Improving medical image perception by hierarchical clustering based segmentation

It has been well documented that radiologists' performance is not perfect: they make both false positive and false negative decisions. For example, approximately thirty percent of early lung cancer is missed on chest radiographs when the evidence is clearly visible in retrospect [1]. Currently Computer-Aided Detection (CAD) uses software, designed to reduce errors by drawing radiologists' attention to possible abnormalities by placing prompts on images. Alberdi et al examined the effects of CAD prompts on performance, comparing the negative effect of no prompt on a cancer case with prompts on a normal case. They showed that no prompt on a cancer case can have a detrimental effect on reader sensitivity and that the reader performs worse than if the reader was not using CAD. This became particularly apparent when difficult cases were being read. They suggested that the readers were using CAD as a decision making tool instead of a prompting aid. They conclude that "incorrect CAD can have a detrimental effect on human decisions" [2]. The goal of this paper is to explore the possibility of using Hierarchical Clustering based Segmentation (HCS) [3], as a perceptual aid, to improve the performance of the reader

Towards the synthesis and characterization of metallocarbohedrenes

Metallocarbohedrene, Ti8C12, has been synthesised in the solid state by resistive evaporation of Ti-covered graphite electrodes in a dynamic helium atmosphere. It forms along with other Ti-containing clusters, all of which are air sensitive. Exposure of the soot to electron-rich molecules increases air stability. The clusters are evaporated thermally yielding chemical ionization mass spectra. The ions do not fragment significantly upon collisional activation. Vacuum evaporation of the soot yields a Ti-containing film. The infrared spectrum of the soot shows characteristic peaks attributable to molecular compounds which change rapidly upon exposure to air

Nedunelvaadai, - An Agam book from the perspective of Thinai Theories

The Sangam literature stands out as the classical literature of Tamil with its own uniqueness. Sangam literature can also be called Thinai literature. Tolkappiyar interprets the meaning of Thinai as a discipline. This discipline can be divided into Agam and Puram. Of these, the Agam discipline deals with the life of love, and the Puram discipline deals with the context of life, such as country-based warfare and heroism. The basic natural environment required by man is the source of the formulation of the theory of Thinai. This principle serves as a tool for distinguishing between the Agam and the Puram of the disciplines sung in a verse. On the basis of this, this Thinai theory has been introduced into the Patthuppaattu books of Sangam literature and examined in Nedunelvaadai, which consists of Agam-Puram concepts. It has been found out which Thinai prevails by quoting both the Thinai messages. It was examined here that Nedunelvadai is an Agam-Puram book containing the messages of the two Thinais since Nakkiran has mentioned the original messages of the Agatthinai and the symbolic flower "Vembu" for the Purathinai

Some results on range labeling

In this article, We have extended to Range labeling for some trees as for Star trees, Spider trees and Banana tres

Macroscopic synthesis and characterization of giant fullerenes

Thermal treatment of carbon soot produced by arc evaporation of nickel-filled graphite rods in 500 Torr of helium gives giant fullerenes showing characteristic IR, Raman, NMR and powder XRD signatures. Transmission electron micrographs show faceted structures with pentagonal, hexagonal and spherical shapes. The simplicity and similarity of the IR spectrum with those of smaller fullerenes suggest that the material is a form of large fullerenes. Chemical treatment of the material gives carbon onions

Iron environment non-equivalence in both octahedral and tetrahedral sites in NiFe2O4 nanoparticles: study using Mössbauer spectroscopy with a high velocity resolution

Mössbauer spectrum of NiFe2O4 nanoparticles was measured at room temperature in 4096 channels. This spectrum was fitted using various models, consisting of different numbers of magnetic sextets from two to twelve. Non-equivalence of the 57Fe microenvironments due to various probabilities of different Ni2+ numbers surrounding the octahedral and tetrahedral sites was evaluated and at least 5 different microenvironments were shown for both sites. The fit of the Mössbauer spectrum of NiFe 2O4 nanoparticles using ten sextets showed some similarities in the histograms of relative areas of sextets and calculated probabilities of different Ni2+ numbers in local microenvironments. © 2012 American Institute of Physics

Evaluation of modified alvarado score in diagnosis of acute appendicitis in adults

BACKGROUND: The most common surgical emergency in the world is Acute Appendicitis. Inspite of greater than hundred years of experience, diagnosis of acute appendicitis still evades the surgeon, Negative appendicectomy rate is been 20% to 30% as reported. Surgeons are using various scoring systems to diagnose and operate the cases. AIM OF THE STUDY: Aim of study is to evaluate use of “Modified Alvarado score” in diagnosis of “Acute Appendicitis” to reduce unwanted appendicectomies. METHODOLOGY: A study of 100 patients presenting with abdominal pain and provisionally diagnosed as acute appendicitis were taken. A score was calculated for each case based on Modified Alvarado score. Patients with score between 5-9 were operated and < 5 treated conservatively. Ultrasonogram was done in all patients with score > 5 to rule out other diagnosis mimicking acute appendicitis. After surgery the appendix specimen was sent for histopathological examination and was correlated with the clinical presentation. Hence results of operative, conservative and HPE reviewed. RESULTS AND OBSERVATION: In this study females were more in number with a ratio of 1.2 : 1 with females. The result of this study showed that score (7-9) had a sensitivity of 95% in males, in females had sensitivity of 88.46%. The score (5-6) in men & females had a sensitivity of 73.91% and 65.38% respectively. INTERPRETATION AND CONCLUSION: The high scores in Modified Alvarado score is dependable aid in the early diagnosis of “Acute Appendicitis” in men but it is not true as far as women are concerned. Ultrasonography of abdomen is a useful tool in avoiding negative appendicectomy

Tumor escape and progression under immune pressure.

Although cancers develop and progress in immunocompetent hosts, immunological therapies for cancer have been proposed as alternative or complementary approaches to more standard therapy. It was initially thought that tumors were silent to the immune system, and that breaking immunological tolerance could result in immune-mediated tumor rejection. However, we have learned that cancer patients have preexisting immune responses against their tumor antigens which, nevertheless, fail to protect them, in part because of increased activity of the immune suppressor cells such as myeloid-derived suppressor cells (MDSC). Attempts to develop combinatorial therapies by depleting suppressor cells or blocking suppressor pathways and at the same time actively inducing immune responses in vivo or adoptively transferring tumor-specific T cells have largely failed. Very limited success has been achieved only against melanoma, using adoptive T-cell therapy, or prostate cancer, using a vaccine which improves patient survival but has no apparent inhibitory effect on disease progression. Further progress in the immunotherapy of cancer has been halted because of a poor understanding of the cellular components of the immune responses working together in favor of or against the tumors, as well as our inability to reliably reprogram immune responses towards the most effective phenotypes against cancer. This special issue is focused on understanding the escape mechanisms that malignant cells develop to hijack antitumor immune responses as well as strategies to overcome tumor escape. Four main areas that are covered in this issue include the following. Opposing Functions of the Immune System in Tumor Inhibition and Tumor ProgressionRobert Schreiber proposed the term “cancer immunoediting” in order to broadly describe the dual host-protecting and tumor-sculpting actions of the immune system that not only survey for, and eliminate, nascent malignant cells but also shape neoplastic disease through equilibrium and escape mechanisms. In this issue, M. Aris et al. discuss the dual function of the immune system in controlling and promoting tumor progression in cutaneous melanoma. They propose that tumor evolution is because of a continuous feedback between tumor cells and their environment, and thus different combinatorial therapeutic approaches can be implemented according to the tumor stage. A. Amedei et al. discuss recent knowledge on the contribution of T cells in oncogenesis. They review the different types, “friend or foe,” of T-cell response in gastric cancer. Tumor-Associated Modulation of Immune Checkpoint MoleculesUpon activation, T cells develop negative feedback regulatory mechanisms in order to avoid overstimulation. These include the expression of checkpoint molecules such as PD-1 and CTLA-4. T cells that recognize and respond to tumor antigens produce IFN-γ. A dual function of IFN-γ is the induction of apoptosis in target cells and upregulation of PD-L1 that interacts with PD-1 positive T cells, thereby resulting in the exhaustion of tumor-reactive T cells. Expression of CTLA-4 on activated T cells also results in T-cell anergy upon interaction with costimulatory molecules on DCs. S. Sapozink et al. describe new immunomodulatory approaches currently in the development pipeline, with focus on the novel CEACAM1 immune checkpoint, and compare its potential to the extensively described lymphocyte inhibitory targets, CTLA4 and PD-1. E. Rozali et al. provide an extensive review of the literature on the immunoregulatory role of PD-L2 in cancer-induced immune suppression and discuss the results of recent studies targeting PD-L2 in cancer. L. Cruz-Merino et al. discuss immune escape mechanisms in Hodgkin’s lymphoma (HL) and summarize the clinical, histological, pathological, and biological factors in HL, with special emphasis on the improvement of prognosis and their impact on treatment strategies. L. Farnault et al. introduce various mechanisms involved in the escape of hematological malignancies from NK-cell surveillance. These include NK-cell qualitative and qualitative deficiencies that occur through modulating the inhibitory and activating stimuli. Tumor-Induced Immune SuppressionMalignant cells produce cytokines and chemokines that facilitate the expansion or differentiation of immune suppressor cells such as Tregs, MDSC, and M2 macrophages. G. Zhou and H. Levitsky summarize the findings from some recent preclinical and clinical studies, focusing on how tumor cells advance their survival and expansion by hijacking therapy-induced immune effector mechanisms that would otherwise mediate their destruction. A particularly interesting notion that is touched upon involves tumor-independent treatment-induced homeostatic counter-regulation. M. Jadus et al. cover the escape mechanisms of bronchogenic lung cancer that must be overcome before they can be successfully treated. They also review the history of immunotherapy directed towards lung cancers. N. Hao et al. discuss the role of tumor-associated macrophages including M1 and M2 subsets during tumour progression and metastasis, highlighting the immunosuppressive role of M2 macrophages. V. Levina et al. investigate the role of indoleamine 2,3-dioxygenase (IDO1) in tumor escape and metastasis using 4T1 mammary carcinoma model. They show that IDO1 can not only suppress antitumour immune responses but also promote tumour cell proliferation. Improved Immunotherapeutic Strategies to Overcome Tumor EscapeImmunotherapy combined with blockade of immune suppressor pathways has been developed to overcome tumor-induced immune suppression. Cornelissen et al. discuss the interplay between a dual function of the immune responses against mesothelioma which can either inhibit or stimulate tumor growth and review the challenges associated with immunotherapy. They also discuss possible strategies and opportunities to overcome tumor escape. R. Casalegno-Garduño et al. analyze the expression of the leukemia-associated antigen receptor for hyaluronan acid-mediated motility (RHAMM) in patients suffering from acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Their results suggest that immunotherapies like peptide vaccination or adoptive transfer of RHAMM-specific T cells might improve the immune response and the clinical outcome in AML/MDS patients. S.Wallner et al. summarize the current knowledge about the negative regulatory role of Cbl-b in T-cell activation and its potential therapeutic implications for cancer immunotherapy. H. Nagai et al. demonstrate that sorafenib-induced Th1 dominance can prevent the escape of tumor cells from the host immune system in liver cirrhosis (LC) patients with advanced hepatocellular carcinoma (aHCC).Overall, this special issue provides a well-rounded synopsis of representative research efforts addressing the issues related to “tumor escape and progression under immune pressure.

Lack of evidence for MHC-unrestricted (atypical) recognition of mucin by mucinous pancreatic tumour-reactive T-cells

Cytotoxic T-cells generated against heterologous, mucinous pancreatic tumour cells were shown to recognize mucin in a major histocombatibility complex (MHC)-unrestricted fashion. In contrast, the present study demonstrates a typical allogeneic response of heterologous cytotoxic T-cells established against mucin-expressing pancreatic tumour cells. Heterologous cytotoxic T cells lysed targets that were used as stimulators and other targets that shared human leucocyte antigen (HLA) with the stimulator. These cytotoxic T-cells lysed mucin-expressing stimulator cells but not autologous tumour cells in spite of expressing mucin on their surface. Likewise, tumour-infiltrating CD4+T-cells proliferated against its own tumour cell target, while such T-cells did not respond to heterologous, mucin-expressing pancreatic tumour cells. Culturing heterologous tumour-specific cytotoxic T-cells with purified pancreatic tumour cell-mucin rendered them unresponsive to their target cells. Furthermore, purified mucin did not produce a mucin-specific response in mucinous pancreatic tumour patients' primary T-cells even in the presence of antigen-presenting cells. Our study finds no evidence for MHC-unrestricted recognition of mucin by pancreatic cancer patients' T-cells. © 2000 Cancer Research Campaig