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Homola M, Kľuka J, Hozzová P, Svátek V, Vacura M. Towards Higher-order OWL. Künstl Intell 2020. [DOI: 10.1007/s13218-020-00665-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Chytrá K, Novák L, Rejtar P, Homola M, Daníčková K, Cĕrvinková I. RADIATION EXPOSURE OF PAEDIATRIC GENERAL RADIOGRAPHY, FLUOROSCOPY AND CT PROCEDURES IN THE CZECH REPUBLIC-PILOT STUDY. Radiat Prot Dosimetry 2019; 186:391-396. [PMID: 31832648 DOI: 10.1093/rpd/ncz238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The pilot dose survey on paediatric general radiography, fluoroscopy and CT procedures was performed in four university hospitals. The analysis of data was focused on the radiography and CT imaging of head, chest, abdomen, pelvis and spine and fluoroscopic procedures of gastrointestinal and urinary tracts. The survey was conducted by the National Radiation Protection Institute. Two hospitals exported data from the patient dose management system, while the others collected the data manually. The methodology of diagnostic reference levels assessment was proposed and tested. Local diagnostic reference levels were calculated in terms of air kerma-area product $P_{KA}$, CT air kerma-length product $P_{KL,CT}$ and volumetric CT air kerma index $C_{VOL}$. The lack of procedure standardisation, e.g. in tube voltage setting irrespective of patient's weight, was revealed at one hospital. Dose and exposure parameters distributions with respect to patient's anatomical constitution are presented in this article. In future, this pilot study will be a base for national survey of paediatric diagnostic reference levels.
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Affiliation(s)
- Kateřina Chytrá
- 1National Radiation Protection Institute, Prague, Czech Republic
| | - Leoš Novák
- 1National Radiation Protection Institute, Prague, Czech Republic
| | - Pavel Rejtar
- 2University Hospital Hradec Kralove, Czech Republic
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Skala T, Tudos Z, Homola M, Moravec O, Kocher M, Cerna M, Ctvrtlik F, Odstrcil F, Langova K, Klementova O, Taborsky M. The impact of ECG synchronization during acquisition of left‑atrium computed tomography model on radiation dose and arrhythmia recurrence rate after catheter ablation of atrial fibrillation - a prospective, randomized study. BRATISL MED J 2019; 120:177-183. [PMID: 31023034 DOI: 10.4149/bll_2019_033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND The impact of ECG gating during computed tomography (CT) acquisition of left atrium (LA) model on radiation dose, image quality and ablation event-free survival rate after catheter ablation (CA) of atrial fibrillation (AF) is not well defined. METHODS Sixty-two patients with paroxysmal atrial fibrillation were randomized for two types of LA CT (with vs without ECG gating) before CA. Pulmonary veins isolation was performed in all patients. Patients were followed for 12 months after CA. RESULTS There was no difference between the groups in CA length (131.61±32.57 vs 119.84±33.18 min; p=0.108), CA fluoroscopy time (4.48±2.19 vs 3.89±1.83 min; p=0.251), CA fluoroscopy dose (3.99±2.79 vs 3.91 vs2.91 Gy*cm2; p=0.735), visual data quality (1.77±0.88 vs 2.0±0.63; p=0.102) and registration error (2.42±0.72 vs 2.43±0.46 mm; p=0.612). We found a significant difference in CT Dose index (89.55±5.99 vs 19.19±4.33 mGy; p<0.0001) and Dose Length product (1438.87±147.75 vs 328.21±73.83 mGy*cm; p<0.0001). Twelve months after CA, 25 of 31 patients in the gated group and 24 of 31 patients in the non-gated group were free of AF (80.65 vs 77.42 %; p=0.838). CONCLUSION ECG gating of computed tomography of LA before AF ablation burdens patients with a four times higher radiation dose while improving neither the quality of CT model or fusion of CT with the electroanatomic map. As a result, it has no significant impact on arrhythmia recurrence rate after ablation (Tab. 3, Fig. 3, Ref. 25).
