Revalidation of PET/computed tomography criteria (Hopkins criteria) for the assessment of therapeutic response in lung cancer patients: inter-reader reliability, accuracy and survival outcomes

BACKGROUND/AIM: Systematic reporting using qualitative evaluation of PET/computed tomography (CT) results has been demonstrated to be very accurate and reproducible in posttherapy assessment of lung cancer (so-called Hopkins criteria). Our aim was to test, in a different cohort of patients, the Hopkins criteria for assessment of therapeutic response in lung cancer and to compare the results with those obtained using a semi-quantitative evaluation of uptake. METHODS: This is a retrospective study. A total of 85 patients with known lung cancer who underwent fluorine-18 fluorodeoxyglucose PET/CT assessment within 24 weeks (mean 7.9 weeks) of completion of treatment were included. Treatments included surgical resection, chemotherapy, radiation therapy, immunotherapy or combinations thereof. PET/CT interpretation was done by two nuclear medicine physicians, and discrepancies were resolved by a third interpreter. Studies were scored both according to the Hopkins criteria using qualitative assessment of tracer uptake for the primary tumour, locoregional disease in the mediastinum and distant metastatic sites and by applying the same five-point score using a semi-quantitative measure, maximum standardized uptake value. Overall scores of 1, 2 and 3 were considered negative for residual disease, while scores of 4 and 5 were considered positive. Patients were followed up for a median of 18.5 months (range 2-139 months). Kaplan-Meier plots with a Mantel-Cox log-rank test were performed, considering death as the endpoint. Inter-reader variability was assessed using percent agreement and kappa statistics. RESULTS: The Cohen κ coefficient analysis showed substantial agreement between the two interpreters on the five-point Hopkins criteria scoring, with a κ of 0.73. There was almost perfect agreement between the interpreters with respect to classification as positive or negative according to the Hopkins criteria, with a κ of 0.89. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the Hopkins criteria were 88.5% [95% confidence interval (CI) 80.6-96.5%), 79.2% (95% CI 63.2-95.1%), 91.5% (95% CI 84.4-98.6%), 73.1% (95% CI 61.8-84.4%) and 85.9% (95% CI 78.5-93.3%), respectively. There was almost perfect agreement between the qualitative and semi-quantitative scoring with a κ of 0.87, with sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the semi-quantitative Hopkin's criteria of 86.9% (95% CI 78.4-95.4%), 79.2% (95% CI 62.9-95.4%), 91.4% (95% CI 84.2-98.6%), 70.4% (95% CI 58.6-82.1%) and 84.7% (95% CI 80.8-92.4%), respectively. CONCLUSION: The use of Hopkins criteria for posttherapy assessment in patients with lung cancer represents an easy and reproducible method with substantial to almost perfect interobserver agreement and high positive predictive value and accuracy; moreover, it is easily understood by referring physicians. Additionally, there was no significant difference when applying a semi-quantitative measure to the same five-point score

Paleomagnetism of the Cambro-Ordovician McClure Mountain alkalic complex, Colorado

The Middle to Late Cambrian loop in the North American apparent polar wander path (APWP) has been variously attributed to tectonic rotations, remagnetizations and primary magnetizations. Although no primary thermal remanent magnetizations or primary detrital remanent magnetizations have as yet been demonstrated, the temporally self-consistent nature of the loop has been used as an argument for primary magnetizations. We have studied 535 +/- 5 Ma nepheline syenites and syenites of the McClure Mountain alkalic complex, as well as 495 +/- 10 Ma red trachyte dikes which intruded the complex, in an effort to find a primary TRM. Because Zijderveld analysis yielded consistent results for only one trachyte dike, remagnetization great-circle analysis was employed, giving a pole for the trachyte dikes at the tip of the loop (43[deg]N, 114[deg]E), while the syenites and nepheline synenites gave a pole at the base of the loop (18[deg]N, 142[deg]E). The magnetic carrier in the trachytes is hematite which apparently formed during a pervasive hydrothermal alteration. K---Ar whole rock dating of the trachytes suggests a Pennsylvanian age for the alteration, and thus a late Paleozoic remagnetization of the trachytes. Thus, the low-latitude Cambrian pole is confirmed, but we find no evidence in this study to support the primary nature of the Cambrian APWP.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24648/1/0000061.pd

Reply to a comment on ‘‘A case for a comet impact trigger for the Paleocene/Eocene thermal maximum and carbon isotope excursion’’ by G.R. Dickens and J.M. Francis

