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1.
Plant Biol (Stuttg) ; 24(7): 1132-1145, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36103113

RESUMO

During the particularly severe hot summer drought in 2018, widespread premature leaf senescence was observed in several broadleaved tree species in Central Europe, particularly in European beech (Fagus sylvatica L.). For beech, it is yet unknown whether the drought evoked a decline towards tree mortality or whether trees can recover in the longer term. In this study, we monitored crown dieback, tree mortality and secondary drought damage symptoms in 963 initially live beech trees that exhibited either premature or normal leaf senescence in 2018 in three regions in northern Switzerland from 2018 to 2021. We related the observed damage to multiple climate- and stand-related parameters. Cumulative tree mortality continuously increased up to 7.2% and 1.3% in 2021 for trees with premature and normal leaf senescence in 2018, respectively. Mean crown dieback in surviving trees peaked at 29.2% in 2020 and 8.1% in 2019 for trees with premature and normal leaf senescence, respectively. Thereafter, trees showed first signs of recovery. Crown damage was more pronounced and recovery was slower for trees that showed premature leaf senescence in 2018, for trees growing on drier sites, and for larger trees. The presence of bleeding cankers peaked at 24.6% in 2019 and 10.7% in 2020 for trees with premature and normal leaf senescence, respectively. The presence of bark beetle holes peaked at 22.8% and 14.8% in 2021 for trees with premature and normal leaf senescence, respectively. Both secondary damage symptoms occurred more frequently in trees that had higher proportions of crown dieback and/or showed premature senescence in 2018. Our findings demonstrate context-specific differences in beech mortality and recovery reflecting the importance of regional and local climate and soil conditions. Adapting management to increase forest resilience is gaining importance, given the expected further beech decline on dry sites in northern Switzerland.


Assuntos
Fagus , Fagus/fisiologia , Secas , Suíça , Senescência Vegetal , Árvores/fisiologia
2.
Sci Total Environ ; 851(Pt 1): 157926, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-35985592

RESUMO

Ongoing climate warming is increasing evapotranspiration, a process that reduces plant-available water and aggravates the impact of extreme droughts during the growing season. Such an exceptional hot drought occurred in Central Europe in 2018 and caused widespread defoliation in mid-summer in European beech (Fagus sylvatica L.) forests. Here, we recorded crown damage in 2021 in nine mature even-aged beech-dominated stands in northwestern Switzerland along a crown damage severity gradient (low, medium, high) and analyzed tree-ring widths of 21 mature trees per stand. We aimed at identifying predisposing factors responsible for differences in crown damage across and within stands such as tree growth characteristics (average growth rates and year-to-year variability) and site-level variables (mean canopy height, soil properties). We found that stand-level crown damage severity was strongly related to soil water availability, inferred from tree canopy height and plant available soil water storage capacity (AWC). Trees were shorter in drier stands, had higher year-to-year variability in radial growth, and showed higher growth sensitivity to moisture conditions of previous late summer than trees growing on soils with sufficient AWC, indicating that radial growth in these forests is principally limited by soil water availability. Within-stand variation of post-drought crown damage corresponded to growth rate and tree size (diameter at breast height, DBH), i.e., smaller and slower-growing trees that face more competition, were associated with increased crown damage after the 2018 drought. These findings point to tree vigor before the extreme 2018 drought (long-term relative growth rate) as an important driver of damage severity within and across stands. Our results suggest that European beech is less likely to be able to cope with future climate change-induced extreme droughts on shallow soils with limited water retention capacity.


Assuntos
Fagus , Secas , Florestas , Solo , Árvores , Água
3.
Nat Commun ; 11(1): 1351, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32165619

RESUMO

The majority of variation in six traits critical to the growth, survival and reproduction of plant species is thought to be organised along just two dimensions, corresponding to strategies of plant size and resource acquisition. However, it is unknown whether global plant trait relationships extend to climatic extremes, and if these interspecific relationships are confounded by trait variation within species. We test whether trait relationships extend to the cold extremes of life on Earth using the largest database of tundra plant traits yet compiled. We show that tundra plants demonstrate remarkably similar resource economic traits, but not size traits, compared to global distributions, and exhibit the same two dimensions of trait variation. Three quarters of trait variation occurs among species, mirroring global estimates of interspecific trait variation. Plant trait relationships are thus generalizable to the edge of global trait-space, informing prediction of plant community change in a warming world.


