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Influence of Varying Assessment Parameters on the Diagnostic Accuracy of Magnetic Resonance Imaging in the Local Staging of Prostate Cancer. Urol Int 2015; 96:309-14. [DOI: 10.1159/000441733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 10/15/2015] [Indexed: 11/19/2022]
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MR imaging features for improved diagnosis of hepatocellular carcinoma in the non-cirrhotic liver: Multi-center evaluation. Eur J Radiol 2015; 84:1879-87. [PMID: 26194029 DOI: 10.1016/j.ejrad.2015.06.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 06/26/2015] [Accepted: 06/28/2015] [Indexed: 01/10/2023]
Abstract
PURPOSE To determine MR-imaging features for the differentiation between hepatocellular carcinoma (HCC) and benign hepatocellular tumors in the non-cirrhotic liver. MATERIAL AND METHODS 107 consecutive patients without liver cirrhosis (46 male; 45 ± 14 years) who underwent liver resection due to suspicion of HCC were included in this multi-center study. The following imaging features were assessed: lesion diameter and demarcation, satellite-lesions, central-scar, capsule, fat-content, hemorrhage, vein-infiltration and signal-intensity (SI) on native T1-, T2- and dynamic-enhanced T1-weighted images (center versus periphery). In addition, contrast-media (CM) uptake in the liver specific phase was analyzed in a sub-group of 42 patients. RESULTS Significant differences between HCC (n=55) and benign lesions (n=52) were shown for native T1-, T2- and dynamic-enhanced T1-SI, fat-content, and satellite-lesions (all, P<.05). Independent predictors for HCC were T1-hypointensity (odds-ratio, 4.81), T2-hypo-/hyperintensity (5.07), lack of central tumor-enhancement (3.36), and satellite-lesions (5.78; all P<0.05). Sensitivity and specificity of HCC was 91% and 75% respectively for two out-of four independent predictors, whereas specificity reached 98% for all four predictors. Sub-analysis, showed significant differences in liver specific CM uptake between HCC (n=18) and benign lesions (n=24; P<0.001) and revealed lack of liver specific CM uptake (odds-ratio, 2.7) as additional independent feature for diagnosis of HCC. CONCLUSION Independent MRI features indicating HCC are T1-hypointensity, T2-hypo- or hyperintensity, lack of central tumor-enhancement, presence of satellite-lesions and lack of liver specific CM-uptake. These features may have the potential to improve the diagnosis of HCC in the non-cirrhotic liver.
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MRI for characterization of primary tumors in the non-cirrhotic liver: Added value of Gd-EOB-DTPA enhanced hepatospecific phase. Eur J Radiol 2014; 83:1074-1079. [DOI: 10.1016/j.ejrad.2014.03.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 03/12/2014] [Accepted: 03/18/2014] [Indexed: 12/23/2022]
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TIMES-SS--recent refinements resulting from an industrial skin sensitisation consortium. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2014; 25:367-391. [PMID: 24785905 DOI: 10.1080/1062936x.2014.900520] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The TImes MEtabolism Simulator platform for predicting Skin Sensitisation (TIMES-SS) is a hybrid expert system, first developed at Bourgas University using funding and data from a consortium of industry and regulators. TIMES-SS encodes structure-toxicity and structure-skin metabolism relationships through a number of transformations, some of which are underpinned by mechanistic 3D QSARs. The model estimates semi-quantitative skin sensitisation potency classes and has been developed with the aim of minimising animal testing, and also to be scientifically valid in accordance with the OECD principles for (Q)SAR validation. In 2007 an external validation exercise was undertaken to fully address these principles. In 2010, a new industry consortium was established to coordinate research efforts in three specific areas: refinement of abiotic reactions in the skin (namely autoxidation) in the skin, refinement of the manner in which chemical reactivity was captured in terms of structure-toxicity rules (inclusion of alert reliability parameters) and defining the domain based on the underlying experimental data (study of discrepancies between local lymph node assay Local Lymph Node Assay (LLNA) and Guinea Pig Maximisation Test (GPMT)). The present paper summarises the progress of these activities and explains how the insights derived have been translated into refinements, resulting in increased confidence and transparency in the robustness of the TIMES-SS predictions.
