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1.
J Microsc ; 244(2): 122-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21696391

RESUMO

The combination of noninvasive compositional analysis by Raman microspectrometry with high-resolution imaging in the scanning electron microscope greatly expands the analytical capabilities of the electron microscope. However, the chemical preparation of scanning electron microscope (SEM) specimens, although adequate for low-resolution imaging of superficial detail, is not the true representation of the chemistry and composition of the sample, as extraction and aggregation artefacts as a result of dehydrating and cross-linking agents are abundant. The original chemical composition and ultrastructure is only preserved using cryo preparation methods. Therefore, a complete cryo transfer flange was designed and built to add cryogenic control of specimens to the configuration of the EMRAM instrument, a combined Raman spectrometer and XL-30 ESEM instrument. The Raman spectra of two model specimen, polystyrene beads and 2.3M sucrose were studied at ambient and cryogenic temperatures as well as during a heating ramp. Comparing the fingerprint regions of polystyrene and sucrose, both measured at ambient and at cryogenic conditions, only small spectral differences were observed for the main peaks of both molecules. A pronounced sharpening of the bands occurred in the 800-400 cm(-1) region, a result of the reduction of intermolecular interactions. The enhanced visibility of the lower frequency modes may offer interesting potential for more detailed interpretation of Raman spectra.


Assuntos
Microscopia Crioeletrônica/métodos , Microscopia Eletrônica de Varredura/métodos , Análise Espectral Raman/métodos , Congelamento
2.
J Microsc ; 242(1): 104-10, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21126247

RESUMO

A combined scanning electron microscope and focussed ion beam instrument is suitable for micro- and nanopatterning, cross-sectioning and subsequent imaging, of specimens at room temperature as well as under cryo conditions. In order to reveal internal details, samples are conventionally milled with the ion beam positioned perpendicular to the sample surface. Using this approach certain limitations are frequently encountered, e.g. accumulation of redeposited material, shadowing effects, image distortion and a limited imaging area. Here we show an approach in which samples are pre-trimmed using a microtome to obtain a sample block face that is parallel to the ion beam. This new grazing incidence geometry eliminates the need for removal of bulk material with the ion beam and enables immediate fine polishing of a pre-selected area of interest. Many of the limitations previously described are avoided and in addition milling time is reduced, whilst creating larger cross-sectional areas. Another advantage is that electron imaging can be accomplished by tilting the sample surface perpendicular to the electron beam, providing a geometrically undistorted image. The proposed approach is suitable for materials that can be microtomed, both in ambient and cryogenic conditions, and proves to be of particular benefit for biological and food samples.


Assuntos
Íons , Microscopia Eletrônica de Varredura/instrumentação , Animais , Processamento de Imagem Assistida por Computador , Camundongos , Células NIH 3T3 , Temperatura
3.
Hum Reprod ; 24(9): 2158-72, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19458318

RESUMO

BACKGROUND: An estimated 3.5 million children have been born to date using assisted reproduction technologies. We reviewed the data in order to evaluate current knowledge of medical outcome for IVF/ICSI children born after cryopreservation, slow freezing and vitrification of early cleavage stage embryos, blastocysts and oocytes. METHODS: A systematic review was performed. We searched the PubMed, Cochrane and Embase databases from 1984 to September 2008. Inclusion criteria for slow freezing of early cleavage stage embryos were controlled studies reporting perinatal or child outcomes. For slow freezing and vitrification of blastocysts and oocytes, and vitrification of early cleavage stage embryos, case reports on perinatal or child outcomes were also included. Three reviewers independently read and evaluated all selected studies. RESULTS: For early cleavage embryos, data from controlled studies indicated a better or at least as good obstetric outcome, measured as preterm birth and low birthweight for children born after cryopreservation, as compared with children born after fresh cycles. Most studies found comparable malformation rates between frozen and fresh IVF/ICSI. For slow freezing of blastocysts and for vitrification of early cleavage stage embryos, blastocysts and oocytes, limited neonatal data was reported. We found no long-term child follow-up data for any cryopreservation technique. CONCLUSION: Data concerning infant outcome after slow freezing of embryos was reassuring. Properly controlled follow-up studies of neonatal outcome are needed after slow freezing of blastocysts and after vitrification of early cleavage stage embryos, blastocysts and oocytes. In addition, child long-term follow-up studies for all cryopreservation techniques are essential.


