Radiation Exposure in Nonvascular Fluoroscopy-Guided Interventional Procedures

Purpose

To investigate the radiation exposure in non-vascular fluoroscopy guided interventions and to search strategies for dose reduction.

Materials and Methods

Dose area product (DAP) of 638 consecutive non-vascular interventional procedures of one year were analyzed with respect to different types of interventions; gastrointestinal tract, biliary interventions, embolizations of tumors and hemorrhage. Data was analyzed with special focus on the fluoroscopy doses and frame doses. The third quartiles (Q3) of fluoroscopy dose values were defined in order to set a reference value for our in-hospital practice.

Results

Mean fluoroscopy times of gastrostomy, jejunostomy, right and left sided percutaneous biliary drainage, chemoembolization of the liver and embolization due to various hemorrhages were 5.9, 8.6, 13.5, 16.6, 17.4 and 25.2 min, respectively. The respective Q3 total DAP were 52.9, 73.3, 155.1, 308.4, 428.6 and 529.3 Gy*cm². Overall, around 66% of the total DAP originated from the radiographic frames with only 34% of the total DAP applied by fluoroscopy (P < 0.001). The investigators experience had no significant impact on the total DAP applied, most likely since there was no stratification to intervention-complexity.

Conclusion

To establish Diagnostic Reference Levels (DRLs), there is a need to establish a registry of radiation dose data for the most commonly performed procedures. Documentation of interventional procedures by fluoroscopy “grabbing” has the potential to considerably reduce radiation dose applied and should be used instead of radiographic frames whenever possible.     

Inhibition of corneal inflammation following keratoplasty by birch leaf extract

The objective of this study was to determine the effect of birch leaf (Betula pendula) extract (BPE) on corneal inflammation following keratoplasty in the rat model. T cells were stimulated in vitro in the presence of BPE. Proliferation, activation phenotype and the number of apoptotic/necrotic cells in cell culture were analyzed by flow cytometry. Corneal transplantation was performed between Fisher and Lewis rats. Recipient rats were either treated with cyclosporine A at a low dosage (Low-dose CsA=LDCsA) or received LDCsA in combination with BPE (2×1ml/day). Clinical signs for corneal inflammation and rejection time points were determined. Infiltrating leukocytes were analyzed histologically. BPE specifically inhibited T cell proliferation in vitro by inducing apoptosis. The phenotype was not affected. In vivo, BPE significantly delayed the onset of corneal opacification (p<0.05). The amount of infiltrating CD45(+) leukocytes and CD4(+) T cells (p<0.001) was significantly reduced by BPE, whereas infiltration of CD163(+) macrophages was not significantly different between the two groups. BPE selectively induces apoptosis of activated T cells. Accordingly, BPE treatment significantly reduces infiltrating T cells and subsequent corneal opacification following keratoplasty. Our findings suggest BPE as a promising anti-inflammatory drug to treat corneal inflammation.     

Primary orbital liposarcoma misdiagnosed as thyroid associated orbitopathy

Orbital malignancy can mimic thyroid associated orbitopathy (TAO) due to overlap of clinical and radiographic findings, which include proptosis, extraocular muscle (EOM) enlargement on imaging, and EOM restriction with diplopia. We report a case of primary orbital liposarcoma masquerading as TAO which required exenteration.     

Shear stress influences the pluripotency of murine embryonic stem cells in stirred suspension bioreactors

Pluripotent embryonic stem cells (ESCs) have been used increasingly in research as primary material for various tissue‐engineering applications. Pluripotency, or the ability to give rise to all cells of the body, is an important characteristic of ESCs. Traditional methods use leukaemia inhibitory factor (LIF) to maintain murine embryonic stem cell (mESC) pluripotency in static and bioreactor cultures. When LIF is removed from mESCs in static cultures, pluripotency genes are downregulated and the cultures will spontaneously differentiate. Recently we have shown the maintenance of pluripotency gene expression of mESCs in stirred suspension bioreactors during differentiation experiments in the absence of LIF. This is undesired in a differentiation experiment, where the goal is downregulation of pluripotency gene expression and upregulation of gene expression characteristic to the differentiation. Thus, the objective of this study was to examine how effectively different levels of shear stress [100 rpm (6 dyne/cm²), 60 rpm (3 dyne/cm²)] maintained and influenced pluripotency in suspension bioreactors. The pluripotency markers Oct‐4, Nanog, Sox‐2 and Rex‐1 were assessed using gene expression profiles and flow‐cytometry analysis and showed that shear stress does maintain and influence the gene expression of certain pluripotency markers. Some significant differences between the two levels of shear stress were seen and the combination of shear stress and LIF was observed to synergistically increase the expression of certain pluripotency markers. Overall, this study provides a better understanding of the environmental conditions within suspension bioreactors and how these conditions affect the pluripotency of mESCs. Copyright © 2012 John Wiley & Sons, Ltd.     

Extracorporeal membrane oxygenation in adult patients with hematologic malignancies and severe acute respiratory failure

Introduction

Acute respiratory failure (ARF) is the main reason for intensive care unit (ICU) admissions in patients with hematologic malignancies (HMs). We report the first series of adult patients with ARF and HMs treated with extracorporeal membrane oxygenation (ECMO).

Methods

This is a retrospective cohort study of 14 patients with HMs (aggressive non-Hodgkin lymphoma (NHL) n = 5; highly aggressive NHL, that is acute lymphoblastic leukemia or Burkitt lymphoma, n = 5; Hodgkin lymphoma, n = 2; acute myeloid leukemia, n = 1; multiple myeloma, n = 1) receiving ECMO support because of ARF (all data as medians and interquartile ranges; age, 32 years (22 to 51 years); simplified acute physiology score II (SAPS II): 51 (42 to 65)). Etiology of ARF was pneumonia (n = 10), thoracic manifestation of NHL (n = 2), sepsis of nonpulmonary origin (n = 1), and transfusion-related acute lung injury (n = 1). Diagnosis of HM was established during ECMO in four patients, and five first received (immuno-) chemotherapy on ECMO.

