795 research outputs found
On the biological relevance of MHC class II and B7 expression by tumour cells in melanoma metastases
A large number of studies have indicated that specific immune reactivity plays a crucial role in the control of malignant melanoma. In this context, expression of MHC I, MHC II and B7 molecules by melanoma cells is seen as relevant for the immune response against the tumour. For a better understanding of the biological relevance of MHC II and B7 expression by tumour cells in metastatic melanoma, we studied the expression of these molecules in melanoma metastases in relation to the inflammatory response, regression of the tumour and survival from 27 patients treated with biochemotherapy (30 mg m−2 Cisplatin and 250 mg m−2 decarbazine (dimethyl-triazene-imidazole-carboxamide, DTIC) on days 1–3 i.v., and 107 IU IFN-α2b 3 days a week s.c., q. 28d). In 19 out of 27 lesions studied, we found expression of MHC II by the tumour cells, while only in one out of 11 tumour biopsies obtained from untreated metastatic melanoma patients, MHC II expression was detected. Expression of B7.1 and B7.2 by tumour cells was found in nine out of 24 and 19 out of 24 lesions, respectively. In all cases where B7.1 expression was found, expression of B7.2 by the tumour cells was also seen. In general, no or only few inflammatory cells positive for B7 were found. Expression of MHC II by tumour cells was positively correlated with the presence of tumour-infiltrating lymphocytes, regression of the lesion, and with time to progression (TTP) and overall survival (OS) of the patient. However, no significant correlation between B7.1 or B7.2 expression and regression of the tumour, TTP or OS was found. In light of other recent findings, these data altogether do support a role as biomarker for MHC II expression by tumour cells; however, its exact immunological pathomechanism(s) remain to be established
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Comparative effectiveness of drugs used to constrict the patent ductus arteriosus: a secondary analysis of the PDA-TOLERATE trial (NCT01958320).
ObjectiveTo evaluate the effectiveness of drugs used to constrict patent ductus arteriosus (PDA) in newborns < 28 weeks.MethodsWe performed a secondary analysis of the multi-center PDA-TOLERATE trial (NCT01958320). Infants with moderate-to-large PDAs were randomized 1:1 at 8.1 ± 2.1 days to either Drug treatment (n = 104) or Conservative management (n = 98). Drug treatments were assigned by center rather than within center (acetaminophen: 5 centers, 27 infants; ibuprofen: 7 centers, 38 infants; indomethacin: 7 centers, 39 infants).ResultsIndomethacin produced the greatest constriction (compared with spontaneous constriction during Conservative management): RR (95% CI) = 3.21 (2.05-5.01)), followed by ibuprofen = 2.03 (1.05-3.91), and acetaminophen = 1.33 (0.55-3.24). The initial rate of acetaminophen-induced constriction was 27%. Infants with persistent moderate-to-large PDA after acetaminophen were treated with indomethacin. The final rate of constriction after acetaminophen ± indomethacin was 60% (similar to the rate in infants receiving indomethacin-alone (62%)).ConclusionIndomethacin was more effective than acetaminophen in producing ductus constriction
Family medicine in the Baltic countries
publishersversio
Estrogen-Like Effects of Cadmium in Vivo Do Not Appear to be Mediated via the Classical Estrogen Receptor Transcriptional Pathway
Cadmium is a toxic metal classified as human carcinogen and ubiquitously found in our
environment mainly from anthropogenic activities. Exposure to cadmium has been
associated with increased risk of certain hormone-dependent cancers in humans, and the
metal has been proposed to possess endocrine disruptive properties by mimicking the
physiological actions of estrogens. However, the mechanisms behind these effects are
unclear.
The overall aim of this thesis was to provide mechanistic insights into the
estrogenicity of cadmium that may have implications for the human health. To achieve
this aim, investigations on the estrogen-like effects of cadmium as well as possible
involvement of classical/non-classical estrogen receptor signaling was studied in mice,
and these mechanisms were further scrutinized in cell-based models. Furthermore,
associations of biomarker of cadmium exposure with endogenous circulating sex
hormones were evaluated in a population-based study of women.
Results presented here indicate that exposure to cadmium does not affect the genomic
estrogen response in vivo in mice, suggesting that classical estrogen signaling is not
targeted by cadmium. However, some estrogen-like effects were observed in cadmium
exposed mice, i.e. significant thickening of uterine epithelia, in the absence of uterine
weight increase, and activation of ERK1/2 MAPKs in the liver. This suggests the
existence of alternative signaling pathways modulated by cadmium. In addition,
exposure to a wide dose range of cadmium, dose-dependently increased the expression
of the endogenous genes Mt1, Mt2, p53, c-fos, and Mdm2 in mouse liver, with p53 being
the most sensitive gene. However, phosphorylation of ERK1/2 was already induced at
the lowest exposure level (0.5µg/kg body weight), rendering ERK1/2 a more sensitive
marker of exposure than any change in gene expression. Furthermore, in vivo findings
suggest that cadmium-induced effects are markedly concentration dependent: low-level
exposure activates protein-kinases whereas high-level exposure turns on cellular stress
responses. The data from in vitro studies indicate that cadmium at regular human
exposure levels activates protein-kinase signaling through Raf-MEK-ERK/MAPKs, and
we identified EGFR and GPR30 as the mediating receptors. This cadmium-induced
activation of protein-kinases further leads to a disturbance in Mdm2/p53 balance, with a
significant increase in the Mdm2/p53 ratio in the presence of genotoxic compounds,
which in turn suggest that cadmium may disrupt stress response to genotoxins. In 438
postmenopausal women, a positive association was observed between the concentrations
of cadmium in blood and testosterone in serum, while an inverse association was
observed with estradiol. This may suggest that cadmium affects steroidogenesis.