Assuntos
Criopreservação , Embrião de Mamíferos , Oócitos , Resultado da Gravidez , Blastocisto , Criança , Desenvolvimento Infantil , Anormalidades Congênitas/epidemiologia , Criopreservação/métodos , Técnicas de Cultura Embrionária , Feminino , Fertilização in vitro , Congelamento , Humanos , Mortalidade Infantil , Recém-Nascido , Gravidez , Injeções de Esperma Intracitoplásmicas
4.
Int J Gynaecol Obstet ; 17(6): 598-600, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-6106581

RESUMO

A retrospective analysis of 1 1 1 consecutive ectopic pregnancies was done regarding diagnostic difficulties and delay. Absence of amenorrhea before onset of symptoms was frequent (44.1%), as was a negative two-minute slide pregnancy test (50.0%). The main factors causing diagnostic delay were the use of therapeutic drug trials and misdiagnosis at curettage. Diagnostic delay can be reduced by early use of more sensitive pregnancy tests in patients predisposed to ectopic pregnancy, more critical use of drug trial therapy in patients with gynecologic diagnostic problems, early resort to laparoscopy and rapid pathologic examination of tissue obtained from curettage done in suspected cases of spontaneous abortion or menorrhagia to detect decidual changes or Arias-Stella phenomenon.


Assuntos
Gravidez Ectópica/diagnóstico , Análise Química do Sangue , Endométrio/anatomia & histologia , Feminino , Humanos , Gravidez , Testes de Gravidez , Estudos Retrospectivos
5.
Food Chem ; 141(2): 1466-71, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23790940

RESUMO

Food colouring plays a vital and a determining role in the processing and the manufacturing of food products because the appearance of products is critical for attracting consumers and influencing their food choices. However, factors such as legislative restrictions, limited number of approved colourants and the processing, formulation and stability issues of the natural colourants severely limits the application of food colouring in actual product formats. Hence, finding alternatives to the currently utilised formulation practises, represents an important area of research. Here, we report a simple colloidal approach to prepare colour blends by co-incorporating colourants with contrasting aqueous solubility profiles in composite colloidal particles. Curcumin and indigocarmine were selected as water insoluble and water soluble food-grade colourants respectively and incorporated in the colloidal particles prepared from food protein-zein. Composite particles obtained by loading of curcumin and indigocarmine (at different ratios) had mean particle size ranging from 76 to 300nm. The spherical shape of the colloidal particles was confirmed using transmission electron microscopy and the colloidal dispersions were further characterised using UV-Vis and fluorescence spectroscopy. The incorporation of colourants in colloidal particles led to the generation of different shade of colour in yellow-green-blue range. The encapsulation also led to the stabilization of individual pigments against photodegradation. Such composite colloidal particles could potentially serve as an approach for developing tuneable colouring system for food and nutraceutical applications.


Assuntos
Curcumina/química , Corantes de Alimentos/química , Índigo Carmim/química , Coloides/química , Solubilidade
6.
Hum Reprod Update ; 19(2): 87-104, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23154145

RESUMO

BACKGROUND: Assisted reproduction technology (ART) is used worldwide, at increasing rates, and data show that some adverse outcomes occur more frequently than following spontaneous conception (SC). Possible explanatory factors for the well-known adverse perinatal outcome in ART singletons were evaluated. METHODS: PubMed and Cochrane databases from 1982 to 2012 were searched. Studies using donor or frozen oocytes were excluded, as well as those with no control group or including <100 children. The main outcome measure was preterm birth (PTB defined as delivery <37 weeks of gestation), and a random effects model was used for meta-analyses of PTB. Other outcomes were very PTB, low-birthweight (LBW), very LBW, small for gestational age and perinatal mortality. RESULTS: The search returned 1255 articles and 65 of these met the inclusion criteria. The following were identified as predictors for PTB in singletons: SC in couples with time to pregnancy (TTP) > 1 year versus SC singletons in couples with TTP ≤ 1 year [adjusted odds ratio (AOR) 1.35, 95% confidence interval (CI) 1.22, 1.50]; IVF/ICSI versus SC singletons from subfertile couples (TTP > 1 year; AOR 1.55, 95% CI 1.30, 1.85); conception after ovulation induction and/or intrauterine insemination versus SC singletons where TTP ≤ 1 year (AOR 1.45, 95% CI 1.21, 1.74); IVF/ICSI singletons versus their non-ART singleton siblings (AOR 1.27, 95% CI 1.08, 1.49). The risk of PTB in singletons with a 'vanishing co-twin' versus from a single gestation was AOR of 1.73 (95% CI 1.54, 1.94) in the narrative data. ICSI versus IVF (AOR 0.80, 95% CI 0.69-0.93), and frozen embryo transfer versus fresh embryo transfer (AOR 0.85, 95% CI 0.76, 0.94) were associated with a lower risk of PTB. CONCLUSIONS: Subfertility is a major risk factor for adverse perinatal outcome in ART singletons, however, even in the same mother an ART singleton has a poorer outcome than the non-ART sibling; hence, factors related to the hormone stimulation and/or IVF methods per se also may play a part. Further research is required into mechanisms of epigenetic modification in human embryos and the effects of cryopreservation on this, whether milder ovarian stimulation regimens can improve embryo quality and endometrial conditions, and whether longer culture times for embryos has a negative influence on the perinatal outcome.


