Anticipation of radiation dose to the conceptus from occupational exposure of pregnant staff during fluoroscopically guided electrophysiological procedures

Conceptus dose from occupational exposure. INTRODUCTION: A female employee working in the electrophysiology suite has the right to know potential radiation hazards to the unborn child before she is pregnant or before she decides to formally declare her pregnancy. Moreover, the employer of a declared pregnant worker must evaluate the work situation and ensure that the conceptus dose is kept below the maximum permissible level during the remaining gestation period. The aim of this study was to develop a method for conceptus dose anticipation and determination of maximum workload allowed for the pregnant employee who participates in fluoroscopically guided electrophysiological procedures. METHODS AND RESULTS: A C-arm fluoroscopy system, an anthropomorphic phantom, and a radiation meter were used to obtain scattered air kerma dose rates separately for each of the three fluoroscopic projections typically used in the electrophysiology suite. Air kerma to conceptus dose conversion factors for all trimesters of gestation were calculated using Monte Carlo simulation. A formula is presented for the anticipation of the conceptus dose from occupational exposure of pregnant staff during fluoroscopically guided electrophysiological procedures. Normalized data are provided for conceptus dose estimation from occupational exposure of pregnant staff working in any electrophysiology laboratory. A methodology for estimation of maximum workload allowed for each month of the remaining gestation period of a worker who declared her pregnancy is proposed, which ensures that the regulatory dose limits are not exceeded. CONCLUSION: Data presented may be used for the implementation of a radiation protection program designed for pregnant staff working in an electrophysiological suite.     

Asymptomatic avascular necrosis in patients with primary antiphospholipid syndrome in the absence of corticosteroid use: a prospective study by magnetic resonance imaging

OBJECTIVE: To evaluate the prevalence of avascular necrosis (AVN), using magnetic resonance imaging (MRI), in patients with primary antiphospholipid syndrome (APS) and in patients with systemic lupus erythematosus (SLE), with or without anticardiolipin antibodies (aCL), who are asymptomatic for AVN and have not taken corticosteroids. METHODS: Seventy-nine subjects who were asymptomatic for AVN were evaluated by MRI of the femoral heads: 30 patients with primary APS who had never received corticosteroids, 19 SLE patients who had never received steroids (divided into 2 groups, aCL positive and aCL negative, in order to examine any association between AVN and aCL), and 30 healthy subjects who were age- and sex-matched with patients with primary APS. Established MRI criteria were used for a diagnosis of AVN. RESULTS: Asymptomatic AVN was evident in 6 (20%) of 30 patients with primary APS: 3 of them (1 man, 2 women) had intermediate bilateral AVN, and 3 (all women) had early AVN (bilateral in 1 patient). Results of hip and pelvis radiography and dynamic scintigraphy were negative. Followup MRI 6 months later revealed no changes. At the time of the initial MRI examination, the mean (+/-SD) age of patients in whom AVN was identified was 31.2 +/- 7.3 years, and that of patients without AVN was 42.4 +/- 11.9 years (P = 0.036). Livedo reticularis occurred significantly more commonly in the group with AVN (P = 0.041). None of the healthy subjects and none of the patients with SLE demonstrated AVN on MRI. CONCLUSION: AVN can be detected by MRI in 20% of patients with primary APS. Younger patients tend to develop AVN more frequently than do older patients, and the presence of livedo reticularis may identify individuals at risk for AVN. Clinicians should be aware of this possible clinical manifestation of primary APS, because early diagnosis can lead to early intervention.     

Vertebral fragility and structural redundancy

The mechanisms of age‐related vertebral fragility remain unclear, but may be related to the degree of “structural redundancy” of the vertebra; ie, its ability to safely redistribute stress internally after local trabecular failure from an isolated mechanical overload. To better understand this issue, we performed biomechanical testing and nonlinear micro‐CT–based finite element analysis on 12 elderly human thoracic ninth vertebral bodies (age 76.9 ± 10.8 years). After experimentally overloading the vertebrae to measure strength, we used nonlinear finite element analysis to estimate the amount of failed tissue and understand the failure mechanisms. We found that the amount of failed tissue per unit bone mass decreased with decreasing bone volume fraction (r² = 0.66, p < 0.01). Thus, for the weak vertebrae with low bone volume fraction, overall failure of the vertebra occurred after failure of just a tiny proportion of the bone tissue (<5%). This small proportion of failed tissue had two sources: the existence of fewer vertically oriented load paths to which load could be redistributed from failed trabeculae; and the vulnerability of the trabeculae in these few load paths to undergo bending‐type failure mechanisms, which further weaken the bone. Taken together, these characteristics suggest that diminished structural redundancy may be an important aspect of age‐related vertebral fragility: vertebrae with low bone volume fraction are highly susceptible to collapse because so few trabeculae are available for load redistribution if the external loads cause any trabeculae to fail. © 2012 American Society for Bone and Mineral Research.     

