Extremely high serum ferritin levels as diagnostic tool in adult-onset Still's disease.

The diagnosis of adult-onset Still's disease (ASD) is difficult to establish due to the nonspecific clinical and laboratory findings. A markedly raised serum ferritin level is a typical finding, although it is not well understood why ferritin levels are extremely high in ASD. We discuss several possible explanations leading to the extremely high levels of ferritin.

[A man with dyspnoea after a kidney transplant]. / Een man met kortademigheid na niertransplantatie.

We present a 62-year-old man with a kidney transplant in the past. Because of progressive dyspnoea a CT-scan was made, which showed ground glass in the upper fields with calcifications. He was diagnosed with metastatic pulmonary calcification, which is mostly seen in patient with renal failure and secondary hyperparathyroidism.

Wall shear stress at the initiation site of cerebral aneurysms.

Hemodynamics are believed to play an important role in the initiation of cerebral aneurysms. In particular, studies have focused on wall shear stress (WSS), which is a key regulator of vascular biology and pathology. In line with the observation that aneurysms predominantly occur at regions of high WSS, such as bifurcation apices or outer walls of vascular bends, correlations have been found between the aneurysm initiation site and high WSS. The aim of our study was to analyze the WSS field at an aneurysm initiation site that was neither a bifurcation apex nor the outer wall of a vascular bend. Ten cases with aneurysms on the A1 segment of the anterior cerebral artery were analyzed and compared with ten controls. Aneurysms were virtually removed from the vascular models of the cases to mimic the pre-aneurysm geometry. Computational fluid dynamics (CFD) simulations were created to assess the magnitude, gradient, multidirectionality, and pulsatility of the WSS. To aid the inter-subject comparison of hemodynamic variables, we mapped the branch surfaces onto a two-dimensional parametric space. This approach made it possible to view the whole branch at once for qualitative evaluation. It also allowed us to empirically define a patch for quantitative analysis, which was consistent among subjects and encapsulated the aneurysm initiation sites in our dataset. To test the sensitivity of our results, CFD simulations were repeated with a second independent observer virtually removing the aneurysms and with a 20 % higher flow rate at the inlet. We found that branches harboring aneurysms were characterized by high WSS and high WSS gradients. Among all assessed variables, the aneurysm initiation site most consistently coincided with peaks of temporal variation in the WSS magnitude.

Does Arterial Flow Rate Affect the Assessment of Flow-Diverter Stent Performance?

BACKGROUND AND PURPOSE: Our aim was to assess the performance of flow-diverter stents. The pre- and end-of-treatment angiographies are commonly compared. However, the arterial flow rate may change between acquisitions; therefore, a better understanding of its influence on the local intra-aneurysmal hemodynamics before and after flow-diverter stent use is required. MATERIALS AND METHODS: Twenty-five image-based aneurysm models extracted from 3D rotational angiograms were conditioned for computational fluid dynamics simulations. Pulsatile simulations were performed at different arterial flow rates, covering a wide possible range of physiologic flows among 1-5 mL/s. The effect of flow-diverter stents on intra-aneurysmal hemodynamics was numerically simulated with a porous medium model. Spatiotemporal-averaged intra-aneurysmal flow velocity and flow rate were calculated for each case to quantify the hemodynamics after treatment. The short-term flow-diverter stent performance was characterized by the relative velocity reduction inside the aneurysm. RESULTS: Spatiotemporal-averaged intra-aneurysmal flow velocity before and after flow-diverter stent use is linearly proportional to the mean arterial flow rate (minimum R2 > 0.983 of the linear regression models for untreated and stented models). Relative velocity reduction asymptotically decreases with increasing mean arterial flow rate. When the most probable range of arterial flow rate was considered (3-5 mL/s), instead of the wide possible flow range, the mean SD of relative velocity reduction was reduced from 3.6% to 0.48%. CONCLUSIONS: Both intra-aneurysmal aneurysm velocity and flow-diverter stent performance depend on the arterial flow rate. The performance could be considered independent of the arterial flow rates within the most probable range of physiologic flows.