Assuntos
Desenvolvimento Vegetal , Tundra , Clima , Ecossistema , Plantas/classificação , Plantas/genética
4.
Glob Ecol Biogeogr ; 28(2): 78-95, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31007605

RESUMO

AIM: Plant functional groups are widely used in community ecology and earth system modelling to describe trait variation within and across plant communities. However, this approach rests on the assumption that functional groups explain a large proportion of trait variation among species. We test whether four commonly used plant functional groups represent variation in six ecologically important plant traits. LOCATION: Tundra biome. TIME PERIOD: Data collected between 1964 and 2016. MAJOR TAXA STUDIED: 295 tundra vascular plant species. METHODS: We compiled a database of six plant traits (plant height, leaf area, specific leaf area, leaf dry matter content, leaf nitrogen, seed mass) for tundra species. We examined the variation in species-level trait expression explained by four traditional functional groups (evergreen shrubs, deciduous shrubs, graminoids, forbs), and whether variation explained was dependent upon the traits included in analysis. We further compared the explanatory power and species composition of functional groups to alternative classifications generated using post hoc clustering of species-level traits. RESULTS: Traditional functional groups explained significant differences in trait expression, particularly amongst traits associated with resource economics, which were consistent across sites and at the biome scale. However, functional groups explained 19% of overall trait variation and poorly represented differences in traits associated with plant size. Post hoc classification of species did not correspond well with traditional functional groups, and explained twice as much variation in species-level trait expression. MAIN CONCLUSIONS: Traditional functional groups only coarsely represent variation in well-measured traits within tundra plant communities, and better explain resource economic traits than size-related traits. We recommend caution when using functional group approaches to predict tundra vegetation change, or ecosystem functions relating to plant size, such as albedo or carbon storage. We argue that alternative classifications or direct use of specific plant traits could provide new insights for ecological prediction and modelling.

5.
Top Catal ; 61(20): 2052-2061, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30930589

RESUMO

The selective hydrogenation of propyne over a Pd-black model catalyst was investigated under operando conditions at 1 bar making use of advanced X-ray diffraction (bulk sensitive) and photo-electron spectroscopy (surface sensitive) techniques. It was found that the population of subsurface species controls the selective catalytic semi-hydrogenation of propyne to propylene due to the formation of surface and near-surface PdCx that inhibits the participation of more reactive bulk hydrogen in the hydrogenation reaction. However, increasing the partial pressure of hydrogen reduces the population of PdCx with the concomitant formation of a ß-PdHx phase up to the surface, which is accompanied by a lattice expansion, allowing the participation of more active bulk hydrogen which is responsible for the unselective total alkyne hydrogenation. Therefore, controlling the surface and subsurface catalyst chemistry is crucial to control the selective alkyne semi-hydrogenation.

6.
J Clin Pathol ; 66(11): 956-61, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23775435

RESUMO

BACKGROUND: High levels of cyclin E (CCNE) are accompanied by shorter survival in cyclophosphamide, hydroxydaunorubicin, oncovin and prednisone (CHOP)-treated diffuse large B-cell lymphomas (DLBCL), independent of the international prognostic index (IPI). Data on the prognostic role of CCNE in the 'rituximab (R)-era' are lacking. METHODS: To test reproducibility and applicability of observations from the 'pre-R era' to the 'R era', we examined the prognostic role of CCNE expression by immunohistochemistry in 1579 DLBCL on tissue microarrays (TMA); 339 patients were treated by CHOP and 635 by R-CHOP. RESULTS: 1209 samples (77%) were evaluable; failures were due to missing TMA punches and fixation artefacts. Mean expression of CCNE was 13% (0-85%); applying a cut-off of >16%, 382 DLBCL (31%) were positive. CCNE did not correlate with any of the known variables (IPI, primary site, cell of origin, proliferation, and BCL2- or C-MYC rearrangements). We were able to reproduce data suggesting an IPI- and response to therapy independent, negative prognostic impact of CCNE in CHOP-treated DLBCL patients: CCNE-positive cases had a median survival of 16 months compared with 57 months in negative ones (p=0.012). In R-CHOP-treated patients the prognostic impact of CCNE was abrogated and only IPI, cell of origin and response to therapy had a prognostic significance. CONCLUSIONS: Addition of R to CHOP overcomes the negative prognostic impact of CCNE in DLBCL. Thus, R not only prolongs survival in DLBCL but also serves a cautionary note that prognostic factors should not be transferred into the 'R era' without proper scientific studies.


