Repeated home drinking water sampling to improve detection of particulate lead spikes: a simulation study.

BACKGROUND: Lead can be present in drinking water in soluble and particulate forms. The intermittent release of lead particulates in drinking water can produce highly variable water lead levels (WLLs) in individual homes, a health concern because both particulate and soluble lead are bioavailable. More frequent water sampling would increase the likelihood of identifying sporadic lead "spikes," though little information is available to aid in estimating how many samples are needed to achieve a given degree of sensitivity to spike detection. OBJECTIVE: To estimate the number of rounds of tap water sampling needed to determine with a given level of confidence that an individual household is at low risk for the intermittent release of lead particulates. METHODS: We simulated WLLs for 100,000 homes on 15 rounds of sampling under a variety of assumptions about lead spike release. A Markovian structure was used to describe WLLs for individual homes on subsequent rounds of sampling given a set of transitional probabilities, in which homes with higher WLLs at baseline were more likely to exhibit a spike on repeated sampling. RESULTS: Assuming 2% of homes had a spike on the first round of sampling and a mid-range estimate of transitional probabilities, the initial round of sampling had a 6.4% sensitivity to detect a spike. Seven rounds of sampling would be needed to increase the sensitivity to 50%, which would leave unrecognized the more than 15,000 homes that intermittently exhibit spikes. SIGNIFICANCE: For assessing household risk for lead exposure through drinking water, multiple rounds of water sampling are needed to detect the infrequent but high spikes in WLLs due to particulate release. Water sampling procedures for assessment of lead exposure in individual homes should be modified to account for the infrequent but high spikes in WLL. IMPACT: It has been known for decades that intermittent "spikes" in water lead occur due to the sporadic release of lead particulates. However, conventional water sampling strategies do not account for these infrequent but hazardous events. This research suggests that current approaches to sampling tap water for lead testing identify only a small fraction of homes in which particulate spikes occur, and that sampling procedures should be changed substantially to increase the probability of identifying the hazard of particulate lead release into drinking water.

Conducting research on building psychosocial support for Syrian refugee families in a humanitarian emergency.

BACKGROUND: This case study describes research, which is located in Turkey, where more than 750,000 Syrian refugees reside autonomously in Istanbul. The research developed and pilot tested a novel model for helping urban refugee families with limited to no access to evidence-based mental health services, by delivering a transdiagnostic family intervention for common mental disorders in health and non-health sector settings using a task-sharing approach. This case study addresses the following question: What challenges were encountered in developing and piloting a low intensity trans-diagnostic family support intervention in a humanitarian emergency setting? DISCUSSION: The rapidly growing scale of humanitarian crises requires new response capabilities geared towards addressing populations with prolonged high vulnerability to mental health consequences and limited to no access to mental health, health, and social resources. The research team faced multiple challenges in conducting this research in a humanitarian emergency setting including: 1) Non-existent or weak partnerships geared towards mental health research in a humanitarian emergency; 2) Lack of familiarity with task-sharing; 3). Insufficient language and cultural competency; 3) Fit with families' values and demands; 4) Hardships of urban refugees. Through the research process, the research team learned lessons concerning: 1) building a coalition of academic and humanitarian organization partners; 2) investing in the research capacity building of local researchers and partners; 3) working in a community-collaborative and multi-disciplinary approach. CONCLUSION: Conducting research in humanitarian emergency settings calls for innovative collaborative and multidisciplinary approaches to understanding and addressing many sociocultural, contextual, practical and scientific challenge.

Optimal decision-making in oncology development programs based on probability of success for phase III utilizing phase II/III data on response and overall survival.

In clinical development, there is a trade-off between investment and level of confidence in the potential of the drug before going into phase III. Reduced investment requires the use of short-term endpoints. On new compounds, only limited information about the relationship between treatment effects of short- and long-term endpoints is usually available. Therefore, decision-making solely based on short-term endpoints does not seem desirable. Our goal is to plan an efficient development program, which uses short- and long-term endpoints data for decision-making. We found that with limited prior information and restrictions on maximum sample size, decision-making after phase II cannot be substantially improved. We follow the concept of a "phase 2+" design where after a go-to-phase-III-decision, further follow-up data from phase II are employed to make interim decisions on phase III. The program will be stopped early when additional phase II and/or available phase III data lead to a low probability of success (PoS). We utilize information from a multi-categorical short-term endpoint (response status) and a long-term endpoint (overall survival (OS)) to determine the PoS in phase III with OS as the primary endpoint. Optimal combinations of decision boundaries and time points are demonstrated in a simulation study. Our results show that the proposed second look using additional follow-up data from phase II/III improves PoS estimates compared to the first look, especially when prior data about the control arm is available. The proposed planning strategy allows a customized compromise between the quality of decision-making and program duration.