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Diagnostic performance of a non-contrast-enhanced magnetic resonance imaging protocol for potential living related kidney donors. Acad Radiol 2013; 20:393-400. [PMID: 23498978 DOI: 10.1016/j.acra.2012.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 11/26/2012] [Accepted: 12/04/2012] [Indexed: 01/15/2023]
Abstract
RATIONALE AND OBJECTIVES The objective of the study was to evaluate the performance of a non-contrast-enhanced magnetic resonance (MR) imaging protocol for preoperative screening of living related kidney donors. MATERIALS AND METHODS Forty consecutive subjects (mean age 52.2 ± 11.3 years, range 29-73 years) underwent MR imaging with T2-weighted sequences (coronal and axial plane), with a non-contrast-enhanced respiratory-gated three-dimensional steady state free precession MR angiography (NCE-MRA) sequence and with contrast-enhanced magnetic resonance MR angiography (CE-MRA) sequences in the arterial and venous phases. Two blinded readers independently assessed arterial and venous anatomy and potential kidney lesions. Results of non-contrast-enhanced images were compared to CE-MRA and in a subgroup of 21 subjects to surgery as standard of reference. RESULTS Regarding arterial anatomy, NCE-MRA yielded sensitivity, specificity, and accuracy of 100%, 89%, and 91% compared to CE-MRA. Three kidneys were found to have more accessory renal arteries at NCE-MRA than at CE-MRA. In the subgroup of 21 subjects, 1 surgically proven accessory artery was depicted with NCE-MRA but not with CE-MRA. Accuracy of T2-weighted images regarding accessory veins or variant venous course was 99%, with one missed circumaortic vein on T2-weighted images. Two simple cysts were missed on T2-weighted and NCE-MRA but not on CE-MRA images. CONCLUSION A non-contrast-enhanced MR imaging protocol including NCE-MRA and T2-weighted images allows for the accurate screening of living related kidney donors and may serve as an alternative to CE-MRA.
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Two- versus three-dimensional dual gradient-echo MRI of the liver: a technical comparison. Eur Radiol 2012; 23:408-16. [PMID: 22865276 DOI: 10.1007/s00330-012-2614-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 07/03/2012] [Accepted: 07/08/2012] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To compare 2D spoiled dual gradient-echo (SPGR-DE) and 3D SPGR-DE with fat and water separation for the assessment of focal and diffuse fatty infiltration of the liver. METHODS A total of 227 consecutive patients (141 men; 56 ± 14 years) underwent clinically indicated liver MRI at 1.5 T including multiple-breath-hold 2D SPGR-DE and single-breath-hold 3D SPGR-DE with automatic reconstruction of fat-only images. Two readers assessed the image quality and number of fat-containing liver lesions on 2D and 3D in- and opposed-phase (IP/OP) images. Liver fat content (LFC) was quantified in 138 patients without chronic liver disease from 2D, 3D IP/OP, and 3D fat-only images. RESULTS Mean durations of 3D and 2D SPGR-DE acquisitions were 23.7 ± 2.9 and 97.2 ± 9.1 s respectively. The quality of all 2D and 3D images was rated diagnostically. Three-dimensional SPGR-DE revealed significantly more breathing artefacts resulting in lower image quality (P < 0.001); 2D and 3D IP/OP showed a similar detection rate of fat-containing lesions (P = 0.334) and similar LFC estimations (mean: +0.4 %; P = 0.048). LFC estimations based on 3D fat-only images showed significantly higher values (mean: 2.7 % + 3.5 %) than those from 2D and 3D IP/OP images (P < 0.001). CONCLUSION Three dimensional SPGR-DE performs as well as 2D SPGR-DE for the assessment of focal and diffuse fatty infiltration of liver parenchyma. The 3D SPGR-DE sequence used was quicker but more susceptible to breathing artefacts. Significantly higher LFC values are derived from 3D fat-only images than from 2D or 3D IP/OP images.