Assuntos
Anticorpos Monoclonais Murinos/administração & dosagem , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Ciclina E/metabolismo , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Proteínas Oncogênicas/metabolismo , Idoso , Estudos de Coortes , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Prednisona/administração & dosagem , Prognóstico , Reprodutibilidade dos Testes , Rituximab , Análise Serial de Tecidos , Resultado do Tratamento , Vincristina/administração & dosagem
7.
Curr Med Chem ; 19(25): 4218-38, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22680633

RESUMO

Histone deacetylase (HDAC) inhibitors are a group of anticancer drugs which cause growth arrest and apoptosis of several tumor cells. HDAC inhibitors have been also found to increase the anticancer efficacy of several treatment modalities i.e. chemotherapy or radiotherapy. Here, we review the literature on combinations of HDAC inhibitors both with ionizing radiation and with other drugs, highlighting DNA-damaging compounds. The results of numerous studies with several types of cancer cells discussed in this review demonstrate that HDAC inhibitors enhance the effect of DNA damaging agents, such as inhibitors of topoisomerases, inhibitors of DNA synthesis, DNA-intercalators and agents covalently modifying DNA (i.e. doxorubicin, etoposid, 5-fluorouracil, cisplatin, melphalan, temozolomide and ellipticine) or of irradiation. Hence, the use of HDAC inhibitors combined with these antitumor drugs or ionizing radiation is a promising tool which may make treatment of patients suffering from many types of cancer more efficient. Several molecular mechanisms are responsible for the observed higher sensitivity of tumor cells towards therapeutic agents elicited by HDAC inhibitors. These mechanisms are discussed also in this review.


Assuntos
Antineoplásicos/farmacologia , DNA/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Sinergismo Farmacológico , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/uso terapêutico , Histona Desacetilases/metabolismo , Humanos , Terapia de Alvo Molecular/métodos , Neoplasias/metabolismo , Neoplasias/radioterapia
8.
Biochim Biophys Acta ; 1814(1): 175-85, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20576524

RESUMO

An antineoplastic alkaloid ellipticine is a prodrug, whose pharmacological efficiency is dependent on its cytochrome P450 (CYP)- and/or peroxidase-mediated activation in target tissues. The aim of this review was to summarize our knowledge on the molecular mechanisms of ellipticine action in the cancer cells. The CYP-mediated ellipticine metabolites 9-hydroxy- and 7-hydroxyellipticine and the product of ellipticine oxidation by peroxidases, the ellipticine dimer, are the detoxication metabolites of this compound. In contrast, two carbenium ions, ellipticine-13-ylium and ellipticine-12-ylium, derived from two activation ellipticine metabolites, 13-hydroxyellipticine and 12-hydroxyellipticine, generate two major deoxyguanosine adducts in DNA found in the human breast adenocarcinoma MCF-7 cells, leukemia HL-60 and CCRF-CEM cells, neuroblastoma IMR-32, UKF-NB-3, and UKF-NB-4 cells and glioblastoma U87MG cells in vitro and in rat breast carcinoma in vivo. Formation of these covalent DNA adducts by ellipticine is the predominant mechanism of its cytotoxicity and anti-tumor activity to these cancer cell lines. Ellipticine is also an inducer of CYP1A, 1B1, and 3A4 enzymes in the cancer cells and/or in vivo in rats exposed to this compound, thus modulating its own pharmacological efficiencies. The study forms the basis to further predict the susceptibility of human cancers to ellipticine and suggests that this alkaloid for treatment in combination with CYP and/or peroxidase gene transfer increasing the anticancer potential of this prodrug. It also suggests ellipticine reactive metabolites 13-hydroxyellipticine and 12-hydroxyellipticine to be good candidates for targeting to tumors absent from the CYP and peroxidase activation enzymes.