Pegfilgrastim vs. filgrastim for supportive care after autologous stem cell transplantation: can we decide?

Granulocyte-colony-stimulating factors are helpful for the support of patients receiving autologous hematopoietic stem cell transplantation, resulting in faster neutrophil recovery and lower incidence of febrile neutropenia (FN). Our aim was to evaluate the use of pegfilgrastim vs. filgrastim with regard to absolute neutrophil count (ANC) recovery, risk, and duration of FN and length of hospital stay. Mean difference was the summary effect for continuous data, and odds ratio for binary data, using random-effects modeling. MEDLINE, EMBASE, and the Cochrane Registry of Randomized Controlled Trials were included in the search. Randomized controlled trials (RCTs), case-control studies, and studies with historical control group for filgrastim were eligible. Of the initial 114 studies screened, 12 studies were analyzed (four were RCTs, including one phase III trial). The use of pegfilgrastim resulted in a one d gain in ANC recovery (mean difference -0.82, 95% CI -1.07 to -0.57, p < 0.001) and duration of FN (-0.67, 95% CI -1.28 to -0.06, p < 0.001) but had no effect on the risk of FN or length of stay. Pegfilgrastim was more expensive (baseline marginal cost €116.97, p < 0.001), which was largely determined by the treatment duration and pegfilgrastim cost. Non-randomized setting attenuated the effect on duration of FN whereas delayed onset of filgrastim injections (to pegfilgrastim) overestimated the protective effect on the risk of FN. Both drugs are at least equally effective, though methodology and disease stratification in published trials warrant further improvement.     

Posttraumatic focal dystonia of the shoulder

Focal posttraumatic shoulder dystonia is a rare and not easily identifiable entity. Its true pathophysiologic nature, predisposing factors, and disease course remain debatable.This article describes a rare case of a 40-year-old man with late symptoms of focal shoulder dystonia after peripheral trauma of his left shoulder girdle. The shoulder was indirectly injured from the impact of a fall off his motorbike 3 years earlier. He was referred to the authors' institution because remarkable reduction of arm abduction, muscle spasms, and circumscribed hypertrophy of the trapezius muscle were noted while his head and neck were in neutral position and had a full range of motion. The left shoulder had a fixed elevated posture compared with the contralateral shoulder. A continuous burning pain was localized over the area of the hypertrophied trapezius muscle, radiating to the ipsilateral side of the head and neck. Dystonic movements of the trapezius, rhomboid, and supraspinatus muscles were observed. The abduction of the shoulder was significantly decreased, and any repetitive effort for arm abduction induced an exaggeration of his movement disorder, leading to a more pronounced shoulder elevation.Plain radiographs and magnetic resonance imaging of the left shoulder revealed a suprascapular tendinitis with no other abnormalities. Repeated needle electromyography of the left trapezius muscle and neurography of the accessory nerve on both sides were normal. Injections of botulinum toxin A were effective in the resolution of muscle hypertrophy and abnormal posture.     

