The structure of Lippmann heliochromes: Cajal and the 1908 Nobel Prize in Physics

The 1908 Nobel Prize in Physics was awarded to Luxembourgeois Gabriel Lippmann (1848-1921), Professor of Mathematical and Experimental Physics at la Sorbonne, for his method of reproducing colors photographically based on the theory of wave interference. In the preceding several years, the eminent neurohistologist - and avid photographer - Santiago Ramón y Cajal (1852-1934) had been experimenting with Lippmann heliochromes, studying under the microscope the structure of the laminae of Zenker that produce mixed colors, and especially white. Those studies led to a series of technical papers by Cajal, the culmination being an article published 100 years ago in the Annual Report of the Board of Regents of the Smithsonian Institution in Washington, DC. A few years later, Cajal published Photography in Colors, his classic monograph on the physicochemical principles of the 'art of Daguerre,' bearing further testimony to his exuberant productivity, far-reaching interests, and scientific genius. The present article reflects on the workings of the mind of Cajal and his fundamental knowledge that was a precondition for his success in neurohistology. It highlights the links between the early photographic studies of Cajal and Lippmann, masters of the biological and physical sciences, respectively. Special emphasis is placed on Lippmann's discovery of heliochromes and the microscopic analyses performed on them by Cajal, including elements from relevant contemporary studies and discoveries.     

Ovarian carcinoma presenting with axillary lymph node metastasis: a case diagnosed by fine-needle aspiration and brief review of the literature

Ovarian carcinoma is a lethal disease and a main cause of morbidity and mortality among gynecological malignancies. Metastatic ovarian carcinoma to the axillary node is an exceptionally infrequent pathological entity. We report a case of ovarian carcinoma, which presented with axillary lymph node metastasis and review the previously documented cases. A 63-year-old woman with a medical history of stage IIIb ovarian carcinoma was admitted to our hospital complaining of a mass in her right axilla. Fine-needle aspiration (FNA) biopsy was performed. Cytological examination revealed a poorly differentiated carcinoma with immunocytochemical features consistent with metastatic ovarian carcinoma. This case illustrates a rare presentation of ovarian carcinoma and underlines the need to consider it in the differential diagnosis of axillary lesions.     

Coronary Left Main and Non‐Left Main Bifurcation Angles: How are the Angles Modified by Different Bifurcation Stenting Techniques?

Background: Investigation of the correlation between bifurcation angles and outcomes is limited with discordant results. The aim of this study is to investigate left main (LM) and non‐left main (N‐LM) bifurcation angles and their modification after percutaneous coronary intervention (PCI). Measurement of all three angles adds to our understanding of bifurcation anatomy and the resultant effect of different stenting techniques. Methods and Results: All three bifurcation angles were described according to the European Bifurcation Club definition: the A (proximal bifurcation angle), the B (distal bifurcation angle) and the C (main branch angle). Measurements were performed in 75 LM and 140 N‐LM bifurcations. In LM bifurcations baseline mean values of C, A, and B were 151°± 28°, 131°± 32°, and 78 ± 28°, respectively. In bifurcations with 2 stents the B significantly decreased by a mean of 10° (P = 0.003) and A increased by 10° (P = 0.006). Crush stenting significantly decreased B (A – 14°; P = 0.020) and increased A (A + 21°; P = 0.005), particularly non‐true bifurcations. In N‐LM bifurcations mean values for C, A, and B were 156°± 19°, 144°± 22°, and 60°± 20°, respectively. Similar to LM bifurcations, the B became narrower mainly at the expense of the A, which became wider. In both types of bifurcations the greatest variation in A and B was found following 2‐stent techniques performed in T‐shaped (≥70°) bifurcations. Conclusions: In both LM and N‐LM bifurcations we found a significant difference in A and B pre‐ and post‐PCI. This difference was driven by the 2‐stent technique and was most evident with a baseline bifurcation angle ≥70°. The Crush technique caused the largest angle variation post‐procedure, particularly in non‐true LM bifurcations. (J Interven Cardiol 2010;23:382–393)     

Assessment of respiratory mechanics by impulse oscillometry in orthopneic patients with acute left ventricular failure

Backround

This study investigated the respiratory function and mechanics of patients with orthopnea caused by acute left ventricular failure (ALVF).

Methods

The study comprised 40 patients with ALVF and 15 control subjects. All patients underwent lung function tests and impulse oscillometry in both sitting and supine positions. In a subgroup of 22 patients, isosorbide dinitrate was administered and impulse oscillometry was performed 15 minutes later in the supine position.

Results

No patient reported dyspnea while seated, and the orthopnea score was 2.9 ± 1.4. Left ventricular ejection fraction was 43% ± 10%. Patients demonstrated restrictive spirometric pattern in the sitting position, whereas functional residual capacity was comparable to that of the control group. In the supine position, all pulmonary volumes decreased, except inspiratory capacity which increased. Respiratory reactance (Xrs5) was higher in patients in both sitting (421.8 ± 630.6%pred vs 147.2 ± 72.8%pred, P = .01) and supine (699.8 ± 699.9%pred vs 251.2 ± 151.6%pred, P ≤ .001) positions. Respiratory resistance (Rrs5) (10.6% ± 17.8% mean decrease) and Xrs5 (17.2% ± 39.4% mean decrease) improved after nitrates administration. Orthopnea was better correlated with Xrs5%pred in the supine position (r = .42, P = .007). Ejection fraction was positively correlated with inspiratory capacity %pred (r = .42, P = .007) in the sitting position.