Comparative Survival among Older Adults with Advanced Kidney Disease Managed Conservatively Versus with Dialysis.

BACKGROUND AND OBJECTIVES: Outcomes of older patients with ESRD undergoing RRT or conservative management (CM) are uncertain. Adequate survival data, specifically of older patients, are needed for proper counseling. We compared survival of older renal patients choosing either CM or RRT. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A retrospective survival analysis was performed of a single-center cohort in a nonacademic teaching hospital in The Netherlands from 2004 to 2014. Patients with ESRD ages ≥70 years old at the time that they opted for CM or RRT were included. Patients with acute on chronic renal failure needing immediate start of dialysis were excluded. RESULTS: In total, 107 patients chose CM, and 204 chose RRT. Patients choosing CM were older (mean±SD: 83±4.5 versus 76±4.4 years; P<0.001). The Davies comorbidity scores did not differ significantly between both groups. Median survival of those choosing RRT was higher than those choosing CM from time of modality choice (median; 75th to 25th percentiles: 3.1, 1.5-6.9 versus 1.5, 0.7-3.0 years; log-rank test: P<0.001) and all other starting points (P<0.001 in all patients). However, the survival advantage of patients choosing RRT was no longer observed in patients ages ≥80 years old (median; 75th to 25th percentiles: 2.1, 1.5-3.4 versus 1.4, 0.7-3.0 years; log-rank test: P=0.08). The survival advantage was also substantially reduced in patients ages ≥70 years old with Davies comorbidity scores of ≥3, particularly with cardiovascular comorbidity, although the RRT group maintained its survival advantage at the 5% significance level (median; 75th to 25th percentiles: 1.8, 0.7-4.1 versus 1.0, 0.6-1.4 years; log-rank test: P=0.02). CONCLUSIONS: In this single-center observational study, there was no statistically significant survival advantage among patients ages ≥80 years old choosing RRT over CM. Comorbidity was associated with a lower survival advantage. This provides important information for decision making in older patients with ESRD. CM could be a reasonable alternative to RRT in selected patients.

Accuracy and reproducibility of patient-specific hemodynamic models of stented intracranial aneurysms: report on the Virtual Intracranial Stenting Challenge 2011.

Validation studies are prerequisites for computational fluid dynamics (CFD) simulations to be accepted as part of clinical decision-making. This paper reports on the 2011 edition of the Virtual Intracranial Stenting Challenge. The challenge aimed to assess the reproducibility with which research groups can simulate the velocity field in an intracranial aneurysm, both untreated and treated with five different configurations of high-porosity stents. Particle imaging velocimetry (PIV) measurements were obtained to validate the untreated velocity field. Six participants, totaling three CFD solvers, were provided with surface meshes of the vascular geometry and the deployed stent geometries, and flow rate boundary conditions for all inlets and outlets. As output, they were invited to submit an abstract to the 8th International Interdisciplinary Cerebrovascular Symposium 2011 (ICS'11), outlining their methods and giving their interpretation of the performance of each stent configuration. After the challenge, all CFD solutions were collected and analyzed. To quantitatively analyze the data, we calculated the root-mean-square error (RMSE) over uniformly distributed nodes on a plane slicing the main flow jet along its axis and normalized it with the maximum velocity on the slice of the untreated case (NRMSE). Good agreement was found between CFD and PIV with a NRMSE of 7.28%. Excellent agreement was found between CFD solutions, both untreated and treated. The maximum difference between any two groups (along a line perpendicular to the main flow jet) was 4.0 mm/s, i.e. 4.1% of the maximum velocity of the untreated case, and the average NRMSE was 0.47% (range 0.28-1.03%). In conclusion, given geometry and flow rates, research groups can accurately simulate the velocity field inside an intracranial aneurysm-as assessed by comparison with in vitro measurements-and find excellent agreement on the hemodynamic effect of different stent configurations.

Comparing implants with hearing aids in profoundly deaf children.