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Performance of unenhanced respiratory-gated 3D SSFP MRA to depict hepatic and visceral artery anatomy and variants. Eur J Radiol 2012; 81:e823-9. [DOI: 10.1016/j.ejrad.2012.02.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 02/24/2012] [Indexed: 12/26/2022]
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Feasibility of semiquantitative liver perfusion assessment by ferucarbotran bolus injection in double-contrast hepatic MRI. J Magn Reson Imaging 2012; 36:168-76. [PMID: 22334302 DOI: 10.1002/jmri.23611] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 01/11/2012] [Indexed: 01/15/2023] Open
Abstract
PURPOSE To evaluate the feasibility of semiquantitative measurement of liver perfusion from analysis of ferucarbotran induced signal-dynamics in double-contrast liver MR-imaging (DC-MRI). MATERIALS AND METHODS In total 31 patients (21 men; 58 ± 10 years) including 18 patients with biopsy proven liver cirrhosis prospectively underwent clinically indicated DC-MRI at 1.5 Tesla (T) with dynamic T2-weighted gradient-echo imaging after ferucarbotran bolus injection. Breathing artefacts in tissue and input time curves were reduced by Savitzky-Golay-filtering and semiquantitative perfusion maps were calculated using a model free approach. Hepatic blood flow index (HBFI) and splenic blood flow index (SBFI) were determined by normalization of arbitrary perfusion values to the perfusion of the erector spinae muscle resulting in a semiquantitative perfusion measure. RESULTS In 30 of 31 patients the evaluated protocol could successfully be applied. Mean HBF was 7.7 ± 2.46 (range, 4.6-12.8) and mean SBF was 13.20 ± 2.57 (range, 8.5-17.8). A significantly lower total HBF was seen in patients with cirrhotic livers as compared to patients with noncirrhotic livers (P < 0.05). In contrast, similar SBF was observed in cirrhotic and noncirrhotic patients (P = 0.11). CONCLUSION Capturing the signal dynamics during bolus injection of ferucarbotran in DC-MRI of the liver allows for semiquantitative assessment of hepatic perfusion that may be helpful for a more precise characterisation of liver cirrhosis and focal liver lesions.
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[Recurrent Baker's cyst]. PRAXIS 2011; 100:927-930. [PMID: 21792809 DOI: 10.1024/1661-8157/a000616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A 50-year old female patient with unilateral knee pain demonstrated a recurrent ultrasound-proven popliteal cyst (Baker's cyst). Even though a proper differential diagnosis was done, the MRT of the knee showed in a secondary step a tibial fissure as the cause of the treatment-refractory knee pain and Baker's cyst. A fracture of the tibia is a rare cause for a symptomatic Baker's cysts. Mechanical, degenerative or inflamed diseases of the joint are more frequent associated with a Baker's cyst.
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A decision aid to rule out pneumonia and reduce unnecessary prescriptions of antibiotics in primary care patients with cough and fever. BMC Med 2011; 9:56. [PMID: 21569472 PMCID: PMC3118372 DOI: 10.1186/1741-7015-9-56] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 05/13/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Physicians fear missing cases of pneumonia and treat many patients with signs of respiratory infection unnecessarily with antibiotics. This is an avoidable cause for the increasing worldwide problem of antibiotic resistance. We developed a user-friendly decision aid to rule out pneumonia and thus reduce the rate of needless prescriptions of antibiotics. METHODS This was a prospective cohort study in which we enrolled patients older than 18 years with a new or worsened cough and fever without serious co-morbidities. Physicians recorded results of a standardized medical history and physical examination. C-reactive protein was measured and chest radiographs were obtained. We used Classification and Regression Trees to derive the decision tool. RESULTS A total of 621 consenting eligible patients were studied, 598 were attending a primary care facility, were 48 years on average and 50% were male. Radiographic signs for pneumonia were present in 127 (20.5%) of patients. Antibiotics were prescribed to 234 (48.3%) of patients without pneumonia. In patients with C-reactive protein values below 10 μg/ml or patients presenting with C-reactive protein between 11 and 50 μg/ml, but without dyspnoea and daily fever, pneumonia can be ruled out. By applying this rule in clinical practice antibiotic prescription could be reduced by 9.1% (95% confidence interval (CI): 6.4 to 11.8). CONCLUSIONS Following validation and confirmation in new patient samples, this tool could help rule out pneumonia and be used to reduce unnecessary antibiotic prescriptions in patients presenting with cough and fever in primary care. The algorithm might be especially useful in those instances where taking a medical history and physical examination alone are inconclusive for ruling out pneumonia.
