A standard test phantom for the performance assessment of magnetic resonance guided high intensity focused ultrasound (MRgHIFU) thermal therapy devices

Purpose: Test objects for High Intensity Focused Ultrasound (HIFU) are required for the standardization and definition of treatment, Quality Assurance (QA), comparison of results between centers and calibration of devices. This study describes a HIFU test object which provides temperature measurement as a function of time, in a reference material compatible with Magnetic Resonance (MR) and ultrasound.Materials and methods: T-Type fine wire thermocouples were used as sensors and 5 correction methods for viscous heating artifacts were assessed. The phantom was tested in a MR-HIFU Philips Sonalleve device over a period of 12 months, demonstrating stability and validity to evaluate the performance of the device.Results: The study furnished useful information regarding the MR-HIFU sessions and highlighted potential limitations of the existing QA and monitoring methods. The importance of temperature monitoring along the whole acoustic path was demonstrated as MR Thermometry readings differed in the three MR plane views (coronal, sagittal, transverse), in particular when the focus was near a soft-tissue/bone interface, where there can be an MR signal loss with significant temperature and thermal dose underestimation (138% variation between the three plane views).Conclusions: The test object was easy to use and has potential as a valid tool for training, QA, research and development for MR guided HIFU and potentially ultrasound guided devices.

Unravelling racial differences in hypertensive heart disease by multiparametric cardiovascular magnetic resonance: a phenotype-wide association study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Dr Georgiopoulos was supported by the Onassis Foundation under the special grant & support program for scholars" association members

Introduction – Black Afro-Caribbean hypertensives (BAHs) are exposed to a higher risk of heart failure (HF) than white hypertensives (WHs). Arterial afterload is higher in BAHs due to increased arterial stiffness and vascular volume; BAHs develop more often left ventricular (LV) hypertrophy, dilatation and systolic dysfunction than WHs. However, it is unclear whether other racial differences concur to the more pronounced LV remodelling in BAHs.

Methods – This cross-sectional study included hypertensive patients undergoing cardiovascular magnetic resonance for their clinical work-up (1.5T Aera Siemens-Healthcare). Clinical history and haemodynamic parameters were collected in all participants; a subset of patients had complete bio-humoral assay of the renin-angiotensin-aldosterone system (RAAs). Arm cuff pressure was measured during CMR. The CMR protocol included: i) Arterial afterload / LV arterial-coupling - pulse-wave-velocity (PWV), aortic (Ea) and LV elastance (Ees) by aorta anatomic and phase-contrast velocity-encoding imaging; ii) ventricular remodelling and function - LV and right ventricular (RV) volumes, mass, EF, LV peak-filling rate by short-axis cine images; global circumferential and longitudinal strains by cine feature tracking; iii) left atrial (LA) remodelling volumes and reservoir, conduit and booster functions by long-axis cine images; iv) tissue characterisation: T2 and pre/post-contrast T1 relaxation times, extracellular volume (ECV) by single mid-ventricular short-axis T1/T2-mapping.

Results – 34 BAHs and 35 WHs (52 ± 12 vs 45 ± 14 years, P < 0.05; 61% vs 65% males P = NS) were included in the study. Baseline features are summarised in the Table. LV systolic dysfunction was more prevalent in BAH than WHs (P = 0.038). Of note, BAHs tended to have greater LV volumes and significantly higher LV mass and septal thickness than WHs. In BAHs, but not in WHs, PWV was associated with increased septal thickness after correction for blood pressure and age (β-value: 0.447, P = 0.02). Normalised RV mass was greater in BHA than WHs; RV mass suits for the identification of racial or circulating factors predisposing to hypertrophy being largely unaffected by systemic afterload. In our study LV diastolic function and LA volumes were similar between BAHs and WHs, and none of the subjects had conditions associated with pre-capillary pulmonary hypertension. Hence, higher RV-mass in BAHs pinpoints a racial susceptibility to myocardial hypertrophy. Finally, in a subset of patients with RAAs assays (n = 43), the aldosterone/renin ratio was higher in BAHs than WHs (67.04 [IQR: 19.37-209.73] vs 13.77 [IQR: 7.47-40.43], P = 0.01).

Conclusion – BAHs have heightened LV remodelling than WHs because of racial predisposition to develop hypertrophy which also encompasses derangements in RAAs. Altogether, these findings may account for the greater risk for HF in BAHs than WHs.