Assuntos
Antineoplásicos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Elipticinas/metabolismo , Peroxidase/metabolismo , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Elipticinas/química , Elipticinas/farmacologia , Humanos , Estrutura Molecular , Oxirredução
9.
Parasitology ; 137(11): 1645-52, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20500919

RESUMO

SUMMARY OBJECTIVE: Bilharziosis is one of the most important helminthal infections in humans and is caused by blood flukes of the genus Schistosoma. Three different life stages of the parasite occur within the mammalian host: schistosomula located in the skin, pre-adults located in the lung and adult worms located in the portal venous system. Erythrocytes are a major source of nutrient supply for adults. However, sources of nutrition for the developing stages are still unclear. METHODS: To investigate whether schistosomula, pre-adults and adults of Schistosoma mansoni ingest human serum albumin (HSA) in vitro, these life stages were incubated with aminofluorescein-labelled human serum albumin (Afl-HSA) for 5 h. To test the uptake of albumin in vivo, the albumin conjugate was given intravenously to S. mansoni infected NMRI mice 24 h before harvesting the 3 life stages. RESULTS: In comparison to the control group schistosomula, pre-adults, and adults showed an accumulation of Afl-HSA within the oesophagus and intestinal caecum in vitro and in vivo. CONCLUSION: Our findings suggest that albumin seems to be a major source of energy supply for the early schistosomal life stages and an additive energy support for adult worms. Since albumin has been used successfully as a drug carrier for chemotherapeutic substances against malignant disorders, further studies will focus on albumin as a carrier for anthelminthics in a drug-targeting model.


Assuntos
Fluoresceína/metabolismo , Schistosoma mansoni/crescimento & desenvolvimento , Esquistossomose mansoni/parasitologia , Albumina Sérica/metabolismo , Animais , Animais não Endogâmicos , Anti-Helmínticos/farmacologia , Modelos Animais de Doenças , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Pulmão/metabolismo , Pulmão/parasitologia , Camundongos , Microscopia de Fluorescência , Schistosoma mansoni/efeitos dos fármacos , Schistosoma mansoni/metabolismo , Pele/metabolismo , Pele/parasitologia
10.
Transplant Proc ; 40(10): 3725-7, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19100475

RESUMO

Methothrexate (MTX) causes unwanted adverse events by affecting gastrointestinal and bone marrow cells when used as an immunosuppressant. Our aim was to reduce those side effects by covalent binding of methothrexate to human serum albumin (HSA) targeting rapidly proliferating lymphocytes, which are known to ingest albumin as an energy source. Twenty-one rats received a kidney transplant. Group A (n = 5) received standard immunosupression (free MTX); group B (n = 9), albumin-MTX conjugates; and group C (n = 7) albumin control. The primary endpoint of this animal study was transplant survival, which was evaluated as death due to uremia. The study was terminated on day 100. Placebo-treated rat recipients (group C) rejected their grafts at a median of 8 days, which was prolonged to 17 days in standard immunosuppressed rats (group A), resulting in doubling transplant survival compared to nonimmunosuppressed animals. However, the same dose given as HSA-conjugated MTX prolonged the median survival time to 43 days. (group B). Hence, the administration of conjugated methotrexate appeared to result in a doubling of transplant survival compared with standard immunosuppression. Moreover, two animals receiving MTX-HSA became long-term survivors without additional immunosuppression. Further studies should be performed to evaluate the significance of these findings in larger animals and possibly in clinical studies.


Assuntos
Sobrevivência de Enxerto/efeitos dos fármacos , Imunossupressores/uso terapêutico , Transplante de Rim/fisiologia , Metotrexato/uso terapêutico , Albumina Sérica/uso terapêutico , Animais , Rejeição de Enxerto/prevenção & controle , Meia-Vida , Masculino , Metotrexato/farmacocinética , Ratos , Ratos Endogâmicos Lew , Ratos Endogâmicos , Albumina Sérica/farmacocinética , Transplante Homólogo
11.
Kidney Int ; 73(11): 1209-11, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18480852

RESUMO

Ingestion of aristolochic acid (AA) is associated with the development of AA-nephropathy and Balkan endemic nephropathy, which are characterized by chronic renal failure, tubulointerstitial fibrosis, and urothelial cancer. Understanding which enzymes are involved in AA activation and/or detoxification is important in assessing susceptibility to AA. Xiao et al. demonstrate that hepatic cytochrome P450s in mice detoxicate AA and thereby protect kidney from injury. The relative contribution of enzymes activating AA to induce urothelial cancer in humans remains to be resolved.


