Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 93
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
World J Urol ; 39(5): 1499-1507, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32591903

RESUMO

BACKGROUND: The previous attempts for pT2 substaging of prostate cancer (PCa) were insufficient in providing prognostic subgroups and the search for new prognostic parameters to subcategorize pT2 PCa is, therefore, needed. Therefore, the current study investigated the association between tumor distribution patterns and the biochemical recurrence (BCR)-free survival rate in pT2pN0R0 PCa. METHODS: Following radical prostatectomy, the anatomical distribution of PCa in 743 men with pT1-pT3pN0 disease was analyzed to determine 20 types of PCa distribution patterns. Then, 245 men with pT2pN0R0 PCa was considered for prognostic evaluation with a mean follow-up period of 60 months. The spatial distribution patterns of PCa were evaluated using a cMDX©-based map model of the prostate. An analysis including 552,049 comparison operations was performed to assist in the evaluation of the similarity levels of the distribution patterns. A k-mean cluster analysis was applied to determine groups with similar distribution patterns. A decision-tree analysis was performed to divide these groups according to frequency of BCR. The BCR-free survival rate was analyzed using Kaplan-Meier curves. Predictors of progression were investigated using a Cox proportional hazards model. RESULTS: BCR occurred in 8.2% of the 245 men with pT2pN0R0 PCa. The median time of recurrence was 60 months (interquartile range [IQR]: 42-77). In univariate and multivariate analyses, the prostate volume and the distribution patterns were independent predictors for BCR, whereas the sub-staging of pT2 tumors, Gleason grading, prostate-specific antigen (PSA) level, and relative tumor volume were not. In the patients with pT2pN0R0 disease, PCa distribution patterns with the apical involvement were significantly associated with the risk of BCR (P = 0.001). CONCLUSION: The spread tumor patterns with the apical involvement are associated with a high-risk of BCR in the pT2 tumor stage. The vertical tumor spread could be considered in developing improved prognostic pT2 sub-categories.


Assuntos
Recidiva Local de Neoplasia/epidemiologia , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/patologia , Idoso , Intervalo Livre de Doença , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/sangue , Estadiamento de Neoplasias , Antígeno Prostático Específico/sangue , Prostatectomia , Neoplasias da Próstata/sangue , Neoplasias da Próstata/cirurgia , Estudos Retrospectivos , Medição de Risco
2.
Prostate ; 77(4): 396-405, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27862105

RESUMO

BACKGROUND: Fresh tissue is mandatory to perform high-quality translation studies. Several models for tissue extraction from prostatectomy specimens without guidance by frozen sections are already introduced. However, little is known about the sampling efficacy of these models, which should provide representative tissue in adequate volumes, account for multifocality and heterogeneity of tumor, not violate the routine final pathological examination, and perform quickly without frozen section-based histological control. The aim of the study was to evaluate the sampling efficacy of the existing tissue extraction models without guidance by frozen sections ("blind") and to develop an optimized model for tissue extraction. METHODS: Five hundred thirty-three electronic maps of the tumor distribution in prostates from a single-center cohort of the patients subjected to radical prostatectomy were used for analysis. Six available models were evaluated in silico for their sampling efficacy. Additionally, a novel model achieving the best sampling efficacy was developed. RESULTS: The available models showed high efficacies for sampling "any part" from the tumor (up to 100%), but were uniformly low in efficacy to sample all tumor foci from the specimens (with the best technique sampling only 51.6% of the all tumor foci). The novel 4-level extraction model achieved a sampling efficacy of 93.1% for all tumor foci. CONCLUSIONS: The existing "blind" tissue extraction models from prostatectomy specimens without frozen sections control are suitable to target tumor tissues but these tissues do not represent the whole tumor. The novel 4-level model provides the highest sampling efficacy and a promising potential for integration into routine. Prostate 77: 396-405, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Bancos de Espécimes Biológicos , Prostatectomia/métodos , Neoplasias da Próstata/patologia , Manejo de Espécimes/métodos , Bancos de Espécimes Biológicos/normas , Estudos de Coortes , Secções Congeladas/métodos , Secções Congeladas/normas , Humanos , Masculino , Prostatectomia/normas , Método Simples-Cego , Manejo de Espécimes/normas
3.
BJU Int ; 116(1): 57-64, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24552505