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Computed angiogram of the upper extremities for diagnosing a rare cause of brachial arterial embolism: the 'Pitcher Syndrome'. Eur Heart J 2010; 31:2782. [DOI: 10.1093/eurheartj/ehq269] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Pulmonary Kaposi's sarcoma after heart transplantation: a case report. J Med Case Rep 2010; 4:206. [PMID: 20602747 PMCID: PMC2904355 DOI: 10.1186/1752-1947-4-206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Accepted: 07/05/2010] [Indexed: 11/23/2022] Open
Abstract
Introduction Kaposi's sarcomas have been associated with different conditions of immunosuppression and are also known to be a typical complication of solid organ transplantations. Case presentation We report the case of a 65-year-old Turkish man with a history of heart transplantation 10 months ago who presented for clarification of his dyspnea. The patient had a known history of chronic obstructive pulmonary disease and a smoking history of 40 pack years. Radiologically, three progressively growing intra-pulmonary nodules were detected. The histology was diagnostic for a Kaposi's sarcoma. Visceral and especially primary intra-pulmonary Kaposi's sarcomas are very rare and have been described to have a rather unfavorable prognosis. Conclusions Even with a history suggestive for conventional lung cancer, Kaposi's sarcomas should be considered in patients after transplantation of solid organs. It should be noted that in a minority of cases this tumor exists in the absence of the typical cutaneous lesions.
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[Your ultrasound diagnosis? Hypertrophic pyloric stenosis]. PRAXIS 2003; 92:1987-1988. [PMID: 14669499 DOI: 10.1024/0369-8394.92.47.1987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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NK and CTL recognition of a single chain H-2Dd molecule: distinct sites of H-2Dd interact with NK and TCR. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1999; 163:3699-708. [PMID: 10490965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
We generated transgenic mice expressing a single-chain beta2-microglobulin (beta2m)-H-2Dd. The cell-surface beta2m-H-2Dd molecule was expressed on a beta2m-deficient background and reacted with appropriate mAbs. It was of the expected m.w. and directed the normal development of CD8+ T cells in the thymus of a broad TCR repertoire. It also presented both exogenously provided and endogenous peptide Ags to effector CD8+ T cells. In tests of NK cell education and function, it failed to reveal any interaction with NK cells, suggesting that the site of the interaction of NK receptors with H-2Dd was disrupted. Thus, the sites of TCR and NK receptor interaction with H-2Dd are distinct, an observation consistent with independent modes of TCR and NK receptor evolution and function.
