Linking measures of adolescent nicotine dependence to a common latent continuum

Using the theoretical model of nicotine dependence (ND) operationalized within the Diagnostic and Statistical Manual of Mental Disorder, fourth Edition (DSM-IV: American Psychiatric [American Psychiatric Association, 1994. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. American Psychiatric Association, Washington, DC]) as a frame of reference, we used methods based in item response theory to link alternative instruments assessing adolescent nicotine dependence severity to a common latent continuum. A multi-ethnic cohort of 6th-10th graders selected from the Chicago Public Schools (CPS) completed five household interviews over 2 years. Youth who reported at least some cigarette use in the last 30 days prior to the interviews at waves W3-W5 completed measures of DSM-IV ND, the Modified Fagertrom Tolerance Questionnaire (mFTQ: Prokhorov et al., 1998) and the Nicotine Dependence Syndrome Scale (NDSS: Shiffman et al., 2004), yielding samples of 253, 241, and 296 respondents at W3-W5, respectively. Confirmatory factor analysis supported a primary dimension of ND. Each instrument's items had complementary and stable relationships to ND across multiple waves of assessment. By aligning symptoms along a common latent ND continuum, we evaluated the consistency of symptoms from different instruments that target similar content. Further, these methods allowed for the examination of the DSM-IV as a continuous index of ND, evaluation of the degree of heterogeneity in levels of ND within groups above and below diagnostic thresholds, and the utility of using the pattern or particular DSM-IV symptoms that led to each score in further differentiating levels of ND. Finally, we examined concurrent validity of the ND continuum and levels of current of smoking at each wave of assessment.     

Participation of Women in Clinical Trials Supporting FDA Approval of Cardiovascular Drugs

Background

Concerns exist that women are underrepresented in trials of cardiovascular medications.

Proton radiotherapy in management of pediatric base of skull tumors

PURPOSE: Primary skull base tumors of the developing child are rare and present a formidable challenge to both surgeons and radiation oncologists. Gross total resection with negative margins is rarely achieved, and the risks of functional, structural, and cosmetic deficits limit the radiation dose using conventional radiation techniques. Twenty-nine children and adolescents treated with conformal proton radiotherapy (proton RT) were analyzed to assess treatment efficacy and safety. MATERIALS AND METHODS: Between July 1992 and April 1999, 29 patients with mesenchymal tumors underwent fractionated proton (13 patients) or fractionated combined proton and photon (16 patients) irradiation. The age at treatment ranged from 1 to 19 years (median 12); 14 patients were male and 15 female. Tumors were grouped as malignant or benign. Twenty patients had malignant histologic findings, including chordoma (n = 10), chondrosarcoma (n = 3), rhabdomyosarcoma (n = 4), and other sarcomas (n = 3). Target doses ranged between 50.4 and 78.6 Gy/cobalt Gray equivalent (CGE), delivered at doses of 1.8-2.0 Gy/CGE per fraction. The benign histologic findings included giant cell tumors (n = 6), angiofibromas (n = 2), and chondroblastoma (n = 1). RT doses for this group ranged from 45.0 to 71.8 Gy/CGE. Despite maximal surgical resection, 28 (97%) of 29 patients had gross disease at the time of proton RT. Follow-up after proton RT ranged from 13 to 92 months (mean 40). RESULTS: Of the 20 patients with malignant tumors, 5 (25%) had local failure; 1 patient had failure in the surgical access route and 3 patients developed distant metastases. Seven patients had died of progressive disease at the time of analysis. Local tumor control was maintained in 6 (60%) of 10 patients with chordoma, 3 (100%) of 3 with chondrosarcoma, 4 (100%) of 4 with rhabdomyosarcoma, and 2 (66%) of 3 with other sarcomas. The actuarial 5-year local control and overall survival rate was 72% and 56%, respectively, and the overall survival of the males was significantly superior to that of the female patients (p = 0.002). Of the patients with benign tumors, 1 patient (giant cell tumor) had local failure at 10 months. The other 8 patients continued to have local tumor control; all 9 patients were alive at last follow-up (actuarial 5-year local control and overall survival rate of 89% and 100%, respectively). Severe late effects (motor weakness and sensory deficits) were observed in 2 (7%) of 29 patients. CONCLUSION: Proton RT for children with aggressively recurring tumors after major skull base surgery can offer a considerable prospect of tumor control and survival. Longer follow-up is necessary to assess the real value of protons, in particular with regard to bone growth and cosmetic outcome.     

