Pulmonary Kaposi's sarcoma after heart transplantation: a case report

ABSTRACT: INTRODUCTION: Kaposi's sarcomas have been associated with different conditions of immunosuppression and are also known to be a typical complication of solid organ transplantations. CASE PRESENTATION: We report of a 65 year old man of Turkish origin with a history of heart transplantation 10 months ago who presented for clarification of his dyspnoea. The patient had a known history of chronic obstructive pulmonary disease and a smoking history of 40 pack years. Radiologically, three progressively growing intrapulmonary nodules were detected. The histology was diagnostic for a Kaposi's sarcoma. Visceral and especially primary intrapulmonary Kaposi's sarcomas are very rare and have been described to have a rather unfavourable prognosis. CONCLUSION: Even with a history suggestive for conventional lung cancer, Kaposi's sarcomas should be considered in patients after transplantation of solid organs. It should be noticed that in a minority of cases this tumour exists in the absence of the typical cutaneous lesions

Single cell analysis of kynurenine and System L amino acid transport in T cells

Acknowledgements We thank Cantrell group members for their critical discussion of the data, the Biological Resources unit, Sarah Thomson (for rLM work) and the Flow Cytometry facility (A. Whigham and R. Clarke) at the University of Dundee. This work was supported by the Wellcome Trust (Principal Research Fellowship to D.A.C. 097418/Z/11/Z and 205023/Z/16/Z, and Wellcome Trust Equipment Award 202950/Z/16/Z).Peer reviewedPublisher PD

Immunology Taught by Bacteria

It has been proposed that the innate immune system might discriminate living and virulent pathogens from dead or harmless microbes, but the molecular mechanisms by which this discrimination could occur remain unclear. Although studies of model antigens and adjuvants have illuminated important principles underlying immune responses, the specific immune responses made to living, virulent pathogens can only be discovered by studies of the living, virulent pathogens themselves. Here, I review what one particular bacterium, Legionella pneumophila, has taught us about the innate immune response. Pathogens differ greatly in the mechanisms they use to invade, replicate within, and transmit among their hosts. However, a theme that emerges is that the pathogenic activities sensed by host cells are conserved among multiple pathogenic bacteria. Thus, immunology taught by L. pneumophila may lead to a more general understanding of the host response to infection

Telomerase activity and telomere length in primary and metastatic tumors from pediatric bone cancer patients

The presence of telomerase activity has been analyzed in almost all tumor types and tumor-derived cell lines. However, there are very few studies that focus on the presence of telomerase activity in bone tumors, and most of them report analysis on very few samples or bone-derived cell lines. The objective of this study was to analyze the telomere length and telomerase activity in primary tumors and metastatic lesions from pediatric osteosarcoma and Ewing's sarcoma patients. The presence of telomerase activity was analyzed by the telomeric repeat amplification protocol assay, and the telomere length was measured by Southern blot. Results were related to survival and clinical outcome. Telomerase activity was detected in 85% of the bone tumor metastases (100% Ewing's sarcomas and 75% osteosarcomas) but only in 12% of the primary tumors (11.1% osteosarcomas and 12.5% Ewing's sarcomas). Bone tumor tissues with telomerase activity had mean telomere lengths 3 kb shorter than those with no detectable telomerase activity (p = 0.041). The presence of telomerase activity was associated with survival (p = 0.009), and longer event-free survival periods were found in patients who lacked telomerase activity compared with those who had detectable telomerase activity levels in their tumor tissues (p = 0.037). The presence of longer telomeres in primary pediatric bone tumors than in metastases could be indicative of alternative mechanisms of lengthening of telomeres for their telomere maintenance rather than telomerase activity. Nevertheless, the activation of telomerase seems to be a crucial step in the malignant progression and acquisition of invasive capability of bone tumors

Conformation-regulated mechanosensory control via titin domains in cardiac muscle

The giant filamentous protein titin is ideally positioned in the muscle sarcomere to sense mechanical stimuli and transform them into biochemical signals, such as those triggering cardiac hypertrophy. In this review, we ponder the evidence for signaling hotspots along the titin filament involved in mechanosensory control mechanisms. On the way, we distinguish between stress and strain as triggers of mechanical signaling events at the cardiac sarcomere. Whereas the Z-disk and M-band regions of titin may be prominently involved in sensing mechanical stress, signaling hotspots within the elastic I-band titin segment may respond primarily to mechanical strain. Common to both stress and strain sensor elements is their regulation by conformational changes in protein domains

Subtelomeric study of 132 patients with mental retardation reveals 9 chromosomal anomalies and contributes to the delineation of submicroscopic deletions of 1pter, 2qter, 4pter, 5qter and 9qter