Contrary to Dickens and Francis’s claim that we ‘challenge the idea of a massive CH4 re- lease during the PETM (Paleocene/Eocene thermal maximum)’, our consideration of an extraterrestrial carbon contribution to the carbon isotope excursion (CIE) is specifically limited to the initial and most rapid decrease in N13C, which accounts for less than half of the full magnitude of the CIE. Thermal dissociation in response to the warm- ing at the PETM is explicitly allowed in our hypothesis, as reiterated in our conclusions that the impact ‘may have triggered a more gradual thermal dissociation of seafloor methane hydrates’. We directly challenge only that portion of the hydrate dissociation hypothesis that relies on gradual warming intrinsic to Earth’s climate system as the triggering mechanism. Such a mechanism is not consistent with the documented essentially synchronous and instantaneous warming and decrease in N13C values at the onset of the event and is also at odds with the occurrence of the CIE during an interval of low amplitude orbital forcing of climate. Instead, we postulate a comet impact as an explanation for the rapid onset of the event

A case for a comet impact trigger for the Paleocene/Eocene thermal maximum and carbon isotope excursion

We hypothesize that the rapid onset of the carbon isotope excursion (CIE) at the Paleocene/Eocene boundary (V55 Ma) may have resulted from the accretion of a significant amount of 12C-enriched carbon from the impact of a V10 km comet, an event that would also trigger greenhouse warming leading to the Paleocene/Eocene thermal maximum and, possibly, thermal dissociation of seafloor methane hydrate. Indirect evidence of an impact is the unusual abundance of magnetic nanoparticles in kaolinite-rich shelf sediments that closely coincide with the onset and nadir of the CIE at three drill sites on the Atlantic Coastal Plain. After considering various alternative mechanisms that could have produced the magnetic nanoparticle assemblage and by analogy with the reported detection of iron-rich nanophase material at the Cretaceous/Tertiary boundary, we suggest that the CIE occurrence was derived from an impact plume condensate. The sudden increase in kaolinite is thus thought to represent the redeposition on the marine shelf of a rapidly weathered impact ejecta dust blanket. Published reports of a small but significant iridium anomaly at or close to the Paleocene/Eocene boundary provide supportive evidence for an impact

Paleomagnetism and the orocline hypothesis

Oroclines were originally defined by Carey as curved mountain belts which initially were straight, or at least straighter than they are today. In the last few years, the definition has been broadened to include any curved mountain belt, regardless of its original shape.Since the occurrence of oroclinal bending is best recorded in the change of declination as a function of tectonic setting, paleomagnetic and structural data from six potential oroclines have been compiled and analyzed to determine the amount of rotation displayed by the change of paleomagnetic declination relative to the change in strike of the fold belt.The arcuate belts investigated are: the Sicilian-Calabrian Arc and the Umbrian Arc of Italy, the Swiss portion of the Jura Mountains, the central portion of the Appalachian Mountains (from Pennsylvania to Virginia, U.S.A.), the Wyoming-Idaho overthrust belt of western North America and the Hercynides of Western and Central Europe.The Jura Mountains and the Pennsylvania-Virginia portion of the Appalachians fail to show significant oroclinal bending. The Wyoming-Idaho belt shows a combination of rotated (possibly oroclinal) and unrotated thrust sheets.In the Sicilian-Calabrian Arc significant oroclinal bending caused by the impingement of the Calabria-Peloritani nappes in the Late Tertiary can be demonstrated, while the Umbrian Arc of similar age, in the Northern Apennines, also shows oroclinal bending on a smaller scale.Hercynian Europe (the only belt included in which deformation of basement rocks can be demonstrated) shows oroclinal bending (at least 80[deg]) as well as a marked original curvature (70[deg]) in its western part.Common to all the oroclines studied in this paper is the probable impingement of a rigid block or continental margin during the orogeny, causing subsequent deformation and bending of the fold belt.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25531/1/0000072.pd

Application of Reflected Global Navigation Satellite System (GNSS-R) Signals in the Estimation of Sea Roughness Effects in Microwave Radiometry

In February-March 2009 NASA JPL conducted an airborne field campaign using the Passive Active L-band System (PALS) and the Ku-band Polarimetric Scatterometer (PolSCAT) collecting measurements of brightness temperature and near surface wind speeds. Flights were conducted over a region of expected high-speed winds in the Atlantic Ocean, for the purposes of algorithm development for salinity retrievals. Wind speeds encountered were in the range of 5 to 25 m/s during the two weeks deployment. The NASA-Langley GPS delay-mapping receiver (DMR) was also flown to collect GPS signals reflected from the ocean surface and generate post-correlation power vs. delay measurements. This data was used to estimate ocean surface roughness and a strong correlation with brightness temperature was found. Initial results suggest that reflected GPS signals, using small low-power instruments, will provide an additional source of data for correcting brightness temperature measurements for the purpose of sea surface salinity retrievals