Speech perception, speech production, and spoken language skills of 13 age-matched groups of prelingually deaf children, all enrolled in the same educational setting, were compared. Each group consisted of three children, two with hearing aids but different degrees of hearing loss (pure-tone average > 100 dB HL and pure-tone average between 90 and 100 dB HL) and one who had used a Nucleus multichannel implant (Cochlear Corp., Englewood, Colo.) for 3 years. The implanted group exhibited significantly better performance in all areas than aided children with greater than 100 dB losses. However, children with hearing losses in the 90 to 100 dB range who received hearing aids and auditory oral instruction at an early age performed just as well as children who had used implants for 3 years.

Speech perception abilities of adult and pediatric Nucleus implant recipients using the Spectral Peak (SPEAK) coding strategy.

A series of 73 postlinguistically deafened adults and 34 prelinguistically deafened children were evaluated with the Spectral Peak (SPEAK) coding strategy of the Nucleus 22-channel cochlear implant. The adults who received consecutive implants demonstrated rapid acquisition of open-set speech recognition skills in the initial postoperative period. Group mean sentence recognition improved to 53.5% (n = 52) after 2 weeks, 62.1% (n = 55) after 1 month, 69.8% (n = 57) after 3 months, and 74.4% (n = 42) after 6 months of use. At the 6-month evaluation interval, 43% of subjects scored greater than 90% on sound-alone sentence recognition in quiet and only one patient (2.4%) scored less than 10%. Mean monosyllabic word recognition was 35.6% after 6 months of use. The 34 prelinguistically deafened children were converted from the Multipeak strategy to Spectral Peak strategy at four large pediatric implant centers. After 6 months of using the new coding strategy, the children demonstrated significant improvements in their speech perception abilities.

Speech and language acquisition in young children after cochlear implantation.

Auditory and speech intelligibility scores of 22 prelingually profoundly deaf children who had used cochlear implants for between 1 and 7 years in an intensive auditory/oral educational program greatly exceeded those previously obtained from similar samples of deaf children using hearing aids. Half of the children obtained language quotient scores within the average range for normal-hearing children and the majority obtained reading quotients within 80% of normal levels. Normal levels of language and reading development were associated with early implantation and open set speech perception.

The impact of equations on calculation of lean body mass by bioelectrical impedance analysis in RDT patients.

Several equations are available to derive lean body mass (LBM) from bioelectrical impedance analysis (BIA). The purpose of this study was to investigate in dialysis patients the impact of the equation used on the outcome of LBM assessment. To avoid dyshydration as a confounder, vena cava diameter measurement was used to assess normohydration in the 21 patients studied. Five equations were compared. In a previously published study to assess total body water using antipyrine as a gold standard, Deurenberg's formula was advocated to be used in the estimation of LBM by BIA. Therefore, this formula was used as a basis for comparison with the other four equations. One equation gave results comparable to those obtained by Deurenberg's formula. Despite high correlations and agreement according to Bland and Altman analysis, the other three equations showed a significant difference with Deurenberg-derived LBM. Thus, the equation used has a major impact on the outcome of LBM estimations.

Vibrotactile stimulation: case study with a profoundly deaf child.

This case study reports results obtained from a young, profoundly deaf child, M, who was fitted with a single-channel vibrotactile device, the Tactaid I, at 29 months of age. Her progress in speech and language development was evaluated over a 14-month period. During this period, M learned to understand 101 words through lipreading and the Tactaid I, and to produce consistent approximations of 90 words. Her scores on language tests with hearing-impaired norms progressed from below average to above average for her age. M's scores on language tests with hearing norms also reflected significant progress, although she did not achieve normal language development. These results indicate that a single-channel vibrotactile aid may facilitate the acquisition of spoken language in a profoundly deaf child who is unable to benefit from a conventional hearing aid.

Communication of oral deaf and normally hearing children at 36 months of age.

Eighteen orally educated deaf and 18 normally hearing 36-month-old children were observed in a play session with their mother. Communicative behavior of the child was coded for modality and communicative function. Although the oral deaf children used a normal range of functions, both the quantity and proportions differed from normally hearing children. Whereas the normally hearing 3-year-olds used speech almost exclusively, the deaf children exhibited about equal use of speech, vocalizations, and gestures. Spoken language scores of the deaf children at 5 years of age were best predicted by (a) more frequent use of speech at age 36 months, (b) more frequent use of the Statement function, and (c) relatively infrequent use of the Directive function. It is suggested that some communicative functions are more informative or heuristic than others, and that the early use of these functions is most likely to predict later language competence.