In conclusion, data presented in this thesis collectively suggests that cadmium-induced
estrogen-like effects do not involve classical estrogen receptor signaling but rather
appear to be mediated via membrane-associated signaling. The activation/
transactivation of GPR30/EGFR-Raf-MEK-ERK/MAPKs and Mdm2 represent a general
mechanism by which cadmium may exert its effects. Since EGFR, ERK and Mdm2 are
all known key players in cancer promotion, cadmium-induced activation of these and
disturbance in the estradiol/testosterone balance in women may have implications for the
promotion/development of hormone-related cancers
ADULT BRAIN Quantitative MRI for Analysis of Active Multiple Sclerosis Lesions without Gadolinium-Based Contrast Agent
ABSTRACT BACKGROUND AND PURPOSE: Contrast-enhancing MS lesions are important markers of active inflammation in the diagnostic work-up of MS and in disease monitoring with MR imaging. Because intravenous contrast agents involve an expense and a potential risk of adverse events, it would be desirable to identify active lesions without using a contrast agent. The purpose of this study was to evaluate whether pre-contrast injection tissue-relaxation rates and proton density of MS lesions, by using a new quantitative MR imaging sequence, can identify active lesions
The molybdenum isotopic composition of the modern ocean
Natural variations in the isotopic composition of molybdenum (Mo) are showing increasing potential as a tool in geochemistry. Although the ocean is an important reservoir of Mo, data on the isotopic composition of Mo in seawater are scarce. We have recently developed a new method for the precise determination of Mo isotope ratios on the basis of preconcentration using a chelating resin and measurement by multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), which allows us to measure every stable Mo isotope. In this study, 172 seawater samples obtained from 9 stations in the Pacific, Atlantic, and Southern Oceans were analyzed, giving global coverage and the first full depth-profiles. The average isotope composition in δA/95Mo (relative to a Johnson Matthey Mo standard solution) was as follows: δ92/95Mo = –2.54 ± 0.16‰ (2SD), δ94/95Mo = –0.73 ± 0.19‰, δ96/95Mo = 0.85 ± 0.07‰, δ97/95Mo = 1.68 ± 0.08‰, δ98/95Mo = 2.48 ± 0.10‰, and δ100/95Mo = 4.07 ± 0.18‰. The δ values showed an excellent linear correlation with atomic mass of AMo (R2 = 0.999). Three-isotope plots for the Mo isotopes were fitted with straight lines whose slopes agreed with theoretical values for mass-dependent isotope fractionation. These results demonstrate that Mo isotopes are both uniformly distributed and follow a mass-dependent fractionation law in the modern oxic ocean. A common Mo standard is urgently required for the precise comparison of Mo isotopic compositions measured in different laboratories. On the other hand, our results strongly support the possibility of seawater as an international reference material for Mo isotopic composition
Neurofilament levels, disease activity and brain volume during follow-up in multiple sclerosis
BACKGROUND: There is a need for clinically useful biomarkers of disease activity in clinically isolated syndrome (CIS) and relapsing remitting MS (RRMS). The aim of this study was to assess the correlation between neurofilament light chain (NFL) in cerebrospinal fluid (CSF) and serum and the relationship between NFL and other biomarkers, subsequent disease activity, and brain volume loss in CIS and RRMS. METHODS: A panel of neurodegenerative and neuroinflammatory markers were analyzed in repeated CSF samples from 41 patients with CIS or RRMS in a prospective longitudinal cohort study and from 22 healthy controls. NFL in serum was analyzed using a single-molecule array (Simoa) method. “No evidence of disease activity-3” (NEDA-3) status and brain volume (brain parenchymal fraction calculated using SyMRI®) were recorded during 4 years of follow-up. RESULTS: NFL levels in CSF and serum correlated significantly (all samples, n = 63, r 0.74, p < 0.001), but CSF-NFL showed an overall stronger association profile with NEDA-3 status, new T2 lesions, and brain volume loss. CSF-NFL was associated with both new T2 lesions and brain volume loss during follow-up, whereas CSF-CHI3L1 was associated mainly with brain volume loss and CXCL1, CXCL10, CXCL13, CCL22, and MMP-9 were associated mainly with new T2 lesions. CONCLUSIONS: Serum and CSF levels of NFL correlate, but CSF-NFL predicts and reflects disease activity better than S-NFL. CSF-NFL levels are associated with both new T2 lesions and brain volume loss. Our findings further add to the accumulating evidence that CSF-NFL is a clinically useful biomarker in CIS and RRMS and should be considered in the expanding NEDA concept. CSF-CXCL10 and CSF-CSF-CHI3L1 are potential markers of disease activity and brain volume loss, respectively
Dark Matter Constraints from a Joint Analysis of Dwarf Spheroidal Galaxy Observations with VERITAS
We present constraints on the annihilation cross section of WIMP dark matter
based on the joint statistical analysis of four dwarf galaxies with VERITAS.
These results are derived from an optimized photon weighting statistical
technique that improves on standard imaging atmospheric Cherenkov telescope
(IACT) analyses by utilizing the spectral and spatial properties of individual
photon events. We report on the results of 230 hours of observations of
five dwarf galaxies and the joint statistical analysis of four of the dwarf
galaxies. We find no evidence of gamma-ray emission from any individual dwarf
nor in the joint analysis. The derived upper limit on the dark matter
annihilation cross section from the joint analysis is at 1 TeV for the bottom quark () final state,
at 1 TeV for the tau lepton
() final state and at 1 TeV for the gauge boson () final state.Comment: 14 pages, 9 figures, published in PRD, Ascii tables containing
annihilation cross sections limits are available for download as ancillary
files with readme.txt file description of limit
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