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1.
Trop Anim Health Prod ; 50(8): 1797-1805, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29948775

RESUMO

The study evaluated small-scale dairy systems with continuous grazing of pastures based on three temperate grasses festulolium (FL), tall fescue (TF), and perennial ryegrass (RG), compared with subtropical kikuyu grass (KG). All pastures were associated with white clover (Trifolium repens L.). Twelve multiparous Holstein cows were assigned to a 4 × 4 Latin square replicated three times with 14-day experimental periods. Sampling and analyses of pastures, concentrates, and animal variables followed standard procedures. FL showed a significantly (p < 0.05) higher mean sward height, but there were no differences (p > 0.05) in net herbage accumulation. There were significant differences (p < 0.05) among pastures for CP, NDF, ADF, in vitro digestibility of OM (IVOMD), and estimated metabolizable energy (eME). There were no differences (p > 0.05) between treatments for milk yield and composition, live weight, or body condition score. There were significant differences (p < 0.05) in fatty acid values for pastures in C14:0, C16:1, and C18:3n3. There were significant differences between treatments (p < 0.05) in milk contents for C18:0, C18:1t11, and C18:2c9t11. Grazing FL, TF, RG, or KY pastures showed no differences in milk yields. Higher values for C18:0, C18:1t11, and C18:2c9t11 were detected in KY, RG, and TF. RG had significantly higher MUFA than FL and higher PUFA than TF. A value under 65% of SFA, a ratio of n-6/n-3 lower than 4, and an atherogenic index of 1.7 are indicators of milk with beneficial effects for human health.


Assuntos
Ração Animal/análise , Indústria de Laticínios/métodos , Ácidos Graxos/química , Leite/química , Poaceae , Animais , Bovinos , Feminino , Lactação , Ácidos Linoleicos Conjugados/química , Lolium , México , Chuva , Distribuição Aleatória , Estações do Ano , Trifolium
2.
Radiologia ; 59(3): 264-269, 2017.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27771017

RESUMO

In recent years, the use of vaccines has been standardized within vaccination programs. Adverse effects at the puncture site are usually mild and transient. Nevertheless, in some cases, persistence subcutaneous nodules can develop; these are often underdiagnosed because they are so rare and because of the long time that can transpire between the vaccination and their appearance. Histologically, they consist of a lymphoid follicular hyperplasia that occurs as a reaction to the aluminum particles usually used as an adjuvant in some vaccines. We were unable to find any reference in the radiological literature to these soft-tissue nodules secondary to vaccination. We report the characteristic ultrasound findings that will enable radiologists to identify or strongly suspect these lesions and thereby avoid unnecessary imaging tests that might lead to confusion and inadequate management of these patients.


Assuntos
Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Ultrassonografia , Vacinação/efeitos adversos , Adolescente , Feminino , Humanos , Hiperplasia , Tela Subcutânea , Adulto Jovem
3.
Phys Rev E ; 109(1-1): 014107, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38366493

RESUMO

One of the main issues that real energy converters present, when they produce effective work, is the inevitable entropy production. Within the context of nonequilibrium thermodynamics, entropy production tends to energetically degrade human-made or living systems. On the other hand, it is not useful to think about designing an energy converter that works in the so-called minimum entropy production regime since the effective power output and efficiency are zero. In this paper we establish some energy conversion theorems similar to Prigogine's theorem with constrained forces. The purpose of these theorems is to reveal trade-offs between design and the so-called operation modes for (2×2)-linear isothermal energy converters. The objective functions that give rise to those thermodynamic constraints show stability. A two-mesh electric circuit was built as an example to demonstrate the theorems' validity. Likewise, we reveal a type of energetic hierarchy for power output, efficiency, and dissipation function when the circuit is tuned to any of the operating regimes studied here. These are maximum power output (MPO), maximum efficient power (MPη), maximum omega function (MΩ), maximum ecological function (MEF), maximum efficiency (Mη), and minimum dissipation function (mdf).

4.
Rev Gastroenterol Mex ; 78(1): 12-20, 2013.
Artigo em Espanhol | MEDLINE | ID: mdl-23374541

RESUMO

BACKGROUND: Helicobacter pylori (Hp) is recognized as a type 1 carcinogen for gastric cancer associated with pre-neoplastic lesions (atrophy and intestinal metaplasia [IM]). Its relation with p53, which intervenes in the cell cycle, has had contradictory results. AIMS: To analyze p53 expression in gastric mucosa and its relation with Hp infection. METHODS: A 3-month prospective, observational, cross-sectional study was conducted. Patients that had no evidence of acute or clinically significant gastric pathology had biopsies taken according to the Sydney system at the Hospital Juárez de México and the histopathologic studies were done at the Hospital Español de México. RESULTS: Hp prevalence was 32.7% in 104 patients. There were no cases of atrophy or dysplasia. A total of 91% of the infected patients were positive for p53. Of the non-infected patients, 14% were positive for p53 and 60% of them had IM. Of the IM patients, 75% presented with positive p53. Of the patients without IM, 31 presented with positive p53, and Hp was positive in 85% of them. There was association between Hp and p53 and between p53 and IM (P<.0001 and P<.0006, respectively). CONCLUSIONS: Significant association was shown between Hp and p53 expression, even in patients with pre-neoplastic lesions that no longer presented with Hp. Given that the identification of pre-neoplastic lesions is important for the prevention of cancer, immunohistochemistry could benefit routine biopsy carried out during endoscopy for the detection of Hp, by identifying patients with expression of the important oncogene regulator, p53.


Assuntos
Mucosa Gástrica/metabolismo , Expressão Gênica/fisiologia , Genes p53/fisiologia , Infecções por Helicobacter/metabolismo , Helicobacter pylori , Proteína Supressora de Tumor p53/biossíntese , Adulto , Biópsia , Estudos Transversais , Feminino , Mucosa Gástrica/patologia , Expressão Gênica/genética , Genes p53/genética , Infecções por Helicobacter/genética , Infecções por Helicobacter/microbiologia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
5.
J Environ Manage ; 95 Suppl: S349-54, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21071132

RESUMO

The objective of this study is to investigate the effect of incorporation of ash from biomass incinerator as raw material on the production of ceramic bricks for their application in construction. So, for the fabrication of bricks, compositions were prepared with addition of increasing amounts of waste ash (0%, 10%, 20%, 30%, 40% and 50% in wt.) in the clay body. The mixed samples were sintered using conventional powder processing based on powder compaction at 54.5 MPa and firing them at 950 °C without the addition of additives. Effect on apparent density, water absorption and mechanical properties were investigated. The results showed that water absorption increased and apparent density and compressive strength decreased with higher amounts of ash. Bricks with an ash content up to 20% meet the UNE standards compressive strength. As a result, since interesting performances were observed, the potential use of ashes from biomass incinerator up to 20 wt.% in ceramic formulations of industrial interest was confirmed. In this sense, incorporating ashes into clay body reduces environmental problems and total cost of raw material disposition.


Assuntos
Materiais de Construção , Incineração , Reciclagem , Resíduos , Silicatos de Alumínio , Biomassa , Cerâmica , Argila , Força Compressiva , Material Particulado
6.
J Environ Manage ; 95 Suppl: S343-8, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21723033

RESUMO

The main aim of this study is to assess the effect of incorporating waste sludge on the properties and microstructure of clay used for bricks manufacturing. Wastewater treatment plants produce annually a great volume of sludge. Replacing clay in a ceramic body with different proportions of sludge can reduce the cost due to the utilization of waste and, at the same time, it can help to solve an environmental problem. Compositions were prepared with additions of 1%, 2.5%, 5%, 7.5%, 10% and 15% wt% waste sludge in body clay. In order to determine the technological properties, such as bulk density, linear shrinkage, water suction, water absorption and compressive strength, press-moulded bodies were fired at 950 °C for coherently bonding particles in order to enhance the strength and the other engineering properties of the compacted particles. Thermal heating destroys organic remainder and stabilizes inorganic materials and metals by incorporating oxides from the elemental constituent into a ceramic-like material. Results have shown that incorporating up to 5 wt% of sludge is beneficial for clay bricks. By contrast, the incorporation of sludge amounts over 5 wt% causes deterioration on the mechanical properties, therefore producing low-quality bricks.


