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1.
Ann Surg Oncol ; 2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39181997

RESUMO

INTRODUCTION: Nonampullary duodenal adenocarcinoma (NDA) accounts for approximately 5% of all gastrointestinal cancers. Complete surgical resection (R0) with regional draining lymph node removal is mandatory as treatment to potentially cure nonampullary duodenal cancer or to achieve long-term survival. METHODS: According to existing literature, minimally invasive surgery has been reported to be safe and oncologically equivalent in pancreaticoduodenectomy for pancreatic and duodenal cancer. We describe a fully laparoscopic approach for the left-side adenocarcinoma of the duodenum "left-side" is defined with reference to the mesenteric vessels (III-IV segment). RESULTS: For the first time in literature, this multimedia paper describes a fully laparoscopic complete resection (R0) of the left side of the duodenum (III-IV segment) with locoregional lymph node resection. The main steps of the procedure are described using the concept of the critical view of safety. Reconstruction of intestinal continuity was ensured by full intracorporeal anastomosis. CONCLUSIONS: Through the tips and indications presented in this article, we supply a guide to the minimally invasive approach and increase operating surgeons' familiarity with such a complex procedure.

2.
Folia Morphol (Warsz) ; 82(1): 119-126, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34966995

RESUMO

BACKGROUND: In our study we used immunohistochemical technique to demonstrate the presence of the cytokines tumour necrosis factor alpha (TNF-α), interleukin 1beta (IL-1ß), transforming growth factor beta1 (TGF-ß1) and intercellular adhesion molecule-1 (ICAM-1) in porcine coronaries even in physiological conditions. MATERIALS AND METHODS: Inflammatory cytokines are polypeptide mediators which act as a communication signal between immune system cells and other types of cellsin different organs and tissues, both in human and pig coronary circulation. RESULTS: Our results show that pro-inflammatory cytokines TNF-α, IL-1ß, TGF-ß1 and ICAM-1 are also present in the medium tunica of the coronary arteries under physiological conditions. These results may be compared with those found in coronary atherosclerosis, where the increase in TNF-α has a dramatic effect on the function of the left ventricle, and the high value of IL-1 correlates directly with the extent of myocardial necrosis. In our study we observe the damage and activation of endothelial cells; this induces endothelial dysfunction by accumulation and oxidation of low density lipoproteins (LDL). The formation of oxidized LDL could play a central role in the amplification of the inflammatory response causing an increased expression of pro-inflammatory cytokines which promotes leukocyte recruitment in the intimal layer. These leukocytes, after the adhesion to the endothelium, penetrate the intimate tunic. CONCLUSIONS: Therefore inflammatory processes promote the onset and evolution of atheroma and the development of thrombotic complications.


Assuntos
Fator de Crescimento Transformador beta1 , Fator de Necrose Tumoral alfa , Humanos , Suínos , Animais , Fator de Necrose Tumoral alfa/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/farmacologia , Molécula 1 de Adesão Intercelular/metabolismo , Molécula 1 de Adesão Intercelular/farmacologia , Interleucina-1beta/metabolismo , Interleucina-1beta/farmacologia , Células Endoteliais/metabolismo , Vasos Coronários , Citocinas
3.
Folia Morphol (Warsz) ; 81(1): 117-123, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33438186

RESUMO

BACKGROUND: Thoracic outlet syndrome (TOS) represents a clinical condition caused by compression of the neurovascular structures that cross the thoracic outlet. TOS can be classified in: 1) neurogenic TOS (NTOS), 2) venous TOS (VTOS), 3) arterial TOS (ATOS). Many different causes can determine the syndrome: congenital malformations, traumas, and functional impairments. MATERIALS AND METHODS: This manuscript reviews how the congenital malformations play an important role in adult age; however, TOS also affects patients of all ages. RESULTS: Radiological imaging like X-ray (radiography), magnetic resonance and computed tomography can provide useful information to assess TOS causes and decide a potential surgery. 79% of the patients included in the first two stages of nerve, artery, vein (NAV) staging experienced excellent results with kinesiotherapy; whereas patients included in the third and fourth stage of NAV staging were subject to surgery. CONCLUSIONS: The treatment of acute forms of TOS involves thrombolysis and anticoagulant therapy; surgery is appropriate for true NTOS, vascular TOS and in some cases when conservative treatment fails.