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MESH Headings
- Animals
- Antigens, Ly
- CD8-Positive T-Lymphocytes/cytology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/virology
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cytotoxicity, Immunologic/genetics
- Cytotoxicity, Immunologic/immunology
- H-2 Antigens/biosynthesis
- H-2 Antigens/genetics
- H-2 Antigens/metabolism
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Lectins, C-Type
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Protein Binding/genetics
- Protein Binding/immunology
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Receptors, NK Cell Lectin-Like
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
- T-Lymphocytes, Cytotoxic/virology
- Transgenes/immunology
- Vaccinia virus/immunology
- beta 2-Microglobulin/deficiency
- beta 2-Microglobulin/genetics
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Enteric lesions in SCID mice infected with "Helicobacter typhlonicus," a novel urease-negative Helicobacter species. LABORATORY ANIMAL SCIENCE 1999; 49:496-505. [PMID: 10551450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
BACKGROUND AND PURPOSE Several rodent helicobacters have been associated with chronic active hepatitis or inflammatory bowel disease. Severe combined immunodeficient (SCID) mice appear to be inherently susceptible to disease attributable to these emerging pathogens. With the advent of polymerase chain reaction (PCR) analysis, it has become clear that several as yet unidentified Helicobacter species may also colonize rodents, but their capacity to cause disease is unknown. METHODS A Helicobacter species isolated from feces of a BALB/c mouse and provisionally named "H. typhlonicus" was used to inoculate helicobacter-free 4-week-old SCID mice (n = 11 males and 11 females). At various weeks after inoculation, mice were sacrificed and liver and intestinal specimens were collected for histologic examination and PCR analyses. RESULTS The C.B-17 scid/scid mice inoculated with "H. typhlonicus" developed moderate to severe proliferative typhlocolitis, similar to that seen in SCID mice infected with H. hepaticus or H. bilis. However, in contrast to mice infected with H. hepaticus or H. bilis, lesions of chronic active hepatitis were not detected in mice inoculated with "H. typhlonicus." A similar disease syndrome developed in SCID mice cohabitated with B6D2F1 mice naturally infected with a novel Helicobacter species that was genetically identical to "H. typhlonicus." CONCLUSION "Helicobacter typhlonicus" joins a growing list of helicobacters that are capable of inducing enteric disease in immunodeficient mice.
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Transgenic mice demonstrate AP-1 (activator protein-1) transactivation is required for tumor promotion. Proc Natl Acad Sci U S A 1999; 96:9827-32. [PMID: 10449779 PMCID: PMC22295 DOI: 10.1073/pnas.96.17.9827] [Citation(s) in RCA: 315] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Activator protein-1 (AP-1) is a transcription factor that consists of either a Jun-Jun homodimer or a Jun-Fos heterodimer. Transactivation of AP-1 is required for tumor promoter-induced transformation in mouse epidermal JB6 cells and for progression in mouse and human keratinocytes. Until now, the question of whether AP-1 transactivation is required for carcinogenesis in vivo has remained unanswered, as has the issue of functionally significant target genes. To address these issues we have generated a transgenic mouse in which transactivation mutant c-jun (TAM67), under the control of the human keratin-14 promoter, is expressed specifically in the basal cells of the epidermis where tumor induction is initiated. The keratin-14-TAM67 transgene was expressed in the epidermis, tongue, and cervix, with no apparent abnormalities in any tissue or organ. TAM67 expression blocked 12-O-tetradecanoylphorbol 13-acetate (TPA, phorbol 12-tetradecanoate 13-acetate) induction of the AP-1-regulated luciferase in AP-1 luciferase/TAM67 mice, but did not inhibit induction of candidate AP-1 target genes, collagenase-1 or stromelysin-3. More interestingly, TAM67 expression did not inhibit TPA-induced hyperproliferation. In two-stage skin carcinogenesis experiments, the transgenic animals showed a dramatic inhibition of papilloma induction. We conclude that transactivation of a subset of AP-1-dependent genes is required for tumor promotion and may be targeted for cancer prevention.
