Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
J Biophotonics ; 17(6): e202300513, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38531615

RESUMO

Cystic echinococcosis (CE) is a global health concern caused by cestodes, posing diagnostic challenges due to nonspecific symptoms and inconclusive radiographic results. Diagnosis relies on histopathological evaluation of affected tissue, demanding comprehensive tools. In this retrospective case study, Fourier transform infrared microscopy was explored for detecting and identifying CE through biochemical changes in human tissue sections. Tissue samples from 11 confirmed CE patients were analyzed. Archived FFPE blocks were cut and stained, and then CE-positive unstained sections were examined using Fourier transform infrared microscopy post-deparaffinization. Results revealed the method's ability to distinguish echinococcus elements from human tissue, irrespective of organ type. This research showcases the potential of mid-infrared microscopy as a valuable diagnostic tool for CE, offering promise in enhancing diagnostic precision in the face of the disease's complexities.


Assuntos
Equinococose , Humanos , Equinococose/diagnóstico por imagem , Equinococose/patologia , Espectroscopia de Infravermelho com Transformada de Fourier , Microscopia , Estudos Retrospectivos , Feminino
2.
J Biophotonics ; 16(11): e202300015, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37578837

RESUMO

The present study presents an alternative analytical workflow that combines mid-infrared (MIR) microscopic imaging and deep learning to diagnose human lymphoma and differentiate between small and large cell lymphoma. We could show that using a deep learning approach to analyze MIR hyperspectral data obtained from benign and malignant lymph node pathology results in high accuracy for correct classification, learning the distinct region of 3900 to 850 cm-1 . The accuracy is above 95% for every pair of malignant lymphoid tissue and still above 90% for the distinction between benign and malignant lymphoid tissue for binary classification. These results demonstrate that a preliminary diagnosis and subtyping of human lymphoma could be streamlined by applying a deep learning approach to analyze MIR spectroscopic data.


Assuntos
Aprendizado Profundo , Linfoma , Humanos , Linfoma/diagnóstico por imagem , Linfoma/patologia , Diagnóstico Diferencial , Linfonodos , Diagnóstico por Imagem
3.
Analyst ; 140(18): 6363-72, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26236782

RESUMO

Mid-infrared (MIR) microscopy imaging is a vibrational spectroscopic technique that uses infrared radiation to image molecules of interest in thin tissue sections. A major advantage of this technology is the acquisition of local molecular expression profiles, while maintaining the topographic integrity of the tissue. Therefore, this technology has become an essential tool for the detection and characterization of the molecular components of many biological processes. Using this method, it is possible to investigate the spatial distribution of proteins and small molecules within biological systems by in situ analysis. In this study, we have evaluated the potential of mid-infrared microscopy imaging to study biochemical changes which distinguish between reactive lymphadenopathy and cancer in genetically modified mice with different phenotypes. We were able to demonstrate that MIR microscopy imaging and multivariate image analyses of different mouse genotypes correlated well with the morphological tissue features derived from HE staining. Using principal component analyses, we were also able to distinguish spectral clusters from different phenotype samples, particularly from reactive lymphadenopathy (follicular hyperplasia) and cancer (follicular lymphoma).


Assuntos
Raios Infravermelhos , Linfoma Folicular/diagnóstico , Microscopia/métodos , Baço/patologia , Animais , Diagnóstico Diferencial , Hiperplasia/diagnóstico , Linfoma Folicular/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fenótipo
4.
Cell ; 96(4): 517-27, 1999 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-10052454

RESUMO

A chimera with the green fluorescent protein (GFP) has been constructed to visualize the dynamic properties of the endosome-microtubule linker protein CLIP170 (GFP-CLIP170). GFP-CLIP170 binds in stretches along a subset of microtubule ends. These fluorescent stretches appear to move with the growing tips of microtubules at 0.15-0.4 microm/s, comparable to microtubule elongation in vivo. Analysis of speckles along dynamic GFP-CLIP170 stretches suggests that CLIP170 treadmills on growing microtubule ends, rather than being continuously transported toward these ends. Drugs affecting microtubule dynamics rapidly inhibit movement of GFP-CLIP170 dashes. We propose that GFP-CLIP170 highlights growing microtubule ends by specifically recognizing the structure of a segment of newly polymerized tubulin.