Assuntos
Cerâmica/química , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Absorção , Força Compressiva , Indústrias
8.
Ann Dyslexia ; 69(2): 186-203, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30989486

RESUMO

In transparent orthographic systems, the main characteristic of developmental dyslexia is poor reading fluency. Several studies have reported that children with dyslexia have difficulties forming orthographic representations of words, which hampers good reading fluency. This study aimed at evaluating whether the semantic-phonological training prior to word reading could facilitate the formation of orthographic representations and leading an improvement in reading fluency. Twenty-four native Spanish-speaking children with developmental dyslexia carried out two different reading tasks. In one of them, participants previously received semantic and phonological information about stimuli whereas in the other task no previous information was provided. Eight different unfamiliar words (four short and four long) were used in each reading task and the reduction of the length effect across reading blocks was taken as a formation index of new orthographic representations. Results showed low accuracy, slow speed reading, and difficulties in developing orthographic representations despite of repeated reading, probably due to the instability in decoding processes. However, the previous phonological and semantic training had a facilitator effect in the formation of orthographic representations, as indicated by the decrease in the length effect.


Assuntos
Dislexia , Leitura , Semântica , Criança , Coleta de Dados , Feminino , Humanos , Masculino , Espanha
10.
Bioresour Technol ; 203: 32-41, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26720137

RESUMO

This study was performed to identify suitable conditions for the in-situ reduction of excess sludge production by intercalated digesters in recycle-activated sludge (RAS) flow. The objective was to compare and model biological sludge mass reduction and the biodegradation of endogenous residues (XP) by digestion under hypoxic, aerobic, anaerobic, and five intermittent-aeration conditions. A mathematical model based on the heterotrophic endogenous decay constant (bH) and including the biodegradation of XP was used to fit the long-term data from the digesters to identify and estimate the parameters. Both the bH constant (0.02-0.05 d(-1)) and the endogenous residue biodegradation constant (bP, 0.001-0.004 d(-1)) were determined across the different mediums. The digesters with intermittent aeration cycles of 12 h-12 h and 5 min-3 h (ON/OFF) were the fastest, compared to the aerobic reactor. The study provides a basis for rating RAS-digester volumes to avoid the accumulation of XP in aeration tanks.


Assuntos
Reatores Biológicos , Modelos Biológicos , Esgotos , Gerenciamento de Resíduos/métodos , Aerobiose , Anaerobiose , Biodegradação Ambiental , Reciclagem
11.
Int J Food Sci ; 2016: 3926847, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27597950

RESUMO

A protein concentrate (PC) was obtained from Grouper fish skin and it was used to prepare films with different amounts of sorbitol and glycerol as plasticizers. The best performing films regarding resistance were then modified with various concentrations of CaCl2, CaSO4 (calcium salts), and glucono-δ-lactone (GDL) with the purpose of improving their mechanical and barrier properties. These films were characterized by determining their mechanical properties and permeability to water vapor and oxygen. Formulations with 5% (w/v) protein and 75% sorbitol and 4% (w/v) protein with a mixture of 15% glycerol and 15% sorbitol produced adequate films. Calcium salts and GDL increased the tensile fracture stress but reduced the fracture strain and decreased water vapor permeability compared with control films. The films prepared represent an attractive alternative for being used as food packaging materials.

12.
Eur J Clin Nutr ; 59(12): 1397-408, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16160701

RESUMO

OBJECTIVE: The aim of this study was to assess the ability of a single 24-h dietary recall (24HDR) and food questionnaires (FQ) to predict plasma carotenoid levels at the ecological level by assessing the relationship between mean plasma carotenoid levels and mean intake of fruit and vegetables measured by 24HDR and FQ across 16 European regions. DESIGN: A random subsample of 3089 subjects was included, stratified by age and gender. They provided blood samples and dietary information between 1992 and 2000 as part of the European Prospective Investigation into Cancer and Nutrition. RESULTS: Using Spearman's correlation coefficients, the correlations between mean regional 24HDR fruit and vegetable variables and corresponding mean plasma carotenoid levels were generally higher than the correlations using FQ means. The highest correlation was between the 24HDR citrus fruit variable and beta-cryptoxanthin (r = 0.90). For 24HDR, total fruits and vegetables were highly correlated with lutein, zeaxanthin, and beta-cryptoxanthin (r = 0.83-0.87), while vegetables were more closely related with lutein (r = 0.69) and zeaxanthin (r = 0.68), and fruits correlated with zeaxanthin (r = 0.87) and beta-cryptoxanthin (r = 0.84). Root vegetables (r = 0.81) and total carrots (r = 0.71) were well correlated with alpha-carotene. In the multivariate models adjusting for age, body mass index, and season, and using observations of means stratified by sex and region, the association was generally higher for 24HDR compared to FQ. CONCLUSION: Mean regional intakes of fruits and vegetables in several European countries were closely correlated with corresponding mean plasma levels of individual carotenoids. Fruits and vegetables measured by 24HDR were generally better able to predict plasma carotenoids at the ecological level.


Assuntos
Antioxidantes/metabolismo , Carotenoides/sangue , Frutas , Rememoração Mental , Inquéritos e Questionários/normas , Verduras , Biomarcadores/sangue , Calibragem , Estudos de Coortes , Europa (Continente) , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e Especificidade
13.
Cell Prolif ; 29(1): 13-31, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8603107

RESUMO

Spontaneous germ cell degeneration occurs in the testis of the adult rat. Accumulating data supports the idea that this degeneration takes place via apoptosis. We have determined that morphology, acridine orange staining and ultrastructural features of these cell deaths clearly take the form of apoptosis. Furthermore, with acridine orange staining it was possible to detect a cell population showing early signs of death. The characterization of the main morphological features of these cells allowed us to identify several steps of maturing germ cells undergoing degeneration that have not previously been described. We have re-evaluated in toluidine blue stained semithin sections the germ cell types that undergo cell death at every stage of the spermatogenic cycle in the adult rat and concluded that, spermatogonia undergo cell death coinciding with their mitotic peaks, spermatocytes during preleptotene, leptotene, zygotene, pachytene and during metaphase I and spermatids during all their maturation steps. The biological significance of these cell deaths, at these steps of germ cell development, in relation to apoptosis, is discussed.


Assuntos
Apoptose/fisiologia , Espermatogênese/fisiologia , Espermatozoides/citologia , Testículo/citologia , Laranja de Acridina , Animais , Corantes , Estudos de Avaliação como Assunto , Células Germinativas/citologia , Células Germinativas/ultraestrutura , Masculino , Meiose/fisiologia , Microscopia Eletrônica , Microscopia de Fluorescência , Microtomia , Mitose/fisiologia , Ratos , Ratos Wistar , Espermátides/citologia , Espermátides/ultraestrutura , Espermatozoides/ultraestrutura
14.
Eur J Cancer ; 34(14 Spec No): 2204-11, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10070288

RESUMO

The objective of this study, part of the wider EUROCARE II collaborative project, was to examine variations by age and country in the relative survival of women from breast cancer in Europe, based on data fro 145,000 cases in 1985-1989 and trends based on (245,000) cases for 1978-1989. Data were supplied by 42 cancer registries in 17 countries to a common protocol. Results for some countries where the participating registries covered only small proportions of the total population may not be representative of the whole country. In 1985-1989 there were wide differences among the 17 countries: survival was above the European average in Iceland, Finland, Sweden, Switzerland, France and Italy; around average in Denmark, The Netherlands, Germany and Spain; below average in Scotland, England and Slovenia; and well below average in Slovakia, Poland and Estonia. In France, Spain and Italy, but not in the U.K., there were wide differences in survival among the participating registries. Survival generally declined with age, particularly in the elderly (75 years and over)--this was most marked in Denmark, Scotland and England. Over the period 1978-1989, 1-year survival improved by 2% overall and 5-year survival by 6%. There were improvements in 5-year survival in all countries except Iceland, Germany, Switzerland and Estonia, and in all age groups except the youngest (15-44 years). It is likely that differences in the access to and quality of care in the various countries played a large part in explaining the differences in survival.


Assuntos
Neoplasias da Mama/mortalidade , Adolescente , Adulto , Distribuição por Idade , Idoso , Europa (Continente)/epidemiologia , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Sistema de Registros/estatística & dados numéricos , Características de Residência , Análise de Sobrevida , Taxa de Sobrevida
15.
Eur J Cancer ; 39(5): 654-65, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12628846

RESUMO

This is a population-based study aimed at evaluating incidence and mortality trends for prostate cancer in France, Italy and Spain, during the prostate-specific antigen (PSA) era, considering elderly people aged 70 years and over and younger adults aged between 40 and 69 years. Trends were estimated by a log-linear Poisson regression model and expressed as an Estimated Annual Percent Change (EAPC). Incidence increased sharply in almost all areas. Spain showed the lowest increases. Incidence started to rise around 1985 in France and after 1990 in Italy and Spain. Mortality increased until the late 1980s in all countries, then declined in France and Italy (-2.5% in 40-69 year age group), but not in Spain. Younger people showed a much higher rise in incidence than the elderly, while mortality decreased mainly in the younger adults. The decrease in mortality was more marked in those areas and the younger age group where the rise in incidence was higher and started earlier, i.e. in France and in younger people, suggesting that the PSA test may have had a positive effect on mortality, although other clinical advances also have to be taken into account.


Assuntos
Neoplasias da Próstata/epidemiologia , Adulto , Distribuição por Idade , Idoso , França/epidemiologia , Humanos , Incidência , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Neoplasias da Próstata/mortalidade , Sistema de Registros , Características de Residência , Espanha/epidemiologia
16.
Eur J Cancer ; 37(13): 1659-67, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11527693

RESUMO

The EUROCARE project analysed cancer survival data from 45 population-based cancer registries in 17 European countries, revealing wide international differences in cancer survival. We calculated 5-year relative survival for 1836287 patients diagnosed with one of 13 cancers during the period 1978-1989. The data, from 20 cancer registries in 13 countries, were grouped into four regions: Finland, Sweden, Iceland (Northern Europe); Denmark, England and Scotland (UK and Denmark); France, The Netherlands, Germany, Italy and Switzerland (Western Europe); Estonia and Poland (Eastern Europe), and broken down into four periods (1978-1980, 1981-1983, 1984-1986, 1987-1989). For each cancer, mean European and regional survival was estimated as the weighted mean of 5-year relative survival in each country. Survival increased with time for all tumours, particularly for cancers of testis (12% increase, i.e. from 79.9 to 91.9%), breast, large bowel, skin melanoma (approximately 9-10%), and lymphomas (approximately 7%). For most solid tumours, survival was highest in Northern Europe and lowest in Eastern Europe, and also low in the UK and Denmark. Regional variation was less marked for the lymphomas. Survival improved more in Western than Northern Europe, and the differences between these regions fell for bowel cancer (from 8.0% for those diagnosed in 1978-1980 to 2% for those diagnosed in 1987-1989), breast cancer (from 7.4% to 3.9%), skin melanoma (from 13.4% to 11.0%) and Hodgkin's disease (from 7.2 to 0.6%). For potentially curable malignancies such as Hodgkin's disease, large bowel, breast and testicular cancers, there were substantial increases in survival, suggesting an earlier diagnosis and more effective treatment. The persisting regional differences suggest there are corresponding differences in the availability of diagnostic and therapeutic facilities, and in the effectiveness of healthcare systems.


Assuntos
Neoplasias/mortalidade , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Europa (Continente)/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Sistema de Registros , Características de Residência , Distribuição por Sexo , Análise de Sobrevida , Taxa de Sobrevida
17.
Eur J Cancer ; 34(14 Spec No): 2264-70, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10070297

RESUMO

In this paper different patterns of survival by age and gender are presented for 17 European countries which participated in the EUROCARE II programme. Survival data were available for 701,521 patients aged between 65 and 99 years from 44 population-based cancer registries. Age-standardised relative survival rates at 1 and 5 years from diagnosis were computed. Relative risks (RRs) of death for those aged between 65 and 99 years compared with those aged between 55 and 64 years were estimated by gender and country. In general, the elderly had a large survival disadvantage, particularly 1 year after diagnosis and in women. Poorer survival rates in the elderly were observed for patients from Eastern European countries for almost all sites. However, relative survival of the elderly with respect to younger patients was similar in the different geographic areas. The results are in agreement with other population-based studies, confirming a worse prognosis for the elderly in both sexes. This may be explained by changes in biology and the natural history of the tumour and the occurrence of severe comorbidities, potentially affecting preventive, diagnostic and therapeutic strategies. The lack of equality in providing adequate treatment to elderly cancer patients should be addressed as a matter of urgency by health-care providers.