Hip joint moments in symptomatic vs. asymptomatic people with mild radiographic hip osteoarthritis.

Our primary objective was to examine external hip joint moments during walking in people with mild radiographic hip osteoarthritis (OA) with and without symptoms and disease-free controls. Three groups were compared (symptomatic with mild radiographic hip OA, n = 12; asymptomatic with mild radiographic hip OA, n = 13; OA-free controls, n = 20). Measures of the external moment (peak and impulse) in the sagittal, frontal and transverse plane during walking were determined. Variables were compared according to group allocation using mixed linear regression models that included individual gait trials, with group allocation as fixed effect and walking speed as a random effect. Participants with evidence of radiographic disease irrespective of symptoms walked 14-16% slower compared to disease-free controls (p = 0.002). Radiographic disease without symptoms was not associated with any altered measures of hip joint moment compared to asymptomatic OA-free controls once speed was taken into account (p ≥ 0.099). People with both mild radiographic disease and symptoms had lower external peak hip adduction moment (p = 0.005) and lower external peak internal rotation moment (p < 0.001) accounting for walking speed. Among angular impulses, only the presence of symptoms was associated with a reduced hip internal rotation impulse (p = 0.002) in the symptomatic group. Collectively, our observations suggest that symptoms have additional mechanical associations from radiographic disease alone, and provide insight into potential early markers of hip OA. Future research is required to understand the implications of modifying walking speed and/or the external hip adduction and internal rotation moment in people with mild hip OA.

A note on marginalization of regression parameters from mixed models of binary outcomes.

This article discusses marginalization of the regression parameters in mixed models for correlated binary outcomes. As is well known, the regression parameters in such models have the "subject-specific" (SS) or conditional interpretation, in contrast to the "population-averaged" (PA) or marginal estimates that represent the unconditional covariate effects. We describe an approach using numerical quadrature to obtain PA estimates from their SS counterparts in models with multiple random effects. Standard errors for the PA estimates are derived using the delta method. We illustrate our proposed method using data from a smoking cessation study in which a binary outcome (smoking, Y/N) was measured longitudinally. We compare our estimates to those obtained using GEE and marginalized multilevel models, and present results from a simulation study.

Concurrent generation of multivariate mixed data with variables of dissimilar types.

Data sets originating from wide range of research studies are composed of multiple variables that are correlated and of dissimilar types, primarily of count, binary/ordinal and continuous attributes. The present paper builds on the previous works on multivariate data generation and develops a framework for generating multivariate mixed data with a pre-specified correlation matrix. The generated data consist of components that are marginally count, binary, ordinal and continuous, where the count and continuous variables follow the generalized Poisson and normal distributions, respectively. The use of the generalized Poisson distribution provides a flexible mechanism which allows under- and over-dispersed count variables generally encountered in practice. A step-by-step algorithm is provided and its performance is evaluated using simulated and real-data scenarios.

Radiological Findings of Michel Aplasia.

INTRODUCTION: Congenital abnormalities of the inner ear is the most common cause of neurosensory hearing loss. Michel inner ear deformity is a rare developmental anomaly refers to the total aplasia of the inner ear. It is caused by developmental arrest of otic placode early during the third week of gestational age. CASE REPORT: We have discussed here that three year old girl diagnosed Michel aplasia with temporal bone computed tomography (CT) and temporal magnetic resonance imaging (MRI) findings.

Bilateral cleft foot: Radiographic and prenatal ultrasound features of two siblings with a review of literature.

Cleft foot deformity, also known as ectrodactyly, is a rare congenital developmental defect of extremities caused by malformation in continuity of apical ectoderm. The syndrome typically involves malformation or absence of the central rays of the feet and is characterized by deformities like median deep clefts of distal extremities. Routine examination of feet during second-trimester ultrasound (US) may increase the detection rates of foot malformations. Many malformations can be diagnosed with 2-dimensional (2D) US, but 3-dimensional (3D) US also helps better understanding of the foot malformations. In the present study, we report the case of two brothers (a fetus and a 5-year-old) with cleft foot deformity. 2D and 3D second trimester US findings of one case and the foot radiography findings of the other are presented here.