Residential proximity to agricultural pesticide use and incidence of breast cancer in the California Teachers Study cohort

We examined the association between residential proximity to agricultural pesticide use and breast cancer incidence among members of the California Teachers Study cohort, a large study of professional school employees with extensive information on breast cancer risk factors, followed for cancer incidence since 1995. We identified 1552 invasive breast cancer cases, diagnosed between 1996 and 1999, among 114,835 cohort members. We used California Pesticide Use Reporting data to select pesticides for analysis based on use volume, carcinogenic potential, and exposure potential; a Geographic Information System was used to estimate pesticide applications within a half-mile radius of subjects' residences. We applied Cox proportional hazard models to estimate hazard rate ratios (HR) for selected pesticides, adjusting for age, race, and socioeconomic status. We saw no association between residential proximity to recent agricultural pesticide use and invasive breast cancer incidence. HR estimates for the highest compared to the lowest exposure categories for groups of agents were as follows: probable or likely carcinogens (1.07, 95% confidence interval (CI): 0.86-1.32), possible or suggestive carcinogens (1.06, 95% CI: 0.87-1.29), mammary carcinogens (1.15, 95% CI: 0.90-1.48), and endocrine disruptors (1.03, 95% CI: 0.86-1.25). HR estimates for other groups and individual pesticides did not differ from unity, nor was there a trend for any groupings of or individual pesticides examined. Stratifying by menopausal status or family history of breast cancer did not substantially affect our results. Our analyses suggest that breast cancer incidence is not elevated in areas of recent, high agricultural pesticide use in California.     

Lazy eyes zebrafish mutation affects Müller glial cells,compromising photoreceptor function and causing partial blindness

A behavioral assay based on the optokinetic reflex was used to screen chemically mutagenized zebrafish larvae for deficits in visual function. A homozygous recessive mutation, lazy eyes (lze), was isolated based on the observation that 5-day postfertilization (dpf) mutants displayed weaker and less frequent eye movements than wild-type fish in response to moving stripes. Electroretinographic (ERG) recordings revealed that mutants had severely reduced a- and b-wave amplitudes relative to wild-type fish, indicating outer retinal dysfunction. Retinal lamination and cellular differentiation were normal in the lze retina; however, mutant photoreceptor cells had small outer segments and pyknotic nuclei were occasionally observed in the outer retina and the marginal zone of lze. Cone, rod, amacrine, bipolar, and Müller cell marker analyses indicated that the typical lze retina contained fewer rod photoreceptors and fewer Müller cells than wild-type fish at 5 dpf. At 3 dpf, however, mutant retinas had normal numbers of rod photoreceptors and Müller cells, suggesting that the initial differentiation of these cell types occurred normally. Rod photoreceptor histology was normal at this early stage, but Müller cells were often hypertrophied, suggesting that they were unhealthy. Constant light rearing of mutant animals accelerated the Müller cell degeneration, severely worsened the visual deficit, but had no obvious affect on the photoreceptors. When ERG responses and Müller cell degeneration from the same mutant animals were analyzed, the extent of the Müller cell loss matched closely the degree to which ERG responses were reduced. In summary, the lze gene appears to be required for Müller cell viability and normal visual function. The lze mutant may be a model for the study of the involvement of Müller cells in photoreceptor development and function.     

Follicular lesions of the thyroid: a retrospective study of 1,348 fine needle aspiration biopsies

