Search results for "Transform"
showing 10 items of 3975 documents
Nested PCR for detection of HSV-1 in oral mucosa
2015
Background: It has been estimated that 15%-20% of human tumours are driven by infection and inflammation, and viral infections play an important role in malignant transformation. The evidence that herpes simplex virus type 1 (HSV-1) could be involved in the aetiology of oral cancer varies from weak to persuasive. This study aimed to investigate by nested PCR (NPCR) the prevalence of HSV-1 in samples from normal oral mucosa, oral leukoplakia, and oral squamous cell carcinoma (OSCC). Material and Methods: We investigated the prevalence of HSV-1 in biopsies obtained from 26 fresh, normal oral mucosa from healthy volunteers as well as 53 oral leukoplakia and 27 OSCC paraffin-embedded samples. D…
Surrogate data approaches to assess the significance of directed coherence: Application to EEG activity propagation
2009
This paper addresses the topic of evaluating the significance of frequency domain measures of causal coupling in multivariate time series through generation of surrogate data. The considered approaches are the traditional Fourier Transform (FT) algorithm and a new causal FT (CFT) algorithm for surrogate data generation. Both algorithms preserve the FT modulus of the original series; differences are in the phase relationships, that are completely destroyed for FT surrogates and imposed after switching off the link over the considered causal direction for CFT surrogates. The ability of the algorithms to assess causality in the frequency domain was tested using the directed coherence as discri…
Testing Frequency-Domain Causality in Multivariate Time Series
2010
We introduce a new hypothesis-testing framework, based on surrogate data generation, to assess in the frequency domain, the concept of causality among multivariate (MV) time series. The approach extends the traditional Fourier transform (FT) method for generating surrogate data in a MV process and adapts it to the specific issue of causality. It generates causal FT (CFT) surrogates with FT modulus taken from the original series, and FT phase taken from a set of series with causal interactions set to zero over the direction of interest and preserved over all other directions. Two different zero-setting procedures, acting on the parameters of a MV autoregressive (MVAR) model fitted on the ori…
Inability of Laplace's law to estimate sub-bandage pressures after applying a compressive bandage: a clinical study
2021
Objective: The aim of the current study was to compare pressures exerted on the lower limb by a high compression bandage as recorded by sub-bandage sensors and those estimated by Laplace's law. The correlation between pressures obtained in each anatomical zone and the corresponding limb perimeters were explored. Method: For the measurement of sub-bandage pressures, four anatomical zones in the lower right limb were determined. Pressures were recorded by nine pneumatic sensors and a PicoPress transducer. A two-layer compression bandage system (UrgoK2, Urgo Group, France) was used for the dressing. Pressures were registered in supine position. Sensor pressures were compared with those estimat…
Transforming Growth Factor Beta 1 Serum Levels in Patients with Preinvasive and Invasive Lesions of the Breast
2004
Transforming growth factor beta (TGF-beta)1 is thought to be involved in breast carcinogenesis. TGF-beta1 acts in an antiproliferative manner in the early stages of breast carcinogenesis, but promotes tumor progression and metastases in the advanced stages of the disease. No data have been published on serum TGF-beta1 in breast cancer. We investigated TGF-beta1 serum levels in patients with breast cancer (n=135), ductal carcinoma in situ (DCIS) I to III (n=67) or fibroadenoma (n=35), and in healthy women (n=40) to determine its value as a differentiation marker between malignant, pre-invasive and benign diseases and as a predictive marker for metastatic spread. Median (range) TGF-beta1 seru…
Monocyte Chemoattractant Protein-1 Serum Levels in Patients with Breast Cancer
2003
The chemokine monocyte chemoattractant protein (MCP)-1 is thought to be involved in breast carcinogenesis. We evaluated MCP-1 serum levels in patients with breast cancer (n = 135), ductal carcinoma in situ (DCIS) I-III (n = 30), benign breast lesions (n = 143) and in healthy women (n = 27). We determined the value of MCP-1 serum levels as a differentiation marker between malignant, preinvasive and benign breast diseases and as a predictive marker for the biological phenotype of breast carcinoma. Median (range) MCP-1 serum levels in patients with breast cancer, DCIS I-III, benign breast lesions and healthy women were 200 (57-692) pg/ml, 194 (58-525) pg/ml, 174 (39-529) pg/ml and 175 (67-425)…
Incidence and profile of benign epithelial tumors of salivary glands from a single center in Northeast of Brazil
2020
Background Benign tumors of the salivary glands are a group of lesions with varied histopathological and clinical spectrum. The aim was to determine the incidence and clinicopathological characteristics of benign salivary gland neoplasms diagnosed between 2007 and 2016 in a single center located in northeastern Brazil. Material and Methods Records regarding sex, age, anatomical location, histopathological subtype and treatment were retrieved, and data were analyzed using the Stata/IC software (version 12.0). Results There were above 7,100 cases of neoplasms in the head and neck region, of which 403 corresponded to salivary gland neoplasms. Of these, 238 (59%) were benign, being pleomorphic …
Induction of bone morphogenetic protein-6 in skin wounds. Delayed reepitheliazation and scar formation in BMP-6 overexpressing transgenic mice.
1998
Growth factors of the transforming growth factor-beta superfamily are involved in cutaneous wound healing. In this study we analyze the expression of the bone morphogenetic protein-6 (BMP-6) gene, a transforming growth factor-beta related gene, in skin wounds. In normal mouse skin high levels of BMP-6 mRNA and protein are expressed by postmitotic keratinocytes of stratified epidermis until day 6 after birth. BMP-6 expression is strongly reduced in adult epidermis with diminished mitotic activity. After skin injury we found large induction of BMP-6-specific RNA and protein in keratinocytes at the wound edge and keratinocytes of the newly formed epithelium as well as in fibroblast shaped cell…
Expression of caveolin-1 in tooth germ, ameloblastoma and ameloblastic carcinoma
2020
Background The caveolin-1 protein (structural component of membrane caveolae) plays important roles in several biological functions, such as endocytosis, cell adhesion, and cell signaling. However, this protein has been associated with mechanisms of tumorigenesis in several neoplasms. The expression patterns and roles of caveolin-1 in the oral epithelium and in embryonic and odontogenic tumor tissues are still unclear. Material and Methods The expression of caveolin-1 was evaluated in samples of the normal gingival epithelium (n=7), human tooth germ (TG) (n=12), ameloblastoma (AM) (n=83), and ameloblastic carcinoma (AC) (n=9) by immunohistochemistry. Additionally, AM samples were analyzed b…
Four-phase rhinomanometry: a multicentric retrospective analysis of 36,563 clinical measurements
2015
Rhinomanometry can still be considered as the standard technique for the objective assessment of the ven- tilatory function of the nose. Reliable technical requirements are given by fast digital sensors and modern information technology. However, the xyimaging of the pressure-flow relation typically shows loops as a sign of hysteresis, with the need for resolution of the breath in four phases. The three pillars of 4-phase rhinomanometry (4PR) are the replacement of estimations by measurements, the introduc- tion of parameters related to the subjective sensing of obstruction, and the graphical information regarding the disturbed function of the nasal valve. In a meta-analysis of 36,563 clini…