Inter-rater reliability as a reflection of ambiguity in the communication of deaf and normally-hearing children.

This study involves (a) procedures for coding intentionality and communicative function from the behavior of young children, (b) determining inter-rater reliability on those decisions, and (c) making judgments about which data to use for presentation and analysis. Communication data from videotaped interactions of 48 deaf and 96 normally-hearing children (12-54 months of age) and their mothers were obtained from two independent coders. As predicted, the percent-agreement between coders was higher for older children and for hearing children compared to deaf children. It is argued that the ambiguity reflected in poor coder agreement for less skilled communicators may represent the extent to which these children are understood. It is suggested that for such children data analysis should be restricted to those behaviors on which two independent coders agree.

[Acute tumor lysis syndrome due to mono-therapy with a corticosteroid in a patient with non-Hodgkin lymphoma]. / Acuut tumorlysissyndroom door monotherapie met een corticosteroïd bij een patiënt met non-Hodgkin-lymfoom.

A 20-year-old man was hospitalised because he nearly suffocated when lying on his back. After bronchoscopy which revealed severe external compression of the airways, suddenly respiratory insufficiency developed. Because a malignant lymphoma was suspected chemotherapy was started, using monotherapy with prednisolone as the risk of acute tumour lysis syndrome (ATLS) is high with polychemotherapy of bulky tumours. Nevertheless ATLS developed, for which haemodialysis had to be applied. The tumour, a T-cell lymphoblastic non-Hodgkin lymphoma with high grade malignancy, was treated successfully with cyclophosphamide, doxorubicin, vincristine en prednisone. ATLS is characterized by hyperkalaemia, hyperuricaemia, hyperphosphataemia, hypocalcaemia, lactate acidosis and acute renal failure. It can occur in the course of aggressive cytoreductive therapy in rapidly growing lymphoproliferative malignancies with large tumour size, due to massive tumour cel lysis. Corticosteroid monotherapy is a very rare cause of ATLS.

Approximating hemodynamics of cerebral aneurysms with steady flow simulations.

Computational fluid dynamics (CFD) simulations can be employed to gain a better understanding of hemodynamics in cerebral aneurysms and improve diagnosis and treatment. However, introduction of CFD techniques into clinical practice would require faster simulation times. The aim of this study was to evaluate the use of computationally inexpensive steady flow simulations to approximate the aneurysm's wall shear stress (WSS) field. Two experiments were conducted. Experiment 1 compared for two cases the time-averaged (TA), peak systole (PS) and end diastole (ED) WSS field between steady and pulsatile flow simulations. The flow rate waveform imposed at the inlet was varied to account for variations in heart rate, pulsatility index, and TA flow rate. Consistently across all flow rate waveforms, steady flow simulations accurately approximated the TA, but not the PS and ED, WSS field. Following up on experiment 1, experiment 2 tested the result for the TA WSS field in a larger population of 20 cases covering a wide range of aneurysm volumes and shapes. Steady flow simulations approximated the space-averaged WSS with a mean error of 4.3%. WSS fields were locally compared by calculating the absolute error per node of the surface mesh. The coefficient of variation of the root-mean-square error over these nodes was on average 7.1%. In conclusion, steady flow simulations can accurately approximate the TA WSS field of an aneurysm. The fast computation time of 6 min per simulation (on 64 processors) could help facilitate the introduction of CFD into clinical practice.

Dutch guideline for the management of electrolyte disorders--2012 revision.

Electrolyte disorders are common and often challenging in terms of differential diagnosis and appropriate treatment. To facilitate this, the first Dutch guideline was developed in 2005, which focused on hypernatraemia, hyponatraemia, hyperkalaemia, and hypokalaemia. This guideline was recently revised. Here, we summarise the key points of the revised guideline, including the major complications of each electrolyte disorder, differential diagnosis and recommended treatment. In addition to summarising the guideline, the aim of this review is also to provide a practical guide for the clinician and to harmonise the management of these disorders based on available evidence and physiological principles.