RESUMO

OBJECTIVE: To evaluate the spatial distribution of prostate cancer detected at a single positive biopsy (PBx) and a repeat PBx (rPBx). PATIENTS AND METHODS: We evaluated 533 consecutive men diagnosed with prostate cancer who underwent radical prostatectomy using a clinical map document based on XML (cMDX©)-based map model of the prostate. We determined the number of cancer foci, relative tumour volume, Gleason score, zone of origin, localisation, and pathological stage after stratification according to the number of PBx sessions (PBx vs rPBx). The distribution of 3966 prostate cancer foci was analysed and visualised on heat maps. The colour gradient of the heat map was reduced to six colours representing the frequency classification of prostate cancer using an image posterisation effect. Additionally, the spatial distribution of organ-confined prostate cancer between PBx and rPBx was evaluated. RESULTS: Prostate cancer diagnosed on PBx was mostly localised to the apical portion and the peripheral zone of the prostate. Prostate cancer diagnosed on rPBx was more frequently found in the anterior portion and the base of the prostate. Organ-confined prostate cancer foci were mostly localised in the dorsolateral zone of the prostate in men at PBx, whereas men at rPBx had more prostate cancer foci in the anterior portion. CONCLUSIONS: The spatial distribution of prostate cancer with rPBx differs significantly from the spatial distribution of prostate cancer with PBx. The whole anterior portion of the prostate should be considered by rPBx.


Assuntos
Próstata/patologia , Neoplasias da Próstata/patologia , Biópsia , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias
4.
World J Urol ; 33(12): 1937-43, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25910478

RESUMO

PURPOSE: En bloc resection of bladder tumors (ERBT) may improve staging quality and perioperative morbidity and influence tumor recurrence. This study was designed to evaluate the safety, efficacy, and recurrence rates of electrical versus laser en bloc resection of bladder tumors. METHODS: This European multicenter study included 221 patients at six academic hospitals. Transurethral ERBT was performed with monopolar/bipolar current or holmium/thulium laser energy. Staging quality measured by detrusor muscle involvement, various perioperative parameters, and 12-month follow-up data was analyzed. RESULTS: Electrical and laser ERBT were used to treat 156 and 65 patients, respectively. Median tumor size was 2.1 cm; largest tumor was 5 cm. Detrusor muscle was present in 97.3 %. A switch to conventional TURBT was significantly more frequent in the electrical ERBT group (26.3 vs. 1.5 %, p < 0.001). Median operation duration (25 min), postoperative irrigation (1 day), catheterization time (2 days), and hospitalization (3 days) were similar. Overall complication rate was low (Clavien ≥ 3, n = 6 [2.7 %]). Hemoglobin was significantly lower after electrical ERBT (p = 0.0013); however, overall hemoglobin loss was not clinically relevant (0.38 g/dl). Patients (n = 148) were followed for 12 months; 33 (22.3 %) had recurrences. In total, 63.6 % recurrences occurred outside the ERBT resection field. No difference was noted between ERBT groups. CONCLUSIONS: ERBT is safe and reliable regardless of the energy source and provides high-quality resections of tumors >1 cm. Recurrence rates did not differ between groups, and the majority of recurrences occurred outside the ERBT resection field.


Assuntos
Carcinoma/cirurgia , Cistectomia , Terapia a Laser , Lasers de Estado Sólido/uso terapêutico , Neoplasias da Bexiga Urinária/cirurgia , Urotélio , Idoso , Carcinoma/patologia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Neoplasias da Bexiga Urinária/patologia
5.
Int J Med Sci ; 12(1): 1-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25552912

RESUMO

OBJECTIVE: Peritoneal adhesions following surgery are a common, serious pathology with severe complications. Appropriate animal adhesion models are essential for the assessment of adhesion preventing medical devices. This study introduces a variation of an established rat model in which highest degree adhesions are induced with excellent reproducibility (OPAM=optimized peritoneal adhesion model). Thus, this model seems to be eligible to study effects of adhesion preventing devices. METHODS: 24 Lewis male rats were divided into four groups (OPAM, WSFX, sham-OPAM, sham-WSFX). The OPAM technique comprised cecal abrasion, creation of an abdominal wall defect plus approximation of injured areas by a suture, which was compared to a setting of lesions without suture fixation (WSFX). All rats were sacrificed at day 7. Macroscopic and histopathological evaluations were performed. RESULTS were statistically analyzed using ANOVA and Dunnett's test. RESULTS: In OPAM rats macroscopic analyses revealed a 90% incidence adhesion of cecum to the abdominal wall, all adhesions imposing as complete agglutination. In WSFX animals incidence of adhesions formation was 75%, while in both sham groups there were no adhesions at all. Histology showed the structure of adhesions with merged smooth muscle of colon and skeletal muscle of abdominal wall in all cases. CONCLUSION: OPAM technique provides adhesions of injured areas with a better probability than with conventional methods. All OPAM adhesions impressed as highest degree adhesions, i.e. agglutination. Due to high reproducibility in incidence and extend of adhesion formation, the OPAM is recommended for testing of adhesion prevention medical devices.