A Mixed-effects Location-Scale Model for Ordinal Questionnaire Data.

In health studies, questionnaire items are often scored on an ordinal scale, for example on a Likert scale. For such questionnaires, item response theory (IRT) models provide a useful approach for obtaining summary scores for subjects (i.e., the model's random subject effect) and characteristics of the items (e.g., item difficulty and discrimination). In this article, we describe a model that allows the items to additionally exhibit different within-subject variance, and also includes a subject-level random effect to the within-subject variance specification. This permits subjects to be characterized in terms of their mean level, or location, and their variability, or scale, and the model allows item difficulty and discrimination in terms of both random subject effects (location and scale). We illustrate application of this location-scale mixed model using data from the Social Subscale of the Drinking Motives Questionnaire (SS-DMQ) assessed in an adolescent study. We show that the proposed model fits the data significantly better than simpler IRT models, and is able to identify items and subjects that are not well-fit by the simpler models. The proposed model has useful applications in many areas where questionnaires are often rated on an ordinal scale, and there is interest in characterizing subjects in terms of both their mean and variability.

Unenhanced 3D turbo spin echo MR angiography of lower extremity arteries: comparison with 128-MDCT angiography.

PURPOSE: This study aimed to investigate the feasibility and diagnostic power of unenhanced 3D turbo spin echo MR angiography sequence (a technique based on subtraction of corresponding images acquired in diastole and systole, Syngo Native Space-Siemens healthcare) to identify peripheral artery disease (PAD). MATERIALS AND METHODS: Thirty patients (619 arterial segments in total) suspected with PAD and who were assessed with lower extremity MDCT angiography were examined starting from the level of aortic bifurcation for both lower extremities by 3D native space MR angiography. Two readers assessed the image quality of native space MR angiography and number of lesions, their degrees of stenosis and localizations. The differences and compliance between the readers in the parameters assessed were investigated. RESULTS: Out of 619 segments; Reader 1 considered 187 segments (30.2 %) and Reader 2 considered 177 segments (28.6 %) to have poor and inadequate MR image quality. When compared to CTA, sensitivity, specificity and diagnostic accuracy of native space MR angiography were calculated as 81.0, 83.1, 82.6 %, respectively, by Reader 1, while the same parameters were calculated as 69.9, 92.6, 84.9 %, respectively, by Reader 2. When the two readers were examined together, sensitivity, specificity, diagnostic accuracy were found to be 76.3, 88.1, 83.7 %, respectively, and the positive predictive value and negative predictive value was 70.3 and 89.9 %, respectively. A significantly better image quality was acquired with the age group below 50 years (p = 0.002). CONCLUSION: Native space MR angiography technique can be used as the first-step imaging technique before contrast-enhanced examinations in young and middle age patients with suspected PAD and for patients with the risk of nephrogenic systemic fibrosis in chronic renal failure.

Eagle Syndrome Causing Vascular Compression with Cervical Rotation: Case Report.

BACKGROUND: Eagle syndrome is a condition caused by an elongated styloid process. Unilateral face, neck and ear pain, stinging pain, foreign body sensation and dysphagia can be observed with this syndrome. Rarely, the elongated styloid process may cause pain by compressing the cervical segment of the internal carotid and the surrounding sympathetic plexus, and that pain spreading along the artery can cause neurological symptoms such as vertigo and syncope. CASE REPORT: In this case report we presented a very rare eagle syndrome with neurological symptoms that occurred suddenly with cervical rotation. The symptoms disappeared as suddenly as they occurred, with the release of pressure in neutral position. We also discussed CT angiographic findings of this case. CONCLUSIONS: Radiological diagnosis of the Eagle syndrome that is manifested with a wide variety of symptoms and causes diagnostic difficulties when it is not considered in the differential diagnosis is easy in patients with specific findings. CT angiography is a fast and effective examination in terms of showing compression in patients with the Eagle syndrome that is considered to be atypical and causes vascular compression.

Aspergilloma Mimicking Metastasis in a Case with Laryngeal Carcinoma.

INTRODUCTION: Aspergilloma is a fungal ball which is composed of hyphal structure fungus, fibrin, mucus and cellular debris and settled in a pre-existing pulmonary cavity or an ectatic bronchial. It may cause colonization in patients with an immunosuppressive and underlying lung disease. Although chest radiography provides valuable information, it can be scanned more effectively by computed tomography (CT). Monitoring fungal ball within the cavity in CT provides establishing the diagnosis. CASE REPORT: However, in this case report, we presented a case with operated laryngeal carcinoma whom we first had considered to have metastasis and who had received a diagnosis of aspergilloma in CT and Positron emission tomography (PET). CONCLUSION: Imaging findings may remain limited in definitive diagnosis of aspergilloma. Therefore, surgical resection will allow for both pathological diagnosis and treatment.

Unusual case of spinal epidermoid cyst and a concomitant spinal arachnoid cyst.

A 38-year-old woman presented with a 12-month history of subjective weakness and pain in her legs. Thoracolumbar MRI revealed two spinal intradural cystic lesions at T5-6 and T11 levels, respectively. The lesion located at the T5-6 level was heterogeneously hyperintense on T2-weighted images and heterogeneously hypointense on T1-weighted images. This lesion showed high signal intensity on diffusion weighted MRI (DWI) and low signal intensity on apparent diffusion coefficient images (ADC). According to the MRI findings, we reported this tumour as a spinal epidermoid cyst. The pathology result suggested that the lesion was an epidermoid cyst. The second intradural lesion, at the T11 level, showed a hypointense signal on T1 and hyperintense signal on T2 images. However, in contrast to the superior lesion, this lesion was hypointense on DWI and hyperintense on ADC. We evaluated the second lesion as an arachnoid cyst according to the MRI findings.

Assessment of ovarian reserve in euthyroid adolescents with Hashimoto thyroiditis.

AIM: We aimed to investigate the ovarian function and reserve in euthyroid adolescents (TSH < 2.5 mIU/L) diagnosed with Hashimoto thyroiditis (HT). METHODS: This case-control study included 30 adolescent girls (mean age 15.1 ± 1.4 years) newly diagnosed as HT with presence of high thyroid antibodies with gland heterogeneity in ultrasound and age-matched 30 healthy female subjects. Anti-ovarian antibody (AOAb), LH/FSH ratio, estradiol, anti-mullerian hormone (AMH), inhibin-B, total testosterone, antral follicle count, ovarian volumes and uterine length were measured. The clinical, laboratory, and ultrasound data of the HT and control groups were compared. RESULTS: There were no significant differences between the girls with HT and healthy controls in relation to LH/FSH ratio, estradiol and inhibin-B levels. AOAb (p = 0.02), AMH (p = 0.007) and total testosterone levels were higher in HT group than the control group (p = 0.03). AOAb level was found to be positively correlated with LH/FSH ratio (p = 0.03), AMH (p = 0.01) and inhibin-B (p < 0.001) in HT group. CONCLUSION: This study demonstrated that the adolescent girls diagnosed with autoimmune thyroiditis had normal ovarian reserve based on measurements of AMH, inhibin B, FSH, LH/FSH ratio, estradiol and antral follicle counts.

Treatment of osteoporotic vertebral compression fractures with percutaneous vertebroplasty under local anesthesia: clinical and radiological results.

BACKGROUND: Vertebroplasty (VP) is a commonly used method for the treatment of osteoporotic vertebral fractures (OVF). The aim of this study is to analyze retrospectively the efficacy of PV in symptomatic osteoprotic spine fractures. METHODS: Patients with symptomatic osteoporotic spine fractures were included in our study. Visual analog scale and demographic characteristics were used for clinical examination, local wedge angle and the central height of the vertebral body were measured preoperatively and postoperatively. RESULTS: 95 patients (72 female, 23 male) were included and 118 level vertebroplasty were performed. There was statistical significance in the differences of preoperative VAS scores compared to postoperative first day, first month and sixth month. The radiologic assessment of the mean local wedge angle correction at the postoperative sixth month, was 13.9 and mean increase of mid height of vertebral body was 7.9 mm, but it was not statistically significant. CONCLUSION: VP is at an important point as a minimally invasive method, that provides rapid pain relief in symptomatic osteoporotic vertebral fractures and that prevents the patient being bed-dependent. It is a reliable surgical method, being an alternative to open surgery with minimal complications in patients with comorbidities, which can be arapidley applied and decreases the potential spinal deformity after the fracture and prevents the progression of deformity.

Transthoracic biopsy of lung masses: Non technical factors affecting complication occurrence.

BACKGROUND: To investigate the transthoracic computed tomography (CT)-guided lung nodule biopsy complications and risk factors associated with the development of these complications. METHODS: We retrospectively evaluated a total of 41 CT-guided transthoracic biopsy complications. Data was analyzed by chi-square and independent sample t-tests. RESULTS: Twenty-seven patients (28.7%) developed pneumothorax and eight patients (8.5%) developed parenchymal hemorrhage, and four patients (4.3%) hemothorax and two (2.1%) patients developed subcutaneous emphysema. A significant correlation was obtained between the development of pneumothorax and lesion size (P = 0.040), and the distance that traversed the parenchyma (P = 0.001). There was a statistically significant difference between the parenchymal hemorrhage and lesion size and the distance from passed parenchyma (P values were 0.021 and 0.008, respectively). An increased incidence of parenchymal hemorrhage and pneumothorax was observed at small size and deep-seated lesions. CONCLUSION: Lesion size and the distance that traversed the parenchyma on the biopsy tract are the most important factors that influence the development of complications in CT-guided transthoracic biopsy.

Evaluation of Renal Arteries of 286 Living Donors by Multidetector Computed Tomography Angiography: A Single-Center Study.

OBJECTIVES: In living renal donors, digital subtraction angiography and intravenous pyelogram techniques developing traditional evaluation before transplant have started to give place to more modern and less-invasive methods such as multidetector computerized tomography angiography, and magnetic resonance angiography via the developments in the imaging technology. We aimed to evaluate the renal arteries of living-renal donors by multidetector computerized tomography angiography and to compare the findings with the surgical results. MATERIALS AND METHODS: In our renal transplant center, 286 living-donor candidates to whom multi-detector computerized tomography angiography was applied, were evaluated retrospectively and the findings were compared with the surgical operation notes. RESULTS: In 180 of 286 living donor candidates to whom computerized tomography angiography was applied, bilateral single renal artery was deter-mined. In 79 renal donor candidates, unilateral multiple renal artery; and in 27 renal donor candidates, bilateral multiple renal artery were found. In 58 renal donor candidates, at least 1 polar artery was specified; in 32 renal donor candidates, a unilateral single renal artery; in 10 renal donor candidates, a bilateral double renal artery was determined. When computerized tomography angiography and operative notes were compared, we observed that the findings in 280 donor candidates were the same. In 6 renal donor candidates, differences in the findings were present. Our accuracy rate was 97% and according to the operative notes, our sensitivity and specificity ratios in determining multiple renal arteries were calculated as 98% and 95%. CONCLUSIONS: Multidetector computerized tomography angiography can be used rapidly and efficiently in living-donor renal candidates with high specificity and sensitivity ratios.

CT-guided transthoracic biopsy: histopathologic results and complication rates.

PURPOSE: We aimed to investigate the effectiveness and complications of transthoracic CT-guided biopsy techniques. METHODS: A total of 94 CT-guided percutaneous transthoracic biopsy procedures performed in 85 patients were retrospectively evaluated. Core biopsy technique was used in 87 procedures and transthoracic fine-needle aspiration biopsy was used in seven procedures. RESULTS: Diagnostic results were achieved in 79 of 94 biopsy procedures. Pathology results were malignant in 54 patients, suspicious for malignancy in three patients, benign in five patients, and benign nonspecific in 17 patients. Specific diagnoses were obtained in 59 patients (62.8%) using core biopsy, but no specific diagnosis could be reached with transthoracic fine-needle aspiration biopsy. Complications included pneumothorax in 27 patients (28.7%) and parenchymal hemorrhage during and after the procedure in eight patients (8.5%). CONCLUSIONS: CT-guided percutaneous transthoracic needle biopsy is a highly accurate procedure for histopathological diagnosis of thoracic masses. In addition, percutaneous transthoracic biopsy has an acceptably low complication rate and it reduces the need for more invasive surgical procedures.

Concurrent Generation of Ordinal and Normal Data.

The use of joint models that are capable of handling different data types is becoming increasingly popular in biopharmaceutical practice. Evaluation of various statistical techniques that have been developed for mixed data in simulated environments requires joint generation of multiple variables. In this article, we propose a unified framework for concurrently simulating ordinal and normal data given the marginal characteristics and correlation structure. We illustrate our technique in two simulation settings where we use artificial data as well as real depression score data from psychiatric research, demonstrating negligibly small deviations between the specified and empirically computed quantities.