Mesenchymal stromal cells reset the scatter factor system and cytokine network in experimental kidney transplantation

BACKGROUND

In former studies we showed in a rat model of renal transplantation that Mesenchymal Stromal Cells (MSC) prevent acute rejection in an independent way of their endowing in the graft. In this study we investigated whether MSC operate by resetting cytokine network and Scatter Factor systems, i.e. Hepatocyte Growth Factor (HGF), Macrophage Stimulating Protein (MSP) and their receptors Met and RON, respectively.

METHODS

MSC were injected into the renal artery soon after reperfusion. Controls were grafted untreated and normal rats. Rats were sacrificed 7 days after grafting. Serum and renal tissue levels of IFN-γ, IL-1, IL-2, IL-4, IL-6, IL-10, MSP/RON, HGF/Met systems, Treg lymphocytes were investigated.

RESULTS

In grafted untreated rats IFN-γ increased in serum and renal tissue and IL-6 rose in serum. MSC prevented both the phenomena, increased IL-10 serum levels and Treg number in the graft. Furthermore MSC increased serum and tissue HGF levels, Met tubular expression and prevented the suppression of tubular MSP/RON expression.

CONCLUSIONS

Our results demonstrate that MSC modify cytokine network to a tolerogenic setting, they suppress Th1 cells, inactivate monocytes/macrophage, recruit Tregs. In addition, MSC sustain the expression of the Scatter Factor systems expression, i.e. systems that are committed to defend survival and stimulate regeneration of tubular cells.

The role of therapeutic drug monitoring in the treatment of cytomegalovirus disease in kidney transplantation

Cytomegalovirus (CMV) infection is a common complication following solid organ transplantation that may severely affect the outcome of transplantation. Ganciclovir (GCV) and its prodrug valganciclovir are successfully used to prevent and treat CMV infection; however, in a small percentage of patients, CMV gene mutations may lead to drug resistance. GCV resistance is defined as increasing CMV viremia or progressive clinical disease during prolonged antiviral therapy, due to CMV gene mutation. This has emerged as a new challenge, especially because alternative drugs such as cidofovir and foscarnet have a number of important side effects. Here we report the case of a kidney transplanted patient who experienced life-threatening CMV disease, which initially appeared to be GCV-resistant, but was instead found to be associated with inadequate antiviral drug levels. The patient was then successfully treated by monitoring plasma GCV levels. We suggest using plasma GCV monitoring in the management of all cases of critical CMV disease, in which GCV resistance is suspected.

Antineutrophil cytoplasmic antibody-associated renal vasculitis treated with autologous mesenchymal stromal cells: evaluation of the contribution of immune-mediated mechanisms

We report the first case of renal antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis treated with autologous mesenchymal stromal cells (MSCs). A 73-year-old man was admitted to the hospital for malaise, weight loss, and oliguria. His serum creatinine level was 2.7 mg/dL but it rapidly increased to 7.8 mg/dL; urinalysis showed proteinuria and hematuria, and the ANCA to myeloperoxidase with a perinuclear pattern (pANCA) titer was high (132 IU/mL). Renal biopsy showed necrotizing crescentic glomerulonephritis. Standard immunosuppressive therapy (cyclophosphamide and corticosteroids) was ineffective. Rituximab therapy was started, but it was discontinued after the third dose to minimize the risk of systemic spread of a severe oral Candida infection and to prevent superinfections that were facilitated by leukopenia. The patient received autologous MSCs, 1.5 × 10(6) cells/kg body weight, intravenously. After 7 days, his serum creatinine level decreased to 2.2 mg/dL, pANCA titer decreased to 75 IU/mL, and urinalysis findings normalized. Eight months later, he received a second MSC infusion because his serum creatinine level increased. In 1 week, his creatinine level decreased to 1.9 mg/dL and his pANCA titer decreased to 14 IU/mL. Immunosuppressive therapy was subsequently withdrawn. At the last follow-up visit, 12 months after the second MSC infusion, the patient remained in clinical remission without any therapy. Infusion of MSCs induced expansion of the T-lymphocyte subset expressing a regulatory T-cell phenotype (CD4(+)CD25(+)Foxp3(+)) and a notable reduction in interferon-γ, interleukin 6, and tumor necrosis factor serum levels.