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A dominant-negative mutant of c-Jun inhibits cell cycle progression during the transition of CD4(-)CD8(-) to CD4(+)CD8(+) thymocytes. Int Immunol 1999; 11:1203-16. [PMID: 10421778 DOI: 10.1093/intimm/11.8.1203] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
While Jun/Fos-containing transcription factors are known to be necessary for many TCR-mediated events in mature T cells, relatively little is known about their roles in thymocyte development. We have generated transgenic mice that express a trans-dominant-negative mutant of c-Jun (TAM-67) specifically in thymocytes. Expression of TAM-67 inhibited the up-regulation of AP-1-responsive genes such as c-jun and IL-2 in stimulated thymocytes from transgenic mice. In addition, altered thymocyte development in TAM-67-expressing mice was revealed by a decrease in thymic cellularity ( approximately 50%) which could be accounted for primarily by a reduction in the number of CD4(+)CD8(+) thymocytes, a large percentage of which retained CD25. The decrease in the number of CD4(+)CD8(+) thymocytes did not appear to be due to an enhanced rate of apoptosis but rather to a decrease in the number of CD4(-)CD8(-)CD25(-) cells in the S + G(2)/M stages of the cell cycle. These results indicate that Jun/Fos-containing transcription factors promote the proliferative burst that accompanies the transition from the CD4(-)CD8(-) to the CD4(+)CD8(+) stage of thymocyte development.
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Abstract
BACKGROUND AND AIM This retrospective study examined the prevalence of co-infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) and the frequency of chronic hepatitis in HIV-infected patients with respect to both the different risk groups and the serological results. PATIENTS AND METHODS All Zurich participants of the Swiss HIV Cohort Study were evaluated who had available results of hepatitis B and C serology and ALT. RESULTS Of the total 279 patients, 52% belonged to the intravenous drug user, 34% to the homosexual, and 11% to the heterosexual risk category. Serologically, previously acquired infection with HBV alone could be demonstrated in 92 (33%), HCV alone in 9 (3%), and both HBV and HCV in 130 (47%) patients. Only 3% of patients with sexually acquired HIV infection had anti-HCV antibodies, whereas co-infection with HBV and HCV was present in 87% of intravenous drug users. Among the 222 patients with previous HBV contact, 25 (11%) had positive HBsAg and 91 (41%) had "anti-HBc alone", both assumed to represent active HBV infection. 66 (24%) of 279 patients had chronic hepatitis with ALT elevation lasting > or = 6 months. Chronic hepatitis was present in 46% of those with active HBV and HCV co-infection, in 36% of those with HCV infection alone and in 18% of those with active HBV infection alone (P < 0.001). Of the 66 cases of chronic hepatitis, 58 were associated with HCV infection, and only 2 cases had no serological signs of active HBV or HCV infection. CONCLUSION In patients with sexually acquired HIV infection, HBV had frequently been co-transmitted. In contrast, almost all of those infected by means of intravenous drug use had a co-infection with both HBV and HCV. The latter seems to play the strongest role in the development of chronic hepatitis with persistent ALT elevation. A chronic ALT elevation was almost always associated with serologically active HBV or HCV infection.
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A targeted glucocorticoid receptor antisense transgene increases thymocyte apoptosis and alters thymocyte development. Immunity 1995; 3:647-56. [PMID: 7584154 DOI: 10.1016/1074-7613(95)90135-3] [Citation(s) in RCA: 135] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The exquisite sensitivity of thymocytes to steroid-induced apoptosis, the steroidogenic potential of thymic epithelial cells, and the ability of steroid synthesis inhibitors to enhance antigen-specific deletion of thymocytes in fetal thymic organ cultures suggest a role for glucocorticoids in thymocyte development. To address this further, transgenic mice that express antisense transcripts to the glucocorticoid receptor (GR) specifically in immature thymocytes were generated. The consequent hyporesponsiveness of thymocytes to glucocorticoids was accompanied by a reduction in thymic size, primarily owing to a decrease in the number of CD4+CD8+ cells. While an enhanced susceptibility to T cell receptor (TCR)-mediated apoptosis appeared to be partially responsible for this reduction, thymocyte loss could also be detected before thymocytes progressed to the CD4+CD8+ TCR alpha beta-expressing stage. These results suggest that glucocorticoids are necessary for survival and maturation of thymocytes, and are consistent with a role for steroids in both the transition from CD4-CD8- to CD4+CD8+ cells and the survival of CD4+CD8+ cells stimulated via the TCR.