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Tudos Z, Skala T, Homola M, Moravec O, Taborsky M, Kocher M, Cerna M, Ctvrtlik F, Odstrcil F, Langova K, Klementova O. ECG non-gated multi-detector computed tomography protocol prior to catheter ablation of atrial fibrillation provides sufficient data quality with lower radiation exposure compared to ECG-gated protocol - results of a prospective, randomized and blinded study. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2018; 162:310-318. [PMID: 30181665 DOI: 10.5507/bp.2018.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The role of ECG-gating in left atrium (LA) computed tomography (MDCT) imaging is not precisely defined. METHODS AND RESULTS 62 patients were randomized according to ECG gating with prospective evaluation of image quality, Volume CT Dose Index, Dose Length Product, Effective Dose and registration error between anatomical map and MDCT. We found significant difference in all radiation variables, but not in visual quality, registration error, CA duration, CA fluoroscopy time and CA fluoroscopy dose. CONCLUSION Helical non-gated MDCT achieved a radiation dose more than four times lower with comparable image quality and course of ablation compared to ECG-gated protocol.
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Affiliation(s)
- Zbynek Tudos
- Department of Radiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic
| | - Tomas Skala
- Department of Internal Medicine I - Cardiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic
| | - Martin Homola
- Department of Medical Physics and Radiation Protection, University Hospital Olomouc, Czech Republic
| | - Ondrej Moravec
- Department of Internal Medicine I - Cardiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic
| | - Milos Taborsky
- Department of Internal Medicine I - Cardiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic
| | - Martin Kocher
- Department of Radiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic
| | - Marie Cerna
- Department of Radiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic
| | - Filip Ctvrtlik
- Department of Radiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic
| | - Frantisek Odstrcil
- Department of Radiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic
- Department of Radiological Methods, Faculty of Health Sciences, Palacky University Olomouc, Czech Republic
| | - Katerina Langova
- Department of Medical Biophysics, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic
| | - Olga Klementova
- Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Czech Republic
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Cole MS, Stellrecht KE, Shi JD, Homola M, Hsu DH, Anasetti C, Vasquez M, Tso JY. HuM291, a humanized anti-CD3 antibody, is immunosuppressive to T cells while exhibiting reduced mitogenicity in vitro. Transplantation 1999; 68:563-71. [PMID: 10480417 DOI: 10.1097/00007890-199908270-00020] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND OKT3, a mouse monoclonal antibody (Ab) specific for the human CD3 complex on T cells, is a potent immunosuppressive agent used for the treatment of acute allograft rejection. The utility of the drug has been limited by a neutralizing anti-mouse Ab response and adverse side effects resulting from T cell activation and systemic cytokine release. T cell activation is caused by OKT3-mediated cross-linking of T cells and Fc receptor-bearing cells. Studies in the mouse model have shown that global T cell activation is not necessary for immunosuppression, as Fc receptor-nonbinding anti-CD3 Abs can suppress graft rejection in the absence of the activation effects seen with Fc receptor-binding Abs. Thus, a humanized anti-CD3 antibody with a low affinity for Fc receptors might improve immunosuppressive therapy by reducing the side effects associated with OKT3. METHODS We developed a mouse monoclonal Ab, M291, which competes with OKT3 for binding to T cells. Humanized, complementary-determining region-grafted versions of M291 featuring various Fc were engineered, including a previously described IgG2 mutant deficient in Fc receptor binding (HuM291). RESULTS Compared with OKT3 and HuM291-IgG1, HuM291 was significantly less mitogenic to T cells in vitro and induced the release of much lower levels of the cytokines tumor necrosis factor-alpha, interferon-gamma, and interleukin-10. Despite this reduction in T cell activation, HuM291 retained the ability to modulate the CD3 complex and inhibit the mixed lymphocyte reaction. CONCLUSIONS When evaluated in vivo, HuM291 may be an immunosuppressive agent associated with less of the acute toxicity and immunogenicity seen with OKT3 therapy.
