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Being characterized by the self-adaption and high accuracy, the deep learning-based models have been widely applied in the 1D spectroscopy-related field. However, the "black-box" operation and "end-to-end" working style of the deep learning normally bring the low interpretability, where a reliable visualization is highly demanded. Although there are some well-developed visualization methods, such as Class Activation Mapping (CAM) and Gradient-weighted Class Activation Mapping (Grad-CAM), for the 2D image data, they cannot correctly reflect the weights of the model when being applied to the 1D spectral data, where the importance of position information is not considered. Here, aiming at the visualization of Convolutional Neural Network-based models toward the qualitative and quantitative analysis of 1D spectroscopy, we developed a novel visualization algorithm (1D Grad-CAM) to more accurately display the decision-making process of the CNN-based models. Different from the classical Grad-CAM, with the removal of the gradient averaging (GAP) and the ReLU operations, a significantly improved correlation between the gradient and the spectral location and a more comprehensive spectral feature capture were realized for 1D Grad-CAM. Furthermore, the introduction of difference (purity or linearity) and feature contribute in the CNN output in 1D Grad-CAM achieved a reliable evaluation of the qualitative accuracy and quantitative precision of CNN-based models. Facing the qualitative and adulteration quantitative analysis of vegetable oils by the combination of Raman spectroscopy and ResNet, the visualization by 1D Grad-CAM well reflected the origin of the high accuracy and precision brought by ResNet. In general, 1D Grad-CAM provides a clear vision about the judgment criterion of CNN and paves the way for CNN to a broad application in the field of 1D spectroscopy.
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OBJECTIVES: To investigate age-related changes on passive muscle stiffness in healthy individuals and measure the shear modulus in different age groups. METHODS: Shear wave elastography (SWE) movies of gastrocnemius medialis (GM) were collected during passive stretching induced by ankle rotation from plantarflexion (PF) to dorsiflexion (DF). A series of SWE images at ankle angles of PF 40°, PF 30°, PF 20°, PF 10°, 0°, DF 10°, DF 20°, and DF 30° were collected and shear moduli measured accordingly for analyses. RESULTS: Eighty-six healthy volunteers (27 children, 31 middle-aged adults, and 28 older people) were recruited. No significant difference was observed in the shear modulus between the three groups at ankle angles of PF 40°, PF 30°, PF 20°, PF 10°, and 0° (p > 0.05). The difference in the shear modulus among the three groups became significant as DF increased. At ankle angles of DF 10°, DF 20°, and DF 30°, the shear modulus was the greatest in the older group, followed by the middle-aged group and then the children group (p = 0.007, 0.000, and 0.000, respectively). CONCLUSIONS: Passive muscle stiffness increases with age, and the difference between age groups was pronounced only after reaching a certain degree of stretching. KEY POINTS: ⢠The influence of age on passive muscle stiffness becomes pronounced only after reaching a certain degree of stretching. ⢠Age should be considered when evaluating passive muscle stiffness in muscular disorders.
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Técnicas de Imagem por Elasticidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Tornozelo , Articulação do Tornozelo/diagnóstico por imagem , Criança , Humanos , Pessoa de Meia-Idade , Músculo Esquelético/diagnóstico por imagem , Amplitude de Movimento ArticularRESUMO
This study investigated the prognostic effects of genomic biomarkers for predicting chemoradiotherapy (CRT)-based treatment outcomes in patients with adenocarcinoma (AC) of the uterine cervix. In all, 21 patients receiving definitive CRT were included. In accordance with the International Federation of Gynecology and Obstetrics (FIGO) staging system, 5, 8, and 8 patients were classified as having stage IB3, II, and III disease, respectively. Pretreatment biomarkers were analyzed using tissue microarrays from biopsy specimens. Genomic alterations were examined by next-generation sequencing (NGS). The outcome endpoints were disease-free survival (DFS), distant metastasis-free survival (DMFS), and local relapse-free survival (LRFS). A Cox regression model was used to examine the prognostic effects of the biomarkers and clinical parameters. The presence of myeloid cell leukemia-1 (MCL1) gene amplification and a lower immunohistochemical (IHC) marker of tumor necrotic factor alpha (TNF-α) H-score were two prognostic factors for inferior DFS. The four-year DFS was 28% and 68% for patients with or without MCL1 copy number gain, respectively (p = 0.028). In addition, MCL1 amplification predicted poor DMFS. A lower tumor mutation number (TMN) calculated from nonsynonymous mutations was associated with lower LRFS. For patients with adenocarcinoma of the uterine cervix receiving definitive CRT, prognostic information can be supplemented by MCL1 amplification, the TMN, and the TNF-α H score.
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Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/radioterapia , Biomarcadores Tumorais/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/radioterapia , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Quimiorradioterapia , Intervalo Livre de Doença , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Prognóstico , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/mortalidadeRESUMO
PURPOSE: This study investigated the correlation of the matrix heterogeneity of tumors on 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) with gene-expression profiling in patients with pharyngeal cancer and determined the prognostic factors for radiotherapy-based treatment outcomes. METHODS: We retrospectively reviewed the records of 57 patients with stage III-IV oropharyngeal or hypopharyngeal cancer who had completed definitive therapy. Four groups of the textural features as well as 31 indices were studied in addition to maximum standard uptake value, metastatic tumor volume, and total lesion glycolysis. Immunohistochemical data from pretreatment biopsy specimens (Glut1, CAIX, VEGF, HIF-1α, EGFR, Ki-67, Bcl-2, CLAUDIN-4, YAP-1, c-Met, and p16) were analyzed. The relationships between the indices and genomic expression were studied, and the robustness of various textural features relative to cause-specific survival and primary relapse-free survival was analyzed. RESULTS: The overexpression of VEGF was positively associated with the increased values of the matrix heterogeneity obtained using gray-level nonuniformity for zone (GLNUz) and run-length nonuniformity (RLNU). Advanced T stage (p = 0.01, hazard ratio [HR] = 3.38), a VEGF immunoreactive score of >2 (p = 0.03, HR = 2.79), and a higher GLNUz value (p = 0.04, HR = 2.51) were prognostic factors for low cause-specific survival, whereas advanced T stage, a HIF-1α staining percentage of ≥80%, and a higher GLNUz value were prognostic factors for low primary-relapse free survival. CONCLUSIONS: The overexpression of VEGF was associated with the increased matrix index of GLNUz and RLNU. For patients with pharyngeal cancer requiring radiotherapy, the treatment outcome can be stratified according to the textural features, T stage, and biomarkers.
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Biomarcadores Tumorais/metabolismo , Neoplasias Faríngeas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Planejamento da Radioterapia Assistida por Computador , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/genética , Fluordesoxiglucose F18 , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Faríngeas/metabolismo , Neoplasias Faríngeas/patologia , Neoplasias Faríngeas/radioterapia , Compostos Radiofarmacêuticos , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
BACKGROUND: This study examined genomic factors associated with a reduction in 18fluoro-2-deoxy-D-glucose (FDG) uptake during positron emission tomography-computed tomography (PET-CT) for definitive chemoradiotherapy (CRT) in patients with pharyngeal cancer. METHODS: The pretreatment and interim PET-CT images of 25 patients with advanced pharyngeal cancers receiving definitive CRT were prospectively evaluated. The maximum standardized uptake value (SUVmax) of the interim PET-CT and the reduction ratio of the SUVmax (SRR) between the two images were measured. Genomic data from pretreatment incisional biopsy specimens (SLC2A1, CAIX, VEGF, HIF1A, BCL2, Claudin-4, YAP1, MET, MKI67, and EGFR) were analyzed using tissue microarrays. Differences in FDG uptake and SRRs between tumors with low and high gene expression were examined using the Mann-Whitney test. Cox regression analysis was performed to examine the effects of variables on local control. RESULTS: The SRR of the primary tumors (SRR-P) was 0.59 ± 0.31, whereas the SRR of metastatic lymph nodes (SRR-N) was 0.54 ± 0.32. Overexpression of HIF1A was associated with a high iSUVmax of the primary tumor (P < 0.001) and neck lymph node (P = 0.04) and a low SRR-P (P = 0.02). Multivariate analysis revealed that patients who had tumors with low SRR-P or high HIF1A expression levels showed inferior local control. CONCLUSION: In patients with pharyngeal cancer requiring CRT, HIF1A overexpression was positively associated with high interim SUVmax or a slow reduction in FDG uptake. Prospective trials are needed to determine whether the local control rate can be stratified using the HIF1A level as a biomarker and SRR-P.
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Biomarcadores Tumorais/metabolismo , Fluordesoxiglucose F18/farmacocinética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Faríngeas/metabolismo , Neoplasias Faríngeas/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Faríngeas/diagnóstico por imagem , Compostos Radiofarmacêuticos/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Regulação para CimaRESUMO
The chaperone 70 kDa heat shock protein (Hsp70) is important for cells from bacteria to humans to maintain proteostasis, and all eukaryotes and several prokaryotes encode Hsp70 paralogs. Although the mechanisms of Hsp70 function have been clearly illuminated, the function and evolution of Hsp70 paralogs is not well studied. DnaK is a highly conserved bacterial Hsp70 family. Here, we show that dnaK is present in 98.9% of bacterial genomes, and 6.4% of them possess two or more DnaK paralogs. We found that the duplication of dnaK is positively correlated with an increase in proteomic complexity (proteome size, number of domains). We identified the interactomes of the two DnaK paralogs of Myxococcus xanthus DK1622 (MxDnaKs), which revealed that they are mostly nonoverlapping, although both prefer α and ß domain proteins. Consistent with the entire M. xanthus proteome, MxDnaK substrates have both significantly more multi-domain proteins and a higher isoelectric point than that of Escherichia coli, which encodes a single DnaK homolog. MxDnaK1 is transcriptionally upregulated in response to heat shock and prefers to bind cytosolic proteins, while MxDnaK2 is downregulated by heat shock and is more associated with membrane proteins. Using domain swapping, we show that the nucleotide-binding domain and the substrate-binding ß domain are responsible for the significant differences in DnaK interactomes, and the nucleotide binding domain also determines the dimerization of MxDnaK2, but not MxDnaK1. Our work suggests that bacterial DnaK has been duplicated in order to deal with a more complex proteome, and that this allows evolution of distinct domains to deal with different subsets of target proteins.IMPORTANCEAll eukaryotic and ~40% of prokaryotic species encode multiple 70 kDa heat shock protein (Hsp70) homologs with similar but diversified functions. Here, we show that duplication of canonical Hsp70 (DnaK in prokaryotes) correlates with increasing proteomic complexity and evolution of particular regions of the protein. Using the Myxococcus xanthus DnaK duplicates as a case, we found that their substrate spectrums are mostly nonoverlapping, and are both consistent to that of Escherichia coli DnaK in structural and molecular characteristics, but show differential enrichment of membrane proteins. Domain/region swapping demonstrated that the nucleotide-binding domain and the ß substrate-binding domain (SBDß), but not the SBDα or disordered C-terminal tail region, are responsible for this functional divergence. This work provides the first direct evidence for regional evolution of DnaK paralogs.
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Proteínas de Escherichia coli , Proteoma , Humanos , Proteoma/genética , Proteínas de Escherichia coli/genética , Proteômica , Proteínas de Choque Térmico HSP70/genética , Escherichia coli/genética , Bactérias/metabolismo , Proteínas de Membrana/metabolismo , Nucleotídeos/metabolismoRESUMO
Neurofibromatosis type 2 (NF2) is a rare genetic disease involving multiple tumors of the central and peripheral nervous systems. Most patients with NF2 have bilateral vestibular schwannomas; nonvestibular schwannomas may also develop. While the majority of patients may present with hearing impairment, tinnitus, dizziness and balance disorders, some may present with cutaneous manifestations. We describe the case of a 20-year-old man who initially presented with a solitary subcutaneous painless nodule in the left preauricular area without any other symptoms. He received excisional biopsy for the preauricular mass and the pathologic diagnosis was schwannoma. Magnetic resonance imaging of brain and neck revealed multiple mass lesions over the bilateral cerebellopontine angle cisterns, extending to the bilateral internal auditory canals, bilateral cervical neuroforamens, cervical and upper thoracic spinal canals, and left posterior neck. The patient was diagnosed with NF2 according to the clinical criteria. He underwent gamma knife stereotactic radiosurgery for bilateral vestibular schwannomas and is now under regular monitoring. CONCLUSION: NF2 patients may present with an isolated solitary cutaneous schwannoma with no other associated clinical findings. Further assessment is thus warranted in young patients presenting with a peripheral schwannoma despite absence of other clinical findings.
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Perda Auditiva/etiologia , Neurofibromatose 2/diagnóstico , Pavilhão Auricular/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Neurofibromatose 2/complicações , Neurofibromatose 2/diagnóstico por imagem , Neurofibromatose 2/patologia , Adulto JovemRESUMO
Rice starch with hydrocolloids (pectin, xanthan gum, sodium alginate or ι-carrageenan) was gelatinized and subsequently spray dried to prepare pre-gelatinized rice starch (PRS) with hydrocolloids (PRS-H). The PRS-H displayed concave granular shape with amorphous structure, indicating rice starch in PRS-H was completely gelatinized. Cold paste viscosity of PRS-H was enhanced in comparison with that of PRS. Especially, xanthan and ι-carrageenan increased cold paste viscosity of PRS-H more than pectin and alginate did. Cold paste viscosity of physically mixed PRS and hydrocolloids (PRS+H), and flow behavior of hydrocolloids themselves as well as gelatinized starch-hydrocolloids without spray drying (GRS-H) indicated interactions existed between starch and hydrocolloids during the preparation. Swelling power, water solubility index, and dynamic viscoelastic properties of PRS-H were also adjusted by different hydrocolloids. These results showed that premixing hydrocolloids with starch before gelatinization in method of spray drying would be a suitable methodology for manufacture PRS with altered properties.
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Dessecação , Manipulação de Alimentos/métodos , Gelatina/química , Oryza/química , Amido/química , Alginatos/química , Carragenina/química , Coloides , Pectinas/química , Polissacarídeos Bacterianos/químicaRESUMO
BACKGROUND/AIM: To determine the prognostic effects of immunohistochemical biomarkers for predicting chemoradiotherapy (CRT)-based treatment outcomes in patients with adenocarcinoma of the uterine cervix. MATERIALS AND METHODS: This study included 42 patients receiving definitive CRT. According to the International Federation of Gynecology and Obstetrics staging system, 13, 21, and 8 patients were classified as having stage IB2, II, and III disease, respectively. Baseline immunohistochemical biomarkers, including those for hypoxia, cell proliferation, cell adhesion, immunogenicity, and evasion of apoptosis, were analyzed using tissue microarrays from biopsy specimens. RESULTS: Myeloid cell leukemia-1 (MCL1) overexpression and the presence of pelvic lymph node metastasis were two prognostic factors for inferior cancer-specific survival. A higher H-score for c-MYC proto-oncogene, bHLH transcription factor (c-MYC) was associated with lower pelvic relapse-free survival. CONCLUSION: For patients with adenocarcinoma of the uterine cervix requiring definitive CRT, treatment outcomes can be stratified by the immunohistochemical biomarkers MCL1 and c-MYC for cancer death and local failure, respectively.
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Adenocarcinoma/terapia , Biomarcadores Tumorais/análise , Quimiorradioterapia , Imuno-Histoquímica , Proteína de Sequência 1 de Leucemia de Células Mieloides/análise , Proteínas Proto-Oncogênicas c-myc/análise , Neoplasias do Colo do Útero/terapia , Adenocarcinoma/química , Adenocarcinoma/mortalidade , Adenocarcinoma/secundário , Adulto , Idoso , Quimiorradioterapia/efeitos adversos , Quimiorradioterapia/mortalidade , Progressão da Doença , Intervalo Livre de Doença , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Proto-Oncogene Mas , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Análise Serial de Tecidos , Neoplasias do Colo do Útero/química , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/patologiaRESUMO
To know tumor PD-L1 expression through IHC or the FDG-PET related radiomics, we investigated the association between programmed cell death protein 1 ligand (PD-L1) expression and immunohistochemical (IHC) biomarkers or textural features of 18F-fluoro-2-deoxdeoxyglucose positron emission tomography (18F-FDG PET) in 53 oropharyngeal or hypopharyngeal cancer patients who were ready to undergo radiotherapy-based treatment. Differences in textural features or biomarkers between tumors with and without PD-L1 expression were tested using a Mann-Whitney U test. The predicted values for PD-L1 expression were examined using logistic regression analysis. The mean percentages of tumor PD-L1 expression were 6.2 ± 13.5. Eighteen tumors had PD-L1 expression ≥5%, whereas 30 tumors ≥1%. Using a 5% cutoff, the p16 staining percentage and the textural index of correlation were two factors associated with PD-L1 expression. The odds ratios (ORs) were 17.00 (p = 0.028) and 0.009 (p = 0.015), respectively. When dichotomizing PD-L1 at 1%, the p16 and Ki-67 staining percentages were two predictors for PD-L1 expression with ORs of 11.41 (p = 0.035) and 757.77 (p = 0.045). p16 and Ki-67 staining percentages and several PET/CT-derived textural features can provide supplemental information to determine tumor PD-L1 expression in HNCs.
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Antígeno B7-H1/metabolismo , Biomarcadores Tumorais , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/metabolismo , Fluordesoxiglucose F18 , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/metabolismo , Tomografia por Emissão de Pósitrons , Carcinoma de Células Escamosas/etiologia , Feminino , Neoplasias de Cabeça e Pescoço/etiologia , Humanos , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Masculino , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons/métodos , Prognóstico , Receptor de Morte Celular Programada 1/metabolismo , Curva ROC , Reprodutibilidade dos Testes , Carcinoma de Células Escamosas de Cabeça e PescoçoRESUMO
Octenyl succinic anhydride (OSA) modified starch is widely used in food industries. In this study, rice starch (RS) was pretreated by dynamic high-pressure microfluidization (DHPM) and subsequently modified by OSA. The influence of DHPM on OSA modification of rice starch was investigated. Results showed that DHPM pretreatment enhanced the degree of substitution by changing the morphology and crystallinity of rice starch. Compared with the rice starch modified by OSA without DHPM pretreatment (OSA-RS), the DHPM-pretreated OSA starch (DHPM-OSA-RS) presented higher peak viscosity and lower pasting temperature. DHPM-OSA-RS also exhibited better emulsifying activity and emulsion stability. This study suggested that DHPM will provide an opportunity to change the physicochemical properties of starch, with the resulting starch being more suitable for chemical modification.
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RATIONALE: Immunoglobulin G4-related disease (IgG4-RD) is characterized by tumor-like lesions, a dense lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis. IgG4-RD has been described in a variety of organ systems; however, it rarely involves the central nervous system. PATIENT CONCERNS: A 17-year-old woman visited our clinic with a complaint of blurred vision for the past 5 months. She also reported a painless right submandibular mass that had been present for 1 year. Her best-corrected visual acuity (BCVA) was 2.0 LogMAR, with an almost total visual field defect in the right eye. DIAGNOSES: Magnetic resonance imaging (MRI) revealed lobulated parasellar tumors with perineural spreading along branches of the trigeminal nerves causing right optic nerve compression. A craniotomy with tumor removal and submandibular gland biopsy was performed. Histopathological analysis of the tumor revealed stromal fibrosis with atypical lymphoid infiltrations. Histopathological and immunohistochemical analysis of the submandibular gland confirmed the diagnosis of IgG4-RD. INTERVENTIONS: The patient was administered 500mg/d of pulse methylprednisolone for 3 days, 500mg of intravenous rituximab every 2 weeks (for a total of 2 doses), and 500mg of intravenous pulse cyclophosphamide every month (for a total of 3 doses). OUTCOMES: Two months after the initiation of immunosuppressive therapy, the patient's BCVA returned to 0.1 LogMAR with visual field defect recovery. The follow-up MRI showed the almost complete disappearance of the previously contrast-enhanced lesions. LESSONS: Herein, we report a rare case of IgG4-RD presenting as a parasellar tumor and present a review of the related literature. Based on the case report, we propose that aggressive therapy with glucocorticoid, rituximab, and cyclophosphamide may potentially be useful for treating such cases.
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Imunoglobulina G/imunologia , Doenças do Nervo Óptico/imunologia , Pseudotumor Cerebral/imunologia , Nervo Trigêmeo/patologia , Adolescente , Feminino , Humanos , Imageamento por Ressonância Magnética , Metilprednisolona/uso terapêutico , Doenças do Nervo Óptico/tratamento farmacológico , Doenças do Nervo Óptico/cirurgia , Pseudotumor Cerebral/tratamento farmacológico , Pseudotumor Cerebral/cirurgia , Rituximab/uso terapêutico , Glândula Submandibular/patologiaRESUMO
BACKGROUND: This study determined the prognostic effects of immunohistochemical biomarkers and volumetric parameters predicting radiotherapy-based treatment in patients with p16-negative squamous cell carcinoma of the oropharynx or hypopharynx. RESULTS: VEGF immunoreactivity > 2 and GLUT1 overexpression were prognostic factors for lower cause-specific survival. Moreover, both factors were associated with lower disease-free survival. The predictors of lower primary relapse-free survival were VEGF immunoreactivity > 2 and CT-based gross tumor volume > 16 mL. MATERIALS AND METHODS: Immunohistochemical biomarkers in pretreatment biopsy specimens from 60 patients with p16-negative cancer were analyzed using tissue microarrays. Computed tomography (CT)-based and biological tumor volumes were retrieved through fluorodeoxyglucose positron emission tomography-CT. Correlations of cause-specific, disease-free, and primary relapse-free survival with volumetric parameters and the immunohistochemical biomarker score were investigated. CONCLUSIONS: For patients with p16-negative pharyngeal cancer receiving radiotherapy, treatment outcomes can be stratified by VEGF and GLUT1 expression and CT-based gross tumor volume.
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Renal dysplasia is an aberrant developmental disease usually diagnosed during the perinatal and childhood years. Prevalence is estimated at 0.1% of infants (via ultrasound screening) and 4% of fetuses and infants (via autopsy study). Occurrences may be combined with abnormalities in the collecting system or associated with complex syndromes. Histopathology shows primitive tubules surrounded by a fibromuscular collar. The differential diagnosis includes renal dysplasia, hypoplasia, and renal atrophy. Immunohistochemical expression of the paired box genes 2 and 8 (PAX2/8) and Wilms tumor 1 (WT1) is increased in the primitive ducts and fibromuscular collar, respectively. Renal dysplasia pathogenesis is not well understood, but may be caused by a nephron-inductive deficit due to ampullary inactivity or abnormal budding of the ureteric bud from the mesonephric duct. Either the PAX2 mutation only or cross-talk with the p53 pathway is involved in this deficit. Nephrectomy is the treatment of choice for symptomatic renal dysplasia.