BACKGROUND: Cryptic chromosome imbalances are increasingly acknowledged as a cause for mental retardation and learning disability. New phenotypes associated with specific rearrangements are also being recognized. Techniques for screening for subtelomeric rearrangements are commercially available, allowing the implementation in a diagnostic service laboratory. We report the diagnostic yield in a series of 132 subjects with mental retardation, and the associated clinical phenotypes. METHODS: We applied commercially available subtelomeric fluorescence in situ hybridization (FISH). All patients referred for subtelomeric screening in a 5-year period were reviewed and abnormal cases were further characterized clinically and if possible molecularly. RESULTS: We identified nine chromosomal rearrangements (two of which were in sisters) corresponding to a diagnostic yield of approx. 7%. All had dysmorphic features. Five had imbalances leading to recognizable phenotypes. CONCLUSION: Subtelomeric screening is a useful adjunct to conventional cytogenetic analyses, and should be considered in mentally retarded subjects with dysmorphic features and unknown cause

Ejection Time-Corrected Systolic Velocity Improves Accuracy in the Evaluation of Myocardial Dysfunction: A Study in Piglets

This study aimed to assess the effect of correcting for the impact of heart rate (HR) or ejection time (ET) on myocardial velocities in the long axis in piglets undergoing hypoxia. The ability to eject a higher volume at a fixed ET is a characteristic of contractility in the heart. Systolic velocity of the atrioventricular annulus displacement is directly related to volume changes of the ventricle. Both ET and systolic velocity may be measured in a single heartbeat. In 29 neonatal pigs, systolic velocity and ET were measured with tissue Doppler techniques in the mitral valve annulus, the tricuspid valve annulus, and the septum. All ejection time corrected velocities (S(ET), mean ± SEM, cm/s) decreased significantly during hypoxia (Smva(ET) 15.5 ± 0.2 to 13.2 ± 0.3 (p < 0.001), Sseptal(ET) 9.9 ± 0.1 to 7.8 ± 0.2 (p < 0.001), Stva(ET) 12.1 ± 0.2 to 9.8 ± 0.3 (p < 0.001)). The magnitude of change from baseline to hypoxia was greater for ejection time corrected systolic velocities than for RR-interval corrected velocities (mean ± SEM, cm/s); ΔSmva(ET) 2.3 ± 2.0 vs. ΔSmva(RR) 1.6 ± 1.1 (p = 0.02), ΔSseptal(ET) 2.1 ± 1.0 vs. ΔSseptal(RR) 1.6 ± 1.0 (p < 0.01), ΔStva(ET) 2.3 ± 1.1 vs. ΔStva(RR) 1.8 ± 1.3 (p = 0.04). The receiver operator characteristic (ROC) showed superior performance of S(ET) compared with uncorrected velocities. The decrease in S(ET) during hypoxia was not influenced by important hemodynamic determinants. ET-corrected systolic velocity improves accuracy and decreases variability in the evaluation of systolic longitudinal function and contractility during global hypoxia in neonatal pigs compared with systolic velocity alone. It is robust toward hemodynamic changes. This novel method has the potential of becoming a useful tool in clinical practice

Pathogen-Mediated Proteolysis of the Cell Death Regulator RIPK1 and the Host Defense Modulator RIPK2 in Human Aortic Endothelial Cells

Porphyromonas gingivalis is the primary etiologic agent of periodontal disease that is associated with other human chronic inflammatory diseases, including atherosclerosis. The ability of P. gingivalis to invade and persist within human aortic endothelial cells (HAEC) has been postulated to contribute to a low to moderate chronic state of inflammation, although how this is specifically achieved has not been well defined. In this study, we demonstrate that P. gingivalis infection of HAEC resulted in the rapid cleavage of receptor interacting protein 1 (RIPK1), a mediator of tumor necrosis factor (TNF) receptor-1 (TNF-R1)-induced cell activation or death, and RIPK2, a key mediator of both innate immune signaling and adaptive immunity. The cleavage of RIPK1 or RIPK2 was not observed in cells treated with apoptotic stimuli, or cells stimulated with agonists to TNF-R1, nucleotide oligomerization domain receptor 1(NOD1), NOD2, Toll-like receptor 2 (TLR2) or TLR4. P. gingivalis-induced cleavage of RIPK1 and RIPK2 was inhibited in the presence of a lysine-specific gingipain (Kgp) inhibitor. RIPK1 and RIPK2 cleavage was not observed in HAEC treated with an isogenic mutant deficient in the lysine-specific gingipain, confirming a role for Kgp in the cleavage of RIPK1 and RIPK2. Similar proteolysis of poly (ADP-ribose) polymerase (PARP) was observed. We also demonstrated direct proteolysis of RIPK2 by P. gingivalis in a cell-free system which was abrogated in the presence of a Kgp-specific protease inhibitor. Our studies thus reveal an important role for pathogen-mediated modification of cellular kinases as a potential strategy for bacterial persistence within target host cells, which is associated with low-grade chronic inflammation, a hallmark of pathogen-mediated chronic inflammatory disorders