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Affiliation(s)
- M S Cole
- Protein Design Labs, Inc., Fremont, California 94555, USA
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Hsu DH, Shi JD, Homola M, Rowell TJ, Moran J, Levitt D, Druilhet B, Chinn J, Bullock C, Klingbeil C. A humanized anti-CD3 antibody, HuM291, with low mitogenic activity, mediates complete and reversible T-cell depletion in chimpanzees. Transplantation 1999; 68:545-54. [PMID: 10480415 DOI: 10.1097/00007890-199908270-00018] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND An anti-CD3 antibody that reduces cytokine release syndrome (CRS) while maintaining immunosuppression would be a major advance in the treatment of acute allograft rejection. A humanized (Hu) anti-CD3 IgG2 Ab, HuM291 gamma2 M3 (HuM291; Protein Design Labs, Inc., Mountain View, CA), was engineered with mutations in the upper CH2 region of the Fc domain. The mutations were intended to reduce affinity for Fcgamma receptors, thought to be relevant to CRS. METHODS In vitro studies using chimpanzee peripheral blood mononuclear cells (PBMCs) were conducted to characterize HuM291 and to establish an animal model. A multidose study was conducted in chimpanzees to evaluate the safety, pharmacokinetics, immunomodulatory activity, and immunogenicity of HuM291, when administered at doses ranging from 0.1 to 10 mg. RESULTS HuM291 bound to and effectively downmodulated CD3 from chimpanzee PBMCs and stimulated substantially less cytokine secretion and proliferation of chimpanzee PBMCs compared with OKT3 (Orthoclone OKT3; Ortho Pharmaceutical Corp., Raritan, NJ). Multiple doses of HuM291 (0.1, 1.0, or 10 mg/dose) were not associated with adverse events, signs of toxicity, or CRS, despite cytokine release. HuM291 exhibited a long elimination t1/2 (81.5 hr) and, after three 10-mg doses, sustained serum concentrations > 1000 ng/ml were maintained for 1 week. Multiple 10-mg doses induced complete depletion of circulating CD2+CD3+ T cells for up to 10 days after the last dose; T cells recovered by Day 28. Anti-HuM291 Abs were observed in only 4 of 12 animals and were transient in 2 of those animals. CONCLUSIONS In vitro, HuM291 is substantially less mitogenic than OKT3. In chimpanzees, HuM291 effectively depleted peripheral T cells without eliciting clinical signs of CRS, and recovered T cells were functionally normal.
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Affiliation(s)
- D H Hsu
- Protein Design Labs, Inc., Fremont, California 94555, USA
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Gelber C, Gemmell L, McAteer D, Homola M, Swain P, Liu A, Wilson KJ, Gefter M. Down-regulation of poison ivy/oak-induced contact sensitivity by treatment with a class II MHC binding peptide:hapten conjugate. J Immunol 1997; 158:2425-34. [PMID: 9036993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Immune regulation of contact sensitivity to the poison ivy/oak catechol was studied at the level of class II MHC-restricted T cell recognition of hapten:peptide conjugates. In this study we have shown that 1) T cells from C3H/HeN (H-2k) mice, immunized with a synthetic I-Ak binding peptide coupled to 3-pentadecyl-catechol (PDC; a representative catechol in urushiol), recognized peptides derived from syngeneic cells linked to the same catechol; 2) T cells from draining lymph nodes of C3H/HeN mice skin-painted with PDC proliferated in response to a peptide carrier:PDC conjugate only when it was linked at the 7th, but not the 4th or the 10th, position on the peptide carrier; and 3) tolerization studies confirmed down-regulation of PDC-induced delayed-type hypersensitivity following treatment with a single I-Ak binding peptide carrying PDC covalently bound to a lysine residue at the middle (7th) TCR contact position. Tolerization with peptide:PDC conjugate resulted in abrogation of hapten-specific T cell proliferative responses that correlated with diminished IL-2 secretion. On the basis of these data we propose that it may be sufficient to couple the hapten at a single, well-chosen position on a carrier peptide to target a relevant population of T cells involved in contact sensitivity.