Dose-Response Relations for Anal Sphincter Regarding Fecal Leakage and Blood or Phlegm in Stools after Radiotherapy for Prostate Cancer

BACKGROUND: The estimation of the parameters that describe the dose-response relations of anal sphincter regarding the clinical endpoints of fecal leakage and blood or phlegm in stools is important in the optimization of prostate cancer radiotherapy. Also, the validity of the relative seriality model for this clinical case needs to be examined by associating the clinical follow-up results with the predicted complication rates. PATIENTS AND METHODS: In this study, 65 patients who received radiation therapy for clinically localized prostate adenocarcinoma are analyzed. The clinical treatment outcome and the three-dimensional dose distribution delivered to anal sphincter were available for each patient. A questionnaire was used for assessing the clinical bowel and urinary symptoms. A maximum likelihood fitting was performed to calculate the best estimates of the parameters used by the relative seriality model. The clinical utilization of the calculated parameters in predicting anal sphincter complication probabilities was illustrated by applying the best estimate of the parameters to a subset of the patient population. RESULTS: The estimated values of the parameters for the two clinical endpoints are D (50) = 70.2 Gy, gamma = 1.22, s = 0.35 for fecal leakage and D (50) = 74.0 Gy, gamma = 0.75, s approximately 0 for blood or phlegm in stools. The standard deviations of the parameters were also calculated together with the confidence intervals of the dose-response curves. The analysis proved that the treatment outcome pattern of the patient material can suitably be reproduced by the relative seriality model (probability of finding a worse fit = 60.2%, the area under the receiver operating characteristic curve = 0.72 and 0.69 and chi(2)-test = 0.97 and 0.86, respectively). CONCLUSION: Fecal leakage is characterized by a medium relative seriality whereas blood or phlegm in stools was found to have strong volume dependence (low relative seriality). Diminishing the biologically effective uniform dose to anal sphincter < 40-45 Gy may significantly reduce the risk of fecal leakage or blood or phlegm in stools for patients irradiated for prostate cancer.     

Radiotherapy-Resistant Solitary Bone Plasmacytoma of the Clavicle

Abstract Solitary bone plasmacytoma of the clavicle is an extremely rare tumor, with an incidence of approximately 0.05% among the primary tumors of the skeleton, defying a challenging diagnostic and therapeutic problem. The absence of particular clinical signs and laboratory tests and the abated sensitivity of modern imagination to differentiate the benign or malignant characteristics of an osteolytic lesion of the distal clavicle impeded a definite diagnosis, which can usually be obtained only after an open biopsy of the lesion. The presented case is distinctive, as it refers to a plasmacytoma of the distal end of the clavicle, which expressed unexplained resistance to both the administrated radiotherapy and chemotherapy. The therapeutic quandary finally resolved after the surgical resection of the entire lesion, leaving the patient free of plasma cell disease 37 months after the initial diagnosis.     

Extramembranous pregnancy: a case report.

A rare case of extramembranous pregnancy is reported. It was associated with intermittent loss of liquor and bloody discharge beginning at about the 25th week of gestation. An anencephalic infant was delivered alive from a breech presentation during the 31st week of gestation. The placenta was markedly circumvallate, with short, thick membranes which did not cover more than 10% of the infant. The course of the pregnancy and the examination of the infant and placenta are discussed, and the pertinent literature is reviewed.     

Interleukin-2 receptor common γ-chain signaling cytokines regulate activated T cell apoptosis in response to growth factor withdrawal: Selective induction of anti-apoptotic (bcl-2, bcl-xL) but not pro-apoptotic (bax,bcl-xS) gene expression

Cytokine deprivation from activated T cells leads to apoptosis associated with down-regulation of the bcl-2 gene product. It is not clear, however, how cytokines other than interleukin-2 (IL-2) may affect this process and regulate the involvement of other apoptosis-modulating genes. We show that a group of cytokines including IL-2, IL-4, IL-7 and IL-15, which can all signal through the γ chain of the IL-2R (IL-2Rγ), prevent the apoptosis of IL-2-deprived activated T cells. This rescue involves the induction of the anti-apoptosis genes (bcl-2 and bcl-x_L), but causes little change in expression of bax and bcl-x_S, which promote apoptosis. Furthermore, the prevention of apoptosis and induction of proliferation by the common γ chain cytokines can be dissociated. Thus, when proliferation is blocked, the common γ chain cytokines still induce up-regulation of bcl-2 relative to bax and retard apoptosis. These cytokines can thus regulate the persistence or removal of effector T cells by coordinating the balance between genes which promote and those which inhibit apoptosis, events which are probably mediated at least in part by signals through the common γ chain. These data also implicate inappropriate T cell apoptosis resulting from a dysfunctional common γ-chain as part of the pathophysiological defect in patients with X-linked severe-combined immunodeficiency (SCID).