Assuntos
Síndrome do Desfiladeiro Torácico , Adulto , Artérias/patologia , Humanos , Imageamento por Ressonância Magnética/efeitos adversos , Radiografia , Síndrome do Desfiladeiro Torácico/diagnóstico por imagem , Síndrome do Desfiladeiro Torácico/etiologia , Síndrome do Desfiladeiro Torácico/cirurgia , Tomografia Computadorizada por Raios X
4.
J Nucl Cardiol ; 29(1): 307-318, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32596791

RESUMO

OBJECTIVE: To determine one or more indexes able to detect the presence of cardiac amyloidosis (CA) from planar scintigraphy images after injection of 99mTc-HMDP tracer and to identify the earliest acquisition time able to ensure an accurate diagnosis of amyloid transthyretin CA. METHODS AND RESULTS: A total of 38 patients were included: 18 subjects with a final diagnosis of ATTR-CA and 20 controls. Dynamic planar images of the anterior thorax were acquired, starting at intravenous injection of ≈ 700 MBq of 99mTc-HMDP. From time/activity curves (TAC) of regions of interest such as heart, vascular region, right ribcage, and soft tissues, several indices were considered. From the analysis, it resulted that both TACHeart/Bone(t) and RIheart-bone(t), for t > 6 minutes, well distinguish ATTR-CA patients from controls subjects. This is confirmed by the area under curves (AUC) analysis giving AUC values =.9 at t ≅ 6 minutes and AUC ≅ 1 for t > 10 minutes. CONCLUSIONS: The method proposed allows determining the presence of ATTR-CA, in an inexpensive manner both in terms of examination costs and time spent.


Assuntos
Amiloidose , Difosfonatos , Amiloidose/diagnóstico por imagem , Osso e Ossos , Humanos , Cintilografia
5.
J Nucl Cardiol ; 29(4): 1919-1932, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-33864226

RESUMO

OBJECTIVE: To evaluate the feasibility of kinetic modeling-based approaches from [18F]-Flobetaben dynamic PET images as a non-invasive diagnostic method for cardiac amyloidosis (CA) and to identify the two AL- and ATTR-subtypes. METHODS AND RESULTS: Twenty-one patients with diagnoses of CA (11 patients with AL-subtype and 10 patients with ATTR-subtype of CA) and 15 Control patients with no-CA conditions underwent PET/CT imaging after [18F]Florbetaben bolus injection. A two-tissue-compartment (2TC) kinetic model was fitted to time-activity curves (TAC) obtained from left ventricle wall and left atrium cavity ROIs to estimate kinetic micro- and macro-parameters. Combinations of kinetic parameters were evaluated with the purpose of distinguishing Control subjects and CA patients, and to correctly label the last ones as AL- or ATTR-subtype. Resulting sensitivity, specificity, and accuracy for Control subjects were: 0.87, 0.9, 0.89; as far as CA patients, the sensitivity, specificity, and accuracy were respectively 0.9, 1, and 0.97 for AL-CA patients and 0.9, 0.92, 0.97 for ATTR-CA patients. CONCLUSION: Pharmacokinetic analysis based on a 2TC model allows cardiac amyloidosis characterization from dynamic [18F]Florbetaben PET images. Estimated model parameters allows to not only distinguish between Control subjects and patients, but also between AL- and ATTR-amyloid patients.


Assuntos
Neuropatias Amiloides Familiares , Cardiomiopatias , Estilbenos , Compostos de Anilina , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada
6.
Curr Pharm Des ; 27(16): 1878-1889, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32787756

RESUMO

The idea that performing a proper succession of imaging tests and techniques allows an accurate and early diagnosis of cardiac amyloidosis, avoiding the need to perform the myocardial biopsy, is becoming increasingly popular. Furthermore, being imaging techniques non-invasive, it is possible to perform the follow-up of the pathology through repeated image acquisitions. In the present review, the various innovative imaging methodologies are presented, and it is discussed how they have been applied for early diagnosis of cardiac amyloidosis (CA), also to distinguish the two most frequent subtypes in CA: immunoglobulin light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR); this allows to perform the therapy in a targeted and rapid manner.


Assuntos
Neuropatias Amiloides Familiares , Cardiomiopatias , Amiloidose de Cadeia Leve de Imunoglobulina , Biópsia , Cardiomiopatias/diagnóstico por imagem , Diagnóstico Precoce , Humanos
7.
Folia Morphol (Warsz) ; 80(1): 133-139, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32159845

RESUMO

BACKGROUND: Synovial cysts are currently classified as degenerative lesions affecting the joint capsule or adjacent structures. MATERIALS AND METHODS: In our study we describe the results obtained in an immunohistochemical study comprising 18 patients with synovial cysts, performed to evaluate the pathophysiological role of some inflammatory cytokines such as: interleukin (IL)-1ß, IL-6 and tumour necrosis factor-alpha (TNF-α). RESULTS: Results showed an over-expression of TNF-α, IL-1ß and IL-6 which appears to be involved in the onset and progression of the disease. At the present time it is not possible to affirm that these molecules play a direct role also due to the absence of further and more specific investigations. The authors therefore hypothesize that inhibition of inflammation may have a significant role in the pathogenesis and regression of synovial cysts. CONCLUSIONS: Hence, these inflammatory cytokines may be considered potential therapeutic targets. The development of synthetic inhibitors of these inflammatory factors could lead to a reduction in the intensity of inflammation, thus inhibiting the onset and development of the disease.


Assuntos
Interleucina-6 , Cisto Sinovial , Humanos , Interleucina-1beta , Membrana Sinovial , Fator de Necrose Tumoral alfa
9.
Crit Rev Oncol Hematol ; 133: 17-24, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30661653

RESUMO

Pancreatic ductal adenocarcinoma is one of the leading causes of cancer-related deaths and, currently, surgery is the only curative treatment. Patients with borderline resectable pancreatic cancer (BRPC) can benefit from a multidisciplinary approach and R0 resection, and can achieve the same outcome as resectable patients treated with upfront surgery. However, the definition of BRPC changes according to different classifications with a heterogeneous distribution of patients, and it is thus difficult to compare clinical evidence. We performed a literature review to assess the most suitable classification of BRPC. Our review was conducted using the PubMed database. Only articles containing more than ten patients classified according to NCCN, MDACC or AHPBA/SSAT/SSO classifications were selected. A total of 16 studies were included in our analysis, and were grouped according to one of these three classifications. The total resection rate was 61.4%, with considerable differences between the groups (68.4% for NCCN, 54.9% for MDACC and 53.2% for AHPBA/SSO/SSAT). The total R0 resection rate was 90.1% (89.1% for NCCN, 92.5% for MDACC and 84% for AHPBA/SSO/SSAT). Of the three classifications, NCCN limits the use of confusing terms and uses restrictive criteria to define the most appropriate treatment for each subgroup. However, several reports have suggested that, even in the case of a limited disease, biological and clinical factors should be considered in order to classify patients as resectable. NCCN classification appears to be the classification that allows the highest percentage of patients with BRPC to achieve resection without reducing the R0 resection rate. The choice of therapy should not only be based on imaging results, but also on a wider clinical multidisciplinary evaluation.


Assuntos
Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/cirurgia , Pancreatectomia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/cirurgia , Adenocarcinoma/classificação , Adenocarcinoma/diagnóstico , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Carcinoma Ductal Pancreático/classificação , Carcinoma Ductal Pancreático/patologia , Comportamento de Escolha , Humanos , Pancreatectomia/métodos , Neoplasias Pancreáticas/classificação , Neoplasias Pancreáticas/patologia , Seleção de Pacientes , Prognóstico , Resultado do Tratamento
10.
Eye (Lond) ; 31(11): 1594-1599, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28622321

RESUMO

PurposeTo determine the average time-point at which it is best to define 'sub-optimal response' after ranibizumab treatment for diabetic macular edema (DME) based on the data obtained from real-life clinical practice.MethodsIn this retrospective observational study, 322 consecutive treatment naïve eyes with DME were treated with three loading doses of intravitreal ranibizumab followed by re-treatment based on decision of the treating physician on a case-by-case basis. The demographic data, clinic-based visual acuity measurements and central subfield thickness (CST) assessed on spectral domain optical coherence tomography (OCT) were evaluated at baseline (month 0), 1, 2, 3, 6, and 12 months.ResultsOn an average, the improvement in visual acuity and CST was first seen after the loading dose. However, the maximal response in terms of proportion of patients with improvement in visual acuity and/ or CST in this cohort was observed at 12 months. Patients who presented with low visual acuity at baseline (<37 ETDRS letters) were unlikely to attain driving vision with ranibizumab therapy.ConclusionsOn an average, a 'sub-optimal response' after ranibizumab therapy is best defined at month 12 as patients may continue to improve with treatment.


Assuntos
Retinopatia Diabética/tratamento farmacológico , Edema Macular/tratamento farmacológico , Ranibizumab/administração & dosagem , Acuidade Visual , Inibidores da Angiogênese/administração & dosagem , Retinopatia Diabética/complicações , Retinopatia Diabética/fisiopatologia , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Injeções Intravítreas , Edema Macular/etiologia , Edema Macular/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Tomografia de Coerência Óptica/métodos , Resultado do Tratamento , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores
11.
Curr Pharm Des ; 20(39): 6171-81, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24745919

RESUMO

Cardiac health depends on the heart's ability to utilize different substrates to support overall oxidative metabolism. To characterize a variety of cardiac diseases, there is an ever-growing demand for an accurate non-invasive approach to evaluating myocardial substrate metabolism. Data obtained from quantitative metabolic imaging modalities add functional information to the anatomic imaging modalities and can aid patient management. The goal of this review is to emphasize the role of non-invasive imaging techniques (such as PET, SPECT, MR spectroscopy and spectroscopic imaging) to detect the metabolic footprints of heart disease. The advancements of models and methods to estimate kinetic parameters of dynamic processes using data acquired from cardiac imaging modalities is discussed.


Assuntos
Doenças Cardiovasculares/metabolismo , Miocárdio/metabolismo , Humanos , Imageamento por Ressonância Magnética , Modelos Moleculares , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único
12.
Bioresour Technol ; 123: 430-8, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22940353

RESUMO

The paper deals with the energy analysis and optimization of a complete biomass-to-electricity energy pathway, starting from raw biomass towards the production of renewable electricity. The first step (biomass-to-biogas) is based on a real pilot plant located in Environment Park S.p.A. (Torino, Italy) with three main steps ((1) impregnation; (2) steam explosion; (3) enzymatic hydrolysis), completed by a two-step anaerobic fermentation. In the second step (biogas-to-electricity), the paper considers two technologies: internal combustion engines and a stack of solid oxide fuel cells. First, the complete pathway has been modeled and validated through experimental data. After, the model has been used for an analysis and optimization of the complete thermo-chemical and biological process, with the objective function of maximization of the energy balance at minimum consumption. The comparison between ICE and SOFC shows the better performance of the integrated plants based on SOFC.


Assuntos
Biocombustíveis/análise , Biomassa , Biotecnologia/métodos , Eletricidade , Enzimas/metabolismo , Vapor , Anaerobiose , Biotecnologia/instrumentação , Eletrodos , Fermentação , Temperatura Alta , Hidrogênio/metabolismo , Hidrólise
13.
NMR Biomed ; 23(1): 66-73, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19708042

RESUMO

The acquisition of magnetic resonance spectroscopy (MRS) signals by multiple receiver coils can improve the signal-to-noise ratio (SNR) or alternatively can reduce the scan time maintaining a reliable SNR. However, using phased array coils in MRS studies requires efficient data processing and data combination techniques in order to exploit the sensitivity improvement of the phased array coil acquisition method. This paper describes a novel method for the combination of MRS signals acquired by phased array coils, even in presence of correlated noise between the acquisition channels. In fact, although it has been shown that electric and magnetic coupling mechanisms produce correlated noise in the coils, previous algorithms developed for MRS data combination have ignored this effect. The proposed approach takes advantage of a noise decorrelation stage to maximize the SNR of the combined spectra. In particular Principal Component Analysis (PCA) was exploited to project the acquired spectra in a subspace where the noise vectors are orthogonal. In this subspace the SNR weighting method will provide the optimal overall SNR. Performance evaluation of the proposed method is carried out on simulated (1)H-MRS signals and experimental results are obtained on phantom (1)H-MR spectra using a commercially available 8-element phased array coil. Noise correlations between elements were generally low due to the optimal coil design, leading to a fair SNR gain (about 0.5%) in the center of the field of view (FOV). A greater SNR improvement was found in the peripheral FOV regions.


Assuntos
Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Espectroscopia de Ressonância Magnética/métodos , Algoritmos , Espectroscopia de Ressonância Magnética/instrumentação , Modelos Teóricos , Análise de Componente Principal
14.
J Appl Microbiol ; 108(5): 1676-84, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19849773

RESUMO

AIMS: The aim of this work was to obtain a deeper insight into the knowledge of microbial composition of Parmigiano Reggiano natural whey starters through different culture-independent methods. METHODS AND RESULTS: Eighteen different Parmigiano Reggiano natural whey starters sampled from three different provinces of this cheese production area and the nonacidified wheys from which they arose have been studied by length heterogeneity polymerase chain reaction (LH-PCR) and fluorescent in situ hybridization (FISH). A high microbial composition variability between different samples has been observed. CONCLUSIONS: Revealing different images of the same community, LH-PCR and FISH have given a more accurate view of the not well-known Parmigiano Reggiano whey starter ecosystem. SIGNIFICANCE AND IMPACT OF THE STUDY: New lights have been shed on Parmigiano Reggiano natural whey starters microbial composition, highlighting how culture-independent approach could be used and improved to study this and other food ecosystems.


Assuntos
Queijo/microbiologia , Microbiologia de Alimentos , Bactérias/genética , Fenômenos Fisiológicos Bacterianos , Ecossistema , Hibridização in Situ Fluorescente , Reação em Cadeia da Polimerase
15.
Int J Med Inform ; 78(8): 503-12, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19345609

RESUMO

PURPOSE: To build and evaluate a national network able to improve the care of thalassemia, a genetic disorder in haemoglobin synthesis often associated with iron accumulation in a variety of organs, due to the continuous blood transfusions. METHODS: The MIOT (Myocardial Iron Overload in Thalassemia) network is constituted by thalassemia and magnetic resonance imaging (MRI) centers. Thalassemia centers are responsible for patient recruitment and collection of anamnestic and clinical data. MRI centers have been equipped with a standardized acquisition technique and an affordable workstation for image analysis. They are able to perform feasible and reproducible heart and liver iron overload assessments for a consistent number of thalassemia patients in a robust manner. All centers are linked by a web-based network, configured to collect and share patient data. RESULTS: On 30th March 2008, 695 thalassemia patients were involved in the network. The completion percentage of the patient records in the database was 85+/-6.5%. Six hundred and thirteen patients (88%) successfully underwent MRI examination. Each MRI center had a specific absorption capacity that remained constant over time, but the network was capable of sustaining an increasing number of patients due to continuous enrollment of new centers. The patient's comfort, assessed as the mean distance from the patient home locations to the MRI centers, significantly increased during the network's evolution. CONCLUSION: The MIOT network seems to be a robust and scalable system in which T2* MRI-based cardiac and liver iron overload assessment is available, accessible and reachable for a significant and increasing number of thalassemia patients in Italy (about 420 per year), reducing the mean distance from the patient locations to the MRI sites from 951km to 387km. A solid, wide and homogeneous database will constitute an important scientific resource, shortening the time scale for diagnostic, prognostic and therapeutical evidence-based research on the management of thalassemia disease.


Assuntos
Internet , Sobrecarga de Ferro/complicações , Imageamento por Ressonância Magnética/métodos , Talassemia/terapia , Humanos , Ferro/metabolismo , Sobrecarga de Ferro/metabolismo , Fígado/metabolismo , Miocárdio/metabolismo , Reprodutibilidade dos Testes , Talassemia/complicações , Talassemia/metabolismo
16.
Curr Pharm Des ; 15(10): 1123-30, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19355953

RESUMO

In this paper the authors deal with the main imaging techniques available to clinical cardiologists, with a brief overview of biophysical and biological aspects which are of relevance for the assessment of health effects related to the exposure of patients to both ionizing and non ionizing radiation. A main contribute is the reviewing published evidence on biological effects of radiation, trying to compose a balanced issue in order to increase awareness and knowledge about radiation exposure from cardiac imaging and implications for health risk.


Assuntos
Diagnóstico por Imagem/efeitos adversos , Coração/diagnóstico por imagem , Miocárdio/patologia , Animais , Ecocardiografia/efeitos adversos , Humanos , Imageamento por Ressonância Magnética/efeitos adversos , Radiografia , Radiometria , Raios X/efeitos adversos
17.
Curr Pharm Des ; 14(18): 1745-52, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18673177

RESUMO

The aim of this paper is to introduce the prominent in vivo cardiovascular imaging modalities such as magnetic resonance imaging, nuclear imaging and ultrasound from both the physical and molecular imaging perspectives. A brief introduction to the molecular imaging principles is also reported. Special emphasis will be given to the imaging parameters of sensitivity and spatial resolution, and the trade-off between spatial resolution, image contrast and target size.


Assuntos
Doenças Cardiovasculares/diagnóstico , Diagnóstico por Imagem/métodos , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/patologia , Humanos , Sensibilidade e Especificidade
18.
J Dairy Sci ; 91(3): 883-91, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18292243

RESUMO

This work aimed to investigate the effects of thermal treatments and yeast extract addition on the composition of the microbial community of natural whey starters for Grana Padano cheese. Different natural whey starter samples were held at 4 degrees C for 24 h (cooling treatment), or at -20 degrees C for 24 h (freezing treatment) to evaluate the possibility of conservation, or at 54 degrees C for 1 h (heat treatment) to evaluate the effect of the temperature commonly used during curd cooking. Separately, another set of samples was enriched with 0.3, 0.5, and 1.0% (wt/vol) of yeast extract to study its effect on the growth of lactic acid bacteria (LAB) in the starter. The new approach in this study is the use of 2 culture-independent methods: length heterogeneity (LH)-reverse transcription (RT)-PCR and fluorescence microscopy. These techniques allowed us to easily, quickly, and reproducibly assess metabolically active LAB in the control and treated samples. The LH-RT-PCR technique distinguished microorganisms based on natural variations in the length of 16S rRNA amplified by RT-PCR, as analyzed by using an automatic gene sequencer. Fluorescence microscopy counts were performed by using a Live/Dead BacLight bacterial viability kit. The repeatability of LH-RT-PCR showed that this technique has great potential to reveal changes in the microbial community of natural whey starters for Grana Padano cheese. All species showed low sensitivity to cold (4 degrees C). However, after the freezing (-20 degrees C) and heating (54 degrees C) treatments, different behaviors of the species were reported, with significant changes in their viability and relative composition. Heating treatment during curd cooking profoundly affected the viability and composition of the community that remained in the cheese and that consequently modified the microbial population. At the same time, this treatment produced the selection of LAB in whey and could be considered as the first step in natural whey starter production. Addition of yeast extract stimulated the growth of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. lactis to the detriment of Lactobacillus helveticus species. Because the yeast extract altered the microflora balance, whey starter conservation at -20 degrees C and yeast extract addition cannot be suggested as technological innovations.


Assuntos
Queijo/microbiologia , Manipulação de Alimentos/métodos , Leite/química , Animais , Temperatura Baixa , Congelamento , Temperatura Alta , Lactobacillus/genética , Lactobacillus/crescimento & desenvolvimento , Microscopia de Fluorescência , RNA Ribossômico 16S/análise , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Streptococcus thermophilus/genética , Streptococcus thermophilus/crescimento & desenvolvimento
19.
Med Biol Eng Comput ; 46(3): 251-61, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18064502

RESUMO

Electrocardiographic (ECG) signals are affected by several kinds of artifacts that may hide vital signs of interest. In this study we apply independent component analysis (ICA) to isolate motion artifacts. Standard or instantaneous ICA, which is currently the most addressed ICA model within the context of artifact removal, is compared to two other ICA techniques. The first technique is a frequency domain approach to convolutive mixture separation. The second is based on temporally constrained ICA, which enables the estimation of only one component close to a particular reference signal. Performance indexes evaluate ECG complex enhancement and relevant heart rate errors. Our results show that both convolutive and constrained ICA implementations perform better than standard ICA, thus opening up a new field of application for these two methods. Moreover, statistical analysis reveals that constrained ICA and convolutive ICA do not significantly differ concerning heart rate estimation, even though the latter overcomes the former in ECG morphology recovery.


Assuntos
Artefatos , Eletrocardiografia/métodos , Processamento de Sinais Assistido por Computador , Interpretação Estatística de Dados , Humanos , Movimento (Física) , Análise de Componente Principal
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