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Affiliation(s)
- C Gelber
- ImmuLogic Pharmaceutical Corporation, Waltham, MA 02154, USA
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Gelber C, Gemmell L, McAteer D, Homola M, Swain P, Liu A, Wilson KJ, Gefter M. Down-regulation of poison ivy/oak-induced contact sensitivity by treatment with a class II MHC binding peptide:hapten conjugate. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.158.5.2425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Immune regulation of contact sensitivity to the poison ivy/oak catechol was studied at the level of class II MHC-restricted T cell recognition of hapten:peptide conjugates. In this study we have shown that 1) T cells from C3H/HeN (H-2k) mice, immunized with a synthetic I-Ak binding peptide coupled to 3-pentadecyl-catechol (PDC; a representative catechol in urushiol), recognized peptides derived from syngeneic cells linked to the same catechol; 2) T cells from draining lymph nodes of C3H/HeN mice skin-painted with PDC proliferated in response to a peptide carrier:PDC conjugate only when it was linked at the 7th, but not the 4th or the 10th, position on the peptide carrier; and 3) tolerization studies confirmed down-regulation of PDC-induced delayed-type hypersensitivity following treatment with a single I-Ak binding peptide carrying PDC covalently bound to a lysine residue at the middle (7th) TCR contact position. Tolerization with peptide:PDC conjugate resulted in abrogation of hapten-specific T cell proliferative responses that correlated with diminished IL-2 secretion. On the basis of these data we propose that it may be sufficient to couple the hapten at a single, well-chosen position on a carrier peptide to target a relevant population of T cells involved in contact sensitivity.
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Affiliation(s)
- C Gelber
- ImmuLogic Pharmaceutical Corporation, Waltham, MA 02154, USA
| | - L Gemmell
- ImmuLogic Pharmaceutical Corporation, Waltham, MA 02154, USA
| | - D McAteer
- ImmuLogic Pharmaceutical Corporation, Waltham, MA 02154, USA
| | - M Homola
- ImmuLogic Pharmaceutical Corporation, Waltham, MA 02154, USA
| | - P Swain
- ImmuLogic Pharmaceutical Corporation, Waltham, MA 02154, USA
| | - A Liu
- ImmuLogic Pharmaceutical Corporation, Waltham, MA 02154, USA
| | - K J Wilson
- ImmuLogic Pharmaceutical Corporation, Waltham, MA 02154, USA
| | - M Gefter
- ImmuLogic Pharmaceutical Corporation, Waltham, MA 02154, USA
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Birch CJ, Lewis FA, Kennett ML, Homola M, Pritchard H, Gust ID. A study of the prevalence of rotavirus infection in children with gastroenteritis admitted to an infectious diseases hospital. J Med Virol 1977; 1:69-77. [PMID: 204738 DOI: 10.1002/jmv.1890010109] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In a 12 month survey of infants and children with gastroenteritis admitted to Fairfield Hospital, Melbourne, rotavirus was found in approximately 42% of patients. This virus was detected more often during the winter months, particularly in children aged between 12 months and 3 years. Detection of rotavirus by electron microscopy was found to be more sensitive than by counterimmunoelectrophoresis. Routine bacterial and viral studies revealed that bacterial pathogens and common enteric viruses were associated with relatively few cases of gastroenteritis. There is little doubt that rotavirus is the most important aetiological agent of acute gastroenteritis in yvirus is the most important aetiological agent of acute gastroenteritis in young children in Melbourne.
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