702 research outputs found
Performance of p16INK4a ELISA as a primary cervical cancer screening test among a large cohort of HIV-infected women in western Kenya: a 2-year cross-sectional study.
ObjectiveA biomarker with increased specificity for cervical dysplasia compared with human papillomavirus (HPV) testing would be an attractive option for cervical cancer screening among HIV-infected women in resource-limited settings. p16(INK4a) has been explored as a biomarker for screening in general populations.DesignA 2-year cross-sectional study.Setting2 large HIV primary care clinics in western Kenya.Participants1054 HIV-infected women in western Kenya undergoing cervical cancer screening as part of routine HIV care from October 2010 to November 2012.InterventionsParticipants underwent p16(INK4a) specimen collection and colposcopy. Lesions with unsatisfactory colposcopy or suspicious for cervical intraepithelial neoplasia 2+ (CIN2+; including CIN2/3 or invasive cervical cancer) were biopsied. Following biopsy, disease status was determined by histopathological diagnosis.Primary and secondary outcome measuresWe measured the sensitivity, specificity and predictive values of p16(INK4a) ELISA for CIN2+ detection among HIV-infected women and compared them to the test characteristics of current screening methods used in general as well as HIV-infected populations.ResultsAverage p16(INK4a) concentration in cervical samples was 37.4 U/mL. After colposcopically directed biopsy, 127 (12%) women were determined to have CIN2+. Receiver operating characteristic analysis showed an area under the curve of 0.664 for p16(INK4a) to detect biopsy-proven CIN2+. At a p16(INK4a) cut-off level of 9 U/mL, sensitivity, specificity, positive and negative predictive values were 89.0%, 22.9%, 13.6% and 93.8%, respectively. The overall p16(INK4a) positivity at a cut-off level of 9 U/mL was 828 (78.6%) women. There were 325 (30.8%) cases of correct p16(INK4a) prediction to detect or rule out CIN2+, and 729 (69.2%) cases of incorrect p16(INK4a) prediction.Conclusionsp16(INK4a) ELISA did not perform well as a screening test for CIN2+ detection among HIV-infected women due to low specificity. Our study contributes to the ongoing search for a more specific alternative to HPV testing for CIN2+ detection
Efecto de la combinación de técnicas de establecimiento sobre el crecimiento inicial de Grevillea robusta A. Cunn. = Effect of establishment technique combinations on initial growth of Grevillea robusta A. Cunn.
El efecto de la combinación de técnicas de establecimiento se evaluó sobre el crecimiento inicial de Grevillea robusta, en el norte de la provincia de Corrientes, Argentina. Los tratamientos incluyeron la combinación de dos factores. El primero de ellos aplicado previo a la plantación de G. robusta y consistió en el manejo de residuos con dos niveles: a) conservación de residuos y b) quema de residuos. El segundo factor consistió en la aplicación de fertilizante con tres niveles: a) sin aplicación de fertilizante, b) aplicación de fertilizante luego del establecimiento de la plantación y, c) aplicación de fertilizante después de un año del establecimiento de la plantación. La combinación de técnicas de establecimiento de la plantación modificó el crecimiento inicial de G. robusta. La mejor combinación fue la quema de residuos con fertilización durante el establecimiento. Con dicha combinación, la plantación logró un incremento en diámetro de 43.7 % a los 36 meses de edad, siendo superior que el obtenido con el tratamiento de conservación de residuos sin aplicación de fertilizante.The effect of establishment technique combinations on initial growth of Grevillea robusta was evaluated in the northern area of the province of Corrientes, Argentina. The treatments included the combination of two factors. The first one was applied previous to planting G. robusta and consisted of slash management with two levels: a) slash conservation and, b) slash burning. The second factor consisted of fertilizer application with three levels: a) unfertilized, b) fertilized after plantation establishment and, c) fertilized a year after plantation establishment. The plantation establishment technique combinations changed the initial growth of G. robusta. The best combination was slash burning with fertilization during establishment. With this combination, the plantation achieved a 43.7 % increase in diameter at 36 months of age, which was superior to that obtained with the slash conservation with no fertilization treatment.EEA MontecarloFil: Martiarena, Rodolfo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Montecarlo; ArgentinaFil: Von Wallis, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Montecarlo; ArgentinaFil: Fernandez, Roberto Anibal. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Montecarlo; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; ArgentinaFil: Knebel, Otto Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Montecarlo; Argentin
ESR of YbRh2Si2 and 174YbRh2Si2 : local and itinerant properties
Below the Kondo temperature the heavy Fermion compound YbRhSi
shows a well defined Electron Spin Resonance (ESR) with local Yb
properties. We report a detailed analysis of the ESR intensity which gives
information on the number of ESR active centers relative to the ESR of well
localized Yb in YPd:Yb. The ESR lineshape is investigated regarding
contributions from itinerant centers. From the ESR of monoisotopic
YbRhSi we could exclude unresolved hyperfine contributions
to the lineshape.Comment: 3 Figure
Computed tomography for myocardial characterization in ischemic heart disease:a state-of-the-art review
This review provides an overview of the currently available computed tomography (CT) techniques for myocardial tissue characterization in ischemic heart disease, including CT perfusion and late iodine enhancement. CT myocardial perfusion imaging can be performed with static and dynamic protocols for the detection of ischemia and infarction using either single- or dual-energy CT modes. Late iodine enhancement may be used for the analysis of myocardial infarction. The accuracy of these CT techniques is highly dependent on the imaging protocol, including acquisition timing and contrast administration. Additionally, the options for qualitative and quantitative analysis and the accuracy of each technique are discussed
Frameshift mutations in coding repeats of protein tyrosine phosphatase genes in colorectal tumors with microsatellite instability
<p>Abstract</p> <p>Background</p> <p>Protein tyrosine phosphatases (PTPs) like their antagonizing protein tyrosine kinases are key regulators of signal transduction thereby assuring normal control of cellular growth and differentiation. Increasing evidence suggests that mutations in PTP genes are associated with human malignancies. For example, mutational analysis of the tyrosine phosphatase (PTP) gene superfamily uncovered genetic alterations in about 26% of colorectal tumors. Since in these studies tumors have not been stratified according to genetic instability status we hypothesized that colorectal tumors characterized by high-level of microsatellite instability (MSI-H) might show an increased frequency of frameshift mutations in those PTP genes that harbor long mononucleotide repeats in their coding region (cMNR).</p> <p>Results</p> <p>Using bioinformatic analysis we identified 16 PTP candidate genes with long cMNRs that were examined for genetic alterations in 19 MSI-H colon cell lines, 54 MSI-H colorectal cancers, and 17 MSI-H colorectal adenomas. Frameshift mutations were identified only in 6 PTP genes, of which PTPN21 show the highest mutation frequency at all in MSI-H tumors (17%).</p> <p>Conclusion</p> <p>Although about 32% of MSI-H tumors showed at least one affected PTP gene, and cMNR mutation rates in PTPN21, PTPRS, and PTPN5 are higher than the mean mutation frequency of MNRs of the same length, mutations within PTP genes do not seem to play a common role in MSI tumorigenesis, since no cMNR mutation frequency reached statistical significance and therefore, failed prediction as a Positive Selective Target Gene.</p
Non Fermi Liquid behavior in the under-screened Kondo model
Using the Schwinger boson spin representation, we reveal a new aspect to the
physics of a partially screened magnetic moment in a metal, as described by the
spin Kondo model. We show that the residual ferromagnetic interaction
between a partially screened spin and the electron sea destabilizes the Landau
Fermi liquid, forming a singular Fermi liquid with a divergence in the low temperature specific heat coefficient
. A magnetic field tunes this system back into Landau Fermi liquid
with a Fermi temperature proportional to . We discuss a
possible link with field-tuned quantum criticality in heavy electron materials.Comment: References corrected. Minor changes to tex
Itinerant metamagnetism of CeRu2Si2 : bringing out the dead. Comparison with the new Sr3Ru2O7 case
Focus is given on the macroscopic and microscopic experimental works realized
during a decade on the clear case of itinerant metamagnetism in the heavy
fermion paramagnetic compound CeRu2Si2 . Emphasis is made on the feedback
between the band structure, the exchange coupling and the lattice instability.
Sweeps in magnetic field, pressure and temperature feel the pseudogap of this
strongly correlated electronic system as well as its equivalent CeRu2Ge2 at a
fictitious negative pressure. Some mysteries persist as the complete
observation of the FS above the metamagnetic field HM and the detection of the
dynamical ferromagnetic fluctuation near HM. The novelty of the bilayer
ruthenate Sr3Ru2O7 is discussed by comparison. Despite differences in spin and
electronic dimensionality many common trends emerge.Comment: 14 pages, 9 figure
Specific Heat Study of Non-Fermi Liquid Behavior in CeNi_2Ge_2: Anomalous Peak in Quasi-Particle Density-of-States
To investigate the non-Fermi liquid (NFL) behavior in a nonalloyed system
CeNi_2Ge_2, we have measured the temperature and field dependences of the
specific heat C on a CeNi_2Ge_2 single crystal. The distinctive temperature
dependence of C/T (~a-b*T^(1/2)) is destroyed in almost the same manner for
both field directions of B//c-axis and B//a-axis. The overall behavior of
C(T,B) and the low-temperature upturn in magnetic susceptibility can be
reproduced, assuming an anomalous peak of the quasi-particle-band
density-of-states (DOS) at the Fermi energy possessing (epsilon)^(1/2) energy
dependence. Absence of residual entropy around T=0 K in B~0 T has been
confirmed by the magnetocaloric effect measurements, which are consistent with
the present model. The present model can also be applied to the NFL behavior in
CeCu_{5.9}Au_{0.1} using a ln(epsilon)-dependent peak in the DOS. Possible
origins of the peak in the DOS are discussed.Comment: 4 pages, LaTeX, using jpsj.sty, to be published in J. Phys. Soc. Jpn.
66 No. 10 (1997), 7 figures available at
http://494-475.phys.metro-u.ac.jp/ao/ceni2ge2.htm
Prevalence of Human Papillomavirus infection by age and cervical cytology in Thika, Kenya
Human papillomavirus (HPV) infections cause cervical cancer and premalignant dysplasia. Data on HPV and cervical cancer in Kenya are scarce. Type-specific HPV prevalence data provides a basis for assessing the impact of HPV vaccination programs on cervical cytology and how HPV based screening will influence cervical cancer prevention. To investigate HPV infections in a population in Kenya, we obtained cervical cells specimen from 498 women in a population in Thika district. We report HPV type specific prevalence and distribution data for 498 women (age range 18-74 years; mean age 36 years) recruited into the study in relation to age and cervical cytology. The study was conducted between January to May 2010. Pap smears were performed, HR HPV DNA were detected by Digene Hybrid capture 2® (hc2) test and HPV genotyping was performed with Multiplex Luminex HPV genotyping kit (Multimetrix, Progen, Germany). Samples from 106 women (21.3%) tested positive for HPV. Multiple HPV types were detected in 40 (37.7% of HC2-positive samples) and the rest had infection with single HPV type. The most common HR HPV type at all ages was HPV16, 52, 56, 66, and 18. There was a marked decline in the prevalence of HR-HPV with age.
The pattern of HR HPV distribution in this population was slightly different from existing literature, which has important consequences for HPV vaccination and prevention programs
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