Magnetic field generated resistivity maximum in graphite

In zero magnetic field, B, the electrical resistivity, rho(O,T) of highly oriented pyrolytic (polycrystalline) graphite drops smoothly with decreasing T, becoming constant below 4 K. However, in a fixed applied magnetic field B, the resistivity rho(B,T) goes through a maximum as a function of T, with larger maximum for larger B. The temperature of the maximum increases with B, but saturates to a constant value near 25 K (exact T depends on sample) at high B. In single crystal graphite a maximum in rho(B,T) as a function of T is also present, but has the effects of Landau level quantization superimposed. Several possible explanations for the rho(B,T) maximum are proposed, but a complete explanation awaits detailed calculations involving the energy band structure of graphite, and the particular scattering mechanisms involved

Large needle aspiration biopsy and galectin-3 determination in selected thyroid nodules with indeterminate FNA-cytology

Thyroid fine-needle aspiration biopsy (FNA)-cytology is widely used for the preoperative characterisation of thyroid nodules but this task is difficult for follicular lesions, which often remain undefined. We propose a strategy for improving the preoperative characterisation of selected follicular thyroid proliferations, which is based on large needle aspiration biopsy (LNAB) and galectin-3 expression analysis. Eighty-five thyroid specimens were obtained by LNAB (20-gauge needles) from thyroid nodules with indeterminate follicular FNA-cytology. Aspirated material was processed as a tissue microbiopsy to obtain cell blocks for both cyto/histo-morphological evaluation and galectin-3 expression analysis, by using a purified monoclonal antibody to galectin-3 and a biotin-free immunoperoxidase staining method. Preoperative diagnosis was compared to the final histology. LNAB and cell-block technique allow a preliminary distinction between nodules with a homogeneous microfollicular/trabecular structure, as frequently observed in tumours, and lesions with mixed normo–micro–macrofollicular architecture, as observed in goitre. Furthermore, LNAB provides optimal substrates for galectin-3 expression analysis. Among 85 cases tested, 14 galectin-3-positive cases were discovered preoperatively (11 thyroid cancers and three adenomas confirmed at the final histology), whereas galectin-3-negative cases were 71 (one carcinoma and 70 benign proliferations at the final histology). Sensitivity, specificity and diagnostic accuracy of this integrated morphologic and phenotypic diagnostic approach were 91.6, 97.2 and 95.3%, respectively. In conclusion, LNAB plus galectin-3 expression analysis when applied preoperatively to selected thyroid nodules candidate to surgery can potentially reduce unnecessary thyroid resections

Romosozumab reduces incidence of new vertebral fractures across severity grades among postmenopausal women with osteoporosis

Vertebral fractures (VFs) are the most common type of osteoporotic fracture, and their prevalence and severity are key risk factors for future fragility fractures. Here, we assess the treatment effect of romosozumab on the incidence of new on-study VFs according to Genant severity grades (mild, moderate, and severe). Data are reported from two phase 3 clinical studies for patients who received romosozumab versus placebo through 12 months, followed by denosumab through 24 months (FRAME: NCT01575834), and for patients who received romosozumab through 12 months, followed by alendronate through 24 months, versus alendronate only through 24 months (ARCH: NCT01631214). The treatment effect of romosozumab is reported for all included patients, and for patients with prevalent and severe baseline VFs. The incidence of new moderate-or-severe VFs was reduced through 12 months for patients treated with romosozumab versus placebo (FRAME; 0.25% versus 1.42%, respectively; p < 0.001) or alendronate (ARCH; 2.78% versus 4.00%, respectively; p = 0.042). Furthermore, the treatment effect of romosozumab on the incidence of new VFs across moderate and severe severity grades was independent of baseline VF prevalence or severity; through 12 months, consistent reductions in new moderate-or-severe VFs were observed regardless of prevalent (FRAME; p = 0.18) or severe (ARCH; p = 0.52) VFs at baseline. Reductions in the incidence of new moderate and severe VFs were sustained through 24 months, after transition from romosozumab to denosumab or alendronate, independent of baseline VF prevalence or severity; no significant interactions were observed between the incidence of new moderate-or-severe VFs and the presence of prevalent (FRAME; p = 0.81) or severe (ARCH; p = 0.99) VFs at baseline. With increasing recommendations for initial treatment with bone-forming agents for postmenopausal women with osteoporosis, these analyses will help to inform treatment decisions for patients at very high risk of VF

Gene expression in papillary thyroid carcinoma reveals highly consistent profiles

Papillary thyroid carcinoma (PTC) is clinically heterogeneous. Apart from an association with ionizing radiation, the etiology and molecular biology of PTC is poorly understood. We used oligo-based DNA arrays to study the expression profiles of eight matched pairs of normal thyroid and PTC tissues. Additional PTC tumors and other tissues were studied by reverse transcriptase–PCR and immunohistochemistry. The PTCs showed concordant expression of many genes and distinct clustered profiles. Genes with increased expression in PTC included many encoding adhesion and extracellular matrix proteins. Expression was increased in 8/8 tumors for 24 genes and in 7/8 tumors for 22 genes. Among these genes were several previously known to be overexpressed in PTC, such as MET, LGALS3, KRT19, DPP4, MDK, TIMP1, and FN1. The numerous additional genes include CITED1, CHI3L1, ODZ1, N33, SFTPB, and SCEL. Reverse transcriptase–PCR showed high expression of CITED1, CHI3L1, ODZ1, and SCEL in 6/6 additional PTCs. Immunohistochemical analysis detected CITED1 and SFTPB in 49/52 and 39/52 PTCs, respectively, but not in follicular thyroid carcinoma and normal thyroid tissue. Genes underexpressed in PTC included tumor suppressors, thyroid function-related proteins, and fatty acid binding proteins. Expression was decreased in 7/8 tumors for eight genes and decreased in 6/8 tumors for 19 genes. We conclude that, despite its clinical heterogeneity, PTC is characterized by consistent and specific molecular changes. These findings reveal clues to the molecular pathways involved in PTC and may provide biomarkers for clinical use