nucleon sector, N(1880)1/2^{+}, N(1900)3/2^{+}, N(2000)5/2^{+}, and N(1990)7/2^{+}. For the nucleon resonances, these decay modes are reported here for the first time. Further new decay modes proceed via N(1440)1/2^{+}π, N(1520)3/2^{-}π, N(1680)5/2^{+}π, and Nσ. The latter decay modes are observed in the decay of N^{*} resonances and at most weakly in Δ^{*} decays. It is argued that these decay modes provide evidence for a 3-quark nature of N^{*} resonances rather than a quark-diquark structure.

First measurement of the helicity asymmetry for γp → pπ0 in the resonance region.

The first measurement of the helicity dependence of the photoproduction cross section of single neutral pions off protons is reported for photon energies from 600 to 2300 MeV, covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, and BnGa partial wave analyses. Strikingly large differences between data and predictions are observed, which are traced to differences in the helicity amplitudes of well-known and established resonances. Precise values for the helicity amplitudes of several resonances are reported.

Cutaneous granulomas and epidermodysplasia verruciformis in early onset combined immunodeficiency syndrome.

Cutaneous granulomas with prominent caseating necrosis are a rare manifestation of immunodeficiency. Extensive and recalcitrant cutaneous viral infections can also be seen. We present a case of an 18-year-old white man with an early onset poorly characterized combined immunodeficiency syndrome who, over the past 5 years, developed enlarging tender red-purple plaques on his extremities and pink near-confluent macules on his chest and back. Previous biopsies of the red-purple plaques showed features of granuloma annulare. Histopathological examination of old and new biopsies revealed both sarcoidal and palisading necrobiotic granulomas with perforating features and elastophagocytosis. Stains and tissue cultures were negative for bacterial and fungal organisms. In addition, biopsy of a macule on the back demonstrated verruca plana with characteristics of epidermodysplasia verruciformis. As an infant, the patient had failure to thrive and a combined immunodeficiency, but was lost to follow-up for 15 years. He currently continues to have severe hypogammaglobinemia and cellular immunodeficiency. Intravenous immunoglobulin and prednisone were initiated and his plaques improved rapidly. Topical imiquimod was ineffective for the verruca plana. The patient and his parents are currently undergoing whole exome sequencing including evaluation for epidermodysplasia verruciformis 1 and 2 gene mutations. This case highlights the importance of including genetic immunodeficiency disorders in the clinical and histopathological differential diagnosis for cutaneous sarcoidal or palisading necrobiotic granulomas and for extensive cutaneous viral infection.

Two redundant octanoyltransferases and one obligatory lipoyl synthase provide protein-lipoylation autonomy to plastids of Arabidopsis.

Octanoyltransferases (LIP2) are important for the lipoylation of several α-ketoacid decarboxylases and glycine decarboxylase, all of which are essential multienzyme complexes of central metabolism, by attaching de novo-synthesised octanoyl moieties to the respective target subunits. Lipoyl synthase (LIP1) then inserts two sulphur atoms each into the protein-bound octanoyl chains to generate the functional lipoamide arms. In plants, most of the above multienzyme complexes occur only in mitochondria. Pyruvate dehydrogenase is an exception, since it also occurs in plastids. Plastidial LIP1 and LIP2 are known, but it is not clear how essential these enzymes are. Here, we report that not just one but two redundant LIP2 isoforms, LIP2p and LIP2p2, operate in plastids of Arabidopsis. The combined deletion of the two isoenzymes is embryo-lethal. Deletion of the plastidial lipoyl synthase LIP1p is also embryo-lethal, indicating that all plastidial LIP1 activity is due to LIP1p. These features suggest that protein lipoylation is based on an autonomous and partially redundant de novo lipoylation pathway in plastids.

Stereological assessment of mouse lung parenchyma via nondestructive, multiscale micro-CT imaging validated by light microscopic histology.

Quantitative assessment of the lung microstructure using standard stereological methods such as volume fractions of tissue, alveolar surface area, or number of alveoli, are essential for understanding the state of normal and diseased lung. These measures are traditionally obtained from histological sections of the lung tissue, a process that ultimately destroys the three-dimensional (3-D) anatomy of the tissue. In comparison, a novel X-ray-based imaging method that allows nondestructive sectioning and imaging of fixed lungs at multiple resolutions can overcome this limitation. Scanning of the whole lung at high resolution and subsequent regional sampling at ultrahigh resolution without physically dissecting the organ allows the application of design-based stereology for assessment of the whole lung structure. Here we validate multiple stereological estimates performed on micro-computed tomography (µCT) images by comparing them with those obtained via conventional histology on the same mouse lungs. We explore and discuss the potentials and limitations of the two approaches. Histological examination offers higher resolution and the qualitative differentiation of tissues by staining, but ultimately loses 3-D tissue relationships, whereas µCT allows for the integration of morphometric data with the spatial complexity of lung structure. However, µCT has limited resolution satisfactory for the sterological estimates presented in this study but not for differentiation of tissues. We conclude that introducing stereological methods in µCT studies adds value by providing quantitative information on internal structures while not curtailing more complex approaches to the study of lung architecture in the context of physiological or pathological studies.