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22 result(s) for "Mazal, P"
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Supervised machine learning enables non-invasive lesion characterization in primary prostate cancer with 68GaGa-PSMA-11 PET/MRI
PurposeRisk classification of primary prostate cancer in clinical routine is mainly based on prostate-specific antigen (PSA) levels, Gleason scores from biopsy samples, and tumor-nodes-metastasis (TNM) staging. This study aimed to investigate the diagnostic performance of positron emission tomography/magnetic resonance imaging (PET/MRI) in vivo models for predicting low-vs-high lesion risk (LH) as well as biochemical recurrence (BCR) and overall patient risk (OPR) with machine learning.MethodsFifty-two patients who underwent multi-parametric dual-tracer [18F]FMC and [68Ga]Ga-PSMA-11 PET/MRI as well as radical prostatectomy between 2014 and 2015 were included as part of a single-center pilot to a randomized prospective trial (NCT02659527). Radiomics in combination with ensemble machine learning was applied including the [68Ga]Ga-PSMA-11 PET, the apparent diffusion coefficient, and the transverse relaxation time-weighted MRI scans of each patient to establish a low-vs-high risk lesion prediction model (MLH). Furthermore, MBCR and MOPR predictive model schemes were built by combining MLH, PSA, and clinical stage values of patients. Performance evaluation of the established models was performed with 1000-fold Monte Carlo (MC) cross-validation. Results were additionally compared to conventional [68Ga]Ga-PSMA-11 standardized uptake value (SUV) analyses.ResultsThe area under the receiver operator characteristic curve (AUC) of the MLH model (0.86) was higher than the AUC of the [68Ga]Ga-PSMA-11 SUVmax analysis (0.80). MC cross-validation revealed 89% and 91% accuracies with 0.90 and 0.94 AUCs for the MBCR and MOPR models respectively, while standard routine analysis based on PSA, biopsy Gleason score, and TNM staging resulted in 69% and 70% accuracies to predict BCR and OPR respectively.ConclusionOur results demonstrate the potential to enhance risk classification in primary prostate cancer patients built on PET/MRI radiomics and machine learning without biopsy sampling.
68Ga-PSMA 11 ligand PET imaging in patients with biochemical recurrence after radical prostatectomy – diagnostic performance and impact on therapeutic decision-making
Objective To evaluate the diagnostic performance of [ 68 Ga]Ga-PSMA HBED-CC conjugate 11 positron emission tomography (PSMA-PET) in the early detection of metastases in patients with biochemical recurrence (BCR) after radical prostatectomy (RP) for clinically non-metastatic prostate cancer, to compare it to CT/MRI alone and to assess its impact on further therapeutic decisions. Material and methods We retrospectively assessed 117 consecutive hormone-naïve BCR patients who had 68 Ga-PSMA 11 PET/CT ( n  = 46) or PET/MRI ( n  = 71) between May 2014 and January 2017. BCR was defined as two PSA rises above 0.2 ng/ml. Two dedicated uro-oncological imaging experts (radiology/nuclear medicine) reviewed separately all images. All results were presented in a blinded sequential fashion to a multidisciplinary tumorboard in order to assess the influence of PSMA-PET imaging on decision-making. Results The median time from RP to BCR was 36 months (IQR 16–72). Overall, 69 (59%) patients received postoperative radiotherapy. Median PSA level at the time of imaging was 1.04 ng/ml (IQR 0.58–1.87). PSMA-positive lesions were detected in 100 (85.5%) patients. Detection rates were 65% for a PSA value of 0.2 to <0.5 ng/ml, 85.7% for 0.5 to <1, 85.7% for 1 to <2 and 100% for ≥2. PSMA-positive lesions could be confirmed by either histology (16%), PSA decrease in metastasis-directed radiotherapy (45%) or additional information in diffusion-weighted imaging when PET/MRI was performed (18%) in 79% of patients. PSMA-PET detected lesions in 67 patients (57.3%) who had no suspicious correlates according to the RECIST 1.1 criteria on MRI or CT. PSMA-PET changed therapeutic decisions in 74.6% of these 67 patients ( p  < 0.001), with 86% of them being considered for metastases-directed therapies. Conclusions We confirm the high performance of PSMA-PET imaging for the detection of disease recurrence sites in patients with BCR after RP, even at relatively low PSA levels. Moreover, it adds significant information to standard CT/MRI, changing treatment strategies in a significant number of patients.
