Curious case of calciphylaxis leading to acute mitral regurgitation.

Calciphylaxis is uncommon and typically seen in patients with end-stage renal disease. It has been defined as a vasculopathic disorder characterised by cutaneous ischaemia and necrosis due to calcification, intimal fibroplasia and thrombosis of pannicular arterioles. We present the case of a 74-year-old woman with chronic kidney disease stage III who developed calciphylaxis leading to mitral valve calcification, chordae tendineae rupture and acute mitral regurgitation. Although an alternative explanation can typically be found for non-uraemic calciphylaxis, her evaluation did not reveal any usual non-uraemic causes including elevated calcium-phosphorus product, hyperparathyroidism, or evidence of connective tissue disease. Her wounds improved with sodium thiosulfate, pamidronate, penicillin and hyperbaric oxygen therapies but she ultimately decompensated with the onset of acute mitral regurgitation attributed to rupture of a previously calcified chordae tendineae. This case highlights an unusual case of calciphylaxis without clear precipitant as well as a novel manifestation of the disease.

A case of relapsing kikuchi-fujimoto disease.

Kikuchi-Fujimoto disease (KFD) or histiocytic necrotizing lymphadenitis was first described in Japan in 1972. It is described as a benign syndrome most commonly involving cervical lymphadenopathy, fever, and night sweats. The etiology of KFD is unknown but it is thought to be triggered by an autoimmune or viral process with an exaggerated T-cell-mediated immune response. KFD can mimic other serious conditions such as lymphoma, systemic lupus erythematosus (SLE), herpes simplex, and Epstein Barr virus. Diagnosis is confirmed histopathologically. Kikuchi's disease is typically reported to have a self-limiting course, resolving within several months and with a low recurrence rate between 3% and 4%. There is no specific treatment for KFD but any treatment is generally directed towards symptomatic relief with antipyretics and anti-inflammatory medications. In severe cases corticosteroids have been used. Here we describe a case of a previously healthy 26-year-old female that presented with fever and cervical lymphadenopathy. Malignancy and infections were ruled, and she was diagnosed with KFD histopathologically by lymph node biopsy. Her case is a severe case of KFD that despite treatment with multiple courses of corticosteroids and an immune modulating agent, relapsed.

Differentiation state determines neural effects on microvascular endothelial cells.

Growing evidence indicates that nerves and capillaries interact paracrinely in uninjured skin and cutaneous wounds. Although mature neurons are the predominant neural cell in the skin, neural progenitor cells have also been detected in uninjured adult skin. The aim of this study was to characterize differential paracrine effects of neural progenitor cells and mature sensory neurons on dermal microvascular endothelial cells. Our results suggest that neural progenitor cells and mature sensory neurons have unique secretory profiles and distinct effects on dermal microvascular endothelial cell proliferation, migration, and nitric oxide production. Neural progenitor cells and dorsal root ganglion neurons secrete different proteins related to angiogenesis. Specific to neural progenitor cells were dipeptidyl peptidase-4, IGFBP-2, pentraxin-3, serpin f1, TIMP-1, TIMP-4 and VEGF. In contrast, endostatin, FGF-1, MCP-1 and thrombospondin-2 were specific to dorsal root ganglion neurons. Microvascular endothelial cell proliferation was inhibited by dorsal root ganglion neurons but unaffected by neural progenitor cells. In contrast, microvascular endothelial cell migration in a scratch wound assay was inhibited by neural progenitor cells and unaffected by dorsal root ganglion neurons. In addition, nitric oxide production by microvascular endothelial cells was increased by dorsal root ganglion neurons but unaffected by neural progenitor cells.

Unsaturated fatty acids induce mesenchymal stem cells to increase secretion of angiogenic mediators.