Assuntos
Ácidos Aristolóquicos/metabolismo , Carcinógenos/metabolismo , Nefropatias/enzimologia , Fígado/enzimologia , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Neoplasias Urológicas/enzimologia , Animais , Ácidos Aristolóquicos/toxicidade , Carcinógenos/toxicidade , Inativação Metabólica , Nefropatias/induzido quimicamente , Camundongos , NADPH-Ferri-Hemoproteína Redutase/genética , Neoplasias Urológicas/induzido quimicamente , Urotélio
12.
Parasitology ; 135(Pt 1): 105-14, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17767795

RESUMO

The study was designed to determine comparatively the prognostic value of immunoblotting and ELISA in the serological follow-up of young cystic echinococcosis (CE) patients exhibiting either a cured or a progredient (non-cured) course of disease after treatment. A total of 54 patients (mean age 9 years, range from 3 to 15 years) with surgically, radiologically and/or histologically proven CE were studied for a period up to 60 months after surgery. Additionally, some of the patients underwent chemotherapy. Based on the clinical course and outcome, as well as on imaging findings, patients were clustered into 2 groups of either cured (CCE), or non-cured (NCCE) CE patients. ELISA showed a high rate of seropositivity 4 to 5 years post-surgery for both CCE (57.1%) and NCCE (100%) patients, the difference found between the two groups was statistically not significant. Immunoblotting based upon recognition of AgB subcomponents (8 and 16 kDa bands) showed a decrease of respective antibody reactivities after 4 years post-surgery. Only sera from 14.3% of CCE patients recognized the subcomponents of AgB after 4 years, while none (0%) of these sera was still reactive at 5 years post-surgery. At variance, immunoblotting remained positive for AgB subcomponents in 100% of the NCCE cases as tested between 4 and 5 years after surgical treatment. Immunoblotting therefore proved to be a useful approach for monitoring post-surgical follow-ups of human CCE and NCCE in young patients when based upon the recognition of AgB subcomponents.


Assuntos
Equinococose/diagnóstico , Echinococcus granulosus , Ensaio de Imunoadsorção Enzimática/métodos , Immunoblotting/métodos , Adolescente , Animais , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/metabolismo , Criança , Pré-Escolar , Equinococose/imunologia , Equinococose/cirurgia , Echinococcus granulosus/imunologia , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Fatores de Tempo
13.
Parasitology ; 134(Pt 6): 879-88, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17306060

RESUMO

Serology is an important tool for the diagnosis of alveolar echinococcosis (AE) in humans. In order to improve serodiagnostic performance, we have developed an in vitro-produced Echinococcus mulilocularis metacestode vesicle fluid (EmVF) antigen for application in an immunoblot assay. Immunoblot analysis of EmVF revealed an abundant immunoreactive band triplet of 20-22 kDa, achieving a sensitivity of 100% based on the testing of sera from 62 pre-operative and pre-treatment cases of active and inactive AE. Thus, the EmVF-immunoblotting allowed the specific detection of cases seronegative by the Em2- and/or EmII/3-10-ELISA, usually attributable to abortive, inactive cases of AE. The specificity of the EmVF-immunoblotting did not allow discrimination between AE and cystic echinococcosis (CE) but was 100% with respect to non-Echinococcus parasitic infections or cancer malignancies. Based on the findings of this study, it is recommended that the current ELISA test combination (Em2- and II/3-10-ELISA) be complemented with EmVF-immunoblotting, allowing an improved diagnosis of both clinical and subclinical forms of AE, including those associated with E. multilocularis-specific antibody reactivities not detectable by ELISA.


Assuntos
Anticorpos Anti-Helmínticos/sangue , Antígenos de Helmintos/imunologia , Equinococose Hepática/diagnóstico , Echinococcus multilocularis/imunologia , Animais , Anticorpos Anti-Helmínticos/metabolismo , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Testes Sorológicos
14.
Gen Physiol Biophys ; 25(3): 245-61, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17197724

RESUMO

Ellipticine is an antineoplastic agent, whose mode of action is based mainly on DNA intercalation, inhibition of topoisomerase II and formation of DNA adducts mediated by cytochrome P450 (CYP). We investigated the ability of CYP enzymes in rat, rabbit and human hepatic microsomes to oxidize ellipticine and evaluated suitable animal models mimicking its oxidation in humans. Ellipticine is oxidized by microsomes of all species to 7-hydroxy-, 9-hydroxy-, 12-hydroxy-, 13-hydroxyellipticine and ellipticine N(2)-oxide. However, only rat microsomes generated the pattern of ellipticine metabolites reproducing that formed by human microsomes. While rabbit microsomes favored the production of ellipticine N(2)-oxide, human and rat microsomes predominantly formed 13-hydroxyellipticine. The species difference in expression and catalytic activities of individual CYPs in livers are the cause of these metabolic differences. Formation of 7-hydroxy- and 9-hydroxyellipticine was attributable to CYP1A in microsomes of all species. However, production of 13-hydroxy-, 12-hydroxyellipticine and ellipticine N(2)-oxide, the metabolites generating DNA adducts, was attributable to the orthologous CYPs only in rats and humans. CYP3A predominantly generates these metabolites in rat and human microsomes, while CYP2C3 activity prevails in microsomes of rabbits. The results underline the suitability of rat species as a model to evaluate human susceptibility to ellipticine.