Capillary haemangioma of the testis
A case of testicular capillary haemangioma is reported and the importance of intraoperative examination of this very rare lesion emphasised. Capillary haemangioma of the testis can be similar to malignant testicular tumours on clinical presentation, as well as on ultrasonography and magnetic resonance imaging, and therefore should be included in the intraoperative differential diagnosis. Because of the benign nature of this lesion, conservative surgical treatment by means of tumour enucleation with preservation of the testis is possible, if intraoperative examination of frozen sections of representative tissue can be performed.
Kynurenic acid metabolism in the brain of HIV-1 infected patients
Patients who are infected with human immunodeficiency virus type 1 (HIV-1) frequently present with neurological and psychiatric symptoms. Kynurenic acid (KYNA), an intermediate metabolite of L-kynurenine (L-KYN), is a neuroprotectant and a broad-spectrum antagonist at excitatory amino acid (EAA) receptors. The present study examines the biosynthetic machinery of KYNA in the frontal cortex and cerebellum of 25 HIV-1 and 16 control (CO) patients. We measured the contents of L-KYN and KYNA and the activity of enzymes synthesizing KYNA, kynurenine aminotransferases I and II (KAT I and KAT II). The KYNA level was significantly increased in the frontal cortex (209 ± 38% of CO; p < 0.05) and moderately increased in the cerebellum (164 ± 31% of CO) of HIV-1 brains as compared with controls. The bioprecursor of KYNA, L-KYN, was increased in frontal cortex (188 ± 45% of CO) and cerebellum (151 ± 16% of CO; p < 0.05). The elevated KYNA in frontal cortex correlated with significant increases of KAT I (341 ± 95% of CO; p < 0.05) and KAT II (141 ± 8% of CO; p < 0.05). In the cerebellum, a high KYNA content was in the line with increased KAT I (262 ± 52% of CO; p < 0.05) activity, while KAT II was in a control range (85 ± 12% of CO). This study demonstrates that HIV-1 infection associates with elevated KYNA synthesis in the brain. In contrast to KAT II, KAT I was prominently increased in both brain regions investigated. Differences in neurochemical parameters of KYNA metabolism between frontal cortex and cerebellum suggests selective tissue damage. Drugs which influence the synthesis of the endogenous neuroprotectant KYNA may become useful in the therapy of neuropsychiatric manifestations of HIV-1 infected patients.
Fibroblasts Can Express Glial Fibrillary Acidic Protein (GFAP) In Vivo
Neuropathologists use anti-glial fibrillary acidic protein (GFAP) antibodies as specific markers for glial cells, and neurobiologists use GFAP for targeting transgenes to glial cells. Since GFAP has also been detected in non-glial cells, we systematically analyzed GFAP expression in human and murine non-CNS tissues using a panel of anti-GFAP antibodies. In human tissues we confirm previously observed GFAP expression in Schwann cells, myoepithelial cells, and chondrocytes, and show for the first time GFAP expression in fibroblasts of epiglottic and auricular perichondrium, ligamentum flavum, and cardiac valves. In mice we show GFAP expression in Schwann cells, bone marrow stromal cells, chondrocytes, and in fibroblasts of dura mater, skull and spinal perichondrium, and periosteum, connective stroma of oral cavity, dental pulp, and cardiac valves. Anti-GFAP immunoblotting of human non-CNS tissues reveals protein bands with a molecular mass ranging between ≈35 and ≈42 kDa. In GFAP-v-src transgenic mice, whose oncogenic v-src transgene transforms GFAP expressing cells, non-CNS tumors originate from fibroblasts. We conclude that human and murine fibroblasts can express GFAP in vivo. The somatic distribution of GFAP expressing fibroblasts indicates origin from the neural crest. Development of non-CNS tumors from fibroblasts in GFAP-v-src mice functionally confirms GFAP expression in these cells.