Intra-aneurysmal pressure and flow changes induced by flow diverters: relation to aneurysm size and shape.

BACKGROUND AND PURPOSE: Effects of blood flow modification by flow diverters are observed to lead often to aneurysm thrombosis and reverse remodeling. For this process, to further understand the potential roles of intra-aneurysmal blood pressure changes and aneurysm morphologies, 23 patients were studied by numeric simulation. MATERIALS AND METHODS: 3D imaging of aneurysms of different sizes and shapes, all located at the supraclinoid segment of the ICA (n=23), was prepared for CFD simulations. Hemodynamic variables were calculated for conditions before and after virtual FD implantation, reconstituting a vessel wall scaffold across the aneurysm neck. WSS, velocity, residence time, turnover time, and intra-aneurysmal pressure were assessed statistically. RESULTS: After placement of FDs, significant reductions inside the aneurysm were observed for most hemodynamic variables (P<.01) except mean intra-aneurysmal pressures. For minimum/maximum intra-aneurysmal pressure values, small but significant changes were found; however, they were considered too small to be of relevance. CONCLUSIONS: Calculations in 23 cases did not reveal significant intra-aneurysmal mean or peak pressure changes, indicating a minor role of pressure changes in the rare event of secondary ruptures after FD use. Other hemodynamic variables (WSS and velocity) exhibited more significant changes, indicating their role in intra-aneurysmal thrombus formation. Size-dependent, significantly higher reduction in WSS (P=.069) and velocity (P=.013) was observed in small aneurysms compared with larger ones. When it came to shape, there were significantly higher reductions in WSS (P=.055) and velocity (P=.065) and a significantly higher increase in turnover time in fusiform aneurysms compared with saccular aneurysms.

Binary ultrasonography for the internist: yes or no, that's the question!

The authors discuss the pros and cons with regard to ultrasound for the internist. They state that ultrasonography is seldom used by internists and they suggest several reasons for this. After a brief review of the literature they conclude that using ultrasound would probably benefit patients and would lead to a more rapid diagnosis and an increase in safety while performing invasive diagnostic and therapeutic interventions. The authors suggest that internists use ultrasound in a different way compared with radiologists, cardiologists, etc. They introduce the term binary ultrasound: ultrasound should be used to answer clinical questions with a yes or a no.

Patient-specific computational hemodynamics of intracranial aneurysms from 3D rotational angiography and CT angiography: an in vivo reproducibility study.

BACKGROUND AND PURPOSE: Patient-specific simulations of the hemodynamics in intracranial aneurysms can be constructed by using image-based vascular models and CFD techniques. This work evaluates the impact of the choice of imaging technique on these simulations. MATERIALS AND METHODS: Ten aneurysms, imaged with 3DRA and CTA, were analyzed to assess the reproducibility of geometric and hemodynamic variables across the 2 modalities. RESULTS: Compared with 3DRA models, we found that CTA models often had larger aneurysm necks (P = .05) and that most of the smallest vessels (between 0.7 and 1.0 mm in diameter) could not be reconstructed successfully with CTA. With respect to the values measured in the 3DRA models, the flow rate differed by 14.1 ± 2.8% (mean ± SE) just proximal to the aneurysm and 33.9 ± 7.6% at the aneurysm neck. The mean WSS on the aneurysm differed by 44.2 ± 6.0%. Even when normalized to the parent vessel WSS, a difference of 31.4 ± 9.9% remained, with the normalized WSS in most cases being larger in the CTA model (P = .04). Despite these substantial differences, excellent agreement (κ ≥ 0.9) was found for qualitative variables that describe the flow field, such as the structure of the flow pattern and the flow complexity. CONCLUSIONS: Although relatively large differences were found for all evaluated quantitative hemodynamic variables, the main flow characteristics were reproduced across imaging modalities.