Purpose: To test whether platelet-activating factor (PAF) directly causes retinovascular endothelial cell (EC) death.
Methods: Retinovascular density was calculated in rat pups exposed to 80% O(2) from postnatal days (P)6 to P14 (to produce oxygen-induced retinopathy [OIR]), using the adenosine diphosphatase (ADPase) technique, in animals treated with distinct PAF receptor blockers (PCA-4248, BN52021, or THG315). PAF levels were then measured in the retinas. Viability of ECs from piglets and humans in response to C-PAF (a stable PAF analogue) was determined by the reduction of the tetrazolium salt 3-(4,5-dimethyl thiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) by viable cells, incorporation of propidium iodide (PI), TUNEL assay, and release of lactate dehydrogenase. Release of thromboxane (TX) was measured in the cell media.
Results: PAF levels in retina were markedly increased by exposure of isolated rat retinas to H(2)O(2) (1 micro M) and of rat pups placed in 80% O(2). Exposure to 80% O(2) induced retinal vasoobliteration, which was equally significantly inhibited ( approximately 60%) by all PAF receptor blockers tested. C-PAF increased incorporation of PI by isolated rat retinal microvasculature. Also, C-PAF caused time- and concentration-dependent death of cultured retinal ECs, which was prevented by the PAF receptor antagonist CV-3988. This effect of C-PAF was selective on retinal and neurovascular ECs, but not on other ECs. DNA fragmentation (TUNEL) was hardly detected, and inhibition of apoptosis-related processes by nicotinamide, cyclosporin A, and Z-DEVD-FMK and Z-VAD-FMK (caspase inhibitors) barely protected against death in EC, whereas C-PAF increased release of lactate dehydrogenase, implying that necrosis is the nature of EC death. Finally, C-PAF-induced cell death was preceded by an increase in TXB(2) levels and was prevented by TXA(2) synthase inhibition (with CGS12970).
Conclusions: The data suggest PAF plays a major role in vasoobliteration in OIR by triggering death of neuroretinal microvascular ECs. The cell death seems to be mediated at least in part by TXA(2). These effects of PAF may participate in ischemic retinopathies such as diabetes and retinopathy of prematurity.
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Introduction: Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease that affects various body systems, including the skin and facial features. Estrogen promotes lupus in human and mouse models of SLE. In this study, we conducted an in vivo study to investigate the relationship between two estrogen receptors (ERα and ERβ) and platelet-activating factor acetylhydrolase (PAF-AH) on the symptoms of SLE.
View Article and Find Full Text PDFBreast Cancer Res
January 2025
Department of Gynecology and Obstetrics, Erlangen University Hospital, Comprehensive Cancer Center Erlangen-EMN, Friedrich Alexander University of Erlangen-Nuremberg, Erlangen, Germany.
Background: Pathological complete response (pCR) is an established surrogate marker for prognosis in patients with breast cancer (BC) after neoadjuvant chemotherapy. Individualized pCR prediction based on clinical information available at biopsy, particularly immunohistochemical (IHC) markers, may help identify patients who could benefit from preoperative chemotherapy.
Methods: Data from patients with HER2-negative BC who underwent neoadjuvant chemotherapy from 2002 to 2020 (n = 1166) were used to develop multivariable prediction models to estimate the probability of pCR (pCR-prob).
Precis Clin Med
March 2025
Department of Gynecology and Obstetrics, CIO ABCD, University Hospital Düsseldorf, Düsseldorf 40225, Germany.
Background: Circulating cell-free tumor DNA (ctDNA) provides a non-invasive approach for assessing somatic alterations. The German PRAEGNANT registry study aims to explore molecular biomarkers and investigate their integration into clinical practice. In this context, ctDNA testing was included to understand the motivations of clinicians to initiate testing, to identify somatic alterations, and to assess the clinical impact of the results obtained.
View Article and Find Full Text PDFNat Med
January 2025
University of California Los Angeles, Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA.
Addition of pembrolizumab to neoadjuvant chemotherapy followed by adjuvant pembrolizumab improved outcomes in patients with high-risk, early-stage, triple-negative breast cancer. However, whether the addition of neoadjuvant pembrolizumab to chemotherapy would improve outcomes in high-risk, early-stage, estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER/HER2) breast cancer remains unclear. We conducted a double-blind, placebo-controlled phase 3 study (KEYNOTE-756) in which patients with previously untreated ER/HER2 grade 3 high-risk invasive breast cancer (T1c-2 (≥2 cm), cN1-2 or T3-4, cN0-2) were randomly assigned (1:1) to neoadjuvant pembrolizumab 200 mg or placebo Q3W given with paclitaxel QW for 12 weeks, followed by four cycles of doxorubicin or epirubicin plus cyclophosphamide Q2W or Q3W.
View Article and Find Full Text PDFN Engl J Med
January 2025
From the National Surgical Adjuvant Breast and Bowel Project (NSABP) Foundation (C.E.G., E.P.M., N.W., P.R., I.L.W., A.M.B.) and University of Pittsburgh School of Medicine-UPMC Hillman Cancer Center (C.E.G., N.W., P.R., A.M.B.) - both in Pittsburgh; AGO-B and Helios Klinikum Berlin-Buch, Berlin (M.U.), the National Center for Tumor Diseases, Heidelberg University Hospital, and German Cancer Research Center, Heidelberg (A.S.), Evangelische Kliniken Gelsenkirchen, Gelsenkirchen (H.H.F.), Arbeitsgemeinschaft Gynäkologische Onkologie-Breast and Sana Klinikum Offenbach, Offenbach (C.J.), the Department of Gynecology and Obstetrics, University Hospital Erlangen, Comprehensive Cancer Center Erlangen-EMN, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen (P.A.F.), German Breast Group, Neu-Isenburg (P.W., S.L.), and the Center for Hematology and Oncology Bethanien, Goethe University, Frankfurt (S.L.) - all in Germany; National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (C.-S.H.); Instituto do Câncer do Estado de São Paulo, São Paulo (M.S.M.); Orlando Health Cancer Institute, Orlando, FL (E.P.M.); Hospital Universitario La Paz-Instituto de Investigación del Hospital Universitario La Paz, Madrid (A.R.); L'Institut du Cancer de Montpellier-Val d'Aurelle, Montpellier (V.D.), Institut Bergonié, INSERM Unité 1312, and Université de Bordeaux UFR Sciences Médicales, Bordeaux (H.R.B.) - all in France; Providence Cancer Institute, Portland, OR (A.K.C.); the Department of Surgery, Oncology, and Gastroenterology, University of Padua, and Oncology 2, Istituto Oncologico Veneto IRCCS, Padua (V.G.), and the Cancer Center Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo (E.R.C.) - all in Italy; Stanford University School of Medicine, Stanford, CA (I.L.W.); the National Cancer Institute, Mexico City (C.A.-S.); Yale University School of Medicine, Yale Cancer Center, and Smilow Cancer Hospital, New Haven, CT (M.P.D.); the All-Ireland Cooperative Oncology Research Group (J.P.C.), and the Oncology Unit, Cancer Clinical Trials and Research Unit, Beaumont RCSI Cancer Centre, and Cancer Trials Ireland (B.T.H.) - all in Dublin; Fudan University Shanghai Cancer Center, Shanghai, China (Z.S.); Institute for Oncology and Radiology of Serbia, Belgrade (L.S.); Grupo Médico Ángeles, Guatemala City, Guatemala (H.C.-S.); Roche Products, Welwyn Garden City, United Kingdom (A.K., A.S.); and F. Hoffmann-La Roche, Basel, Switzerland (C.L., T.B., B.N., E.R.).
Background: Patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer with residual invasive disease after neoadjuvant systemic therapy have a high risk of recurrence and death. The primary analysis of KATHERINE, a phase 3, open-label trial, showed that the risk of invasive breast cancer or death was 50% lower with adjuvant trastuzumab emtansine (T-DM1) than with trastuzumab alone.
Methods: We randomly assigned patients with HER2-positive early breast cancer with residual invasive disease in the breast or axilla after neoadjuvant systemic treatment with taxane-based chemotherapy and trastuzumab to receive T-DM1 or trastuzumab for 14 cycles.
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