Interlayer pair tunneling and gap anisotropy in YBa2_2Cu3_3O7−δ_{7-\delta}

Recent ARPES measurement observed a large $ab$-axis gap anisotropy, $\Delta(0,\pi)/\Delta(\pi,0)=1.5$, in clean YBa$_2$Cu$_3$O$_{7-\delta}$. This indicates that some sub-dominant component may exist in the $d_{x^2-y^2}$-wave dominant gap. We propose that the interlayer pairing tunneling contribution can be determined through the investigation of the order parameter anisotropy. Their potentially observable features in transport and spin dynamics are also studied.Comment: 4 pages, 3 figure

Concordant paleomagnetic directions from the Tehuantepec Isthmus: Constraints on the Neogene evolution of the North American-Caribbean plate boundary

We report paleomagnetic data for Miocene igneous rocks of the southeastern Tehuantepec Isthmus region, Mexico. Thermal and alternating field demagnetization reveal predominantly normal polarity magnetization, interpreted as primary TRM. The overall mean direction (Dec = 355.6[deg], Inc = 36.5[deg], K = 36.4, a95 = 9.3[deg], N = 8 sites) is statistically indistinguishable from the expected direction, calculated using the North American reference pole. This result indicates that significant rotation or displacement of the Tehuantepec region relative to the craton has not occurred since 13 Ma.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31328/1/0000237.pd

Discordant Silurian paleolatitudes for central Newfoundland: New paleomagnetic evidence from the Springdale Group

Ancient remanences are retained by the Early Silurian (429 + 6/-5 Ma) mafic volcanics of the Springdale Caldera (five sites) and the overlying red beds (seven sites). Dual polarity magnetizations are obtained by thermal demagnetization of samples from the red beds, whereas single polarity directions are observed in the volcanics. High unblocking temperatures indicate hematite as the remanence carrier in both the volcanics and sediments. These high-temperature, characteristic remanences are easily isolated and pass both the tilt and conglomerate tests; they are likely to be of primary Silurian age. Characteristic declinations are predominantly northerly and northeasterly, and indicate significant structural rotations on a local scale. When the results of the red beds and the volcanics are combined they show characteristic inclinations that are shallower than those of the correlative Botwood Group (ca. 36[deg] vs. 43[deg]) but not nearly as shallow as those reported from the King George IV Lake area (0.5[deg]). Mean inclinations obtained from the Springdale red beds are, however, significantly shallower than those of the Springdale volcanics. The same difference can be seen in other previous Silurian paleomagnetic studies of central Newfoundland. We infer that an inclination error affects the red bed magnetizations of the Springdale Group, Botwood Group (Wigwam Formation) and rocks of the King George IV Lake area. Therefore, the results from Silurian red beds should not be used to determine paleolatitudes for central Newfoundland. The mean paleolatitude of the Springdale Group volcanics is 30[deg]. The mean paleolatitudes for both the Springdale volcanics and Botwood volcanics (Lawrenceton Formation) are indistinguishable within paleomagnetic error limits from the predicted paleolatitude of Newfoundland on the northeast-trending North American margin. Thus, no detectable post-Silurian displacement is shown by the volcanics of the Springdale Group with respect to cratonic North America.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30456/1/0000084.pd

Molecular characteristics of infection and colonization isolates of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA)

Staphylococcus aureus is a gram-positive coccus that colonizes the skin and mucous membranes, particularly the anterior nares. Recently, community-acquired MRSA (CA-MRSA) has emerged as a cause of skin and soft-tissue infections in healthy individuals. These strains are sensitive to antimicrobials, carry genes for Panton-Valentine leukocidin (PVL) toxin, and feature the staphylococcal cassette chromosome mec (SCCmec) type IV or V. The suspected mode of transmission involves close contact with carriers, leading to skin or nasal colonization that results in subsequent active infection. This study was undertaken to determine the molecular characteristics of CA-MRSA isolates in children presenting with wound infections at Likas Hospital, Sabah, Malaysia, and the possible mode of transmission. The results showed that the majority of CA-MRSA infection isolates were from scalp abscesses (49%) in 1–5-year-old children (70%) in the Filipino (54%) community. The presence of the mec gene was detected in all isolates and the PVL virulence factor was found in 92% of the isolates. SCCmec typing revealed that 57% of the isolates were untypable, 35% harbored the SCCmecIVa element, and one each had SCCmecIVc, SCCmecV, or SCCmecII. Sixteen S. aureus strains were isolated from nasal swabs in 19 family members of index patients. Fourteen of these cultures were positive for catalase, coagulase, and DNAase. All of the colonization isolates carried the mecA gene and only a third were positive for the PVL toxin. SCCmec typing showed that 79% of the isolates were untypable and two had SCCmecIVa element and one had SCCmecV element. When five pairs of infection and colonizing isolates were compared by spa typing, only two pairs showed identical spa type with possible transmission between the patient and family contact. Further studies are necessary to establish CA-MRSA transmission by performing multiple-site cultures multiple times instead of one-time naresonly sample collection