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1.
Ecol Appl ; 28(3): 622-642, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29509298

RESUMO

Livestock-caused rangeland degradation remains a major policy concern globally and the subject of widespread scientific study. This concern persists in part because it is difficult to isolate the effects of livestock from climate and other factors that influence ecosystem conditions. Further, degradation studies seldom use multiple plant and soil indicators linked to a clear definition of and ecologically grounded framework for degradation assessment that distinguishes different levels of degradation. Here, we integrate two globally applicable rangeland degradation frameworks and apply them to a broad-scale empirical data set for the country of Mongolia. We compare our assessment results with two other recent national rangeland degradation assessments in Mongolia to gauge consistency of findings across assessments and evaluate the utility of our framework. We measured livestock-use impacts across Mongolia's major ecological zones: mountain and forest steppe, eastern steppe, steppe, and desert steppe. At 143 sites in 36 counties, we measured livestock-use and degradation indicators at increasing distances from livestock corrals in winter-grazed pastures. At each site, we measured multiple indicators linked to our degradation framework, including plant cover, standing biomass, palatability, species richness, forage quality, vegetation gaps, and soil surface characteristics. Livestock use had no effect on soils, plant species richness, or standing crop biomass in any ecological zone, but subtly affected plant cover and palatable plant abundance. Livestock effects were strongest in the steppe zone, moderate in the desert steppe, and limited in the mountain/forest and eastern steppes. Our results aligned closely with those of two other recent country-wide assessments, suggesting that our framework may have widespread application. All three assessments found that very severe and irreversible degradation is rare in Mongolia (1-18% of land area), with most rangelands slightly (33-53%) or moderately (25-40%) degraded. We conclude that very severe livestock-induced rangeland degradation is overstated in Mongolia. However, targeted rangeland restoration coupled with monitoring, adaptive management and stronger rangeland governance are needed to prevent further degradation where heavy grazing could cause irreversible change. Given the broad applicability of our degradation framework for Mongolia, we suggest it be tested for application in other temperate grasslands throughout Central Asia and North America.


Assuntos
Ecossistema , Herbivoria , Conservação dos Recursos Naturais , Mongólia , Solo
2.
In Vitro Cell Dev Biol Anim ; 53(8): 706-720, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28643224

RESUMO

For the investigation of molecular processes underlying diseases of the bovine mammary gland, primary bovine mammary epithelial cells (pbMEC) are used. They are known to contribute to the innate immune system of the bovine mammary gland. The functionality of pbMEC depends on the maintenance of in vivo characteristics. So far, the optimization of pbMEC culture conditions was intended in a variety of experiments. For this purpose, most of the studies used stable cell lines or primary cells obtained from udder biopsies of slaughtered animals. By contrast, within our study, pbMEC of healthy and first lactating Brown Swiss cows were non-invasively isolated from fresh milk. The non-invasively isolated pbMEC were cultivated on the extracellular matrix-like scaffold Matrigel®. Further, they were challenged with different compositions of proliferation media, containing lactogenic hormones and/or the essential amino acid L-lysine. Changes in expression levels of genes coding for milk proteins and for components of the janus kinase/signal transducers and activators of transcription (JAK-STAT) and mTOR pathways were analyzed by RT-qPCR. The secreted proteins were analyzed by LC-MS/MS measurements. We showed for the first time the establishment of a physiologically functional 3D cell culture model of pbMEC isolated from fresh milk. This represents a primary cell culture model system, based on non-invasive cell collection, that can be used to unravel physiological processes in an unbiased manner.


Assuntos
Técnicas de Cultura de Células/métodos , Glândulas Mamárias Animais/citologia , Leite/citologia , Cultura Primária de Células/métodos , Animais , Bovinos , Células Epiteliais/citologia , Feminino , Lactação/genética , Lactação/metabolismo , Proteínas do Leite/genética
3.
Am J Pathol ; 151(6): 1673-83, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9403718

RESUMO

Keratin 8 (K8)-deficient adult mice develop a severe disease of the gastrointestinal tract characterized mainly by colorectal hyperplasia and inflammation. Given that hepatocytes contain K8/K18 heteropolymers only, this animal model was used to assess the contribution of these simple epithelium keratins to hepatocyte structural and functional integrity. Homozygous mutant (HMZ), heterozygous, and wild-type (WT) mice were examined for hepatocyte structural and metabolic features and their survival to partial hepatectomy. Except for the presence of few necrotic foci, no other tissular or cellular alterations were observed in nonhepatectomized HMZ mouse livers; glycogen and lipid peroxidation levels were essentially normal, but a small reduction in bile flow was observed. In response to a single pentobarbital injection, HMZ mice had longer sleeping times than heterozygous and WT mice. After a two-thirds partial hepatectomy under pentobarbital anesthesia, all HMZ mice died within a few hours, whereas those anesthetized with ether survived for 1 to 2 days. One hour after hepatectomy after pentobarbital anesthesia, many hepatocytes contained erythrocytes and large vacuoles in the cytoplasm, which suggests damage at the plasma membrane level in response to a sudden increase in portal blood flow. In line with these findings, an uptake of trypan blue by HMZ but not WT mouse hepatocytes was observed during a 10 ml/minute perfusion via the portal vein with a dye-supplemented buffer. Subsequent cellular dispersion led to viable WT mouse hepatocytes but largely nonviable HMZ mouse hepatocytes. Better viability was obtained at lower perfusion rates. Partially hepatectomized heterozygous mice developed liver steatosis, a condition that was not associated with a change in K8 content but perhaps linked to the presence of the neo gene. Transgenic HMZ mouse rescue experiments with a full-length K8 gene confirmed that the phenotypic alterations observed in partially hepatectomized HMZ mice were caused by the disruption of the K8 gene. Taken together, these findings demonstrate that simple epithelium keratins are essential for the maintenance of hepatocyte structural and functional integrity.


Assuntos
Fígado Gorduroso/fisiopatologia , Queratinas/fisiologia , Fígado/fisiopatologia , Animais , Bile/metabolismo , Western Blotting , Sobrevivência Celular , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Epitélio/fisiopatologia , Epitélio/ultraestrutura , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Feminino , Glicogênio/metabolismo , Hepatectomia , Queratinas/deficiência , Peroxidação de Lipídeos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/ultraestrutura , Regeneração Hepática , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Fenobarbital/farmacologia
4.
Cancer Res ; 57(21): 4722-6, 1997 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-9354430

RESUMO

Apoptosis is a mode of cell death that is carefully regulated based on cellular and environmental signals. The ability to modulate the individual cellular machinery and thereby to promote apoptosis is an important strategy in cancer therapy. It has previously been shown that overexpression of the transcription factor E2F-1 can induce apoptosis in quiescent rat embryo fibroblasts. This effect has been reported to occur in a p53-dependent manner. To investigate whether overexpression of E2F-1 could also induce apoptosis in human cancer cells, a recombinant adenovirus vector containing the transgene E2F-1 under control of the cytomegalovirus promoter (Ad5CMVE2F) was used to induce high levels of the E2F-1 protein in human breast and ovarian carcinoma cell lines. Significant morphological changes occurred in four of the five cell lines within 48 h of transduction with the Ad5CMVE2F. These changes were consistent with apoptosis, which was confirmed further by DNA fragmentation assay and fluorescence-activated cell sorting analysis. On the basis of these assays, which show that apoptosis occurred in those cell lines with mutations in the p53 gene, we suggest that the induction of E2F-1-mediated apoptosis does not require wild-type p53 when E2F-1 is overexpressed using an adenovirus-based strategy.


Assuntos
Apoptose , Neoplasias da Mama/patologia , Proteínas de Transporte , Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Neoplasias Ovarianas/patologia , Fatores de Transcrição/metabolismo , Adenoviridae/genética , Apoptose/genética , Western Blotting , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Fragmentação do DNA , Fatores de Transcrição E2F , Fator de Transcrição E2F1 , Feminino , Citometria de Fluxo , Genes do Retinoblastoma/genética , Genes p53/genética , Vetores Genéticos/genética , Humanos , Mutação , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Proteína 1 de Ligação ao Retinoblastoma , Fator de Transcrição DP1 , Fatores de Transcrição/genética , Transfecção , Células Tumorais Cultivadas
5.
Transgenic Res ; 6(6): 359-67, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9423286

RESUMO

Keratin 8 and 18 are commonly used as tumorigenic markers for various types of carcinomas. They are known to be involved in cell migration, cell invasiveness, plasminogen activity and drug and radiation resistance. To ascertain a potential function for simple epithelium keratins in mammary adenocarcinoma in vivo, keratin-8-deficient mice (mK8) were mated with transgenic mice carrying the middle T oncogene driven by the MMTV promoter. The resulting mK8 knockout and control progeny carrying the middle T transgene developed mammary gland tumours with the same incidence. However, the onset of palpable mammary gland tumours occurred earlier in mK8 mutant than in control mice. This effect was prominent in males where the onset in control animals is delayed overall, because of the lower hormonal inducibility of the MMTV promoter. Metastatic foci were observed in the lungs of all females and of a few males, independently of the genotype. Histological analysis revealed no morphological differences of the tumorigenic cells in primary tumours nor in metastatic foci. As expected, keratin 8 was absent in the mK8 tumours. Keratin 7 (mK7), keratin 18 (mK18) and keratin 19 (mK19) protein were observed in both primary and metastatic foci. These results constitute the first in vivo analysis of the role of simple epithelium keratins in mammary carcinogenesis. It demonstrates that the latency, but not the incidence nor the morphological features, of PyV middle T-induced mammary gland tumours is affected by keratin 8 deficiency.


Assuntos
Antígenos Transformantes de Poliomavirus/biossíntese , Queratinas/biossíntese , Queratinas/deficiência , Neoplasias Pulmonares/secundário , Neoplasias Mamárias Animais/genética , Vírus do Tumor Mamário do Camundongo/genética , Fatores Etários , Animais , Antígenos Transformantes de Poliomavirus/genética , Biomarcadores Tumorais/análise , Feminino , Heterozigoto , Queratinas/análise , Pulmão/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Animais/patologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Índice Mitótico , Caracteres Sexuais
6.
Genes Dev ; 8(24): 2964-73, 1994 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-7528156

RESUMO

We report that keratin 8 (mK8) gene disruption causes colorectal hyperplasia in FVB/N mice. The intestinal lesions affect uniformly the cecum, colon, and rectum but not the small intestine. The elongation of the crypts is accompanied by an inflammation of the lamina propria and submucosa. Hepatic, renal, and pancreatic functions tested in clinical assays are within nonpathological range, suggesting that the major defect lies in colonic epithelial cells. Still, small but consistent elevation in the hepatic enzymes alanine (AST) and asparate (ALT) aminotransferase are observed, along with a 70% increase in spleen weight. No homozygous mouse line has been established, because of a markedly reduced fertility of the mK8-/- females. Previously, we reported that the mK8- targeted mutation causes embryonic lethality in (C57B1/6x129Sv) mice. This strong effect of the genetic background on the mK8- mutant phenotype emphasizes the importance of using several inbred mouse strains to reveal the polygenic contribution to mutant phenotypes. Our results demonstrate that genetic modifiers of K8/K18 filament functions, with profound effects on embryogenesis and gut functional integrity, are differentially active in the FVB/N and C57B1/6 genetic backgrounds. More importantly, the increase in mK8-/- gut epithelial cell number, rather than cell disruption, contrasts with the known function of epidermal keratins in providing mechanical strength.


Assuntos
Colo/patologia , Fertilidade/genética , Queratinas/deficiência , Queratinas/genética , Reto/patologia , Envelhecimento/fisiologia , Animais , Sequência de Bases , Ceco/patologia , Cruzamentos Genéticos , Primers do DNA , Feminino , Genótipo , Homozigoto , Hiperplasia , Infertilidade Feminina/genética , Infertilidade Feminina/patologia , Tamanho da Ninhada de Vivíparos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Gravidez
7.
Aust Fam Physician ; 20(9): 1275-81, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1953470

RESUMO

Of the various types of pneumothorax described in this article, tension pneumothorax is the one that constitutes a medical emergency. Decompression of the pleural cavity by inserting a needle attached to a syringe or using a trocar and cannula is life saving.


Assuntos
Pneumotórax , Humanos , Pneumotórax/diagnóstico , Pneumotórax/etiologia , Pneumotórax/terapia
8.
Geburtshilfe Frauenheilkd ; 49(9): 776-81, 1989 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-2806850

RESUMO

A retrospective multicentre study to investigate diagnosis, treatment and end results of treatment of cervical cancer stage Ia, was carried out in 6 departments of gynaecological oncology. After reclassification by a reference pathologist, among the 936 cervical cancer cases primarily diagnosed and treated as stage Ia between 1970 and 1980, only 530 (56.6%) met the criteria of microinvasive cancer stage Ia. Misclassifications concerned all participating centres with statistically significant differences amongst them. Overdiagnosis (reference diagnosis only CIN I-III, 42.5%) was more frequent than underdiagnosis (reference diagnosis stage Ib--0.9%). In comparison to 1970-74, in the period 1975-80 a significant increase of cases detected asymptomatically (86.5%) was observed. The percentage of cases primarily diagnosed by cone biopsy, also increased significantly and amounted to 71.2%. Patients with cervical cancer stage Ia were most frequently treated by surgery alone (93.2%). Radiotherapy alone did not play any important role (5.7%). There were only a few cases treated by combined surgery and radiotherapy (5.7%) with a decreasing trend over time. Women under the age of 45 years were significantly more frequently treated by the conservative method (cone biopsy, simple hysterectomy) than older ones, without any significant relation between depth of invasion and radicality of treatment. A total of 19 (14 local, 5 lymph node) recurrences were diagnosed between 9 and 110 months after primary treatment. Local recurrences could be observed more frequently after limited than extended treatment. There was no significant relation between depth of invasion and frequency of recurrences, but the latter were significantly increased in cases with histologically proven invasion of blood or lymph vessels.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Carcinoma in Situ/patologia , Displasia do Colo do Útero/patologia , Neoplasias do Colo do Útero/patologia , Adulto , Carcinoma in Situ/radioterapia , Carcinoma in Situ/cirurgia , Colo do Útero/patologia , Terapia Combinada , Feminino , Humanos , Metástase Linfática , Invasividade Neoplásica , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Prognóstico , Displasia do Colo do Útero/radioterapia , Displasia do Colo do Útero/cirurgia , Neoplasias do Colo do Útero/radioterapia , Neoplasias do Colo do Útero/cirurgia
10.
Dtsch Z Verdau Stoffwechselkr ; 45(4): 160-6, 1985.
Artigo em Alemão | MEDLINE | ID: mdl-3878772

RESUMO

356 patients with chronic liver diseases hospitalized in our clinic during the period from January 1, 1981, to December 12, 1983, were enrolled in a retrospective study. Of them 55 had been admitted for acute gastrointestinal hemorrhage. It appears that gastroscopy is the only method allowing to localize the origin of the bleeding with high certainty. Bleedings from varices (45%) and ulcers or erosions (22%) were seen most frequently. With regard to case history, clinic, paraclinic and prognosis, no significant differences were found between these various origins of the hemorrhages. Also it is remarkable that all bleedings occur with higher frequency in portal hypertension.


Assuntos
Hemorragia Gastrointestinal/etiologia , Hepatopatias/complicações , Adulto , Idoso , Doença Crônica , Varizes Esofágicas e Gástricas/complicações , Humanos , Hipertensão Portal/complicações , Pessoa de Meia-Idade , Úlcera Péptica Hemorrágica/complicações , Estudos Retrospectivos
11.
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