Mesenchymal stem cells (MSC) represent emerging cell-based therapies for diabetes and associated complications. Ongoing clinical trials are using exogenous MSC to treat type 1 and 2 diabetes, cardiovascular disease and non-healing wounds due to diabetes. The majority of these trials are aimed at exploiting the ability of these multipotent mesenchymal stromal cells to release soluble mediators that reduce inflammation and promote both angiogenesis and cell survival at sites of tissue damage. Growing evidence suggests that MSC secretion of soluble factors is dependent on tissue microenvironment. Despite the contribution of fatty acids to the metabolic environment of type 2 diabetes, almost nothing is known about their effects on MSC secretion of growth factors and cytokines. In this study, human bone marrow-derived MSC were exposed to linoleic acid, an omega-6 polyunsaturated fatty acid, or oleic acid, a monounsaturated fatty acid, for seven days in the presence of 5.38 mM glucose. Outcomes measured included MSC proliferation, gene expression, protein secretion and chemotaxis. Linoleic and oleic acids inhibited MSC proliferation and altered MSC expression and secretion of known mediators of angiogenesis. Both unsaturated fatty acids induced MSC to increase secretion of interleukin-6, VEGF and nitric oxide. In addition, linoleic acid but not oleic acid induced MSC to increase production of interleukin-8. Collectively these data suggest that exposure to fatty acids may have functional consequences for MSC therapy. Fatty acids may affect MSC engraftment to injured tissue and MSC secretion of cytokines and growth factors that regulate local cellular responses to injury.

Mesenchymal stem cells induce dermal fibroblast responses to injury.

Although bone marrow-derived mesenchymal stem cells have been shown to promote repair when applied to cutaneous wounds, the mechanism for this response remains to be determined. The aim of this study was to determine the effects of paracrine signaling from mesenchymal stem cells on dermal fibroblast responses to injury including proliferation, migration and expression of genes important in wound repair. Dermal fibroblasts were co-cultured with bone marrow-derived mesenchymal stem cells grown in inserts, which allowed for paracrine interactions without direct cell contact. In this co-culture model, bone marrow-derived mesenchymal stem cells regulate dermal fibroblast proliferation, migration and gene expression. When co-cultured with mesenchymal stem cells, dermal fibroblasts show increased proliferation and accelerated migration in a scratch assay. A chemotaxis assay also demonstrated that dermal fibroblasts migrate towards bone marrow-derived mesenchymal stem cells. A PCR array was used to analyze the effect of mesenchymal stem cells on dermal fibroblast gene expression. In response to mesenchymal stem cells, dermal fibroblasts up-regulate integrin alpha 7 expression and down-regulate expression of ICAM1, VCAM1 and MMP11. These observations suggest that mesenchymal stem cells may provide an important early signal for dermal fibroblast responses to cutaneous injury.

Elevated cardiac troponins in sepsis: what do they signify?

UNLABELLED: Serum troponins are sensitive markers used to diagnose acute coronary syndrome in association with signs and symptoms of chest pain and EKG changes. Cardiac troponins are elevated in 85% of patients with sepsis in the absence of acute coronary syndrome. Small studies have shown that elevated troponin levels identify patients with sepsis who are at increased risk of mortality. The purpose of this study was to (1) identify the outcome of cardiac troponin positive sepsis patients in our hospital, (2) determine whether the traditional cardiac risk factors predispose septic patients for positive troponin and (3) evaluate the cardiac interventions done for troponin positive patients. CONCLUSION: In our study, patients with elevated troponins had a higher mortality. Hypertension (HTN) and Coronary Artery Disease (CAD) increased the risk of mortality in troponin positive patients. Several interventions were performed including medications, echocardiogram, and cardiology consultation. Treatment medications did not improve mortality rates.

Contribution of bone marrow-derived cells to skin: collagen deposition and wound repair.

The bone marrow provides inflammatory cells and endothelial progenitor cells to healing cutaneous wounds. To further explore the bone marrow contribution to skin and healing wounds, we used a chimeric mouse model in which the bone marrow from enhanced green fluorescent protein (EGFP) transgenic mice is transplanted into normal C57BL mice. We found that normal skin is a target organ for bone marrow-derived cells from both the hematopoietic and the mesenchymal stem cell pool. We present evidence that the bone marrow contribution to normal skin and the healing cutaneous wound is substantially greater than the previously recognized CD45+ subpopulation, where 15%-20% of the spindle-shaped dermal fibroblasts were bone marrow-derived (EGFP+). Furthermore, the bone marrow-derived cells were able to contract a collagen matrix and transcribe both collagen types I and III, whereas the skin-resident cells transcribed only collagen type I. Whereas endothelial progenitor cells were found early during the wound repair process, bone marrow-derived endothelial cells were not seen after epithelialization was complete. Our data show that wound healing involves local cutaneous cells for reconstituting the epidermis but distant bone marrow-derived cells and the adjacent uninjured dermal mesenchymal cells for reconstituting the dermal fibroblast population.