Results

Before ECMO, the PaO₂/FiO₂ ratio was 60 (53 to 65), (3.3 to 3.7). Three patients received venoarterial ECMO because of acute circulatory failure in addition to ARF; all other patients received venovenous ECMO. All patients needed vasopressors, and five needed hemofiltration. Thrombocytopenia occurred in all patients (lowest platelet count was 20 (11 to 21) G/L). Five major bleeding events were noted. ECMO duration was 8.5 (4 to 16) days. ICU and hospital survival was 50%. All survivors were alive at follow-up (36 (10 to 58) months); five patients were in complete remission, one in partial remission, and one had relapsed.

Conclusions

ECMO therapy is feasible in selected patients with HMs and ARF and can be associated with long-term disease-free survival.     

Measuring Acceptability and Preferences for Implementation of Pre-Exposure Prophylaxis (PrEP) Using Conjoint Analysis: An Application to Primary HIV Prevention Among High Risk Drug Users

Although people who use drugs (PWUD) are one of the key risk populations who could benefit from the use of pre-exposure prophylaxis (PrEP), to date, little attention has been given to incorporating PrEP into HIV prevention approaches targeting this underserved group. This study investigated the acceptability of PrEP based on a number of known PrEP attributes among high-risk PWUD in a drug treatment setting. A total of 400 HIV-negative PWUD, who reported drug- and/or sex-related risk behaviors were recruited from a methadone clinic to complete a stated preference (full-profile conjoint) survey. Participants ranked the eight hypothetical PrEP program scenarios with varied combinations of six attributes related to PrEP (cost, dosing, efficacy, side-effects, treatment setting, and frequency of HIV testing). SPSS conjoint procedure was used to estimate the relative importance of each attribute and preferences across eight possible PrEP delivery programs. PrEP acceptability ranged from 30.6 to 86.3% with a mean acceptability of 56.2% across the eight hypothetical PrEP program scenarios. The PrEP program scenario with the highest acceptability had the following attribute levels: insurance covered, daily dosing, 95% effective, no side-effects, treatment at HIV clinic, and HIV testing needed every 6 months. The cost associated with PrEP was the most important attribute (relative importance score: RIS = 38.8), followed by efficacy (RIS = 20.5) and side effects (RIS = 11.9); other attributes had no significant effect. Our findings reported a high acceptability of PrEP in response to different PrEP program scenarios with different attribute profiles. As the result of having this information, researchers and policymakers will be better equipped for evidence informed targeting and dissemination efforts to optimize PrEP uptake among this underserved population.     

Heterogenous haemodynamic effects of adaptive servoventilation therapy in sleeping patients with heart failure and Cheyne–Stokes respiration compared to healthy volunteers

This study investigated the haemodynamic effects of adaptive servoventilation (ASV) in heart failure (HF) patients with Cheyne–Stokes respiration (CSR) versus healthy controls. Twenty-seven HF patients with CSR and 15 volunteers were ventilated for 1 h using a new ASV device (PaceWave?). Haemodynamics were continuously and non-invasively recorded at baseline, during ASV and after ventilation. Prior to the actual study, a small validation study was performed to validate non-invasive measurement of Stroke volume index (SVI). Non-invasive measurement of SVI showed a marginal overall difference of ?0.03 ± 0.41 L/min/m² compared to the current gold standard (Thermodilution-based measurement). Stroke volume index (SVI) increased during ASV in HF patients (29.7 ± 5 to 30.4 ± 6 to 28.7 ± 5 mL/m², p < 0.05) and decreased slightly in volunteers (50.7 ± 12 to 48.6 ± 11 to 47.9 ± 12 mL/m²). Simultaneously, 1 h of ASV was associated with a trend towards an increase in parasympathetic nervous activity (PNA) in HF patients and a trend towards an increase in sympathetic nervous activity (SNA) in healthy volunteers. Blood pressure (BP) and total peripheral resistance response increased significantly in both groups, despite marked inter-individual variation. Effects were independent of vigilance. Predictors of increased SVI during ASV in HF patients included preserved right ventricular function, normal resting BP, non-ischaemic HF aetiology, mitral regurgitation and increased left ventricular filling pressures. This study confirms favourable haemodynamic effects of ASV in HF patients with CSR presenting with mitral regurgitation and/or increased left ventricular filling pressures, but also identified a number of new predictors. This might be mediated by a shift towards more parasympathetic nervous activity in those patients.     

Polymorphisms in cytochrome P450 17A1 and risk of non-Hodgkin lymphoma

Broad cross-talk exists between the endocrine and immune systems. Estrogen receptor expression in lymphocytes suggests that hormonal modulation may influence lymphoma risk. Analysis of genetic polymorphisms that affect oestrogen production, such as cytochrome P450 17A1 (CYP17A1) -34T>C, may provide insight into oestrogen's role in lymphomagenesis. CYP17A1-34T>C and CYP17A1 IVS2 105A>C polymorphisms were analyzed in a non-Hodgkin lymphoma (NHL) population-based case-control study. The CYP17A1-34CC genotype was positively associated with NHL [odds ratio (OR) = 1.44, 95% confidence interval (CI) 1.02-2.03], particularly diffuse large B-cell lymphoma (OR = 1.76, CI 1.14-2.71). Associations of CYP17A1 polymorphisms with increased risk of NHL suggest a role for oestrogen in lymphomagenesis.