Assuntos
Parede Abdominal/patologia , Ceco/patologia , Aderências Teciduais/etiologia , Animais , Ceco/lesões , Ceco/cirurgia , Modelos Animais de Doenças , Masculino , Peritônio/patologia , Complicações Pós-Operatórias/patologia , Ratos Endogâmicos Lew , Reprodutibilidade dos Testes , Aderências Teciduais/patologia
6.
Eur Surg Res ; 55(4): 341-351, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26505616

RESUMO

BACKGROUND: Adhesions due to pelvic/abdominal surgery are a common serious pathology possibly entailing severe complications. This study investigates the adhesion prevention capability of the novel starch-based agent 4DryField® PH, which together with saline solution forms a barrier gel. Herein, an optimized adhesion model (OPAM) inducing severe adhesions/agglutinations with high reproducibility was used. METHODS: In 19 Lewis rats, a 1 × 2 cm abdominal wall defect was created, the peritoneum of the neighboring cecum was abraded, and both injured areas were approximated by suture. Rats were randomized to control (n = 10) or 4DryField PH treatment (n = 9) groups. Another 8 rats had sham surgery for safety assessment of 4DryField PH. At day 7, the quantity and quality of adhesions were assessed macro-/microscopically and evaluated statistically. RESULTS: 4DryField PH treatment significantly reduced the incidence and severity of adhesions as verified by significantly improved adhesion scorings (0.4 vs. 4.5; 1.1 vs. 9). Histology revealed reconstitution of the cecum and abdominal wall including regeneration of the visceral/parietal peritoneum. In sham-operated rats, 4DryField PH did not induce adhesion formation. CONCLUSIONS: 4DryField PH gel was highly effective in preventing adhesions. Histologically, the injured cecum and abdominal wall regenerated well in the presence of 4DryField PH. Considering the severity of OPAM trauma, the potential of 4DryField PH to prevent adhesions can be rated excellent.

7.
Int J Mol Sci ; 16(2): 3856-69, 2015 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-25679447

RESUMO

The multifocal nature of prostate cancer (PCa) creates a challenge to patients' outcome prediction and their clinical management. An approach that scrutinizes every cancer focus is needed in order to generate a comprehensive evaluation of the disease, and by correlating to patients' clinico-pathological information, specific prognostic biomarker can be identified. Our study utilized the Affymetrix SNP 6.0 Genome-wide assay to investigate forty-three fresh frozen PCa tissue foci from twenty-three patients. With a long clinical follow-up period that ranged from 2.0-9.7 (mean 5.4) years, copy number variation (CNV) data was evaluated for association with patients' PSA status during follow-up. From our results, the loss of unique genes on 10q23.31 and 10q23.2-10q23.31 were identified to be significantly associated to PSA recurrence (p < 0.05). The implication of PTEN and FAS loss (10q23.31) support previous reports due to their critical roles in prostate carcinogenesis. Furthermore, we hypothesize that the PAPSS2 gene (10q23.2-10q23.31) may be functionally relevant in post-operative PSA recurrence because of its reported role in androgen biosynthesis. It is suggestive that the loss of the susceptible region on chromosome 10q, which implicates PTEN, FAS and PAPSS2 may serve as genetic predictors of PSA recurrence after radical prostatectomy.


Assuntos
Complexos Multienzimáticos/genética , Recidiva Local de Neoplasia/genética , PTEN Fosfo-Hidrolase/genética , Antígeno Prostático Específico/análise , Neoplasias da Próstata/genética , Sulfato Adenililtransferase/genética , Receptor fas/genética , Idoso , Cromossomos Humanos Par 10/genética , Variações do Número de Cópias de DNA , Deleção de Genes , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Antígeno Prostático Específico/metabolismo , Prostatectomia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/cirurgia
8.
BMC Cancer ; 14: 101, 2014 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-24533449