Assuntos
Neoplasias/mortalidade , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Europa (Continente)/epidemiologia , Feminino , Humanos , Masculino , Prognóstico , Características de Residência , Fatores de Risco , Distribuição por Sexo , Análise de Sobrevida , Taxa de Sobrevida
18.
Am J Surg Pathol ; 18(4): 421-5, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7511356

RESUMO

A primary bronchial tumor with a histological pattern similar to that of epithelial-myoepithelial tumor of the salivary gland is reported in a 55-year-old woman. The tumor was well delimited, although not encapsulated, and showed a polypoid growth. The tumor was composed of two types of neoplastic cells: epithelial cells displaying tubules and myoepithelial cells that either formed compact masses or surrounded the tubular formations. Immunohistochemical study confirmed positive immunoreaction to both high- and low-molecular-weight cytokeratins in the epithelial cells and positive immunoreaction to vimentin, S-100 protein, and myosin in the myoepithelial cells.


Assuntos
Neoplasias Brônquicas/patologia , Mioepitelioma/patologia , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Brônquicas/química , Feminino , Humanos , Imuno-Histoquímica , Queratinas/análise , Pessoa de Meia-Idade , Mioepitelioma/química , Miosinas/análise , Neoplasias Epiteliais e Glandulares/química , Proteínas S100/análise , Neoplasias das Glândulas Salivares/patologia , Vimentina/análise
19.
J Androl ; 18(5): 535-9, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9349752

RESUMO

This study was designed to determine the effects of short episodes of mild hypothermia on cell apoptosis in the testis of the adult rat. Apoptosis was assessed by in situ DNA 3'-end labeling in the testes from rats killed 2 hours after cooling (10 degrees C for 30 minutes), quantitated, and compared with spontaneous apoptosis found in control animals. A significantly increased number of dying germ cells appeared after cold treatment at specific stages (stage XIV, P < 0.0001; stage XII, P < 0.001) of the seminiferous epithelium, mainly due to dying primary metaphasic spermatocytes (P < 0.0001), followed by secondary interphase spermatocytes (P < 0.001), and A2 spermatogonia (P < 0.05). The highly specific effect of mild hypothermia on germ cell apoptosis suggests that the process is tightly regulated.


Assuntos
Apoptose , Hipotermia Induzida , Túbulos Seminíferos/citologia , Testículo/citologia , Animais , Células Epiteliais/citologia , Epitélio/fisiologia , Masculino , Ratos , Ratos Wistar , Túbulos Seminíferos/fisiologia , Espermatozoides/citologia , Espermatozoides/fisiologia , Testículo/fisiologia
20.
J Androl ; 19(4): 487-97, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9733152

RESUMO

Spontaneous germ cell death during spermatogenesis is an important event, and the usefulness of the seminiferous epithelium as an in vivo model to study apoptosis has been evidenced. Nevertheless, the response of the testis to apoptogenic agents has not been analyzed. This study was designed to determine germ cell sensitivity to induction of apoptosis and to provide baseline data on the testis response to several apoptogenic agents. Induced apoptosis was assessed by in situ DNA 3'-end labeling and quantified at every stage of the spermatogenic cycle. The shortest response time for every agent was established based on morphological and quantitative criteria. Our results show significantly increased incidence of germ cell deaths after all treatments, mainly at stages I, XII, and XIV. These specific stages coincide with those at which the greatest numbers of spontaneous germ cell deaths occur in control animals. Moreover, the rapid and highly specific response of germ cells to all the apoptogenic agents used in the present study indicate that apoptosis must be tightly regulated at these stages of the seminiferous epithelium. As a consequence, we propose that the disruption of apoptosis control might be an important determinant for idiopathic male infertility.


Assuntos
Apoptose , Células Germinativas/efeitos dos fármacos , Túbulos Seminíferos/efeitos dos fármacos , Testículo/citologia , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/toxicidade , Animais , Colchicina/toxicidade , Cicloeximida/toxicidade , Citocalasinas/toxicidade , Inibidores Enzimáticos/toxicidade , Supressores da Gota/toxicidade , Marcação In Situ das Extremidades Cortadas , Masculino , Microscopia Eletrônica , Ésteres de Forbol/toxicidade , Inibidores da Síntese de Proteínas/toxicidade , Ratos , Ratos Wistar , Túbulos Seminíferos/ultraestrutura , Testículo/efeitos dos fármacos
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