Assuntos
Recém-Nascido de Baixo Peso , Infertilidade/epidemiologia , Nascimento Prematuro/epidemiologia , Técnicas de Reprodução Assistida/efeitos adversos , Criopreservação , Epigênese Genética , Feminino , Humanos , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Gravidez , Nascimento Prematuro/genética
7.
Acta Obstet Gynecol Scand ; 86(10): 1222-30, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17851811

RESUMO

BACKGROUND: The objective of this study was to investigate the attitudes towards and management of single embryo transfer(SET) among Nordic in vitro fertilisation (IVF) doctors, and to present the rate of SET and multiple pregnancies in the different countries. METHODS: A questionnaire was sent to all IVF doctors in the Nordic countries (n=198, 78.5% responded). Pregnancy rates, SET and multiple births rates were extracted from registries. Main outcome measure was attitudes and management of SET. RESULTS: Almost all doctors thought that a twin pregnancy compared unfavourably to a singleton. A twin rate >10% was acceptable for 5% of Swedish doctors. Corresponding figures for Finnish, Danish and Norwegian doctors were 21, 35 and 35%, respectively. For a woman <36 years, performing her first cycle and with two good quality embryos, almost all doctors would recommend SET. For a woman ≥ 36 years in a similar situation, SET would be recommended only in Sweden and Finland. The pregnancy rate per embryo transfer (ET), the SET rate 2003, the multiple birth rate, and the estimated SET rate 2004 were 33.3, 21.5, 22.7 and 25% (Denmark), 31.3, 43.4, 14 and 51%(Finland), 40.5, 10.5, 26.5 and 16% (Iceland), 30.6, 18, 25.2 and 26% (Norway), and 35.3, 55.1, 11.8 and 71% (Sweden). CONCLUSIONS: The SET and multiple birth rates reflect the attitudes of Nordic IVF doctors to SET and multiple births well.When introducing SET, the attitude of the IVF doctor seems to be important.


Assuntos
Atitude do Pessoal de Saúde , Médicos/estatística & dados numéricos , Transferência de Embrião Único , Adulto , Coeficiente de Natalidade , Coleta de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Padrões de Prática Médica , Gravidez , Gravidez Múltipla , Países Escandinavos e Nórdicos
8.
Hum Reprod ; 19(3): 472-6, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14998938

RESUMO

ICSI is a highly efficient treatment of male factor infertility and therefore increasingly used to treat infertile men successfully. However, when used to treat patients with a genetic cause for their infertility, there may be an increased risk for the offspring. Chromosome aberrations, Y chromosome microdeletions and CFTR (cystic fibrosis transmembrane conductance regulator) mutations alone may explain up to 25% of azoospermia and severe oligozoospermia. These genetic defects could be identified before treatment, in which case informed decisions could be made by the couple to be treated concerning the treatment, prenatal testing or preimplantation genetic diagnosis. Therefore, we propose that men with very low sperm counts (<5 x 10(6)/ml) considering ICSI should always be informed of the possibility of genetic testing. The information should include a precise statement of the implications of the results for the patient, his family and his offspring, and reassurance that a decision to test or not to test, or the subsequent test results will not be used as a reason for withholding treatment. Testing should always remain voluntary, and the couples themselves should decide whether or not they choose to be tested. If an abnormality is identified, patients should be referred to specialist genetic counselling.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Infertilidade Masculina/genética , Infertilidade Masculina/terapia , Injeções de Esperma Intracitoplásmicas/efeitos adversos , Aberrações Cromossômicas , Cromossomos Humanos Y , Deleção de Genes , Humanos , Masculino , Mutação
9.
Hum Reprod ; 15(6): 1217-9, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10831543

RESUMO

To maximize pregnancy rates, physicians who perform IVF, often transfer multiple embryos, which increases the multiple birth risk. Multiple birth infants are at significant risk for a number of adverse outcomes including preterm delivery, low birth weight, congenital malformations, fetal and infant deaths and long term morbidity and disability among survivors. Since the ultimate goal for an IVF treatment is the birth of a healthy infant, an important issue for all kinds of assisted reproductive technologies (ART) must be the reduction or elimination of multiple pregnancies. In this article, different strategies to avoid multiple births in ART are discussed.