RESUMO

BACKGROUND: GATA-5, a zinc-finger transcription factor and member of the GATA family proteins 1-6, is known to be involved in cellular differentiation. We recently found that tumor-specific hypermethylation of the GATA5 CpG island (CGI) occurs in renal cell carcinoma (RCC) and is associated with an adverse clinical outcome. In this study, we investigated whether epigenetic GATA5 alterations may result in changes in GATA5 mRNA expression levels and correlate with the observed prognostic impact of epigenetic changes in GATA5 in RCC. METHODS: Quantitative real-time reverse-transcribed polymerase chain reaction was applied to measure relative GATA5 mRNA expression levels in 135 kidney tissue samples, including 77 clear cell RCC (ccRCC) tissues and 58 paired adjacent normal renal tissue samples. Relative GATA5 expression levels were determined using the ΔΔCt method and detection of three endogenous control genes then compared to previously measured values of relative methylation. RESULTS: The mean relative GATA5 mRNA expression level exhibited an approximately 31-fold reduction in tumor specimens compared with corresponding normal tissues (p < 0.001, paired t-test). Decreased GATA5 mRNA expression was inversely correlated with increased GATA5 CGI methylation (p < 0.001) and was associated with shortened recurrence-free survival in ccRCC patients (p = 0.023, hazard ratio = 0.25). CONCLUSION: GATA5 mRNA expression is decreased in ccRCC, likely due to gene silencing by methylation of the GATA5 CGI. Moreover, reduced GATA5 mRNA levels were associated with a poor clinical outcome, indicating a possible role of GATA5 for the development of aggressive ccRCC phenotypes.


Assuntos
Carcinoma de Células Renais/metabolismo , Ilhas de CpG/genética , Fator de Transcrição GATA5/biossíntese , Recidiva Local de Neoplasia/metabolismo , RNA Mensageiro/biossíntese , Idoso , Biomarcadores Tumorais/biossíntese , Carcinoma de Células Renais/mortalidade , Metilação de DNA/genética , Feminino , Fator de Transcrição GATA5/antagonistas & inibidores , Fator de Transcrição GATA5/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/mortalidade , RNA Mensageiro/antagonistas & inibidores , Taxa de Sobrevida/tendências
9.
World J Urol ; 32(1): 115-21, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24085371

RESUMO

PURPOSE: Age has been linked to outcome in renal cancer patients, but mainly in North American cohorts. In this study, we hypothesized that age is correlated with metastasis and cancer-specific survival in a German cohort regardless of types of treatments. METHODS: A total of 1,538 patients treated for renal malignancies between 1991 and 2010 were evaluated. Mean age and median age are 61.9 ± 11.6 and 62.6 years. Clinicopathologic [tumor type, size, grade, stage and treatment (surgery, chemotherapy, radiation, immunotherapy)] and outcome parameters (metastasis and survival) were examined for an association with age using logistic regression and Cox proportional hazard model, and Kaplan-Meier plots. RESULTS: Age was associated with stage, metastasis, treatment, cancer-specific and overall mortality (p < 0.01). The metastasis-free and cancer-free survival rates for patients >63 years were lower than those for patients ≤63 years (p < 0.0001). In a multivariate analysis, age was an independent prognostic factor of metastasis, cancer-specific and overall mortality (p < 0.0001) even when data were stratified in different decades and treatment was included as one of the parameters. Patients >63 years of age had 29-35% higher risk of metastasis and cancer-specific mortality than younger patients. Median metastasis-free and cancer-specific survival for patients >63 years of age (months: 84.4; 70.3) was ~50% shorter than in patients ≤63 years (months: 151; 144.6). CONCLUSIONS: This large study shows that, despite advances in surgical and non-surgical treatment modalities over the two decades, age is an independent prognostic indicator of metastasis and cancer-specific mortality in renal cancer patients. Patients >63 years have ~30% increased risk for metastasis and ~50% shorter cancer-specific survival.


Assuntos
Fatores Etários , Neoplasias Renais/mortalidade , Neoplasias Renais/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Alemanha/epidemiologia , Humanos , Estimativa de Kaplan-Meier , Neoplasias Renais/epidemiologia , Modelos Logísticos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Adulto Jovem
10.
World J Urol ; 32(4): 931-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24343229

RESUMO

PURPOSE: The purpose of this study was to analyze the efficacy of two different biopsy forceps with respect to their functionality and quality for histological assessment of upper urinary tract biopsies. METHODS: We compared flow rates, active deflection angle and histological quality of specimens taken from upper urinary tract biopsies of 40 consecutively treated patients between October 2011 and October 2012. Two different biopsy forceps [group A = 20 patients: "Piranha (®) " (Boston Scientific, Natick, USA) versus group B = 20 patients: "EF-120-00-3F" (Euromedical GmbH, Siegsdorf, GER)] were assessed. RESULTS: The specimens obtained with the "EF-120-00-3F" were superior in terms of tissue preservation such as intact urothelium/tissue fragmentation and the prevention of artifacts due to tissue compression (existence of artifacts/nucleus evaluation). Furthermore, due to superiority of tissue preservation, tissues obtained with the "EF-120-00-3F" showed better tissue orientation in the sense of anatomic evaluation of invasion and deep layer involvement. Irrigation flow rates did not differ significantly while deflection angle was more impaired with the "Piranha" biopsy forceps. No difference was observed with the handling of both biopsy forceps. CONCLUSIONS: We conclude that the "EF-120-00-3F" biopsy forceps represent a valuable modification of antegradely insertable instruments that qualifies for improved and correct staging as well as diagnosis of upper urinary specimens in comparison with standard biopsy forcipes.


