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2.
Transplantation ; 82(4): 527-33, 2006 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-16926597

RESUMO

BACKGROUND: During the last several years, major progress has been made in developing targeted chemotherapy using cytotoxic drugs covalently bound to human serum albumin (HSA). We explored the activity of two antifolates methotrexate (MTX) and aminopterin (AMPT) bound to HSA in prophylaxis and treatment of experimental acute graft-versus-host disease (aGVHD). METHODS: In all, 113 female F1 hybrid BN/Lew-rats were irradiated with 8.2 Gy (n=103) or 9.9 Gy (n=10). One day after irradiation each rat received 4 x 10 bone marrow cells and 1.5 x 10 spleen T-cells from female Lew-rats. GVHD prophylaxis consisted of MTX-HSA 2 mg/kg (n=25), MTX-HSA 0.5 mg/kg (n=8), AMPT-HSA 0.65 mg/kg (n=8), MTX 0.5 mg/kg (n=17), or native HSA (n=39) given intraperitoneally (IP) on days 0, 4, 8, and 12. Treatment of aGVHD consisted of MTX-HSA 2 mg/kg (n=8) or AMPT-HSA 0.5 mg/kg (n=8) given intraperitoneally at the time of onset of aGVHD and subsequently every fourth day (a total of four doses). RESULTS: All animals receiving native HSA developed lethal aGVHD. Prophylactic treatment with MTX-HSA 2 mg/kg prevented aGVHD in 18 of 25 animals and in 6 of 8 receiving AMPT-HSA. In contrast, five out of nine rats receiving free MTX died due to aGVHD. The survival rates in the prophylactic MTX-HSA 2 mg/kg and AMPT-HSA groups were significantly higher compared to the MTX and control groups (P<0.05), while non hematologic toxicity of MTX-HSA was not detectable. AMPT-HSA at a dose of 0.65 mg/kg as well as MTX at a dose of 0.5 mg/kg were associated with temporary weight loss and lethargy. CONCLUSIONS: The albumin conjugates MTX-HSA and AMPT-HSA effectively prevent experimental aGVHD.


Assuntos
Aminopterina/administração & dosagem , Doença Enxerto-Hospedeiro/prevenção & controle , Imunossupressores/administração & dosagem , Metotrexato/administração & dosagem , Albumina Sérica/administração & dosagem , Doença Aguda , Animais , Feminino , Leucócitos Mononucleares/metabolismo , Ratos , Ratos Endogâmicos Lew , Albumina Sérica/metabolismo
3.
Blood ; 107(4): 1717-23, 2006 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-16278306

RESUMO

CD4+CD25+ regulatory T cells (Tregs) control immune responses to self- and foreign antigens and play a pivotal role in autoimmune diseases, infectious and noninfectious inflammation, and graft rejection. Since recent experimental studies have indicated that Tregs were able to ameliorate graft-versus-host disease (GvHD), we analyzed the number of infiltrating Tregs in the intestinal mucosa as one site of GvH reactivity using immunoenzymatic labeling to enumerate FOXP3+ T cells in 95 intestinal biopsies from 49 allografted patients in comparison with healthy controls and patients with infectious inflammation. While patients with cytomegalovirus (CMV)-colitis or diverticulitis showed a concomitant increase of CD8+ effectors and Tregs, acute and chronic GvHD were characterized by the complete lack of a counter-regulation indicated by a FOXP3+/CD8+ T-cell ratio identical to healthy controls. In contrast, specimens without histologic signs of GvHD demonstrated increased numbers of FOXP3+ per CD8+ T cells, indicating that the potential for Treg expansion is principally maintained in allografted patients. Our findings provide evidence that GvHD is associated with an insufficient up-regulation of Tregs in intestinal GvHD lesions. The determination of FOXP3+/CD8+ ratio can be a helpful tool to discriminate GvHD from infectious inflammation after allogeneic stem cell transplantation.


Assuntos
Fatores de Transcrição Forkhead/imunologia , Doença Enxerto-Hospedeiro/imunologia , Imunidade nas Mucosas , Mucosa Intestinal/imunologia , Linfócitos T/imunologia , Doença Aguda , Antígenos CD/análise , Antígeno CD24/análise , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Doença Crônica , Citometria de Fluxo , Doença Enxerto-Hospedeiro/patologia , Humanos , Infecções/imunologia , Mucosa Intestinal/patologia , Receptores de Interleucina-2/análise , Estudos Retrospectivos , Transplante Homólogo/imunologia , Transplante Homólogo/patologia
4.
Eur J Endocrinol ; 146(1): 89-96, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11751073

RESUMO

OBJECTIVE: The cholecystokinin(2)-receptor (CCK(2)R) promotes secretion and cell growth induced by its ligands cholecystokinin (CCK) and gastrin. The receptor has recently been shown to be expressed in human medullary thyroid carcinomas (MTCs). The objective of this study was to analyze CCK(2)R expression in MTC samples of different tumor stages as well as in non-malignant thyroid tissues. DESIGN AND METHODS: Using RT-PCR we investigated 19 MTC samples and TT-cells (a human MTC cell line), as well as samples of normal thyroid. In addition, we performed immunohistochemistry using calcitonin- and CCK(2)R-specific antibodies on MTCs and samples of C-cell hyperplasia. RESULTS: We demonstrate for the first time that CCK(2)R is expressed not only in MTCs but in all samples of normal thyroid tissue. Using immunohistochemistry the receptor could be localized on calcitonin-secreting C-cells. The highest incidence of CCK(2)R expression in MTCs was observed in early-tumor stages, whereas CCK(2)R could not be detected in advanced or metastasized tumors. CONCLUSIONS: The expression of CCK(2)R in C-cells suggests a physiological function for gastrin and/or CCK in the regulation of calcitonin release, presumably related to bone and calcium metabolism. Moreover, these ligands might act as growth factors in MTCs. Efforts in the development of CCK(2)R scintigraphy for the detection of MTC lesions might have to consider a lower incidence of the receptor in advanced tumor stages.


Assuntos
Carcinoma Medular/metabolismo , Receptores da Colecistocinina/biossíntese , Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/metabolismo , Adolescente , Adulto , Idoso , Comunicação Autócrina/fisiologia , Carcinoma Medular/patologia , Colecistocinina/metabolismo , Feminino , Gastrinas/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Mutação/genética , Oncogenes/genética , Pentagastrina , Receptor de Colecistocinina B , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estimulação Química , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia
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