Assuntos
Redução de Gravidez Multifetal/métodos , Gravidez Múltipla , Técnicas Reprodutivas , Feminino , Humanos , Gravidez
10.
Am J Pathol ; 136(1): 141-57, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2153345

RESUMO

This report describes the cell biology of the development of asbestos bodies after a single intraperitoneal injection of a suspension of crocidolite asbestos fibers into the mouse peritoneal cavity. The majority of the infected fibers were found in aggregates of peritoneal macrophages, exudate cells, and fibrous tissue. These aggregates developed into granulomas containing not only numerous asbestos fibers, but also cells of various types, including macrophages, multinucleated giant cells, fibroblasts, plasma cells, granulocytes, and mast cells. Cytoplasmic ferritin was abundantly present in macrophages and giant cells. In addition, iron-rich inclusion bodies were detected. The results of this study show that asbestos body formation can occur outside the pleural cavity. Asbestos body formation occurred in the granulomas after periods of 1 month and longer. On the basis of morphologic criteria, various types of asbestos body were distinguished. X-ray microanalysis showed that variations in the density of the coat could attributed to the presence of chemical elements in various concentrations. Evidence is presented that asbestos body formation is an extracellular phenomenon.


Assuntos
Amianto/metabolismo , Granuloma/metabolismo , Corpos de Inclusão/metabolismo , Ferro/metabolismo , Doenças Peritoneais/metabolismo , Animais , Amianto/administração & dosagem , Amianto/análise , Asbesto Crocidolita , Agregação Celular , Microanálise por Sonda Eletrônica , Granuloma/patologia , Corpos de Inclusão/análise , Corpos de Inclusão/ultraestrutura , Injeções Intraperitoneais , Ferro/análise , Masculino , Camundongos , Camundongos Endogâmicos , Microscopia Eletrônica , Cavidade Peritoneal/citologia , Doenças Peritoneais/patologia
11.
Calcif Tissue Int ; 54(2): 170-4, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8012873

RESUMO

In the coculture system of periostless metatarsal bones of 17-day-old fetal mice and osteoclast progenitors, osteoclasts will develop. Our goal in the present report was to provide further evidence that in the coculture system of fetal metatarsal bone rudiments with hemopoietic cells, the osteoclasts developing inside the bone rudiments are exclusively derived from the cells suspended in the plasma clot and not from endogenous precursor cells of the bone explants themselves, by using the technique of in situ hybridization with a probe for the mouse Y chromosome. Osteoclast formation in unstripped male metatarsal rudiments, occurring after 3-4 days of culture, was compared with osteoclast formation in cocultures of female metatarsal rudiments and male bone marrow cells, occurring after 5-6 days of culture. Osteoclasts were recognized by their tartrate-resistant acid phosphatase activity. In paraffin sections of cultured male metatarsals, the mean percentage of microscopically identifiable osteoclast nuclei, in which the Y chromosome could be detected, was 43.1 +/- 4.2% (n = 12). For cocultures of female metatarsal bones and male bone marrow cells this mean percentage was 40.9 +/- 5.7% (n = 17). Statistical comparison by means of the two sample t-test indicated no significant difference in the percentages of osteoclast nuclei containing the Y chromosome for both groups. We concluded that the osteoclasts do derive from cocultured cells and not from precursor cells in the bone explant itself.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Células-Tronco Hematopoéticas/citologia , Ossos do Metatarso/citologia , Osteoclastos/citologia , Periósteo , Cromossomo Y , Animais , Diferenciação Celular , Núcleo Celular/química , Núcleo Celular/ultraestrutura , Células Cultivadas , DNA/análise , DNA/genética , Sondas de DNA , Feminino , Células-Tronco Hematopoéticas/ultraestrutura , Imuno-Histoquímica , Hibridização In Situ , Masculino , Ossos do Metatarso/ultraestrutura , Camundongos , Osteoclastos/ultraestrutura , Cromossomo Y/química , Cromossomo Y/ultraestrutura
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