Assuntos
Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Chlorocebus aethiops , Expressão Gênica/fisiologia , Proteínas de Fluorescência Verde , Células HeLa , Humanos , Indicadores e Reagentes/metabolismo , Cinética , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microscopia de Fluorescência , Microtúbulos/efeitos dos fármacos , Proteínas de Neoplasias , Nocodazol/farmacologia , Paclitaxel/farmacologia , Proteínas Recombinantes de Fusão/metabolismo , Células Vero
5.
Carcinogenesis ; 12(2): 211-5, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1995187

RESUMO

Caloric restriction depresses the development of several types of tumours, yet the mechanisms involved are poorly understood. In the present experiment we investigated the development of diethylnitrosamine (DEN)-induced liver tumours in mice treated with caffeine. The latter was found to reduce body growth, possibly due to increased energy expenditure, without reducing food consumption. Newborn mice received an i.p. injection of DEN. At weaning they were either fed lab chow ad libitum, with the same diet containing 0.2% (w/w) of caffeine, or their access to food was restricted to 70% of that consumed by the ad libitum group. Diet caloric restriction starting at weaning in male Swiss mice decreased the rate of development of glucose-6-phosphatase-deficient (G6Pd) preneoplastic foci. At the age of 24 weeks, 10% of the surface of a standardized liver section of ad libitum fed mice was G6Pase negative, compared to only 1% in the restricted mice due to a reduction of the number and size of these preneoplastic foci. The number and size of G6Pd foci decreased to the same extent with the ingestion of a lab chow supplemented with 0.2% of caffeine as with the diet restriction. This finding suggests that restriction slows down hepatic tumour growth by modifying body growth rather than by limited nutrient supply. In parallel, somatomedin-C (Sm-C) and insulin secretion following glucose challenge were decreased in diet restricted mice and those treated with 0.2% caffeine. The serum Sm-C and insulin levels were respectively 480 and 4.6 ng/ml in the restricted mice, 519 and 16.6 ng/ml in the caffeine-fed mice and 664 and 25.7 ng/ml in the ad libitum fed mice. Our results suggest that the decrease of secretion of these two hormones that are known mitogens for hepatocytes in vitro may be responsible at least in part for the reduction in the growth of liver tumours.


Assuntos
Dietilnitrosamina/toxicidade , Fator de Crescimento Insulin-Like I/metabolismo , Insulina/sangue , Neoplasias Hepáticas Experimentais/induzido quimicamente , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Cafeína/efeitos adversos , Dietilnitrosamina/administração & dosagem , Ingestão de Alimentos , Jejum , Injeções Intraperitoneais , Fígado/anatomia & histologia , Neoplasias Hepáticas Experimentais/sangue , Neoplasias Hepáticas Experimentais/etiologia , Camundongos , Tamanho do Órgão/efeitos dos fármacos
6.
Carcinogenesis ; 12(2): 311-5, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1847320

RESUMO

The effects of alternating ad libitum feeding and 30% restriction of the dietary intake on the development of diethylnitrosamine (DEN)-induced hepatic neoplasia were investigated. Dietary restriction retarded the growth of glucose-6-phosphatase-deficient (G6Pd) preneoplastic foci and subsequently that of hepatocellular adenomas and adenocarcinomas. The number of foci in standardized liver sections increased from 4.44 foci/cm2 at 12 weeks to 9.65 foci/cm2 at 24 weeks in ad libitum fed animals but only from 2.35 foci/cm2 to 3.29 foci/cm2 in restricted animals. In animals fed first ad libitum for 12 weeks and then for 12 weeks on a restricted diet, the number of G6Pd foci dropped from 4.44 at 12 weeks to 3.54 at 24 weeks. This reduction appeared to be the result of a regression of the small sized G6Pd foci. Dietary restriction was most efficient in inhibiting the development of G6Pd foci when started early in life. Conversely, the growth of foci was stimulated when the mice first had restricted access to food and thereafter were fed ad libitum. The plasma insulin concentrations after a glucose challenge increased with age. Insulinaemia was much higher in ad libitum fed compared to the restricted mice. It was correlated to the number of G6Pd foci in the liver. This study suggests that insulin, which is a known mitogen for hepatocytes in vitro, may contribute to the promotion of DEN-induced liver tumours in mice.