Assuntos
Biópsia/instrumentação , Instrumentos Cirúrgicos/normas , Sistema Urinário/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia/efeitos adversos , Biópsia/métodos , Carcinoma de Células de Transição/diagnóstico , Carcinoma de Células de Transição/patologia , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Manejo de Espécimes/efeitos adversos , Manejo de Espécimes/instrumentação , Manejo de Espécimes/métodos , Instrumentos Cirúrgicos/efeitos adversos , Neoplasias Urológicas/diagnóstico , Neoplasias Urológicas/patologia
11.
World J Urol ; 32(1): 245-8, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23053210

RESUMO

BACKGROUND: We report on a 62-year-old gentleman presenting at our urological department with an advanced renal cell cancer of the right kidney (10 cm in diameter), with an extensive caval vein thrombus (level IV) and bilateral pulmonary metastases. Another suspicious lesion at the left hemithorax was radiologically described. METHOD: A presurgical, neoadjuvant systemic therapy with sunitinib, a tyrosine kinase inhibitor, was initiated for 4 cycles in total (50 mg/day; 4 weeks on/2 weeks off). The cytoreductive nephrectomy was performed following the fourth cycle of sunitinib and after a 14-day break. Transesophageal echocardiography was used for intraoperative monitoring of the caval vein thrombus. Systemic treatment with sunitinib was continued 4 weeks after surgery. RESULTS: A significant reduction in tumor size, metastatic sites and down-staging of IVC from level IV to level III according to Novick classification was achieved. CONCLUSION: Significant down-staging of the tumor caval vein thrombus which initially reached the right atrium enabled us to perform surgery limited to the abdominal cavity without extracorporeal circulation nor hypothermia.


Assuntos
Neoplasias Renais/terapia , Terapia de Alvo Molecular , Terapia Neoadjuvante , Nefrectomia , Trombectomia , Trombose/cirurgia , Veia Cava Inferior , Antineoplásicos/uso terapêutico , Carcinoma de Células Renais/secundário , Carcinoma de Células Renais/terapia , Ponte Cardiopulmonar , Contraindicações , Humanos , Indóis/uso terapêutico , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Pirróis/uso terapêutico , Sunitinibe , Resultado do Tratamento
12.
BMC Clin Pathol ; 14: 15, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24708743

RESUMO

BACKGROUND: Galectins are known to regulate cell differentiation and growth as well as cell adhesion and apoptosis. Galectins have been discussed as possible prognosticators for survival in renal cell cancer (RCC) and other urological tumors. They might also play an emerging role as possible new marker-proteins for RCC. In this study, we analyzed the expression of galectin-1 and galectin-3 mRNA in order to further investigate their clinical significance in RCC. METHODS: Tissue samples were obtained from 106 patients undergoing surgery for RCC. The expression of galectin-1 and galectin-3 mRNA in normal kidney and corresponding cancer tissue was analyzed using quantitative real time PCR. Differences in expression levels of paired tissue samples were assessed using paired two-sample tests. Associations of relative mRNA expression levels in tumor tissues with clinical findings were analyzed using univariate logistic regression. RESULTS: The expression of galectin-1 (p < 0.001) and -3 (p < 0.001) mRNA were significantly higher in RCC when compared to the adjacent normal kidney tissue. For clear cell RCC, an association of male gender with higher galectin-1 and galectin-3 mRNA expression (p = 0.054, p = 0.034) was detected. For all RCCs, galectin-1 mRNA expression failed to show a significant association with advanced disease as well as a higher rate of lymph node metastases (p = 0.058, p = 0.059). CONCLUSION: The mRNA expression of galectin-1 and galectin-3 is significantly increased in RCC cancer tissue. The higher mRNA expression in tumor tissue of male patients raises the question of a functional connection between galectins and the higher prevalence of RCC in men. Associations with advanced disease might lead to new ways of identifying patients at higher risk of recurrent disease and might even facilitate early metastasectomy with curative intent.

13.
Appl Radiat Isot ; 205: 111178, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38232490

RESUMO

Geometrical and absolute efficiencies play a significant role in the calibration of radioactivity measuring systems, which are regularly complicated. A novel analytical method of efficiency calibration is proposed for cylindrical side-hole type sodium iodide scintillation detectors. Cylindrical side-hole type sodium iodide scintillation detectors have a cylindrical side-hole passing perpendicularly on the sodium iodide crystal axis, which is gathered in the aluminum cover. This detector is a setup for low-level gamma radiation measurement, because of the close 4π solid angle correlated with it, this setup is convenient when low-energy radiation requires efficient detection. Also, the 4π gamma-ray counting is an established way for direct activity measurements and is remarkably well suited for radionuclides with complex gamma-ray spectra. This novel approach depends on the calculation of two primary factors, the photon path length inside the detector active material, and the solid angle, delimited by the radiation source-detector system. In addition, the attenuation of photons by the sodium iodide crystal covering substance is also included by determining the photon path length through this substance. The novel analytical approach calculates the total and geometrical efficiencies of this kind of detector. In comparison, the differences with the published data in the literature indicate that the current approach is favorable in the efficiency measurement of the cylindrical side-hole type sodium iodide scintillation detectors.

14.
Sci Rep ; 14(1): 1578, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38238486

RESUMO

Recently, there has been a surge of interest in the application of radiation-shielding materials. One promising research avenue involves using free-lead metal oxides/polymer composites, which have been studied for their radiation shielding and characterization properties. This study reinforced the dimethylpolysiloxane (silicone rubber) composites with micro- and nano-sized particles of tin oxide, cadmium oxide, and bismuth oxide as additive materials. The composites were tested with 20 and 50 weight fractions, and their attenuation coefficients were measured using a NaI(TI) detector at gamma-ray energies ranging from 59.54 to 1408.01 keV. Also, the thermal and mechanical properties of the composites were observed and compared with those of free silicone rubber. The results showed that the 50% nano metal oxide/SR composites exhibited better thermal stability and attenuation properties than the other composites, also possessing unique attributes such as lightweight composition and exceptional flexibility. Consequently, this composite material holds immense potential for safeguarding vital organs, including the eyes and gonads, during radiological diagnosis or treatment procedures. Its exceptional ability to absorb a significant portion of incident rays makes it an invaluable asset in the field of radiation protection.

15.
Sci Rep ; 14(1): 1279, 2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38218742

RESUMO

This research aimed to examine the radiation shielding properties of unique polymer composites for medical and non-medical applications. For this purpose, polymer composites, based on poly methyl methacrylate (PMMA) as a matrix, were prepared and reinforced with micro- and nanoparticles of ZrO2 fillers at a loading of 15%, 30%, and 45% by weight. Using the high purity germanium (HPGe) detector, the suggested polymer composites' shielding characteristics were assessed for various radioactive sources. The experimental values of the mass attenuation coefficients (MAC) of the produced composites agreed closely with those obtained theoretically from the XCOM database. Different shielding parameters were estimated at a broad range of photon energies, including the linear attenuation coefficient (µ), tenth value layer (TVL), half value layer (HVL), mean free path (MFP), effective electron density (Neff), effective atomic number (Zeff), and equivalent atomic number (Zeq), as well as exposure buildup factor (EBF) and energy absorption buildup factor (EABF) to provide more shielding information about the penetration of γ-rays into the chosen composites. The results showed that increasing the content of micro and nano ZrO2 particles in the PMMA matrix increases µ values and decreases HVL, TVL, and MFP values. P-45nZ sample with 45 wt% of ZrO2 nanoparticles had the highest µ values, which varied between 2.6546 and 0.0991 cm-1 as γ-ray photon energy increased from 0.0595 to 1.408 MeV, respectively. Furthermore, the highest relative increase rate in µ values between nano and micro composites was 17.84%, achieved for the P-45nZ sample at 59.53 keV. These findings demonstrated that ZrO2 nanoparticles shield radiation more effectively than micro ZrO2 even at the same photon energy and filler wt%. Thus, the proposed nano ZrO2/PMMA composites can be used as effective shielding materials to lessen the transmitted radiation dose in radiation facilities.

16.
Oncol Lett ; 28(1): 308, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38784603

RESUMO

Peritoneal carcinomatosis is one of the leading causes of death in patients with gastrointestinal cancer. Newer locoregional treatment concepts include pressurized intraperitoneal aerosol chemotherapy (PIPAC), the regional application of pressurized chemotherapeutic agents to the abdominal cavity, which is usually performed every 4 to 8 weeks. One of the main challenges of PIPAC therapy remains the objective assessment of treatment response. The present study describes a new scoring system to histologically assess the regression of peritoneal cancer following PIPAC therapy, quantitative assessment of histological regression in peritoneal carcinomatosis (QARP). Peritoneal biopsies from 27 patients with peritoneal metastases undergoing PIPAC were obtained and processed in a standardized fashion. Biopsies were scored according to the QARP grading system. The five-tiered system was graded as follows, Grade 0, no residual tumor cells with regressive changes present; grade 1, 1-25% viable tumor cells per tumor focus with regressive changes present; grade 2, 26-50% viable tumor cells per tumor focus with regressive changes present; grade 3, 51-75% viable tumor cells per tumor focus with few regressive changes; grade 4, >75% viable tumor cells per tumor focus with minimal or no regressive changes. Based on the new grading system, the study cohort was divided into QARP responders and QARP non-responders following PIPAC treatment. Higher QARP scores were significantly correlated with higher PCI scores (r=0.32; P=0.007). However, no difference in overall survival was detected between QARP responders and QARP non-responders. Further studies are required to ascertain the reproducibility and prognostic significance of QARP.

17.
Sci Rep ; 14(1): 4242, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38378858

RESUMO

Radioactive iodine isotopes especially 131I are used for diagnosis and treatment of different types of cancer diseases. Due to the leak of radioactive iodine into the patient's urine in turn, the wastewater would be contaminated, so it is worth preparing a novel adsorption green material to remove the radioactive iodine from wastewater efficiently. The removal of 127I and 131I contaminants from aqueous solution is a problem of interest. Therefore, this work presents a new study for removing the stable iodine 127I- and radioactive iodine 131I from aqueous solutions by using the novel nano adsorbent (Nano ZnO/MWCNTs) which is synthesized by the arc discharge method. It is an economic method for treating contaminated water from undesired dissolved iodine isotopes. The optimal conditions for maximum removal are (5 mg/100 ml) as optimum dose with shacking (200 rpm) for contact time of (60 min), at (25 °C) in an acidic medium of (pH = 5). After the adsorption process, the solution is filtrated and the residual iodide (127I-) is measured at a maximum UV wavelength absorbance of 225 nm. The maximum adsorption capacity is (15.25 mg/g); therefore the prepared nano adsorbent (Nano ZnO/MWCNTs) is suitable for treating polluted water from low iodide concentrations. The adsorption mechanism of 127I- on to the surface of (Nano ZnO/MWCNTs) is multilayer physical adsorption according to Freundlich isotherm model and obeys the Pseudo-first order kinetic model. According to Temkin isotherm model the adsorption is exothermic. The removal efficiency of Nano ZnO/MWCNTs for stable iodine (127I-) from aqueous solutions has reached 97.23%, 89.75%, and 64.78% in case of initial concentrations; 0.1843 ppm, 0.5014 ppm and 1.0331 ppm, respectively. For the prepared radio iodine (131I-) solution of radioactivity (20 µCi), the dose of nano adsorbent was (10 mg/100 ml) and the contact time was (60 min) at (pH = 5) with shacking (200 rpm) at (25 °C). The filtration process was done by using a syringe filter of a pore size (450 nm) after 2 days to equilibrate. The removal efficiency reached (34.16%) after the first cycle of treatment and the percentage of residual radio iodine was (65.86%). The removal efficiency reached (94.76%) after five cycles of treatment and the percentage of residual radio iodine was (5.24%). This last percentage was less than (42.15%) which produces due to the natural decay during 10 days.

18.
Sci Rep ; 14(1): 10548, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719844

RESUMO

This study not only provides an innovative technique for producing rigid polyurethane foam (RPUF) composites, but it also offers a way to reuse metallurgical solid waste. Rigid polyurethane (RPUF) composite samples have been prepared with different proportions of iron slag as additives, with a range of 0-25% mass by weight. The process of grinding iron slag microparticles into iron slag nanoparticles powder was accomplished with the use of a high-energy ball mill. The synthesized samples have been characterized using Fourier Transform Infrared Spectroscopy, and Scanning Electron Microscope. Then, their radiation shielding properties were measured by using A hyper-pure germanium detector using point sources 241Am, 133 BA, 152 EU, 137Cs, and 60Co, with an energy range of 0.059-1.408 MeV. Then using Fluka simulation code to validate the results in the energy range of photon energies of 0.0001-100 MeV. The linear attenuation coefficient, mass attenuation coefficient, mean free path, half-value layer and tenth-value layer, were calculated to determine the radiation shielding characteristics of the composite samples. The calculated values are in good agreement with the calculated values. The results of this study showed that the gamma-ray and neutron attenuation parameters of the studied polyurethane composite samples have improved. Moreover, the effect of iron slag not only increases the gamma-ray attenuation shielding properties but also enhances compressive strength and the thermal stability. Which encourages us to use polyurethane iron-slag composite foam in sandwich panel manufacturing as walls to provide protection from radiation and also heat insulation.