Conclusion

Patients with ALVF demonstrated increased respiratory reactance that correlated with orthopnea severity and improved after nitrates administration.     

Role of updraft velocity in temporal variability of global cloud hydrometeor number

Understanding how dynamical and aerosol inputs affect the temporal variability of hydrometeor formation in climate models will help to explain sources of model diversity in cloud forcing, to provide robust comparisons with data, and, ultimately, to reduce the uncertainty in estimates of the aerosol indirect effect. This variability attribution can be done at various spatial and temporal resolutions with metrics derived from online adjoint sensitivities of droplet and crystal number to relevant inputs. Such metrics are defined and calculated from simulations using the NASA Goddard Earth Observing System Model, Version 5 (GEOS-5) and the National Center for Atmospheric Research Community Atmosphere Model Version 5.1 (CAM5.1). Input updraft velocity fluctuations can explain as much as 48% of temporal variability in output ice crystal number and 61% in droplet number in GEOS-5 and up to 89% of temporal variability in output ice crystal number in CAM5.1. In both models, this vertical velocity attribution depends strongly on altitude. Despite its importance for hydrometeor formation, simulated vertical velocity distributions are rarely evaluated against observations due to the sparsity of relevant data. Coordinated effort by the atmospheric community to develop more consistent, observationally based updraft treatments will help to close this knowledge gap.     

Clinical events in the first decade in a cohort of infants with sickle cell disease. Cooperative Study of Sickle Cell Disease [see comments]

Within the Cooperative Study of Sickle Cell Disease, 694 infants with confirmed sickle cell disease were enrolled at less than 6 months of age. Information about the nature and frequency of complications was collected prospectively over a 10-year period. Painful crises and acute chest syndrome were the most common sickle cell-related events in homozygous sickle cell anemia (SS), hemoglobin SC disease (SC), and S beta thalassemia patients (overall incidence in SS patients of 32.4 and 24.5 cases per 100 person-years, respectively). Bacteremia occurred most frequently in SS children under 4 years of age and in SC patients less than 2 years of age. The mortality rate was low in this cohort compared with that found in previous reports. Twenty children, all with Hb SS, died (1.1 deaths per 100 person-years among SS patients). Infection, most commonly with Streptococcus pneumoniae and Hemophilus influenzae, caused 11 deaths. Two children died of splenic sequestration, 1 of cerebrovascular accident, and 6 of unclear causes. Two patients underwent cholecystectomies, and 17 underwent splenectomies after one or more splenic sequestration crises. The experience of this cohort should reflect closely the true clinical course of those children with Hb SS and Hb SC disease who are observed in sickle cell centers in the United States.     

Evidence for a signaling role for the alpha chains of granulocyte- macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 receptors: divergent signaling pathways between GM-CSF/IL-3 and IL-5

In the present study, we have used a human erythroleukemia cell line, TF-1, that proliferates in response to granulocyte macrophage colony stimulating factor (GM-CSF), interleukin-3 (IL-3), and interleukin-5 (IL-5) to investigate the role of receptors for these cytokines in signal transduction mechanisms involved in proliferative responses. The receptors for GM-CSF, IL-3, and IL-5 each possess a cytokine specific alpha subunit, but all three share a common beta chain. Using an immunoblotting system designed to detect phosphotyrosine containing proteins and a permeabilized cell system to detect rapid changes in phosphate turnover on proteins, we show that while GM-CSF and IL-3 use tyrosine phosphorylation to mediate mitogenic signal transduction, IL-5 uses tyrosine dephosphorylation in its signaling pathway. The use of different signaling pathways by these cytokines can be confirmed in a biologic system whereby the proliferation induced in culture by GM-CSF and IL-3 is inhibited by tyrosine kinase inhibitors, but that induced by IL-5 is enhanced. Conversely, GM-CSF- and IL-3-induced proliferation is stimulated by a tyrosine phosphatase inhibitor, yet IL-5-induced proliferation is inhibited. Inhibitors of protein kinase C inhibit IL-3- and GM-CSF-, but not IL-5-induced proliferation. We suggest that, because all these cytokines share the identical beta chain of their receptors, the cytokine specific alpha chain mediates the linkage of each receptor to the individual biochemical signal transduction pathways responsible for the different biologic activities of these cytokines.     

Recurrent pericarditis: still idiopathic? The pros and cons of a well-honoured term

In developed countries, more than 80% of cases of acute pericarditis remain without an established diagnosis after a conventional and standard diagnostic approach. These cases are generally labelled as ‘idiopathic’, i.e. without a known cause. This lack of information is a matter of concern for both patients and clinicians. Some years ago, this term reflected the state of the art of scientific knowledge on the topic. Advances have changed this point of view, in light of available molecular techniques like polymerase chain reaction able to identify viral cardiotropic agents in pericardial fluid and biopsies. Furthermore, the remarkable efficacy of interleukin-1 antagonists, a therapy targeting the innate immune response, suggests clinical and pathogenic similarity between a proportion of patients with idiopathic recurrent pericarditis and classical autoinflammatory diseases. So, it seems useful to discuss the pros and cons of using the term “idiopathic” in light of the new knowledge.