Assuntos
Dietilnitrosamina/toxicidade , Insulina/sangue , Neoplasias Hepáticas Experimentais/etiologia , Adenoma/sangue , Adenoma/induzido quimicamente , Adenoma/etiologia , Animais , Peso Corporal/fisiologia , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/etiologia , Dieta/efeitos adversos , Ingestão de Alimentos/fisiologia , Feminino , Doença de Depósito de Glicogênio Tipo I/metabolismo , Humanos , Resistência à Insulina/fisiologia , Fígado/anatomia & histologia , Fígado/enzimologia , Fígado/patologia , Neoplasias Hepáticas Experimentais/sangue , Neoplasias Hepáticas Experimentais/induzido quimicamente , Masculino , Camundongos , Tamanho do Órgão/fisiologia , Fatores de Tempo
7.
Nucleic Acids Res ; 18(23): 7033-9, 1990 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-2263463

RESUMO

We present a reproducible method for the preparation of nuclear extracts from the yeast Saccharomyces cerevisiae that support efficient RNA polymerase B (II)-dependent transcription. Extracts from both a crude nuclear fraction and Percoll-purified nuclei are highly active for site-specific initiation and transcription of a G-free cassette under the Adenovirus major late promoter. At optimal extract concentrations transcription is at least 5 times more efficient with the yeast extracts than with HeLa whole cell extracts. We show that the transcriptional activity is sensitive to alpha-amanitin and to depletion of factor(s) recognizing the TATA-box of the promoter. The in vitro reaction showed maximal activity after 45 min, was very sensitive to Cl-, but was not affected by high concentrations of potassium. We find that the efficiency of in vitro transcription in nuclear extracts is reproducibly high when spheroplasting is performed with a partially purified beta 1,3-glucanase (lyticase). Therefore a simplified method to isolate the lyticase from the supernatant of Oerskovia xanthineolytica is also presented.


Assuntos
Técnicas Genéticas , RNA Polimerase II/metabolismo , Saccharomyces cerevisiae/genética , Transcrição Gênica , Amanitinas/farmacologia , Núcleo Celular/metabolismo , Glucana Endo-1,3-beta-D-Glucosidase/isolamento & purificação , Glucana Endo-1,3-beta-D-Glucosidase/metabolismo , Complexos Multienzimáticos/isolamento & purificação , Complexos Multienzimáticos/metabolismo , Peptídeo Hidrolases/isolamento & purificação , Peptídeo Hidrolases/metabolismo , Saccharomyces cerevisiae/enzimologia , Esferoplastos , TATA Box , Temperatura , Fatores de Tempo
8.
Food Chem Toxicol ; 28(12): 829-37, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2148922

RESUMO

Commercially available regular instant coffee was given in the diet to barrier-maintained, specified pathogen-free Swiss mice for 2 yr. Groups of 150 males and 150 females were fed diets containing 10, 25 or 50 g instant coffee powder/kg. The animals had already been exposed to coffee in utero. Coffee increased the energy expenditure of the animals as shown by increased daily calorific intake and depressed growth. The overall tumour incidence was inversely correlated to the coffee intake, and no unusual tumour or site of origin was found. The most frequent neoplasms were lymphosarcomas, bronchiolo-alveolar adenomas and adenocarcinomas, as well as hepatocellular adenomas. The incidence of total neoplasms (benign and malignant) decreased from 70.6 and 56.8% in control males and females, respectively, to 34.8 and 36.2%, respectively, in the high-dose group. This decrease, which was essentially due to a reduction in the number of lymphosarcomas and hepatocellular adenomas, was associated with a slower growth rate. The number of leiomyomas in the uterus was slightly increased due to coffee intake as shown by the analysis of positive trend (P less than or equal to 0.05). However, the incidence of this benign tumour was very low; 2.72% of mice affected in the high-dose group, 1.37% in the low-dose group and 0% in the control and medium-dose groups. From this study it is concluded that instant coffee did not increase the incidence of malignant neoplasms in mice when fed at dietary levels of up to 5% for 2 yr.


Assuntos
Café/toxicidade , Neoplasias/induzido quimicamente , Animais , Peso Corporal/efeitos dos fármacos , Testes de Carcinogenicidade , Relação Dose-Resposta a Droga , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Energia/efeitos dos fármacos , Feminino , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Gravidez , Distribuição Aleatória , Reprodução/efeitos dos fármacos , Fatores Sexuais , Organismos Livres de Patógenos Específicos
9.
Nucleic Acids Res ; 18(16): 4817-23, 1990 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-2204028

RESUMO

We report the identification and purification of a yeast factor functionally homologous to the human upstream element factor (UEFh). Although the yeast protein (UEFy) has a higher molecular weight than the HeLa UEF (60 kD versus 45 kD) both have identical DNA-binding properties: the purified UEFy recognizes the Adenovirus 2 (Ad2) major late promoter upstream element (MLP-UE; from nucleotide -49 to -67) as well as the IVa2 upstream element (IVa2-UE; from nucleotide -98 to -122) with a higher affinity for the MLP-UE than for the IVa2-UE. Based on its DNA binding specificity, size and thermostability, the UEFy protein appears also similar or equivalent to the centromere binding protein CP1. In a competition assay with oligonucleotides containing the MLP-UE binding site, a drastic reduction of Ad2 MLP transcription was observed both in a HeLa and in a yeast cell free system, which was restored by addition of either the purified UEFh or UEFy proteins. We conclude that both UEFh and UEFy activate transcription from the Ad2 MLP upon binding to the upstream element, whatever is the in vitro cell-free system (yeast or HeLa). This indicate that some regulatory function represented by the upstream element and its cognate factor, is well conserved between human and yeast.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Regiões Promotoras Genéticas , Saccharomyces cerevisiae/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Adenovírus Humanos/genética , Sequência de Bases , Ligação Competitiva , Sistema Livre de Células , DNA/genética , DNA/metabolismo , Proteínas de Ligação a DNA/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Células HeLa , Humanos , Dados de Sequência Molecular , Homologia de Sequência do Ácido Nucleico , Fatores de Transcrição/isolamento & purificação , Fatores Estimuladores Upstream
10.
Carcinogenesis ; 8(1): 33-7, 1987 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3802392

RESUMO

The aim of this study was to determine whether a dietary restriction, which significantly decreases body weight gain, also influences the development of diethylnitrosamine (DEN)-induced liver tumours in Swiss mice. At birth, mice were injected i.p. with a single dose of DEN (0.4 mumol/g body wt); negative control mice were sham injected. After weaning the animals received a stock diet either ad libitum (control group) or at 30% restriction (restricted group). A positive control group was fed ad libitum and received phenobarbital (500 p.p.m.) in their drinking water. At 12 weeks of age, glucose-6-phosphatase (G6Pase)-deficient foci were present in the liver of 80% of the control animals but only in 32% of the restricted group. Quantitatively, restricted animals had fewer foci per unit volume liver and these were smaller than in the control animals. By 36 weeks of age, hepatocarcinomas were seen in 100% of the control mice while in the restricted group there were no such malignant lesions and only 32% showed adenomas. The results clearly show that restriction of food intake inhibits promotion and progression of induced liver tumours. Amongst other uses, this model permits the study of the effect of dietary restriction on liver tumours, at an early stage.


Assuntos
Dietilnitrosamina , Privação de Alimentos , Neoplasias Hepáticas/induzido quimicamente , Animais , Peso Corporal/efeitos dos fármacos , Ingestão de Energia , Fígado/enzimologia , Fígado/patologia , Camundongos , Tamanho do Órgão/efeitos dos fármacos
11.
J Cardiovasc Surg (Torino) ; 22(2): 163-5, 1981.
Artigo em Inglês | MEDLINE | ID: mdl-6971866

RESUMO

Serum magnesium levels fall significantly after acute myocardial infarction. Even greater decreases have been found in all patients undergoing aorto-coronary bypass surgery. This is probably related to the use of cardiopulmonary bypass. No significant difference in serum magnesium levels was found between those patients who had a well documented peri-operative infarct and those who had an uncomplicated course. Thus determination of serum magnesium levels if of no use in the diagnosis of peri-operative myocardial infarction.


Assuntos
Vasos Coronários/cirurgia , Creatina Quinase/sangue , Magnésio/sangue , Infarto do Miocárdio/diagnóstico , Ponte de Artéria Coronária , Humanos , Infarto do Miocárdio/sangue , Infarto do Miocárdio/enzimologia , Período Pós-Operatório
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA