3,438 research outputs found
Value of SPET/CT image fusion in the assessment of neuroendocrine tumours with 111In-pentetreotide scintigraphy
OBJECTIVE: The purpose of this study was to evaluate the impact and clinical value of anatomical-functional image fusion in the study interpretation and clinical management of patients with neuroendocrine tumours (NET) using somatostatin receptor scintigraphy (SRS) and combined transmission and emission tomography -- single-photon emission tomography/CT (SPET/CT).
MATERIAL AND METHODS: Twelve patients (8 female and 4 male; age range 32-74 y, mean 56 y) with proven or clinically suspected NET were studied with routine planar SRS and SPET/CT at 2 and 24 hours after injection of 111-222 MBq 111In-Pentetreotide. Seven patients came for staging/follow-up and 5 patients for primary tumour localization with staging. Analysis of fused images (SPET/CT) was done on a patient basis, with separated evaluation of SPET, low-dose CT images and fusion images. The gold standard for presence or absence of malignancy was pathology or clinical and imaging follow-up data.
RESULTS: SRS was negative in 6 patients and positive in 6. SPET/CT provided no additional information in 6 patients, including all 6 negative studies. SPET/CT improved localization of SPET detected lesions in 6 positive studies. It defined the extent of the disease and showed bone involvement in 3 of the 6 positive studies. SPET/CT affected the diagnostic interpretation in 6 patients (50 %) and induced changes of management in 3 (25 %).
CONCLUSION: The results of this study indicate that combined anatomical-functional imaging with SPET/CT significantly improves tumour localization and characterization, contributing to a better therapeutic management of patients with NET
Recommended from our members
Oncogenic Gain of Function in Glioblastoma Is Linked to Mutant p53 Amyloid Oligomers.
Tumor-associated p53 mutations endow cells with malignant phenotypes, including chemoresistance. Amyloid-like oligomers of mutant p53 transform this tumor suppressor into an oncogene. However, the composition and distribution of mutant p53 oligomers are unknown and the mechanism involved in the conversion is sparse. Here, we report accumulation of a p53 mutant within amyloid-like p53 oligomers in glioblastoma-derived cells presenting a chemoresistant gain-of-function phenotype. Statistical analysis from fluorescence fluctuation spectroscopy, pressure-induced measurements, and thioflavin T kinetics demonstrates the distribution of oligomers larger than the active tetrameric form of p53 in the nuclei of living cells and the destabilization of native-drifted p53 species that become amyloid. Collectively, these results provide insights into the role of amyloid-like mutant p53 oligomers in the chemoresistance phenotype of malignant and invasive brain tumors and shed light on therapeutic options to avert cancer
Muscle strength and mortality while on a liver transplant waiting list
OBJETIVO: Avaliar a força de músculos respiratórios e de mão em pacientes na lista de espera para o transplante de fígado e associá-los a mortalidade. MATERIAIS E MÉTODOS: Foram estudados retrospectivamente 132 pacientes submetidos à avaliação fisioterapêutica de rotina e que esperavam o transplante de fígado. A força dos músculos ventilatórios foi avaliada por meio das pressões inspiratória e expiratória máximas e a força do membro superior por meio de dinamometria. Os pacientes foram divididos em dois grupos: grupo A, com 51 pacientes (14 mulheres, 50,1±12,3 anos) que morreram enquanto estavam na lista de espera e grupo B, com 81 pacientes (31 mulheres, 45,0±3,8 anos) que sobreviveram até o transplante de fígado. Foi utilizado o teste de t de Student com nível de significância de 5%. RESULTADOS: Os valores médios da pressão inspiratória máxima (PImax) dos grupos A e B foram 65,7±28,0 e 77,5±33,8mmHg (p=0,04), respectivamente, e as pressões expiratórias máximas foram 72,9±32,9 e 84,4±33,1mmHg (p=0,07), respectivamente. Os valores médios da força da mão esquerda dos grupos A e B foram 18,5±8,1 e 21,5±10,5kgf (p=0,08), respectivamente, e da força da mão direita foram 20,2±9,7 e 23,5±12,5kgf (p=0,10), respectivamente. CONCLUSÕES: A PImax é menor nos pacientes que morreram enquanto aguardavam o transplante. No mesmo grupo, foi observado que a pressão expiratória máxima e a força da mão direita e esquerda foram menores, apesar de não apresentarem diferenças estatisticamente significante.OBJECTIVE: To evaluate respiratory muscle strength and hand strength in patients on a liver transplant waiting list and to associate these with mortality. METHODS: one hundred and thirty-two patients who underwent routine physical therapy evaluation while waiting for liver transplantation were studied retrospectively. Respiratory muscle strength was assessed by measuring the maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), and upper-limb strength was evaluated by dynamometry. The patients were divided into two groups: group A, consisting of 51 patients (14 females, 50.1±12.3 years) who died while on the waiting list; and group B, consisting of 81 patients (31 females, 45.0±3.8 years) who survived until the time of liver transplant. Student’s t test was used with a 5% significance level. RESULTS: The mean MIP values for groups A and B were 65.7±28.0 and 77.5±33.8mmHg (p=0.04), respectively, and the mean MEP values were 72.9±32.9 and 84.4±33.1mmHg (p=0.07), respectively. The mean values for left-hand strength in groups A and B were 18.5±8.1 and 21.5±10.5kgf (p=0.08), and the mean values for right-hand strength were 20.2±9.7 and 23.5±12.5kgf (p=0.10), respectively. CONCLUSIONS: MIP was lower in the patients who died while waiting for liver transplantation. In the same group, it was observed that the MEP values and right and left-hand strength were numerically lower, although they did not reach statistically significant differences
Heterogeneities in leishmania infantum infection : using skin parasite burdens to identify highly infectious dogs
Background: The relationships between heterogeneities in host infection and infectiousness (transmission to arthropod vectors) can provide important insights for disease management. Here, we quantify heterogeneities in Leishmania infantum parasite numbers in reservoir and non-reservoir host populations, and relate this to their infectiousness during natural infection. Tissue parasite number was evaluated as a potential surrogate marker of host transmission potential.
Methods: Parasite numbers were measured by qPCR in bone marrow and ear skin biopsies of 82 dogs and 34 crab-eating foxes collected during a longitudinal study in Amazon Brazil, for which previous data was available on infectiousness (by xenodiagnosis) and severity of infection.
Results: Parasite numbers were highly aggregated both between samples and between individuals. In dogs, total parasite abundance and relative numbers in ear skin compared to bone marrow increased with the duration and severity of infection. Infectiousness to the sandfly vector was associated with high parasite numbers; parasite number in skin was the best predictor of being infectious. Crab-eating foxes, which typically present asymptomatic infection and are non-infectious, had parasite numbers comparable to those of non-infectious dogs.
Conclusions: Skin parasite number provides an indirect marker of infectiousness, and could allow targeted control particularly of highly infectious dogs
Perspectives on the Trypanosoma cruzi-host cell receptor interaction
Chagas disease is caused by the parasite Trypanosoma cruzi. The critical initial event is the interaction of the trypomastigote form of the parasite with host receptors. This review highlights recent observations concerning these interactions. Some of the key receptors considered are those for thromboxane, bradykinin, and for the nerve growth factor TrKA. Other important receptors such as galectin-3, thrombospondin, and laminin are also discussed. Investigation into the molecular biology and cell biology of host receptors for T. cruzi may provide novel therapeutic targets
The nuclear receptors of Biomphalaria glabrata and Lottia gigantea: Implications for developing new model organisms
© 2015 Kaur et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedNuclear receptors (NRs) are transcription regulators involved in an array of diverse physiological functions including key roles in endocrine and metabolic function. The aim of this study was to identify nuclear receptors in the fully sequenced genome of the gastropod snail, Biomphalaria glabrata, intermediate host for Schistosoma mansoni and compare these to known vertebrate NRs, with a view to assessing the snail's potential as a invertebrate model organism for endocrine function, both as a prospective new test organism and to elucidate the fundamental genetic and mechanistic causes of disease. For comparative purposes, the genome of a second gastropod, the owl limpet, Lottia gigantea was also investigated for nuclear receptors. Thirty-nine and thirty-three putative NRs were identified from the B. glabrata and L. gigantea genomes respectively, based on the presence of a conserved DNA-binding domain and/or ligand-binding domain. Nuclear receptor transcript expression was confirmed and sequences were subjected to a comparative phylogenetic analysis, which demonstrated that these molluscs have representatives of all the major NR subfamilies (1-6). Many of the identified NRs are conserved between vertebrates and invertebrates, however differences exist, most notably, the absence of receptors of Group 3C, which includes some of the vertebrate endocrine hormone targets. The mollusc genomes also contain NR homologues that are present in insects and nematodes but not in vertebrates, such as Group 1J (HR48/DAF12/HR96). The identification of many shared receptors between humans and molluscs indicates the potential for molluscs as model organisms; however the absence of several steroid hormone receptors indicates snail endocrine systems are fundamentally different.The National Centre for the Replacement, Refinement and Reduction of Animals in Research, Grant Ref:G0900802 to CSJ, LRN, SJ & EJR [www.nc3rs.org.uk]
Search For Heavy Pointlike Dirac Monopoles
We have searched for central production of a pair of photons with high
transverse energies in collisions at TeV using of data collected with the D\O detector at the Fermilab Tevatron in
1994--1996. If they exist, virtual heavy pointlike Dirac monopoles could
rescatter pairs of nearly real photons into this final state via a box diagram.
We observe no excess of events above background, and set lower 95% C.L. limits
of on the mass of a spin 0, 1/2, or 1 Dirac
monopole.Comment: 12 pages, 4 figure
Search for High Mass Photon Pairs in p-pbar --> gamma-gamma-jet-jet Events at sqrt(s)=1.8 TeV
A search has been carried out for events in the channel p-barp --> gamma
gamma jet jet. Such a signature can characterize the production of a
non-standard Higgs boson together with a W or Z boson. We refer to this
non-standard Higgs, having standard model couplings to vector bosons but no
coupling to fermions, as a "bosonic Higgs." With the requirement of two high
transverse energy photons and two jets, the diphoton mass (m(gamma gamma))
distribution is consistent with expected background. A 90(95)% C.L. upper limit
on the cross section as a function of mass is calculated, ranging from
0.60(0.80) pb for m(gamma gamma) = 65 GeV/c^2 to 0.26(0.34) pb for m(gamma
gamma) = 150 GeV/c^2, corresponding to a 95% C.L. lower limit on the mass of a
bosonic Higgs of 78.5 GeV/c^2.Comment: 9 pages, 3 figures. Replacement has new H->gamma gamma branching
ratios and corresponding new mass limit
Ratio of the Isolated Photon Cross Sections at \sqrt{s} = 630 and 1800 GeV
The inclusive cross section for production of isolated photons has been
measured in \pbarp collisions at GeV with the \D0 detector at
the Fermilab Tevatron Collider. The photons span a transverse energy ()
range from 7-49 GeV and have pseudorapidity . This measurement is
combined with to previous \D0 result at GeV to form a ratio
of the cross sections. Comparison of next-to-leading order QCD with the
measured cross section at 630 GeV and ratio of cross sections show satisfactory
agreement in most of the range.Comment: 7 pages. Published in Phys. Rev. Lett. 87, 251805, (2001
Hybrid endoscopic thymectomy : combined transesophageal and transthoracic approach in a survival porcine model with cadaver assessment
BACKGROUND:
Video-assisted thoracoscopic surgery thymectomy has been used in the treatment of Myastenia Gravis and thymomas (coexisting or not). In natural orifice transluminal endoscopic surgery, new approaches to the thorax are emerging as alternatives to the classic transthoracic endoscopic surgery. The aim of this study was to assess the feasibility and reliability of hybrid endoscopic thymectomy (HET) using a combined transthoracic and transesophageal approach.
METHODS:
Twelve consecutive in vivo experiments were undertaken in the porcine model (4 acute and 8 survival). The same procedure was assessed in a human cadaver afterward. For HET, an 11-mm trocar was inserted in the 2nd intercostal space in the left anterior axillary line. A 0° 10-mm thoracoscope with a 5-mm working channel was introduced. Transesophageal access was created through a submucosal tunnel using a flexible gastroscope with a single working channel introduced through the mouth. Using both flexible (gastroscope) and rigid (thoracoscope) instruments, the mediastinum was opened; the thymus was dissected, and the vessels were ligated using electrocautery alone.
RESULTS:
Submucosal tunnel creation and esophagotomy were performed safely without incidents in all animals. Complete thymectomy was achieved in all experiments. All animals in the survival group lived for 14 days. Thoracoscopic and postmortem examination revealed pleural adhesions on site of the surgical procedure with no signs of infection. Histological analysis of the proximal third of the esophagus revealed complete cicatrization of both mucosal defect and myotomy site. In the human cadaver, we were able to replicate all the procedure even though we were not able to identify the thymus.
CONCLUSIONS:
Hybrid endoscopic thymectomy is feasible and reliable. HET could be regarded as a possible alternative to classic thoracoscopic approach for patients requiring thymectomy.This project was funded by the FCT Grants project PTDC/SAU-OSM/105578/2008
- …