Assuntos
Antineoplásicos/metabolismo , Elipticinas/metabolismo , Microssomos Hepáticos/metabolismo , Animais , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Adutos de DNA/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Hidroxilação , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Oxirredução , Coelhos , Ratos , Ratos Wistar , Especificidade da Espécie
16.
Biol Blood Marrow Transplant ; 8(4): 198-205, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12017145

RESUMO

Although high-dose chemotherapy (HDC) with stem cell rescue for the treatment of women with metastatic breast cancer (MBC) is currently a controversial strategy, we report the long-term outcomes of women undergoing high-dose therapy for MBC over the past 12 years while participating in a sequence of research studies transitioning between a single to a double intensification approach. Univariate and multivariate analyses provide a framework to understand the prognostic factors important for event-free and overall survival. Between May 1988 and April 1998, we enrolled 188 women with MBC into 3 trials of previously reported sequential transplantation strategies. Trial I (long induction/single transplantation) accepted 62 women in partial or complete response to an unspecified induction therapy and treated them with high-dose CTCb (cyclophosphamide, thiotepa, and carboplatin) supported by marrow or peripheral blood progenitor cells (PBPC). Trial II (long induction/double transplantation) accepted 68 women in partial or complete response to an unspecified induction therapy, and mobilized stem cells with 2 cycles of AF (doxorubicin and 5-fluorouracil) with granulocyte colony-stimulating factor (G-CSF). These women then received 1 cycle of high-dose single-agent melphalan followed 3 to 5 weeks later by CTCb, each with marrow or PBPC support. Trial III (short induction/double transplantation) enrolled 58 women prior to chemotherapy treatment for metastatic disease. Induction/mobilization consisted of 2 cycles given 14 days apart of doxorubicin and G-CSF. In contrast to trials I and II, patients with stable disease or better response to induction were eligible to proceed ahead with 2 cycles of HDC, 1 being CTCb and the other being dose escalated paclitaxel together with high-dose melphalan (TxM). These 2 HDC regimens were administered 5 weeks apart. TxM was given first in 32 patients and CTCb was given first in 26 patients. The median follow-up periods for trials I, II, and III were 98, 62, and 39 months from the initiation of induction chemotherapy and 92, 55, and 36 months from last high-dose therapy, respectively. The patient characteristics upon entry into these trials were similar. Important differences were that only those patients achieving a partial response or better to induction therapy were enrolled and analyzed for trials I and II, but all patients were analyzed on an intent-to-treat basis for trial III, including those who did not receive intensification. The median event-free survival (EFS) times from induction chemotherapy were 13, 19, and 27 months for trials I, II, and III, respectively (III versus I + II, P = .0004; III versus I, P = .0005; III versus II, P = .005; II versus I, P = .25). The median overall survival (OS) times from induction chemotherapy were 30, 29, and 57 months for trials I, II, and III, respectively (III versus I + II, P = .002; III versus I, P = .003; III versus II, P = .009; II versus I, P = .47). By multivariate Cox regression, participation in the short induction/double transplantation trial III and having no prior adjuvant chemotherapy remained favorable prognostic factors for both EFS and OS. The presence of visceral disease shortened EFS, and hormone sensitivity was of borderline significance. No substantive differences in the characteristics of the patient populations between the 3 trials appeared to interact with outcomes. In conclusion, we found that single transplantation in responding patients after long induction achieves a small cohort of long-term survivors, similar to the results reported by other transplantation centers. Adding a cycle of single-agent high-dose melphalan in this context delayed median time to relapse but did not affect long-term EFS or OS. The double transplantation approach using CTCb and TxM early in the course of treatment was associated with the best EFS and overall survival and was safe, feasible, and tolerable. Treatment duration was only 14 weeks, and this treatment option eliminated lengthy induction chemotherapy. Although selection biases may have in part contributed to this effect, a randomized comparison of standard therapy versus short induction/double transplantation is warranted.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/terapia , Carcinoma/terapia , Transplante de Células-Tronco de Sangue Periférico , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Carboplatina/administração & dosagem , Carcinoma/tratamento farmacológico , Carcinoma/mortalidade , Terapia Combinada , Ciclofosfamida/administração & dosagem , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Esquema de Medicação , Estrogênios , Feminino , Fluoruracila/administração & dosagem , Seguimentos , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Humanos , Tábuas de Vida , Melfalan/administração & dosagem , Metotrexato/administração & dosagem , Pessoa de Meia-Idade , Análise Multivariada , Metástase Neoplásica , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Neoplasias Hormônio-Dependentes/mortalidade , Neoplasias Hormônio-Dependentes/terapia , Paclitaxel/administração & dosagem , Transplante de Células-Tronco de Sangue Periférico/métodos , Progesterona , Prognóstico , Modelos de Riscos Proporcionais , Indução de Remissão , Análise de Sobrevida , Tiotepa/administração & dosagem , Fatores de Tempo , Resultado do Tratamento
17.
Surg Endosc ; 15(11): 1263-6, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11727130

RESUMO

BACKGROUND: There is a scarcity of data on long-term results after laparoscopic hernia repair. Herein we report on the outcome of a group of patients who were followed up for 5 years in a multicenter study on hernia repair. METHODS: A total of 100 patients with 127 hernias were randomized to undergo either transabdominal preperitoneal (TAPP) or Shouldice hernia repair. Follow-up was by clinical examination and standardized questionnaire. RESULTS: Of the 100 patients who underwent surgery, 84 were available for follow-up at 5 years. The TAPP procedure was less painful than the Shouldice repair, with fewer patients receiving narcotic analgesics. The median time to return to 100% activity was shorter in the laparoscopic group (21 days) than in the Shouldice group (40 days). Up to 60 months after the operation, the complication rate was lower in laparoscopically repaired hernias (19/66) than in the open group (25/61). There were two recurrences (3.9%) in the TAPP group and five in the Shouldice group (10.2%). CONCLUSION: The TAPP hernia repair yields comparable or better results than Shouldice herniorrhaphy in terms of postoperative pain, recovery, and recurrence rate.


Assuntos
Hérnia Inguinal/cirurgia , Laparoscopia/métodos , Idoso , Intervalos de Confiança , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Feminino , Seguimentos , Hematoma/etiologia , Humanos , Laparoscopia/efeitos adversos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Medição da Dor , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/prevenção & controle , Satisfação do Paciente , Recidiva , Reoperação , Resultado do Tratamento
18.
J Cancer Res Clin Oncol ; 127(11): 653-8, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11710594

RESUMO

PURPOSE: Integrins are transmembrane heterodimeric molecules that mediate cellular adhesion and are involved in different biological processes, such as tumor development and invasion of tumor cells. Matrixmetalloproteases (MMP) are a family of secreted or membrane proteins capable of digesting extracellular matrix. It has been shown that MMP-2 binds to alphavbeta3 integrin. Recent evidence suggests that a complex of membrane-type MMP (MT1-MMP) and tissue inhibitor of metalloptroteinase-2 (TIMP-2) participate in the activation of alphavbeta3-associated MMP-2. We investigated whether alphavbeta3 and MMP-2 are associated on the membranes of a human cell line, SiHa, and the possible involvement of MT1-MMP and TIMP-2 in the modulation of MMP-2 activity. METHODS: Immunoprecipitation of SiHa membrane extracts with monoclonal antibodies against alphav or MMP-2, and western blots of immunoprecipitates and serum-free conditioned media were performed. TIMP-2 in conditioned medium and MT1-MMP in the membrane fraction was assayed by western blot. Zymography of anti-alphav antibody immunoprecipitates and conditioned media were used to show gelatinolytic activity. RESULTS: The coprecipitation of MMP-2 with alphavbeta3 by anti-alphav antibody is a strong indication that SiHa cell surface alphavbeta3 integrin is a receptor for MMP-2. Immunoblot assays show the expression of MT1-MMP on SiHa cell membranes and secreted TIMP-2 and pro-MMP-2 in the medium. CONCLUSIONS: SiHa cells express all the molecules which are reported to form a complex to activate pro-MMP-2. Active MMP-2 associated with alphavbeta3 may regulate matrix degradation and thereby modulate directed motility of SiHa cells.


Assuntos
Membrana Celular/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Receptores de Vitronectina/biossíntese , Neoplasias do Colo do Útero/metabolismo , Biotinilação , Western Blotting , Linhagem Celular , Dimerização , Eletroforese em Gel de Poliacrilamida , Feminino , Gelatinases/metabolismo , Humanos , Immunoblotting , Metaloproteinase 1 da Matriz/metabolismo , Testes de Precipitina , Inibidor Tecidual de Metaloproteinase-2/metabolismo , Células Tumorais Cultivadas
19.
Bone Marrow Transplant ; 28(5): 447-54, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11593317

RESUMO

Two cycles of high-dose chemotherapy with stem cell support (HDC) may increase the total dose delivered and dose intensity. A brief induction phase and different non-cross-resistant agents for each HDC cycle were used to avoid drug resistance. Twenty-six women with metastatic BC had induction and stem cell mobilization with two cycles of doxorubicin/G-CSF given every 14 days. Patients with stable disease or better after induction received HD CTCb followed by HD melphalan and dose-escalated paclitaxel. At 475 mg/m(2) of paclitaxel by 24-h infusion, dose-limiting transient peripheral sensory neuropathy was encountered. No toxic deaths occurred. Complete and near complete response after completion of therapy was achieved in 22 (85%) of 26 patients. The median EFS was 38 months. The median OS has not yet been reached. At a median follow-up of 33 (25-43) months, actuarial EFS and OS were 54% (95% confidence interval (CI), 39-69%) and 69% (95% CI, 56-79%), respectively. This double transplant approach lasts only 14 weeks and is feasible, safe, and tolerable. Whilst selection biases may in part contribute to favorable EFS and OS, a randomized comparison of standard therapy vs double transplant in both metastatic and locally advanced breast cancer is warranted.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Transplante de Células-Tronco Hematopoéticas , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Terapia Combinada , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Esquema de Medicação , Feminino , Seguimentos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Melfalan/administração & dosagem , Melfalan/efeitos adversos , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Indução de Remissão/métodos , Taxa de Sobrevida , Falha de Tratamento , Resultado do Tratamento
20.
J Neuroimmunol ; 119(2): 214-22, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11585624

RESUMO

Microglial cells are among the first and dominant cell types to respond to CNS injury. Following calcium influx, microglial activation leads to a variety of cellular responses, such as proliferation and release of cytotoxic and neurotrophic mediators. Allograft inflammatory factor-1, AIF-1 is a highly conserved EF-handed, putative calcium binding peptide, associated with microglia activation in the brain. Here, we have analyzed the expression of AIF-1 following spinal cord injury at the lesion site and at remote brain regions. Following spinal cord injury, AIF-1+ cells accumulated in parenchymal pan-necrotic areas and perivascular Virchow-Robin spaces. Subsequent to culmination at day 3--a situation characterized by infiltrating blood borne macrophages and microglia activation--AIF-1+ cell numbers decreased until day 7. In remote areas of Wallerian degeneration and delayed neuronal death, a more discrete and delayed activation pattern of AIF-1+ microglia/macrophages reaching maximum levels at day 14 was observed. There was a considerable match between AIF-1+ cells and PCNA (proliferating cell nuclear antigen) or Ki-67+ labeled cells. AIF-1 expression preceded the expression of ED1, thus indicating a pre-phagocytic role. It appears that AIF-1+ microglia/macrophages are among the earliest cells to respond to spinal cord injury. Our results suggest a role of AIF-1 in the initiation of the early microglial response leading to activation and proliferation essential for the acute response to CNS injury. AIF-1 might modulate microgliosis influencing the efficacy of tissue debris removal, myelin degradation, recruitment of oligodendrocytes and re-organisation of the CNS architecture.


Assuntos
Proteínas de Ligação ao Cálcio/imunologia , Macrófagos/imunologia , Microglia/imunologia , Traumatismos da Medula Espinal/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais , Encéfalo/imunologia , Proteínas de Ligação ao Cálcio/análise , Proteínas de Ligação ao Cálcio/genética , Divisão Celular/imunologia , Imuno-Histoquímica , Ativação de Macrófagos/imunologia , Macrófagos/citologia , Macrófagos/metabolismo , Masculino , Proteínas dos Microfilamentos , Microglia/citologia , Microglia/metabolismo , Dados de Sequência Molecular , Fenótipo , Ratos , Ratos Endogâmicos Lew , Medula Espinal/citologia , Medula Espinal/imunologia , Traumatismos da Medula Espinal/metabolismo
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