Lymphatic endothelial progenitor cells contribute to de novo lymphangiogenesis in human renal transplants
De novo lymphangiogenesis influences the course of different human diseases as diverse as chronic renal transplant rejection 1 and tumor metastasis 2 , 3 . The cellular mechanisms of lymphangiogenesis in human diseases are currently unknown, and could involve division of local preexisting endothelial cells or incorporation of circulating progenitors. We analyzed renal tissues of individuals with gender-mismatched transplants who had transplant rejection and high rates of overall lymphatic endothelial proliferation as well as massive chronic inflammation. Donor-derived cells were detected by in situ hybridization of the Y chromosome. We compared these tissues with biopsies of essentially normal skin and intestine, and two rare carcinomas with low rates of lymphatic endothelial proliferation that were derived from individuals with gender-mismatched bone marrow transplants. Here, we provide evidence for the participation of recipient-derived lymphatic progenitor cells in renal transplants. In contrast, lymphatic vessels of normal tissues and those around post-transplant carcinomas did not incorporate donor-derived progenitors. This indicates a stepwise mechanism of inflammation-associated de novo lymphangiogenesis, implying that potential lymphatic progenitor cells derive from the circulation, transmigrate through the connective tissue stroma, presumably in the form of macrophages, and finally incorporate into the growing lymphatic vessel.
Resection of a Langerhans cell histiocytosis granuloma of the hypothalamus: case report
The natural course and optimal treatment for isolated hypothalamic Langerhans cell histiocytosis (LCH) are unknown.We describe an adult female in whom total resection of a hypothalamic LCH granuloma was performed 12 years after transphenoidal resection of a pituitary adenoma. A retrospective review of the histological specimen of the first operation revealed CD1a positive cells characteristic of LCH along with a plurihormonal adenoma 12 years earlier. No other manifestations of LCH were found and MRI of the brain at the last follow-up 4 years after surgery did not show any recurrent or additional lesion.The diagnosis of isolated hypothalamic LCH is only possible by biopsy and our case demonstrates the feasability of a gross total resection in certain cases.
Expression of aquaporins and PAX-2 compared to CD10 and cytokeratin 7 in renal neoplasms: a tissue microarray study
Diagnostic use of antibodies against aquaporin water channel proteins and PAX-2, a nuclear transcription factor in renal development, was tested in 202 renal neoplasms, using tissue microarray technique. Immunohistochemistry for aquaporin-1, aquaporin-2, PAX-2, CD10, and cytokeratin 7 was performed on 102 clear cell renal cell carcinomas, 44 papillary renal cell carcinomas (among them 34 type 1 and 10 type 2), 24 chromophobe renal cell carcinomas, three collecting duct carcinomas (carcinomas of the collecting ducts of Bellini), and 29 oncocytomas. Aquaporin-1 expression was found in clear cell renal cell carcinomas and papillary renal cell carcinomas of both types (78 and 73%, respectively), but not in chromophobe renal cell carcinomas, collecting duct carcinomas, and oncocytomas. Aquaporin-2 expression was not seen in any of the tested tumors. PAX-2 and CD10 was found in the majority of clear cell renal cell carcinomas (88 and 85%, respectively) but only in few papillary renal cell carcinomas, chromophobe renal cell carcinomas and oncocytomas. Decrease or loss of aquaporin-1 and PAX-2 was shown in higher grades compared to lower grades of clear cell renal cell carcinomas (P<0.0001 and <0.0245, respectively). Cytokeratin 7 was rarely seen in clear cell renal cell carcinomas, type 2 papillary renal cell carcinomas, and oncocytomas, but was found in the majority of type 1 papillary renal cell carcinomas (97.1%) and chromophobe renal cell carcinomas (88%). Aquaporin-1 and PAX-2 expression was found to correlate with nuclear grading for clear cell renal cell carcinomas but not for papillary renal cell carcinomas. No correlation of tumor stage and aquaporin-1 and PAX-2 expression was seen. Aquaporin-1 and PAX-2 are reliable markers for clear cell renal cell carcinomas of lower grades but not for higher grades. CD10 expression remains stable, independent of nuclear grading.
68 Ga-PSMA 11 ligand PET imaging in patients with biochemical recurrence after radical prostatectomy - diagnostic performance and impact on therapeutic decision-making
To evaluate the diagnostic performance of [ Ga]Ga-PSMA conjugate 11 positron emission tomography (PSMA-PET) in the early detection of metastases in patients with biochemical recurrence (BCR) after radical prostatectomy (RP) for clinically non-metastatic prostate cancer, to compare it to CT/MRI alone and to assess its impact on further therapeutic decisions. We retrospectively assessed 117 consecutive hormone-naïve BCR patients who had Ga-PSMA 11 PET/CT (n = 46) or PET/MRI (n = 71) between May 2014 and January 2017. BCR was defined as two PSA rises above 0.2 ng/ml. Two dedicated uro-oncological imaging experts (radiology/nuclear medicine) reviewed separately all images. All results were presented in a blinded sequential fashion to a multidisciplinary tumorboard in order to assess the influence of PSMA-PET imaging on decision-making. The median time from RP to BCR was 36 months (IQR 16-72). Overall, 69 (59%) patients received postoperative radiotherapy. Median PSA level at the time of imaging was 1.04 ng/ml (IQR 0.58-1.87). PSMA-positive lesions were detected in 100 (85.5%) patients. Detection rates were 65% for a PSA value of 0.2 to <0.5 ng/ml, 85.7% for 0.5 to <1, 85.7% for 1 to <2 and 100% for ≥2. PSMA-positive lesions could be confirmed by either histology (16%), PSA decrease in metastasis-directed radiotherapy (45%) or additional information in diffusion-weighted imaging when PET/MRI was performed (18%) in 79% of patients. PSMA-PET detected lesions in 67 patients (57.3%) who had no suspicious correlates according to the RECIST 1.1 criteria on MRI or CT. PSMA-PET changed therapeutic decisions in 74.6% of these 67 patients (p < 0.001), with 86% of them being considered for metastases-directed therapies. We confirm the high performance of PSMA-PET imaging for the detection of disease recurrence sites in patients with BCR after RP, even at relatively low PSA levels. Moreover, it adds significant information to standard CT/MRI, changing treatment strategies in a significant number of patients.
Derivation of Nephrogenic Adenomas from Renal Tubular Cells in Kidney-Transplant Recipients
Nephrogenic adenomas are benign growths in the urothelial mucosa that can cause hematuria or dysuria. Their origin is unknown. This detailed study of nephrogenic adenomas from recipients of kidney grafts showed that in all cases the adenoma had the sex chromosomes of the donor kidney and the immunohistochemical features of renal tubular cells. Nephrogenic adenomas are benign growths that can cause hematuria or dysuria. Nephrogenic adenomas are rare, benign, tumor-like lesions within the urothelial mucosa of the urinary tract. Most nephrogenic adenomas are found in the bladder, but other locations (pelvic urothelium, ureter, and urethra) have been reported. 1 – 6 They occur in patients with chronic bladder inflammation or previous genitourinary surgery, and they are particularly frequent in renal-transplant recipients. 7 – 16 The pathogenesis of these lesions is enigmatic. The favored hypothesis is that nephrogenic adenomas are metaplastic alterations of resident urothelial tissue, and therefore the term “nephrogenic metaplasia” is used synonymously. Another hypothesis postulates development from hamartomatous cells. 17 In this study, we investigated the origin . . .