19.
Biol Trace Elem Res ; 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38941061

RESUMO

Trace element bioaccumulation in marine organisms is a rising international issue due to possible health concerns for humans. Thirteen trace elements were analyzed in the sediment, water, and muscular tissue of Red Sea fish. Additionally, the average daily intake (EDI), the cancer risk (CR), the hazard index (HI), and the target hazard quotient (THQ) of those elements have been taken into consideration when evaluating any possible health concerns related to their consumption. All species presented quantifiable values in muscle for all the analyzed elements (arsenic (As), lead (Pb), copper (Cu), aluminum (Al), boron (B), iron (Fe), barium (Ba), manganese (Mn), nickel (Ni), cadmium (Cd), chromium (Cr), zinc (Zn), and mercury (Hg), except for Cd and Hg, being Fe and Zn the most accumulated elements in all species. Conversely, in water samples, most elements were undeleted except for aluminum, boron, iron, and zinc. All Red Sea fish, however, had concentrations of Zn, Ni, Fe, Cu, and Mn below the upper limit allowed, although most species had higher levels of As, Cr, and Pb (0.48 ± 0.83-5.10 ± 0.79, 1.97 ± 0.46-5.25 ± 0.67 and 2.12 ± 1.01-6.83 ± 0.93 µg/g, respectively).The studied Red Sea fish showed contamination degrees (CD) of Mn, Cu, Fe, Ni, Zn, and Pb were ≤ 1, indicating minimal contamination, with As and Cr showing higher contamination degrees. However, the pollution index values (MPI-elements) can be represented according to ascending order: Lethrinus ramak < Cephalopholis hemistiktos < Pagellus affinis < Trachurus japonicus < Cheilinus lunulatus < Siganus luridus < Parupeneus forsskali < Caesio suevica. The study found that edible tissues are safe for human consumption, with HI values for children and adults less than ten, indicating negligible non-cancer hazards. However, fish consumption presents health risks due to chromium, lead, and arsenic, with THQ values several times greater than 1, and CR-Ni, CR-Cr, and CR-As values exceeding the acceptable 10-4 value in all studied species. This study provides critical insights into trace element contamination in marine fish species, highlighting the need for ongoing monitoring and proactive measures to ensure safe marine fish consumption in the Aqaba Gulf.

20.
Sci Rep ; 14(1): 5284, 2024 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-38438436

RESUMO

Prostate cancer pathology plays a crucial role in clinical management but is time-consuming. Artificial intelligence (AI) shows promise in detecting prostate cancer and grading patterns. We tested an AI-based digital twin of a pathologist, vPatho, on 2603 histological images of prostate tissue stained with hematoxylin and eosin. We analyzed various factors influencing tumor grade discordance between the vPatho system and six human pathologists. Our results demonstrated that vPatho achieved comparable performance in prostate cancer detection and tumor volume estimation, as reported in the literature. The concordance levels between vPatho and human pathologists were examined. Notably, moderate to substantial agreement was observed in identifying complementary histological features such as ductal, cribriform, nerve, blood vessel, and lymphocyte infiltration. However, concordance in tumor grading decreased when applied to prostatectomy specimens (κ = 0.44) compared to biopsy cores (κ = 0.70). Adjusting the decision threshold for the secondary Gleason pattern from 5 to 10% improved the concordance level between pathologists and vPatho for tumor grading on prostatectomy specimens (κ from 0.44 to 0.64). Potential causes of grade discordance included the vertical extent of tumors toward the prostate boundary and the proportions of slides with prostate cancer. Gleason pattern 4 was particularly associated with this population. Notably, the grade according to vPatho was not specific to any of the six pathologists involved in routine clinical grading. In conclusion, our study highlights the potential utility of AI in developing a digital twin for a pathologist. This approach can help uncover limitations in AI adoption and the practical application of the current grading system for prostate cancer pathology.


Assuntos
Inteligência Artificial , Neoplasias da Próstata , Humanos , Masculino , Patologistas , Próstata , Biópsia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA