Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0271188 (Halo)
 461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Halo assay, a method for quantitative analysis of chromatin structure in cell, was developed recently. Due to visualization, feasibility, rapidity, and sensitivity of the method, it has been applied in radiobiology and cancer research. According to previous reports, with some improvement, this method has been established in our laboratory. Employing halo assay, the chromatin structure of two kinds of cell strain with similar genetic background and different radiosensitivity was analyzed and the results show that radiosensitive strain has looser chromatin structure than radioresistant one. It is possible that this difference is related to their different radiosensitivity, thus it's a proof for the relation of chromatin structure and radiosensitivity.
 ...
PMID:[The application of halo assay in analysis of cell chromatin structure]. 759 68

Halo reactions to melanocytic nevi are a well-recognized phenomenon. In contrast, halo reactions to Spitz's nevi have been reported only infrequently. Halo reactions may cause misdiagnosis of an otherwise benign nevus as melanoma because inflammatory cells sometimes obscure the architectural features of the underlying nevus, and may induce cytologic atypia. For Spitz's nevus where the distinction between malignancy and benignancy is already challenging, halo reactions compound the problem. We describe 17 examples of Spitz's nevus with halo reaction, and compare their immunohistochemical features with those of "ordinary" halo nevi. Only 2 of 17 lesions demonstrated clinically apparent halos. Clinical follow-up was available for 12 of 17 cases. None of the 12 has persisted at the biopsy site or metastasized after an average 3.6-year follow-up period. Junctional, compound, intradermal, and combined types of Spitz's nevi were represented. All were characterized by symmetrical lymphocytic infiltrates which permeated the full thickness of the nevus, including junctional nests. Combined Spitz's nevi constituted more than one-half of examples in this series (9/17 cases). The combined Spitz's nevus included a combination of Spitz's nevus with either an ordinary (common, banal) nevus or a superficial congenital type nevus. In these combined Spitz's nevi, the lymphocytic response was often directed exclusively to the Spitz's nevic component. Important distinguishing features from malignant melanoma arising in a pre-existing nevus included symmetry and lateral circumscription of the spitzoid component, no large expansile-appearing aggregates of melanocytes, a decrease in size of nests with increasing dermal depth, a lack of mitotic figures among melanocytes at the base, and a symmetrical and diffusely permeative lymphocytic response. Although the combined Spitz's nevus with halo reaction sometimes appeared asymmetrical at scanning magnification, each component of the combination was symmetrical, when examined independently. Probably because of reactive atypia, nuclear maturation with progressive descent into the dermis was sometimes absent. There were no obvious differences in immunohistochemical staining patterns among 4 Spitz's nevi with halo reaction, 5 regressing melanomas, and 5 benign halo nevi when stained with antibodies to S100, HMB-45, OPD4, CD8, TIA-1, CD1a, CD68, and Ki-67.
 ...
PMID:Spitz's nevi with halo reaction: a histopathologic study of 17 cases. 944 88

Resistance of tumors due to restricted drug accumulation and reversal of DNA lesions in tumor cells as well as normal tissue toxicity limit the efficacy of topoisomerase inhibition based anticancer drugs. It has been proposed that selective inhibition of energy dependent repair processes and enhanced retention of drug in cancer cells can significantly improve the therapeutic efficacy. The purpose of these studies was to verify this proposition by investigating the effects of 2-deoxy-D-glucose (2-DG) an inhibitor of the glycolytic ATP production on the cytotoxicity of certain topoisomerase inhibitors in human tumor cell lines. Human glioma (BMG-1 and U-87) and squamous carcinoma (4197 and 4451) cell lines were investigated with topo-poisons like etoposide (topo II inhibitor), camptothecin (topo I inhibitor) and hoechst-33342 (topo I and II inhibitor). DNA damage induction (halo assay), cell survival (macro colony assay), cytogenetic damage (micronuclei) and apoptosis (morphological analysis) were investigated. Presence of 2-DG for 2 h following exposure to the topoisomerase inhibitors enhanced the cell death (macro colony assay) in a concentration dependent manner and a 2-3-fold increase was observed at 5 mM (equimolar with glucose). Halo assay revealed that 2-DG inhibited the reversal of cleavable complex leading to the accumulation of DNA strand breaks. Under these conditions 2-DG enhanced the drug-induced micronuclei formation by nearly 2 folds with etoposide and hoechst-33342 and a 4-fold increase in delayed apoptosis was observed in case of etoposide. These results clearly demonstrate that presence of 2-DG for a few hours following exposure to topo-inhibitors enhances the cytotoxicity, primarily by increasing the cytogenetic damage.
Cancer Biol Ther 2004 Sep
PMID:2-deoxy-D-glucose enhances the cytotoxicity of topoisomerase inhibitors in human tumor cell lines. 1525 10

Experimental approaches currently used to quantify the activity of antiangiogenic treatments in cancer therapy do not generally address the importance of spatial distribution of microvessels in target tissues. We report a new computerized method to assess tumor vascularization by quantifying the distribution of functional microvessels as revealed by in vivo staining with sulfosuccinimidyl-6-(biotinamido) hexanoate. Our approach was based on pixel dilation of digital images of blood vessels and addressed the space-filling property of the vessel layouts. This was practically achieved computing the number of dilation cycles (Halo index) needed to permeate a pre-defined amount of each image. Our approach was validated on human tumor xenografts in nonobese diabetic/severe combined immunodeficient mice treated with the antiangiogenic drug sorafenib. For each experimental model, area normalization allowed the unbiased comparison of several hundreds of images showing different amounts of vascular tissue. In two different tumor types, comparison of Halo values showed statistically significant differences between control and sorafenib-treated samples. Conversely, this effect was not observed in samples from an additional xenograft known to resist the antiangiogenic treatment. By separating the analysis of vessel area from the quantification of vessel distributions, our approach can potentially contribute to a better evaluation of the antiangiogenic or vascular-disrupting activity of new drugs or treatments.
 ...
PMID:A computational approach to compare microvessel distributions in tumors following antiangiogenic treatments. 1965 44

The exhaled breath temperature (EBT) has been proven to be the expression of airways inflammation as well as of the increased vascularity. Although both these conditions characterize lung cancer pathogenesis, this is the first study where the EBT has been analysed in patients affected by non-small-cell lung cancer. The aim of this study was to verify whether and how the lung cancer being examined influences the EBT for possible future clinical implications. Eighty-two consecutive subjects with a radiological suspicion of lung cancer were enrolled and underwent standard diagnostic and staging procedures for cancer. EBT was measured in all the subjects at the enrolment with the X-Halo device. Forty patients resulted as affected by lung cancer while 42 as false-positive (controls). We found a higher EBT in NSCLC patients compared to healthy subjects. The EBT was correlated with number of packs/year and associated with the stage of lung cancer. We identified a cut-off value for the EBT that is able to screen patients with lung cancer with a high sensitivity and specificity. Our results suggest that lung cancer causes an increase in the EBT, which, whether confirmed and validated, could become a new non-invasive clinical tool in the screening and monitoring of this disease.
...
PMID:Exhaled breath temperature in NSCLC: could be a new non-invasive marker? 2472 95

Although Halo assay is a fast and more economic technique, it is not popular compared to comet assay for the measurement of DNA damage. One of the reasons behind this was nonavailability of suitable user-friendly program. Currently, most of the researchers were analyzing halo images manually using image analysis software (Scion Image or ImageJ). To address this problem, I have developed a semiautomatic halo analysis ImageJ program, HaloJ, and applied in the assessment of DNA damage at the single-cell level. In this article, we have shown that data obtained from the HaloJ program have a very good correlation with the data obtained using comet assay analysis program such as Comet Assay Software Project. To the best of our knowledge, this will be the first program to quantify DNA damage of halo images. This program will be of great use for researchers working on the DNA damage and repair, radiation biology, toxicology, cancer biology, and so on.
...
PMID:HaloJ: an ImageJ program for semiautomatic quantification of DNA damage at single-cell level. 2520 98