Fine needle aspiration (FNA) has proven to be an effective tool in management of patients with thyroid nodules. However, the diagnosis of follicular patterned lesions can be challenging. The surgical and cytopathology computer database at a large referral medical center was searched for cases that had both cytologic and histologic thyroid accessions from January 2004 to November 2008. A total of 1,255 histologic thyroid specimens and 2,776 thyroid FNA biopsies were retrieved for review. Histologically, 272 overt malignancies were identified; 20 (7.4%) were follicular carcinomas. Cytologically, 1,348 cases were follicular-patterned lesions, comprising 1,044 cases of "benign follicular nodules" (BFN), 137 cases of "follicular lesions of undetermined significance" (FLUS), and 167 cases of "suspicious for follicular neoplasm" (SFN). Seventy-nine (7.5%) of BFN, 23 (16.8%) of FLUS, and 65 (38.9%) of SFN cases had histologic follow-up. Overt malignancy, a cystic papillary carcinoma, was identified histologically in only one case of BFN, for a negative predictive value of 98.7%. Overt malignancy was identified histologically in two cases of FLUS, both follicular variant of papillary carcinoma, for a positive predictive value of 8.7%. Overt malignancy was identified histologically in 14 cases of SFN, for a positive predictive value of 21.5%. Five follicular carcinomas were identified histologically in the SFN category, all minimally invasive. Incidental ("occult") papillary microcarcinoma were identified histologically in all three categories. In this study, the risk of overt malignancy increases from 1.3%, to 8.7%, to 21.5% for BFN, FLUS, and SFN, respectively. All follicular carcinomas identified histologically occurred in the SFN category and all were minimally invasive. Papillary microcarcinomas can occur in any of the three diagnostic categories.     

A role for thymic stromal lymphopoietin in CD4(+) T cell development

Thymic stromal lymphopoietin (TSLP) signals via a receptor comprising the interleukin (IL)-7 receptor alpha chain and a distinctive subunit, TSLP receptor (TSLPR), which is most related to the common cytokine receptor gamma chain, gamma(c). We have generated TSLPR knockout (KO) mice and found that although these mice had normal lymphocyte numbers, gamma(c)/TSLPR double KO mice had a greater lymphoid defect than gamma(c) KO mice. This indicates that TSLP contributes to lymphoid development and accounts for some of the residual lymphoid development in gamma(c) KO mice and presumably in patients with X-linked severe combined immunodeficiency. Injection of TSLP into gamma(c) KO mice induced the expansion of T and B cells. Moreover, sublethally irradiated TSLPR KO mice showed weaker recovery of lymphocyte populations than wild-type (WT) littermates, even when neutralizing anti-IL-7 antibodies were injected. Interestingly, TSLP preferentially stimulated the proliferation and survival of CD4(+) single positive thymocytes and peripheral T cells in vitro. Additionally, CD4(+) T cells from TSLPR KO mice expanded less efficiently than WT CD4(+) T cells in irradiated hosts, and TSLP preferentially expanded CD4(+) T cells both in vitro and in vivo. Thus, as compared with other known cytokines, TSLP is distinctive in exhibiting a lineage preference for the expansion and survival of CD4(+) T cells.     

Synchronous Occurrence of Medullary and Papillary Carcinoma of the Thyroid in a Patient with Cutaneous Melanoma: Determination of BRAFV600E in Peripheral Blood and Tissues. Report of a Case and Review of the Literature

The purpose of this study is to describe a case of concurrent medullary and papillary thyroid carcinoma (MTC and PTC) and cutaneous melanoma and to analyze BRAF^V600E mutation in plasma and tissues. We report the clinical history and the laboratory, imaging, and histopathological findings of a 47-year-old man affected by multinodular goiter. BRAF^V600E-mutated DNA was quantified in plasma samples and in cancer sections by quantitative real-time polymerase chain reaction (qPCR). At ultrasound examination, the dominant right nodule of the thyroid was weakly hyperechoic and hypervascularized, while the left one was hypoechoic without internal vascularization. Regional lymphadenomegalia was not detected. Basal plasma calcitonin was elevated, and the patient underwent total thyroidectomy and resection of central cervical lymph nodes. Histopathological examination identified two distinct foci of MTC and PTC and micrometastasis of well-differentiated carcinoma in one of the six resected lymph nodes. RET proto-oncogene germline mutations were not detected. Cutaneous melanoma of the thorax was subsequently diagnosed. BRAF^V600E tissue DNA was detected in PTC and melanoma but not in MTC. The cell-free plasma percentage of BRAF^V600E DNA was detected in pre-thyroidectomy peripheral blood and was drastically reduced after cancer treatments. This study confirms the occurrence of synchronous MTC and PTC and is the first evidence of the co-existence of melanoma and distinct thyroid cancers of different origin. BRAF^V600E allele was detected in PTC and melanoma but not in MTC tissues. BRAF^V600E molecular quantification in pre- and post-treatment blood supports our previous data, suggesting its possible role in diagnosis and follow-up of BRAF-positive tumors.