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Abstract
The Ly-49A molecule is an NK cell receptor specific for MHC class I molecules on target cells. When Ly-49A engages H-2Dd, Ly-49A+ NK cells become globally incapable of killing their targets in vitro. This interaction also occurs in vivo. Ly-49A belongs to a family of highly related molecules, including Ly-49C (5E6 antigen) and LGL-1 that also determine NK cell specificity. In the NK gene complex, the Ly-49 family is genetically linked to genes encoding NKR-P1 and CD69 that are structurally related and capable of activating NK cells. Finally, Ly-49 may be related to human molecules that are selectively expressed on NK cells and influence NK cell specificity. These findings highlight the emerging significance of the Ly-49 family in NK cell activity.
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Abnormal B-cell function in HTLV-I-tax transgenic mice. Oncogene 1995; 10:1045-51. [PMID: 7700628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Transgenic mice that carry the HTLV-I Tax gene develop an exocrinopathy with some similarities to Sjoegren's syndrome. Our experiments reveal that these mice have lymphadenopathy and splenomegaly composed primarily of B lymphocytes, as well as abnormal levels of secreted immunoglobulins. To gain insight into whether the lymphadenopathy manifested by these transgenic mice was the result of induction of cytokines by Tax, we utilized cell lines from these mice to study in vitro B-cell responses. Conditioned media (CM) derived from the cell lines caused B-cells to proliferate when a second signal, surface Ig cross-linking, was provided. The CM also caused a marked enhancement of IgM secretion by spleen cells or by purified B-cells treated with supplemental cytokines. The B-cell proliferative response and enhanced IgM secretion have not been attributed to a known cytokine. These results suggest that the CM from the cell lines contain a factor(s) involved in novel pathways of B-cell growth and differentiation that may participate in the pathologic development of autoimmune disease.
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Host MHC class I molecules modulate in vivo expression of a NK cell receptor. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1994; 153:2407-16. [PMID: 8077656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Target cell expression of certain MHC class I molecules correlates with resistance to lysis by NK cells. To explain this correlation, one hypothesis states that NK cells may possess two types of receptors; one may activate NK cells whereas another, specific for target cell MHC class I molecules, may inhibit natural killing by transducing negative signals. The cell surface molecule, Ly-49, is expressed on an NK cell subpopulation (15% to 20%) in spleens from C57BL/6 (H-2b) mice. Previously, we showed that lysis by Ly-49+ IL-2-activated NK cells was globally inhibited when targets expressed either H-2Dd or an H-2k-class I molecule, consistent with the hypothesis that Ly-49 is an inhibitory NK cell receptor that engages these MHC class I molecules. We now have determined the influence of specific host MHC class I molecules on Ly-49 expression. In two-color flow cytometric examination of splenic cells, Ly-49+ NK1.1+ cells were undetectable in MHC-congenic strains expressing Dd or Dk, in C57BL/6 mice transgenic for membrane-bound Dd, and in B10.D2dm1 mice. These data establish that Dd itself is sufficient for this effect and suggest that Ly-49 engages Dd-alpha 1/alpha 2 domains. Cross-linking of Ly-49 with membrane-bound Dd may be required because Ly-49+ NK1.1+ cells were readily detectable in C57BL/6 strains transgenic for soluble forms of Dd. To examine whether this effect could be the result of down-regulation of Ly-49 expression or negative selection of Ly-49+ cells, we determined Ly-49 expression on highly purified, freshly isolated NK cell populations (> 90% NK1.1+ CD3- cells). These experiments demonstrated that Ly-49+ cells were present in normal numbers but that Ly-49 expression was markedly decreased in congenic mice expressing H-2Dd or Dk, and in the strain transgenic for membrane-bound H-2Dd. Thus, expression of a putative MHC class I-specific NK cell receptor is modulated by its apparent interaction with alpha 1/alpha 2 domains of host MHC class I molecules.