Multiple electrolyte disorders in a neurosurgical patient: solving the rebus

BACKGROUND

It is important to ensure an adequate sodium and volume balance in neurosurgical patients in order to avoid the worsening of brain injury.Indeed, hyponatremia and polyuria, that are frequent in this patient population, are potentially harmful, especially if not promptly recognized.Differential diagnosis is often challenging, including disorders, which, in view of similar clinical pictures, present very different pathophysiological bases, such as syndrome of inappropriate antidiuresis, cerebral/renal salt wasting syndrome and diabetes insipidus.

CASE PRESENTATION

Here we present the clinical report of a 67-year-old man with a recent episode of acute subarachnoid haemorrhage, admitted to our ward because of severe hyponatremia, hypokalemia and huge polyuria.We performed a complete workup to identify the underlying causes of these alterations and found a complex picture of salt wasting syndrome associated to primary polydipsia. The appropriate diagnosis allowed us to correct the patient hydro-electrolyte balance.

CONCLUSION

The comprehension of the pathophysiological mechanisms is essential to adequately recognize and treat hydro-electrolyte disorders, also solving the most complex clinical problems.

GM-CSF contributes to prompt healing of ecthyma gangrenosum lesions in kidney transplant recipient

BACKGROUND

Ecthyma gangrenosum (EG) is an unusual, potentially fatal cutaneous disease, commonly associated with Pseudomonas aeruginosa septicemia.

CASE REPORT

We report the case of a 61-year-old man admitted to the Nephrology Department for fever, leukopenia and inguinal and scrotal painful lesions. Physical examination revealed inguinal and scrotal macules, nodules, blisters and ulcers with central necrosis. P. aeruginosa was isolated from an ulcer. EG was diagnosed. Because of the severe leukopenia, granulocyte-macrophage colony-stimulating factor (GM-CSF) was administered until the white blood cell count significantly increased. Based on antibiogram, intravenous ceftazidime and teicoplanin were given for 11 days. Cutaneous manifestations were completely healed in about 2 months.

CONCLUSION

We suggest that the combination of GM-CSF with appropriate antibiotics can resolve EG and avoid or minimize the risk of septicemia in immunosuppressed patients.

Mesenchymal stromal cells improve renal injury in anti-Thy 1 nephritis by modulating inflammatory cytokines and scatter factors

MSC (mesenchymal stromal cells) can differentiate into renal adult cells, and have anti-inflammatory and immune-modulating activity. In the present study, we investigated whether MSC have protective/reparative effects in anti-Thy1 disease, an Ab (antibody)-induced mesangiolysis resulting in mesangioproliferative nephritis. We studied five groups of rats: (i) rats injected with anti-Thy1.1 Ab on day 0 (group A); (ii) rats injected with anti-Thy1.1 Ab on day 0+MSC on day 3 (group B); (iii) rats injected with anti-Thy1.1 Ab on day 0+mesangial cells on day 3 (group C); (iv) rats injected with saline on day 0+MSC on day 3 (group D); and (v) rats injected with saline on day 0 (group E). Rats were killed on days 1, 3, 7 and 14. MSC prevented the increase in serum creatinine, proteinuria, glomerular monocyte influx and glomerular histopathological injury. Furthermore, MSC suppressed the release of IL-6 (interleukin-6) and TGF-β (transforming growth factor-β), modulated glomerular PDGF-β (platelet-derived growth factor-β), and reset the scatter factors and their receptors, potentiating HGF (hepatocyte growth factor)/Met and inactivating MSP (macrophage-stimulating protein)/Ron (receptor origin nantaise). Few MSC were found in the kidney. These results indicate that MSC improve anti-Thy 1 disease not by replacing injured cells, but by preventing cytokine-driven inflammation and modulating PDGF-β and the scatter factors, i.e. systems that regulate movement and proliferation of monocytes and mesangial cells.

[Non-heart-beating-donor transplant: the first experience in Italy]

A promising way to increase the number of kidneys for transplantation is to expand the donor pool by including non-heart-beating donors (NHBDs). The centers involved in NHBD transplantation programs have reported a 16-40% increase in kidney transplants. A key issue with NHBD is the significantly higher rate of delayed graft function (DGF) and primary non-function (PNF) compared with that associated with heart-beating donor (HBD) transplants. However, although transplants from NHBD are associated with a greater incidence of early adverse events, long-term graft survival appears to be similar to that observed after transplants from HBDs. In addition, the use of extracorporeal membrane oxygenation and mechanical perfusion, the careful selection of recipients and donors, and an adequate therapeutic strategy may at least partially reduce the risk of PNF and DGF and improve transplant outcome.