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Host MHC class I molecules modulate in vivo expression of a NK cell receptor. THE JOURNAL OF IMMUNOLOGY 1994. [DOI: 10.4049/jimmunol.153.6.2407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Target cell expression of certain MHC class I molecules correlates with resistance to lysis by NK cells. To explain this correlation, one hypothesis states that NK cells may possess two types of receptors; one may activate NK cells whereas another, specific for target cell MHC class I molecules, may inhibit natural killing by transducing negative signals. The cell surface molecule, Ly-49, is expressed on an NK cell subpopulation (15% to 20%) in spleens from C57BL/6 (H-2b) mice. Previously, we showed that lysis by Ly-49+ IL-2-activated NK cells was globally inhibited when targets expressed either H-2Dd or an H-2k-class I molecule, consistent with the hypothesis that Ly-49 is an inhibitory NK cell receptor that engages these MHC class I molecules. We now have determined the influence of specific host MHC class I molecules on Ly-49 expression. In two-color flow cytometric examination of splenic cells, Ly-49+ NK1.1+ cells were undetectable in MHC-congenic strains expressing Dd or Dk, in C57BL/6 mice transgenic for membrane-bound Dd, and in B10.D2dm1 mice. These data establish that Dd itself is sufficient for this effect and suggest that Ly-49 engages Dd-alpha 1/alpha 2 domains. Cross-linking of Ly-49 with membrane-bound Dd may be required because Ly-49+ NK1.1+ cells were readily detectable in C57BL/6 strains transgenic for soluble forms of Dd. To examine whether this effect could be the result of down-regulation of Ly-49 expression or negative selection of Ly-49+ cells, we determined Ly-49 expression on highly purified, freshly isolated NK cell populations (> 90% NK1.1+ CD3- cells). These experiments demonstrated that Ly-49+ cells were present in normal numbers but that Ly-49 expression was markedly decreased in congenic mice expressing H-2Dd or Dk, and in the strain transgenic for membrane-bound H-2Dd. Thus, expression of a putative MHC class I-specific NK cell receptor is modulated by its apparent interaction with alpha 1/alpha 2 domains of host MHC class I molecules.
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[Patients with senile dementia--a group of new long-term patients]. PSYCHIATRISCHE PRAXIS 1988; 15:115-21. [PMID: 3136484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A research project is under way at the Department of Psychiatry of the University of Berne, Switzerland, on predictors for new long-term patients, i.e. patients treated on an inpatient basis for more than a year. In a part study all new long-term patients admitted during one year (n = 44) were compared (on the basis of socioeconomic data, disease records, level of intelligence (PMT), psychiatric signs and symptoms pattern (BPRS) and nonadjusted behaviour) with random samples taken from the hospital admissions (n = 58). The overall total of the individual results shows that the new long-term patients originate from two different populations. About 60 per cent are chronically mentally ill patients--mainly schizophrenics--who are additionally under disability in many respects. The remaining two-fifths of the new long-term patients are represented by senile demented patients. It seems that they become permanent psychiatric patients only due to the progressive course of their disease. The article discusses the ways and means to cope with the 50% increase in this patient group that we must anticipate by 2000 A. D. as a result of present age development trends.
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[Criteria of the rehabilitation process in long-term chronic schizophrenic patients]. SOZIAL- UND PRAVENTIVMEDIZIN 1987; 32:144-50. [PMID: 3114979 DOI: 10.1007/bf02083970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
During a year the rehabilitation process of a sample of long stay chronic schizophrenic patients was followed by means of fifteen criteria; the social contacts with outside and working behaviour were continuously registered. The focus was directed toward functional relationships between the indicators.
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Zytogenetische und biochemische Untersuchungen bei der Erzeugung von Injektionschimären beim Rind. Reprod Domest Anim 1986. [DOI: 10.1111/j.1439-0531.1986.tb01577.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Catheter embolism. Surgery 1970; 67:457-61. [PMID: 5413443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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